apply: pass apply state to build_fake_ancestor()
[gitweb.git] / apply.c
diff --git a/apply.c b/apply.c
index 0ed9d132e88f52c678a4a64caf3b49d5bc04ee2e..a9a743cf9c7ec869aeb4d8f57b12e7bf638c202c 100644 (file)
--- a/apply.c
+++ b/apply.c
  * This applies patches on top of some (arbitrary) version of the SCM.
  *
  */
-#include <fnmatch.h>
+
 #include "cache.h"
-#include "quote.h"
 #include "blob.h"
 #include "delta.h"
+#include "diff.h"
+#include "dir.h"
+#include "xdiff-interface.h"
+#include "ll-merge.h"
+#include "lockfile.h"
+#include "parse-options.h"
+#include "quote.h"
+#include "rerere.h"
+#include "apply.h"
+
+static void git_apply_config(void)
+{
+       git_config_get_string_const("apply.whitespace", &apply_default_whitespace);
+       git_config_get_string_const("apply.ignorewhitespace", &apply_default_ignorewhitespace);
+       git_config(git_default_config, NULL);
+}
 
-//  --check turns on checking that the working tree matches the
-//    files that are being modified, but doesn't apply the patch
-//  --stat does just a diffstat, and doesn't actually apply
-//  --numstat does numeric diffstat, and doesn't actually apply
-//  --index-info shows the old and new index info for paths if available.
-//  --index updates the cache as well.
-//  --cached updates only the cache without ever touching the working tree.
-//
-static const char *prefix;
-static int prefix_length = -1;
-static int newfd = -1;
-
-static int p_value = 1;
-static int allow_binary_replacement = 0;
-static int check_index = 0;
-static int write_index = 0;
-static int cached = 0;
-static int diffstat = 0;
-static int numstat = 0;
-static int summary = 0;
-static int check = 0;
-static int apply = 1;
-static int no_add = 0;
-static int show_index_info = 0;
-static int line_termination = '\n';
-static unsigned long p_context = -1;
-static const char apply_usage[] =
-"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--cached] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
-
-static enum whitespace_eol {
-       nowarn_whitespace,
-       warn_on_whitespace,
-       error_on_whitespace,
-       strip_whitespace,
-} new_whitespace = warn_on_whitespace;
-static int whitespace_error = 0;
-static int squelch_whitespace_errors = 5;
-static int applied_after_stripping = 0;
-static const char *patch_input_file = NULL;
-
-static void parse_whitespace_option(const char *option)
+static int parse_whitespace_option(struct apply_state *state, const char *option)
 {
        if (!option) {
-               new_whitespace = warn_on_whitespace;
-               return;
+               state->ws_error_action = warn_on_ws_error;
+               return 0;
        }
        if (!strcmp(option, "warn")) {
-               new_whitespace = warn_on_whitespace;
-               return;
+               state->ws_error_action = warn_on_ws_error;
+               return 0;
        }
        if (!strcmp(option, "nowarn")) {
-               new_whitespace = nowarn_whitespace;
-               return;
+               state->ws_error_action = nowarn_ws_error;
+               return 0;
        }
        if (!strcmp(option, "error")) {
-               new_whitespace = error_on_whitespace;
-               return;
+               state->ws_error_action = die_on_ws_error;
+               return 0;
        }
        if (!strcmp(option, "error-all")) {
-               new_whitespace = error_on_whitespace;
-               squelch_whitespace_errors = 0;
-               return;
+               state->ws_error_action = die_on_ws_error;
+               state->squelch_whitespace_errors = 0;
+               return 0;
        }
-       if (!strcmp(option, "strip")) {
-               new_whitespace = strip_whitespace;
-               return;
+       if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
+               state->ws_error_action = correct_ws_error;
+               return 0;
        }
-       die("unrecognized whitespace option '%s'", option);
+       return error(_("unrecognized whitespace option '%s'"), option);
 }
 
-static void set_default_whitespace_mode(const char *whitespace_option)
+static int parse_ignorewhitespace_option(struct apply_state *state,
+                                                const char *option)
 {
-       if (!whitespace_option && !apply_default_whitespace) {
-               new_whitespace = (apply
-                                 ? warn_on_whitespace
-                                 : nowarn_whitespace);
+       if (!option || !strcmp(option, "no") ||
+           !strcmp(option, "false") || !strcmp(option, "never") ||
+           !strcmp(option, "none")) {
+               state->ws_ignore_action = ignore_ws_none;
+               return 0;
+       }
+       if (!strcmp(option, "change")) {
+               state->ws_ignore_action = ignore_ws_change;
+               return 0;
        }
+       return error(_("unrecognized whitespace ignore option '%s'"), option);
 }
 
-/*
- * For "diff-stat" like behaviour, we keep track of the biggest change
- * we've seen, and the longest filename. That allows us to do simple
- * scaling.
- */
-static int max_change, max_len;
+int init_apply_state(struct apply_state *state,
+                    const char *prefix,
+                    struct lock_file *lock_file)
+{
+       memset(state, 0, sizeof(*state));
+       state->prefix = prefix;
+       state->prefix_length = state->prefix ? strlen(state->prefix) : 0;
+       state->lock_file = lock_file;
+       state->newfd = -1;
+       state->apply = 1;
+       state->line_termination = '\n';
+       state->p_value = 1;
+       state->p_context = UINT_MAX;
+       state->squelch_whitespace_errors = 5;
+       state->ws_error_action = warn_on_ws_error;
+       state->ws_ignore_action = ignore_ws_none;
+       state->linenr = 1;
+       string_list_init(&state->fn_table, 0);
+       string_list_init(&state->limit_by_name, 0);
+       string_list_init(&state->symlink_changes, 0);
+       strbuf_init(&state->root, 0);
+
+       git_apply_config();
+       if (apply_default_whitespace && parse_whitespace_option(state, apply_default_whitespace))
+               return -1;
+       if (apply_default_ignorewhitespace && parse_ignorewhitespace_option(state, apply_default_ignorewhitespace))
+               return -1;
+       return 0;
+}
+
+void clear_apply_state(struct apply_state *state)
+{
+       string_list_clear(&state->limit_by_name, 0);
+       string_list_clear(&state->symlink_changes, 0);
+       strbuf_release(&state->root);
+
+       /* &state->fn_table is cleared at the end of apply_patch() */
+}
+
+static void mute_routine(const char *msg, va_list params)
+{
+       /* do nothing */
+}
+
+int check_apply_state(struct apply_state *state, int force_apply)
+{
+       int is_not_gitdir = !startup_info->have_repository;
+
+       if (state->apply_with_reject && state->threeway)
+               return error("--reject and --3way cannot be used together.");
+       if (state->cached && state->threeway)
+               return error("--cached and --3way cannot be used together.");
+       if (state->threeway) {
+               if (is_not_gitdir)
+                       return error(_("--3way outside a repository"));
+               state->check_index = 1;
+       }
+       if (state->apply_with_reject) {
+               state->apply = 1;
+               if (state->apply_verbosity == verbosity_normal)
+                       state->apply_verbosity = verbosity_verbose;
+       }
+       if (!force_apply && (state->diffstat || state->numstat || state->summary || state->check || state->fake_ancestor))
+               state->apply = 0;
+       if (state->check_index && is_not_gitdir)
+               return error(_("--index outside a repository"));
+       if (state->cached) {
+               if (is_not_gitdir)
+                       return error(_("--cached outside a repository"));
+               state->check_index = 1;
+       }
+       if (state->check_index)
+               state->unsafe_paths = 0;
+       if (!state->lock_file)
+               return error("BUG: state->lock_file should not be NULL");
+
+       if (state->apply_verbosity <= verbosity_silent) {
+               state->saved_error_routine = get_error_routine();
+               state->saved_warn_routine = get_warn_routine();
+               set_error_routine(mute_routine);
+               set_warn_routine(mute_routine);
+       }
+
+       return 0;
+}
+
+static void set_default_whitespace_mode(struct apply_state *state)
+{
+       if (!state->whitespace_option && !apply_default_whitespace)
+               state->ws_error_action = (state->apply ? warn_on_ws_error : nowarn_ws_error);
+}
 
 /*
- * Various "current state", notably line numbers and what
- * file (and how) we're patching right now.. The "is_xxxx"
- * things are flags, where -1 means "don't know yet".
+ * This represents one "hunk" from a patch, starting with
+ * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
+ * patch text is pointed at by patch, and its byte length
+ * is stored in size.  leading and trailing are the number
+ * of context lines.
  */
-static int linenr = 1;
-
 struct fragment {
        unsigned long leading, trailing;
        unsigned long oldpos, oldlines;
        unsigned long newpos, newlines;
+       /*
+        * 'patch' is usually borrowed from buf in apply_patch(),
+        * but some codepaths store an allocated buffer.
+        */
        const char *patch;
+       unsigned free_patch:1,
+               rejected:1;
        int size;
+       int linenr;
        struct fragment *next;
 };
 
+/*
+ * When dealing with a binary patch, we reuse "leading" field
+ * to store the type of the binary hunk, either deflated "delta"
+ * or deflated "literal".
+ */
+#define binary_patch_method leading
+#define BINARY_DELTA_DEFLATED  1
+#define BINARY_LITERAL_DEFLATED 2
+
+/*
+ * This represents a "patch" to a file, both metainfo changes
+ * such as creation/deletion, filemode and content changes represented
+ * as a series of fragments.
+ */
 struct patch {
        char *new_name, *old_name, *def_name;
        unsigned int old_mode, new_mode;
-       int is_rename, is_copy, is_new, is_delete, is_binary;
-#define BINARY_DELTA_DEFLATED 1
-#define BINARY_LITERAL_DEFLATED 2
-       unsigned long deflate_origlen;
+       int is_new, is_delete;  /* -1 = unknown, 0 = false, 1 = true */
+       int rejected;
+       unsigned ws_rule;
        int lines_added, lines_deleted;
        int score;
+       unsigned int is_toplevel_relative:1;
+       unsigned int inaccurate_eof:1;
+       unsigned int is_binary:1;
+       unsigned int is_copy:1;
+       unsigned int is_rename:1;
+       unsigned int recount:1;
+       unsigned int conflicted_threeway:1;
+       unsigned int direct_to_threeway:1;
        struct fragment *fragments;
        char *result;
-       unsigned long resultsize;
+       size_t resultsize;
        char old_sha1_prefix[41];
        char new_sha1_prefix[41];
        struct patch *next;
+
+       /* three-way fallback result */
+       struct object_id threeway_stage[3];
 };
 
-#define CHUNKSIZE (8192)
-#define SLOP (16)
+static void free_fragment_list(struct fragment *list)
+{
+       while (list) {
+               struct fragment *next = list->next;
+               if (list->free_patch)
+                       free((char *)list->patch);
+               free(list);
+               list = next;
+       }
+}
+
+static void free_patch(struct patch *patch)
+{
+       free_fragment_list(patch->fragments);
+       free(patch->def_name);
+       free(patch->old_name);
+       free(patch->new_name);
+       free(patch->result);
+       free(patch);
+}
 
-static void *read_patch_file(int fd, unsigned long *sizep)
+static void free_patch_list(struct patch *list)
 {
-       unsigned long size = 0, alloc = CHUNKSIZE;
-       void *buffer = xmalloc(alloc);
+       while (list) {
+               struct patch *next = list->next;
+               free_patch(list);
+               list = next;
+       }
+}
 
-       for (;;) {
-               int nr = alloc - size;
-               if (nr < 1024) {
-                       alloc += CHUNKSIZE;
-                       buffer = xrealloc(buffer, alloc);
-                       nr = alloc - size;
-               }
-               nr = xread(fd, buffer + size, nr);
-               if (!nr)
+/*
+ * A line in a file, len-bytes long (includes the terminating LF,
+ * except for an incomplete line at the end if the file ends with
+ * one), and its contents hashes to 'hash'.
+ */
+struct line {
+       size_t len;
+       unsigned hash : 24;
+       unsigned flag : 8;
+#define LINE_COMMON     1
+#define LINE_PATCHED   2
+};
+
+/*
+ * This represents a "file", which is an array of "lines".
+ */
+struct image {
+       char *buf;
+       size_t len;
+       size_t nr;
+       size_t alloc;
+       struct line *line_allocated;
+       struct line *line;
+};
+
+static uint32_t hash_line(const char *cp, size_t len)
+{
+       size_t i;
+       uint32_t h;
+       for (i = 0, h = 0; i < len; i++) {
+               if (!isspace(cp[i])) {
+                       h = h * 3 + (cp[i] & 0xff);
+               }
+       }
+       return h;
+}
+
+/*
+ * Compare lines s1 of length n1 and s2 of length n2, ignoring
+ * whitespace difference. Returns 1 if they match, 0 otherwise
+ */
+static int fuzzy_matchlines(const char *s1, size_t n1,
+                           const char *s2, size_t n2)
+{
+       const char *last1 = s1 + n1 - 1;
+       const char *last2 = s2 + n2 - 1;
+       int result = 0;
+
+       /* ignore line endings */
+       while ((*last1 == '\r') || (*last1 == '\n'))
+               last1--;
+       while ((*last2 == '\r') || (*last2 == '\n'))
+               last2--;
+
+       /* skip leading whitespaces, if both begin with whitespace */
+       if (s1 <= last1 && s2 <= last2 && isspace(*s1) && isspace(*s2)) {
+               while (isspace(*s1) && (s1 <= last1))
+                       s1++;
+               while (isspace(*s2) && (s2 <= last2))
+                       s2++;
+       }
+       /* early return if both lines are empty */
+       if ((s1 > last1) && (s2 > last2))
+               return 1;
+       while (!result) {
+               result = *s1++ - *s2++;
+               /*
+                * Skip whitespace inside. We check for whitespace on
+                * both buffers because we don't want "a b" to match
+                * "ab"
+                */
+               if (isspace(*s1) && isspace(*s2)) {
+                       while (isspace(*s1) && s1 <= last1)
+                               s1++;
+                       while (isspace(*s2) && s2 <= last2)
+                               s2++;
+               }
+               /*
+                * If we reached the end on one side only,
+                * lines don't match
+                */
+               if (
+                   ((s2 > last2) && (s1 <= last1)) ||
+                   ((s1 > last1) && (s2 <= last2)))
+                       return 0;
+               if ((s1 > last1) && (s2 > last2))
                        break;
-               if (nr < 0)
-                       die("git-apply: read returned %s", strerror(errno));
-               size += nr;
        }
-       *sizep = size;
+
+       return !result;
+}
+
+static void add_line_info(struct image *img, const char *bol, size_t len, unsigned flag)
+{
+       ALLOC_GROW(img->line_allocated, img->nr + 1, img->alloc);
+       img->line_allocated[img->nr].len = len;
+       img->line_allocated[img->nr].hash = hash_line(bol, len);
+       img->line_allocated[img->nr].flag = flag;
+       img->nr++;
+}
+
+/*
+ * "buf" has the file contents to be patched (read from various sources).
+ * attach it to "image" and add line-based index to it.
+ * "image" now owns the "buf".
+ */
+static void prepare_image(struct image *image, char *buf, size_t len,
+                         int prepare_linetable)
+{
+       const char *cp, *ep;
+
+       memset(image, 0, sizeof(*image));
+       image->buf = buf;
+       image->len = len;
+
+       if (!prepare_linetable)
+               return;
+
+       ep = image->buf + image->len;
+       cp = image->buf;
+       while (cp < ep) {
+               const char *next;
+               for (next = cp; next < ep && *next != '\n'; next++)
+                       ;
+               if (next < ep)
+                       next++;
+               add_line_info(image, cp, next - cp, 0);
+               cp = next;
+       }
+       image->line = image->line_allocated;
+}
+
+static void clear_image(struct image *image)
+{
+       free(image->buf);
+       free(image->line_allocated);
+       memset(image, 0, sizeof(*image));
+}
+
+/* fmt must contain _one_ %s and no other substitution */
+static void say_patch_name(FILE *output, const char *fmt, struct patch *patch)
+{
+       struct strbuf sb = STRBUF_INIT;
+
+       if (patch->old_name && patch->new_name &&
+           strcmp(patch->old_name, patch->new_name)) {
+               quote_c_style(patch->old_name, &sb, NULL, 0);
+               strbuf_addstr(&sb, " => ");
+               quote_c_style(patch->new_name, &sb, NULL, 0);
+       } else {
+               const char *n = patch->new_name;
+               if (!n)
+                       n = patch->old_name;
+               quote_c_style(n, &sb, NULL, 0);
+       }
+       fprintf(output, fmt, sb.buf);
+       fputc('\n', output);
+       strbuf_release(&sb);
+}
+
+#define SLOP (16)
+
+static int read_patch_file(struct strbuf *sb, int fd)
+{
+       if (strbuf_read(sb, fd, 0) < 0)
+               return error_errno("git apply: failed to read");
 
        /*
         * Make sure that we have some slop in the buffer
         * so that we can do speculative "memcmp" etc, and
         * see to it that it is NUL-filled.
         */
-       if (alloc < size + SLOP)
-               buffer = xrealloc(buffer, size + SLOP);
-       memset(buffer + size, 0, SLOP);
-       return buffer;
+       strbuf_grow(sb, SLOP);
+       memset(sb->buf + sb->len, 0, SLOP);
+       return 0;
 }
 
 static unsigned long linelen(const char *buffer, unsigned long size)
@@ -179,13 +449,13 @@ static unsigned long linelen(const char *buffer, unsigned long size)
 
 static int is_dev_null(const char *str)
 {
-       return !memcmp("/dev/null", str, 9) && isspace(str[9]);
+       return skip_prefix(str, "/dev/null", &str) && isspace(*str);
 }
 
 #define TERM_SPACE     1
 #define TERM_TAB       2
 
-static int name_terminate(const char *name, int namelen, int c, int terminate)
+static int name_terminate(int c, int terminate)
 {
        if (c == ' ' && !(terminate & TERM_SPACE))
                return 0;
@@ -195,48 +465,233 @@ static int name_terminate(const char *name, int namelen, int c, int terminate)
        return 1;
 }
 
-static char * find_name(const char *line, char *def, int p_value, int terminate)
+/* remove double slashes to make --index work with such filenames */
+static char *squash_slash(char *name)
 {
-       int len;
-       const char *start = line;
-       char *name;
+       int i = 0, j = 0;
 
-       if (*line == '"') {
-               /* Proposed "new-style" GNU patch/diff format; see
-                * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
-                */
-               name = unquote_c_style(line, NULL);
-               if (name) {
-                       char *cp = name;
-                       while (p_value) {
-                               cp = strchr(name, '/');
-                               if (!cp)
-                                       break;
-                               cp++;
-                               p_value--;
-                       }
-                       if (cp) {
-                               /* name can later be freed, so we need
-                                * to memmove, not just return cp
-                                */
-                               memmove(name, cp, strlen(cp) + 1);
-                               free(def);
-                               return name;
-                       }
-                       else {
-                               free(name);
-                               name = NULL;
-                       }
+       if (!name)
+               return NULL;
+
+       while (name[i]) {
+               if ((name[j++] = name[i++]) == '/')
+                       while (name[i] == '/')
+                               i++;
+       }
+       name[j] = '\0';
+       return name;
+}
+
+static char *find_name_gnu(struct apply_state *state,
+                          const char *line,
+                          const char *def,
+                          int p_value)
+{
+       struct strbuf name = STRBUF_INIT;
+       char *cp;
+
+       /*
+        * Proposed "new-style" GNU patch/diff format; see
+        * http://marc.info/?l=git&m=112927316408690&w=2
+        */
+       if (unquote_c_style(&name, line, NULL)) {
+               strbuf_release(&name);
+               return NULL;
+       }
+
+       for (cp = name.buf; p_value; p_value--) {
+               cp = strchr(cp, '/');
+               if (!cp) {
+                       strbuf_release(&name);
+                       return NULL;
                }
+               cp++;
        }
 
-       for (;;) {
+       strbuf_remove(&name, 0, cp - name.buf);
+       if (state->root.len)
+               strbuf_insert(&name, 0, state->root.buf, state->root.len);
+       return squash_slash(strbuf_detach(&name, NULL));
+}
+
+static size_t sane_tz_len(const char *line, size_t len)
+{
+       const char *tz, *p;
+
+       if (len < strlen(" +0500") || line[len-strlen(" +0500")] != ' ')
+               return 0;
+       tz = line + len - strlen(" +0500");
+
+       if (tz[1] != '+' && tz[1] != '-')
+               return 0;
+
+       for (p = tz + 2; p != line + len; p++)
+               if (!isdigit(*p))
+                       return 0;
+
+       return line + len - tz;
+}
+
+static size_t tz_with_colon_len(const char *line, size_t len)
+{
+       const char *tz, *p;
+
+       if (len < strlen(" +08:00") || line[len - strlen(":00")] != ':')
+               return 0;
+       tz = line + len - strlen(" +08:00");
+
+       if (tz[0] != ' ' || (tz[1] != '+' && tz[1] != '-'))
+               return 0;
+       p = tz + 2;
+       if (!isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
+           !isdigit(*p++) || !isdigit(*p++))
+               return 0;
+
+       return line + len - tz;
+}
+
+static size_t date_len(const char *line, size_t len)
+{
+       const char *date, *p;
+
+       if (len < strlen("72-02-05") || line[len-strlen("-05")] != '-')
+               return 0;
+       p = date = line + len - strlen("72-02-05");
+
+       if (!isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
+           !isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
+           !isdigit(*p++) || !isdigit(*p++))   /* Not a date. */
+               return 0;
+
+       if (date - line >= strlen("19") &&
+           isdigit(date[-1]) && isdigit(date[-2]))     /* 4-digit year */
+               date -= strlen("19");
+
+       return line + len - date;
+}
+
+static size_t short_time_len(const char *line, size_t len)
+{
+       const char *time, *p;
+
+       if (len < strlen(" 07:01:32") || line[len-strlen(":32")] != ':')
+               return 0;
+       p = time = line + len - strlen(" 07:01:32");
+
+       /* Permit 1-digit hours? */
+       if (*p++ != ' ' ||
+           !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
+           !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
+           !isdigit(*p++) || !isdigit(*p++))   /* Not a time. */
+               return 0;
+
+       return line + len - time;
+}
+
+static size_t fractional_time_len(const char *line, size_t len)
+{
+       const char *p;
+       size_t n;
+
+       /* Expected format: 19:41:17.620000023 */
+       if (!len || !isdigit(line[len - 1]))
+               return 0;
+       p = line + len - 1;
+
+       /* Fractional seconds. */
+       while (p > line && isdigit(*p))
+               p--;
+       if (*p != '.')
+               return 0;
+
+       /* Hours, minutes, and whole seconds. */
+       n = short_time_len(line, p - line);
+       if (!n)
+               return 0;
+
+       return line + len - p + n;
+}
+
+static size_t trailing_spaces_len(const char *line, size_t len)
+{
+       const char *p;
+
+       /* Expected format: ' ' x (1 or more)  */
+       if (!len || line[len - 1] != ' ')
+               return 0;
+
+       p = line + len;
+       while (p != line) {
+               p--;
+               if (*p != ' ')
+                       return line + len - (p + 1);
+       }
+
+       /* All spaces! */
+       return len;
+}
+
+static size_t diff_timestamp_len(const char *line, size_t len)
+{
+       const char *end = line + len;
+       size_t n;
+
+       /*
+        * Posix: 2010-07-05 19:41:17
+        * GNU: 2010-07-05 19:41:17.620000023 -0500
+        */
+
+       if (!isdigit(end[-1]))
+               return 0;
+
+       n = sane_tz_len(line, end - line);
+       if (!n)
+               n = tz_with_colon_len(line, end - line);
+       end -= n;
+
+       n = short_time_len(line, end - line);
+       if (!n)
+               n = fractional_time_len(line, end - line);
+       end -= n;
+
+       n = date_len(line, end - line);
+       if (!n) /* No date.  Too bad. */
+               return 0;
+       end -= n;
+
+       if (end == line)        /* No space before date. */
+               return 0;
+       if (end[-1] == '\t') {  /* Success! */
+               end--;
+               return line + len - end;
+       }
+       if (end[-1] != ' ')     /* No space before date. */
+               return 0;
+
+       /* Whitespace damage. */
+       end -= trailing_spaces_len(line, end - line);
+       return line + len - end;
+}
+
+static char *find_name_common(struct apply_state *state,
+                             const char *line,
+                             const char *def,
+                             int p_value,
+                             const char *end,
+                             int terminate)
+{
+       int len;
+       const char *start = NULL;
+
+       if (p_value == 0)
+               start = line;
+       while (line != end) {
                char c = *line;
 
-               if (isspace(c)) {
+               if (!end && isspace(c)) {
                        if (c == '\n')
                                break;
-                       if (name_terminate(start, line-start, c, terminate))
+                       if (name_terminate(c, terminate))
                                break;
                }
                line++;
@@ -244,10 +699,10 @@ static char * find_name(const char *line, char *def, int p_value, int terminate)
                        start = line;
        }
        if (!start)
-               return def;
+               return squash_slash(xstrdup_or_null(def));
        len = line - start;
        if (!len)
-               return def;
+               return squash_slash(xstrdup_or_null(def));
 
        /*
         * Generally we prefer the shorter name, especially
@@ -258,53 +713,238 @@ static char * find_name(const char *line, char *def, int p_value, int terminate)
        if (def) {
                int deflen = strlen(def);
                if (deflen < len && !strncmp(start, def, deflen))
-                       return def;
+                       return squash_slash(xstrdup(def));
        }
 
-       name = xmalloc(len + 1);
-       memcpy(name, start, len);
-       name[len] = 0;
-       free(def);
-       return name;
+       if (state->root.len) {
+               char *ret = xstrfmt("%s%.*s", state->root.buf, len, start);
+               return squash_slash(ret);
+       }
+
+       return squash_slash(xmemdupz(start, len));
 }
 
-/*
- * Get the name etc info from the --/+++ lines of a traditional patch header
- *
- * NOTE! This hardcodes "-p1" behaviour in filename detection.
- *
- * FIXME! The end-of-filename heuristics are kind of screwy. For existing
- * files, we can happily check the index for a match, but for creating a
- * new file we should try to match whatever "patch" does. I have no idea.
- */
-static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
+static char *find_name(struct apply_state *state,
+                      const char *line,
+                      char *def,
+                      int p_value,
+                      int terminate)
 {
-       char *name;
-
-       first += 4;     // skip "--- "
-       second += 4;    // skip "+++ "
-       if (is_dev_null(first)) {
-               patch->is_new = 1;
-               patch->is_delete = 0;
-               name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
-               patch->new_name = name;
-       } else if (is_dev_null(second)) {
-               patch->is_new = 0;
-               patch->is_delete = 1;
-               name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
-               patch->old_name = name;
-       } else {
-               name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
-               name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
-               patch->old_name = patch->new_name = name;
+       if (*line == '"') {
+               char *name = find_name_gnu(state, line, def, p_value);
+               if (name)
+                       return name;
        }
-       if (!name)
-               die("unable to find filename in patch at line %d", linenr);
+
+       return find_name_common(state, line, def, p_value, NULL, terminate);
 }
 
-static int gitdiff_hdrend(const char *line, struct patch *patch)
+static char *find_name_traditional(struct apply_state *state,
+                                  const char *line,
+                                  char *def,
+                                  int p_value)
 {
-       return -1;
+       size_t len;
+       size_t date_len;
+
+       if (*line == '"') {
+               char *name = find_name_gnu(state, line, def, p_value);
+               if (name)
+                       return name;
+       }
+
+       len = strchrnul(line, '\n') - line;
+       date_len = diff_timestamp_len(line, len);
+       if (!date_len)
+               return find_name_common(state, line, def, p_value, NULL, TERM_TAB);
+       len -= date_len;
+
+       return find_name_common(state, line, def, p_value, line + len, 0);
+}
+
+static int count_slashes(const char *cp)
+{
+       int cnt = 0;
+       char ch;
+
+       while ((ch = *cp++))
+               if (ch == '/')
+                       cnt++;
+       return cnt;
+}
+
+/*
+ * Given the string after "--- " or "+++ ", guess the appropriate
+ * p_value for the given patch.
+ */
+static int guess_p_value(struct apply_state *state, const char *nameline)
+{
+       char *name, *cp;
+       int val = -1;
+
+       if (is_dev_null(nameline))
+               return -1;
+       name = find_name_traditional(state, nameline, NULL, 0);
+       if (!name)
+               return -1;
+       cp = strchr(name, '/');
+       if (!cp)
+               val = 0;
+       else if (state->prefix) {
+               /*
+                * Does it begin with "a/$our-prefix" and such?  Then this is
+                * very likely to apply to our directory.
+                */
+               if (!strncmp(name, state->prefix, state->prefix_length))
+                       val = count_slashes(state->prefix);
+               else {
+                       cp++;
+                       if (!strncmp(cp, state->prefix, state->prefix_length))
+                               val = count_slashes(state->prefix) + 1;
+               }
+       }
+       free(name);
+       return val;
+}
+
+/*
+ * Does the ---/+++ line have the POSIX timestamp after the last HT?
+ * GNU diff puts epoch there to signal a creation/deletion event.  Is
+ * this such a timestamp?
+ */
+static int has_epoch_timestamp(const char *nameline)
+{
+       /*
+        * We are only interested in epoch timestamp; any non-zero
+        * fraction cannot be one, hence "(\.0+)?" in the regexp below.
+        * For the same reason, the date must be either 1969-12-31 or
+        * 1970-01-01, and the seconds part must be "00".
+        */
+       const char stamp_regexp[] =
+               "^(1969-12-31|1970-01-01)"
+               " "
+               "[0-2][0-9]:[0-5][0-9]:00(\\.0+)?"
+               " "
+               "([-+][0-2][0-9]:?[0-5][0-9])\n";
+       const char *timestamp = NULL, *cp, *colon;
+       static regex_t *stamp;
+       regmatch_t m[10];
+       int zoneoffset;
+       int hourminute;
+       int status;
+
+       for (cp = nameline; *cp != '\n'; cp++) {
+               if (*cp == '\t')
+                       timestamp = cp + 1;
+       }
+       if (!timestamp)
+               return 0;
+       if (!stamp) {
+               stamp = xmalloc(sizeof(*stamp));
+               if (regcomp(stamp, stamp_regexp, REG_EXTENDED)) {
+                       warning(_("Cannot prepare timestamp regexp %s"),
+                               stamp_regexp);
+                       return 0;
+               }
+       }
+
+       status = regexec(stamp, timestamp, ARRAY_SIZE(m), m, 0);
+       if (status) {
+               if (status != REG_NOMATCH)
+                       warning(_("regexec returned %d for input: %s"),
+                               status, timestamp);
+               return 0;
+       }
+
+       zoneoffset = strtol(timestamp + m[3].rm_so + 1, (char **) &colon, 10);
+       if (*colon == ':')
+               zoneoffset = zoneoffset * 60 + strtol(colon + 1, NULL, 10);
+       else
+               zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
+       if (timestamp[m[3].rm_so] == '-')
+               zoneoffset = -zoneoffset;
+
+       /*
+        * YYYY-MM-DD hh:mm:ss must be from either 1969-12-31
+        * (west of GMT) or 1970-01-01 (east of GMT)
+        */
+       if ((zoneoffset < 0 && memcmp(timestamp, "1969-12-31", 10)) ||
+           (0 <= zoneoffset && memcmp(timestamp, "1970-01-01", 10)))
+               return 0;
+
+       hourminute = (strtol(timestamp + 11, NULL, 10) * 60 +
+                     strtol(timestamp + 14, NULL, 10) -
+                     zoneoffset);
+
+       return ((zoneoffset < 0 && hourminute == 1440) ||
+               (0 <= zoneoffset && !hourminute));
+}
+
+/*
+ * Get the name etc info from the ---/+++ lines of a traditional patch header
+ *
+ * FIXME! The end-of-filename heuristics are kind of screwy. For existing
+ * files, we can happily check the index for a match, but for creating a
+ * new file we should try to match whatever "patch" does. I have no idea.
+ */
+static int parse_traditional_patch(struct apply_state *state,
+                                  const char *first,
+                                  const char *second,
+                                  struct patch *patch)
+{
+       char *name;
+
+       first += 4;     /* skip "--- " */
+       second += 4;    /* skip "+++ " */
+       if (!state->p_value_known) {
+               int p, q;
+               p = guess_p_value(state, first);
+               q = guess_p_value(state, second);
+               if (p < 0) p = q;
+               if (0 <= p && p == q) {
+                       state->p_value = p;
+                       state->p_value_known = 1;
+               }
+       }
+       if (is_dev_null(first)) {
+               patch->is_new = 1;
+               patch->is_delete = 0;
+               name = find_name_traditional(state, second, NULL, state->p_value);
+               patch->new_name = name;
+       } else if (is_dev_null(second)) {
+               patch->is_new = 0;
+               patch->is_delete = 1;
+               name = find_name_traditional(state, first, NULL, state->p_value);
+               patch->old_name = name;
+       } else {
+               char *first_name;
+               first_name = find_name_traditional(state, first, NULL, state->p_value);
+               name = find_name_traditional(state, second, first_name, state->p_value);
+               free(first_name);
+               if (has_epoch_timestamp(first)) {
+                       patch->is_new = 1;
+                       patch->is_delete = 0;
+                       patch->new_name = name;
+               } else if (has_epoch_timestamp(second)) {
+                       patch->is_new = 0;
+                       patch->is_delete = 1;
+                       patch->old_name = name;
+               } else {
+                       patch->old_name = name;
+                       patch->new_name = xstrdup_or_null(name);
+               }
+       }
+       if (!name)
+               return error(_("unable to find filename in patch at line %d"), state->linenr);
+
+       return 0;
+}
+
+static int gitdiff_hdrend(struct apply_state *state,
+                         const char *line,
+                         struct patch *patch)
+{
+       return 1;
 }
 
 /*
@@ -316,116 +956,163 @@ static int gitdiff_hdrend(const char *line, struct patch *patch)
  * their names against any previous information, just
  * to make sure..
  */
-static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
+#define DIFF_OLD_NAME 0
+#define DIFF_NEW_NAME 1
+
+static int gitdiff_verify_name(struct apply_state *state,
+                              const char *line,
+                              int isnull,
+                              char **name,
+                              int side)
 {
-       if (!orig_name && !isnull)
-               return find_name(line, NULL, 1, 0);
+       if (!*name && !isnull) {
+               *name = find_name(state, line, NULL, state->p_value, TERM_TAB);
+               return 0;
+       }
 
-       if (orig_name) {
-               int len;
-               const char *name;
+       if (*name) {
+               int len = strlen(*name);
                char *another;
-               name = orig_name;
-               len = strlen(name);
                if (isnull)
-                       die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
-               another = find_name(line, NULL, 1, 0);
-               if (!another || memcmp(another, name, len))
-                       die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
+                       return error(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
+                                    *name, state->linenr);
+               another = find_name(state, line, NULL, state->p_value, TERM_TAB);
+               if (!another || memcmp(another, *name, len + 1)) {
+                       free(another);
+                       return error((side == DIFF_NEW_NAME) ?
+                           _("git apply: bad git-diff - inconsistent new filename on line %d") :
+                           _("git apply: bad git-diff - inconsistent old filename on line %d"), state->linenr);
+               }
                free(another);
-               return orig_name;
-       }
-       else {
+       } else {
                /* expect "/dev/null" */
                if (memcmp("/dev/null", line, 9) || line[9] != '\n')
-                       die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
-               return NULL;
+                       return error(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
        }
+
+       return 0;
 }
 
-static int gitdiff_oldname(const char *line, struct patch *patch)
+static int gitdiff_oldname(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
-       patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
-       return 0;
+       return gitdiff_verify_name(state, line,
+                                  patch->is_new, &patch->old_name,
+                                  DIFF_OLD_NAME);
 }
 
-static int gitdiff_newname(const char *line, struct patch *patch)
+static int gitdiff_newname(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
-       patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
-       return 0;
+       return gitdiff_verify_name(state, line,
+                                  patch->is_delete, &patch->new_name,
+                                  DIFF_NEW_NAME);
 }
 
-static int gitdiff_oldmode(const char *line, struct patch *patch)
+static int gitdiff_oldmode(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->old_mode = strtoul(line, NULL, 8);
        return 0;
 }
 
-static int gitdiff_newmode(const char *line, struct patch *patch)
+static int gitdiff_newmode(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->new_mode = strtoul(line, NULL, 8);
        return 0;
 }
 
-static int gitdiff_delete(const char *line, struct patch *patch)
+static int gitdiff_delete(struct apply_state *state,
+                         const char *line,
+                         struct patch *patch)
 {
        patch->is_delete = 1;
-       patch->old_name = patch->def_name;
-       return gitdiff_oldmode(line, patch);
+       free(patch->old_name);
+       patch->old_name = xstrdup_or_null(patch->def_name);
+       return gitdiff_oldmode(state, line, patch);
 }
 
-static int gitdiff_newfile(const char *line, struct patch *patch)
+static int gitdiff_newfile(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->is_new = 1;
-       patch->new_name = patch->def_name;
-       return gitdiff_newmode(line, patch);
+       free(patch->new_name);
+       patch->new_name = xstrdup_or_null(patch->def_name);
+       return gitdiff_newmode(state, line, patch);
 }
 
-static int gitdiff_copysrc(const char *line, struct patch *patch)
+static int gitdiff_copysrc(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->is_copy = 1;
-       patch->old_name = find_name(line, NULL, 0, 0);
+       free(patch->old_name);
+       patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
        return 0;
 }
 
-static int gitdiff_copydst(const char *line, struct patch *patch)
+static int gitdiff_copydst(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->is_copy = 1;
-       patch->new_name = find_name(line, NULL, 0, 0);
+       free(patch->new_name);
+       patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
        return 0;
 }
 
-static int gitdiff_renamesrc(const char *line, struct patch *patch)
+static int gitdiff_renamesrc(struct apply_state *state,
+                            const char *line,
+                            struct patch *patch)
 {
        patch->is_rename = 1;
-       patch->old_name = find_name(line, NULL, 0, 0);
+       free(patch->old_name);
+       patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
        return 0;
 }
 
-static int gitdiff_renamedst(const char *line, struct patch *patch)
+static int gitdiff_renamedst(struct apply_state *state,
+                            const char *line,
+                            struct patch *patch)
 {
        patch->is_rename = 1;
-       patch->new_name = find_name(line, NULL, 0, 0);
+       free(patch->new_name);
+       patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
        return 0;
 }
 
-static int gitdiff_similarity(const char *line, struct patch *patch)
+static int gitdiff_similarity(struct apply_state *state,
+                             const char *line,
+                             struct patch *patch)
 {
-       if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
-               patch->score = 0;
+       unsigned long val = strtoul(line, NULL, 10);
+       if (val <= 100)
+               patch->score = val;
        return 0;
 }
 
-static int gitdiff_dissimilarity(const char *line, struct patch *patch)
+static int gitdiff_dissimilarity(struct apply_state *state,
+                                const char *line,
+                                struct patch *patch)
 {
-       if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
-               patch->score = 0;
+       unsigned long val = strtoul(line, NULL, 10);
+       if (val <= 100)
+               patch->score = val;
        return 0;
 }
 
-static int gitdiff_index(const char *line, struct patch *patch)
+static int gitdiff_index(struct apply_state *state,
+                        const char *line,
+                        struct patch *patch)
 {
-       /* index line is N hexadecimal, "..", N hexadecimal,
+       /*
+        * index line is N hexadecimal, "..", N hexadecimal,
         * and optional space with octal mode.
         */
        const char *ptr, *eol;
@@ -440,7 +1127,7 @@ static int gitdiff_index(const char *line, struct patch *patch)
 
        line = ptr + 2;
        ptr = strchr(line, ' ');
-       eol = strchr(line, '\n');
+       eol = strchrnul(line, '\n');
 
        if (!ptr || eol < ptr)
                ptr = eol;
@@ -451,7 +1138,7 @@ static int gitdiff_index(const char *line, struct patch *patch)
        memcpy(patch->new_sha1_prefix, line, len);
        patch->new_sha1_prefix[len] = 0;
        if (*ptr == ' ')
-               patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
+               patch->old_mode = strtoul(ptr+1, NULL, 8);
        return 0;
 }
 
@@ -459,126 +1146,139 @@ static int gitdiff_index(const char *line, struct patch *patch)
  * This is normal for a diff that doesn't change anything: we'll fall through
  * into the next diff. Tell the parser to break out.
  */
-static int gitdiff_unrecognized(const char *line, struct patch *patch)
+static int gitdiff_unrecognized(struct apply_state *state,
+                               const char *line,
+                               struct patch *patch)
 {
-       return -1;
+       return 1;
 }
 
-static const char *stop_at_slash(const char *line, int llen)
+/*
+ * Skip p_value leading components from "line"; as we do not accept
+ * absolute paths, return NULL in that case.
+ */
+static const char *skip_tree_prefix(struct apply_state *state,
+                                   const char *line,
+                                   int llen)
 {
+       int nslash;
        int i;
 
+       if (!state->p_value)
+               return (llen && line[0] == '/') ? NULL : line;
+
+       nslash = state->p_value;
        for (i = 0; i < llen; i++) {
                int ch = line[i];
-               if (ch == '/')
-                       return line + i;
+               if (ch == '/' && --nslash <= 0)
+                       return (i == 0) ? NULL : &line[i + 1];
        }
        return NULL;
 }
 
-/* This is to extract the same name that appears on "diff --git"
+/*
+ * This is to extract the same name that appears on "diff --git"
  * line.  We do not find and return anything if it is a rename
  * patch, and it is OK because we will find the name elsewhere.
  * We need to reliably find name only when it is mode-change only,
  * creation or deletion of an empty file.  In any of these cases,
  * both sides are the same name under a/ and b/ respectively.
  */
-static char *git_header_name(char *line, int llen)
+static char *git_header_name(struct apply_state *state,
+                            const char *line,
+                            int llen)
 {
-       int len;
        const char *name;
        const char *second = NULL;
+       size_t len, line_len;
 
        line += strlen("diff --git ");
        llen -= strlen("diff --git ");
 
        if (*line == '"') {
                const char *cp;
-               char *first = unquote_c_style(line, &second);
-               if (!first)
-                       return NULL;
+               struct strbuf first = STRBUF_INIT;
+               struct strbuf sp = STRBUF_INIT;
 
-               /* advance to the first slash */
-               cp = stop_at_slash(first, strlen(first));
-               if (!cp || cp == first) {
-                       /* we do not accept absolute paths */
-               free_first_and_fail:
-                       free(first);
-                       return NULL;
-               }
-               len = strlen(cp+1);
-               memmove(first, cp+1, len+1); /* including NUL */
+               if (unquote_c_style(&first, line, &second))
+                       goto free_and_fail1;
 
-               /* second points at one past closing dq of name.
+               /* strip the a/b prefix including trailing slash */
+               cp = skip_tree_prefix(state, first.buf, first.len);
+               if (!cp)
+                       goto free_and_fail1;
+               strbuf_remove(&first, 0, cp - first.buf);
+
+               /*
+                * second points at one past closing dq of name.
                 * find the second name.
                 */
                while ((second < line + llen) && isspace(*second))
                        second++;
 
                if (line + llen <= second)
-                       goto free_first_and_fail;
+                       goto free_and_fail1;
                if (*second == '"') {
-                       char *sp = unquote_c_style(second, NULL);
-                       if (!sp)
-                               goto free_first_and_fail;
-                       cp = stop_at_slash(sp, strlen(sp));
-                       if (!cp || cp == sp) {
-                       free_both_and_fail:
-                               free(sp);
-                               goto free_first_and_fail;
-                       }
+                       if (unquote_c_style(&sp, second, NULL))
+                               goto free_and_fail1;
+                       cp = skip_tree_prefix(state, sp.buf, sp.len);
+                       if (!cp)
+                               goto free_and_fail1;
                        /* They must match, otherwise ignore */
-                       if (strcmp(cp+1, first))
-                               goto free_both_and_fail;
-                       free(sp);
-                       return first;
+                       if (strcmp(cp, first.buf))
+                               goto free_and_fail1;
+                       strbuf_release(&sp);
+                       return strbuf_detach(&first, NULL);
                }
 
                /* unquoted second */
-               cp = stop_at_slash(second, line + llen - second);
-               if (!cp || cp == second)
-                       goto free_first_and_fail;
-               cp++;
-               if (line + llen - cp != len + 1 ||
-                   memcmp(first, cp, len))
-                       goto free_first_and_fail;
-               return first;
+               cp = skip_tree_prefix(state, second, line + llen - second);
+               if (!cp)
+                       goto free_and_fail1;
+               if (line + llen - cp != first.len ||
+                   memcmp(first.buf, cp, first.len))
+                       goto free_and_fail1;
+               return strbuf_detach(&first, NULL);
+
+       free_and_fail1:
+               strbuf_release(&first);
+               strbuf_release(&sp);
+               return NULL;
        }
 
        /* unquoted first name */
-       name = stop_at_slash(line, llen);
-       if (!name || name == line)
+       name = skip_tree_prefix(state, line, llen);
+       if (!name)
                return NULL;
 
-       name++;
-
-       /* since the first name is unquoted, a dq if exists must be
+       /*
+        * since the first name is unquoted, a dq if exists must be
         * the beginning of the second name.
         */
        for (second = name; second < line + llen; second++) {
                if (*second == '"') {
-                       const char *cp = second;
+                       struct strbuf sp = STRBUF_INIT;
                        const char *np;
-                       char *sp = unquote_c_style(second, NULL);
 
-                       if (!sp)
-                               return NULL;
-                       np = stop_at_slash(sp, strlen(sp));
-                       if (!np || np == sp) {
-                       free_second_and_fail:
-                               free(sp);
-                               return NULL;
-                       }
-                       np++;
-                       len = strlen(np);
-                       if (len < cp - name &&
+                       if (unquote_c_style(&sp, second, NULL))
+                               goto free_and_fail2;
+
+                       np = skip_tree_prefix(state, sp.buf, sp.len);
+                       if (!np)
+                               goto free_and_fail2;
+
+                       len = sp.buf + sp.len - np;
+                       if (len < second - name &&
                            !strncmp(np, name, len) &&
                            isspace(name[len])) {
                                /* Good */
-                               memmove(sp, np, len + 1);
-                               return sp;
+                               strbuf_remove(&sp, 0, np - sp.buf);
+                               return strbuf_detach(&sp, NULL);
                        }
-                       goto free_second_and_fail;
+
+               free_and_fail2:
+                       strbuf_release(&sp);
+                       return NULL;
                }
        }
 
@@ -586,36 +1286,48 @@ static char *git_header_name(char *line, int llen)
         * Accept a name only if it shows up twice, exactly the same
         * form.
         */
+       second = strchr(name, '\n');
+       if (!second)
+               return NULL;
+       line_len = second - name;
        for (len = 0 ; ; len++) {
-               char c = name[len];
-
-               switch (c) {
+               switch (name[len]) {
                default:
                        continue;
                case '\n':
                        return NULL;
                case '\t': case ' ':
-                       second = name+len;
-                       for (;;) {
-                               char c = *second++;
-                               if (c == '\n')
-                                       return NULL;
-                               if (c == '/')
-                                       break;
-                       }
-                       if (second[len] == '\n' && !memcmp(name, second, len)) {
-                               char *ret = xmalloc(len + 1);
-                               memcpy(ret, name, len);
-                               ret[len] = 0;
-                               return ret;
-                       }
+                       /*
+                        * Is this the separator between the preimage
+                        * and the postimage pathname?  Again, we are
+                        * only interested in the case where there is
+                        * no rename, as this is only to set def_name
+                        * and a rename patch has the names elsewhere
+                        * in an unambiguous form.
+                        */
+                       if (!name[len + 1])
+                               return NULL; /* no postimage name */
+                       second = skip_tree_prefix(state, name + len + 1,
+                                                 line_len - (len + 1));
+                       if (!second)
+                               return NULL;
+                       /*
+                        * Does len bytes starting at "name" and "second"
+                        * (that are separated by one HT or SP we just
+                        * found) exactly match?
+                        */
+                       if (second[len] == '\n' && !strncmp(name, second, len))
+                               return xmemdupz(name, len);
                }
        }
-       return NULL;
 }
 
 /* Verify that we recognize the lines following a git header */
-static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
+static int parse_git_header(struct apply_state *state,
+                           const char *line,
+                           int len,
+                           unsigned int size,
+                           struct patch *patch)
 {
        unsigned long offset;
 
@@ -629,15 +1341,20 @@ static int parse_git_header(char *line, int len, unsigned int size, struct patch
         * or removing or adding empty files), so we get
         * the default name from the header.
         */
-       patch->def_name = git_header_name(line, len);
+       patch->def_name = git_header_name(state, line, len);
+       if (patch->def_name && state->root.len) {
+               char *s = xstrfmt("%s%s", state->root.buf, patch->def_name);
+               free(patch->def_name);
+               patch->def_name = s;
+       }
 
        line += len;
        size -= len;
-       linenr++;
-       for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
+       state->linenr++;
+       for (offset = len ; size > 0 ; offset += len, size -= len, line += len, state->linenr++) {
                static const struct opentry {
                        const char *str;
-                       int (*fn)(const char *, struct patch *);
+                       int (*fn)(struct apply_state *, const char *, struct patch *);
                } optable[] = {
                        { "@@ -", gitdiff_hdrend },
                        { "--- ", gitdiff_oldname },
@@ -665,9 +1382,13 @@ static int parse_git_header(char *line, int len, unsigned int size, struct patch
                for (i = 0; i < ARRAY_SIZE(optable); i++) {
                        const struct opentry *p = optable + i;
                        int oplen = strlen(p->str);
+                       int res;
                        if (len < oplen || memcmp(p->str, line, oplen))
                                continue;
-                       if (p->fn(line + oplen, patch) < 0)
+                       res = p->fn(state, line + oplen, patch);
+                       if (res < 0)
+                               return -1;
+                       if (res > 0)
                                return offset;
                        break;
                }
@@ -687,7 +1408,7 @@ static int parse_num(const char *line, unsigned long *p)
 }
 
 static int parse_range(const char *line, int len, int offset, const char *expect,
-                       unsigned long *p1, unsigned long *p2)
+                      unsigned long *p1, unsigned long *p2)
 {
        int digits, ex;
 
@@ -724,11 +1445,61 @@ static int parse_range(const char *line, int len, int offset, const char *expect
        return offset + ex;
 }
 
+static void recount_diff(const char *line, int size, struct fragment *fragment)
+{
+       int oldlines = 0, newlines = 0, ret = 0;
+
+       if (size < 1) {
+               warning("recount: ignore empty hunk");
+               return;
+       }
+
+       for (;;) {
+               int len = linelen(line, size);
+               size -= len;
+               line += len;
+
+               if (size < 1)
+                       break;
+
+               switch (*line) {
+               case ' ': case '\n':
+                       newlines++;
+                       /* fall through */
+               case '-':
+                       oldlines++;
+                       continue;
+               case '+':
+                       newlines++;
+                       continue;
+               case '\\':
+                       continue;
+               case '@':
+                       ret = size < 3 || !starts_with(line, "@@ ");
+                       break;
+               case 'd':
+                       ret = size < 5 || !starts_with(line, "diff ");
+                       break;
+               default:
+                       ret = -1;
+                       break;
+               }
+               if (ret) {
+                       warning(_("recount: unexpected line: %.*s"),
+                               (int)linelen(line, size), line);
+                       return;
+               }
+               break;
+       }
+       fragment->oldlines = oldlines;
+       fragment->newlines = newlines;
+}
+
 /*
  * Parse a unified diff fragment header of the
  * form "@@ -a,b +c,d @@"
  */
-static int parse_fragment_header(char *line, int len, struct fragment *fragment)
+static int parse_fragment_header(const char *line, int len, struct fragment *fragment)
 {
        int offset;
 
@@ -742,15 +1513,28 @@ static int parse_fragment_header(char *line, int len, struct fragment *fragment)
        return offset;
 }
 
-static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
+/*
+ * Find file diff header
+ *
+ * Returns:
+ *  -1 if no header was found
+ *  -128 in case of error
+ *   the size of the header in bytes (called "offset") otherwise
+ */
+static int find_header(struct apply_state *state,
+                      const char *line,
+                      unsigned long size,
+                      int *hdrsize,
+                      struct patch *patch)
 {
        unsigned long offset, len;
 
+       patch->is_toplevel_relative = 0;
        patch->is_rename = patch->is_copy = 0;
        patch->is_new = patch->is_delete = -1;
        patch->old_mode = patch->new_mode = 0;
        patch->old_name = patch->new_name = NULL;
-       for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
+       for (offset = 0; size > 0; offset += len, size -= len, line += len, state->linenr++) {
                unsigned long nextlen;
 
                len = linelen(line, size);
@@ -762,7 +1546,7 @@ static int find_header(char *line, unsigned long size, int *hdrsize, struct patc
                        continue;
 
                /*
-                * Make sure we don't find any unconnected patch fragmants.
+                * Make sure we don't find any unconnected patch fragments.
                 * That's a sign that we didn't find a header, and that a
                 * patch has become corrupted/broken up.
                 */
@@ -770,7 +1554,9 @@ static int find_header(char *line, unsigned long size, int *hdrsize, struct patc
                        struct fragment dummy;
                        if (parse_fragment_header(line, len, &dummy) < 0)
                                continue;
-                       error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
+                       error(_("patch fragment without header at line %d: %.*s"),
+                                    state->linenr, (int)len-1, line);
+                       return -128;
                }
 
                if (size < len + 6)
@@ -781,48 +1567,101 @@ static int find_header(char *line, unsigned long size, int *hdrsize, struct patc
                 * or mode change, so we handle that specially
                 */
                if (!memcmp("diff --git ", line, 11)) {
-                       int git_hdr_len = parse_git_header(line, len, size, patch);
+                       int git_hdr_len = parse_git_header(state, line, len, size, patch);
+                       if (git_hdr_len < 0)
+                               return -128;
                        if (git_hdr_len <= len)
                                continue;
                        if (!patch->old_name && !patch->new_name) {
-                               if (!patch->def_name)
-                                       die("git diff header lacks filename information (line %d)", linenr);
-                               patch->old_name = patch->new_name = patch->def_name;
+                               if (!patch->def_name) {
+                                       error(Q_("git diff header lacks filename information when removing "
+                                                       "%d leading pathname component (line %d)",
+                                                       "git diff header lacks filename information when removing "
+                                                       "%d leading pathname components (line %d)",
+                                                       state->p_value),
+                                                    state->p_value, state->linenr);
+                                       return -128;
+                               }
+                               patch->old_name = xstrdup(patch->def_name);
+                               patch->new_name = xstrdup(patch->def_name);
+                       }
+                       if (!patch->is_delete && !patch->new_name) {
+                               error("git diff header lacks filename information "
+                                            "(line %d)", state->linenr);
+                               return -128;
                        }
+                       patch->is_toplevel_relative = 1;
                        *hdrsize = git_hdr_len;
                        return offset;
                }
 
-               /** --- followed by +++ ? */
+               /* --- followed by +++ ? */
                if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
                        continue;
 
                /*
                 * We only accept unified patches, so we want it to
                 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
-                * minimum
+                * minimum ("@@ -0,0 +1 @@\n" is the shortest).
                 */
                nextlen = linelen(line + len, size - len);
                if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
                        continue;
 
                /* Ok, we'll consider it a patch */
-               parse_traditional_patch(line, line+len, patch);
+               if (parse_traditional_patch(state, line, line+len, patch))
+                       return -128;
                *hdrsize = len + nextlen;
-               linenr += 2;
+               state->linenr += 2;
                return offset;
        }
        return -1;
 }
 
+static void record_ws_error(struct apply_state *state,
+                           unsigned result,
+                           const char *line,
+                           int len,
+                           int linenr)
+{
+       char *err;
+
+       if (!result)
+               return;
+
+       state->whitespace_error++;
+       if (state->squelch_whitespace_errors &&
+           state->squelch_whitespace_errors < state->whitespace_error)
+               return;
+
+       err = whitespace_error_string(result);
+       if (state->apply_verbosity > verbosity_silent)
+               fprintf(stderr, "%s:%d: %s.\n%.*s\n",
+                       state->patch_input_file, linenr, err, len, line);
+       free(err);
+}
+
+static void check_whitespace(struct apply_state *state,
+                            const char *line,
+                            int len,
+                            unsigned ws_rule)
+{
+       unsigned result = ws_check(line + 1, len - 1, ws_rule);
+
+       record_ws_error(state, result, line + 1, len - 2, state->linenr);
+}
+
 /*
- * Parse a unified diff. Note that this really needs
- * to parse each fragment separately, since the only
- * way to know the difference between a "---" that is
- * part of a patch, and a "---" that starts the next
- * patch is to look at the line counts..
+ * Parse a unified diff. Note that this really needs to parse each
+ * fragment separately, since the only way to know the difference
+ * between a "---" that is part of a patch, and a "---" that starts
+ * the next patch is to look at the line counts..
  */
-static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
+static int parse_fragment(struct apply_state *state,
+                         const char *line,
+                         unsigned long size,
+                         struct patch *patch,
+                         struct fragment *fragment)
 {
        int added, deleted;
        int len = linelen(line, size), offset;
@@ -832,36 +1671,21 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
        offset = parse_fragment_header(line, len, fragment);
        if (offset < 0)
                return -1;
+       if (offset > 0 && patch->recount)
+               recount_diff(line + offset, size - offset, fragment);
        oldlines = fragment->oldlines;
        newlines = fragment->newlines;
        leading = 0;
        trailing = 0;
 
-       if (patch->is_new < 0) {
-               patch->is_new =  !oldlines;
-               if (!oldlines)
-                       patch->old_name = NULL;
-       }
-       if (patch->is_delete < 0) {
-               patch->is_delete = !newlines;
-               if (!newlines)
-                       patch->new_name = NULL;
-       }
-
-       if (patch->is_new && oldlines)
-               return error("new file depends on old contents");
-       if (patch->is_delete != !newlines) {
-               if (newlines)
-                       return error("deleted file still has contents");
-               fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
-       }
-
        /* Parse the thing.. */
        line += len;
        size -= len;
-       linenr++;
+       state->linenr++;
        added = deleted = 0;
-       for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
+       for (offset = len;
+            0 < size;
+            offset += len, size -= len, line += len, state->linenr++) {
                if (!oldlines && !newlines)
                        break;
                len = linelen(line, size);
@@ -870,47 +1694,39 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
                switch (*line) {
                default:
                        return -1;
+               case '\n': /* newer GNU diff, an empty context line */
                case ' ':
                        oldlines--;
                        newlines--;
                        if (!deleted && !added)
                                leading++;
                        trailing++;
+                       if (!state->apply_in_reverse &&
+                           state->ws_error_action == correct_ws_error)
+                               check_whitespace(state, line, len, patch->ws_rule);
                        break;
                case '-':
+                       if (state->apply_in_reverse &&
+                           state->ws_error_action != nowarn_ws_error)
+                               check_whitespace(state, line, len, patch->ws_rule);
                        deleted++;
                        oldlines--;
                        trailing = 0;
                        break;
                case '+':
-                       /*
-                        * We know len is at least two, since we have a '+' and
-                        * we checked that the last character was a '\n' above.
-                        * That is, an addition of an empty line would check
-                        * the '+' here.  Sneaky...
-                        */
-                       if ((new_whitespace != nowarn_whitespace) &&
-                           isspace(line[len-2])) {
-                               whitespace_error++;
-                               if (squelch_whitespace_errors &&
-                                   squelch_whitespace_errors <
-                                   whitespace_error)
-                                       ;
-                               else {
-                                       fprintf(stderr, "Adds trailing whitespace.\n%s:%d:%.*s\n",
-                                               patch_input_file,
-                                               linenr, len-2, line+1);
-                               }
-                       }
+                       if (!state->apply_in_reverse &&
+                           state->ws_error_action != nowarn_ws_error)
+                               check_whitespace(state, line, len, patch->ws_rule);
                        added++;
                        newlines--;
                        trailing = 0;
                        break;
 
-                /* We allow "\ No newline at end of file". Depending
-                 * on locale settings when the patch was produced we
-                 * don't know what this line looks like. The only
-                 * thing we do know is that it begins with "\ ".
+               /*
+                * We allow "\ No newline at end of file". Depending
+                * on locale settings when the patch was produced we
+                * don't know what this line looks like. The only
+                * thing we do know is that it begins with "\ ".
                 * Checking for 12 is just for sanity check -- any
                 * l10n of "\ No newline..." is at least that long.
                 */
@@ -922,10 +1738,14 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
        }
        if (oldlines || newlines)
                return -1;
+       if (!deleted && !added)
+               return -1;
+
        fragment->leading = leading;
        fragment->trailing = trailing;
 
-       /* If a fragment ends with an incomplete line, we failed to include
+       /*
+        * If a fragment ends with an incomplete line, we failed to include
         * it in the above loop because we hit oldlines == newlines == 0
         * before seeing it.
         */
@@ -934,12 +1754,33 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
 
        patch->lines_added += added;
        patch->lines_deleted += deleted;
+
+       if (0 < patch->is_new && oldlines)
+               return error(_("new file depends on old contents"));
+       if (0 < patch->is_delete && newlines)
+               return error(_("deleted file still has contents"));
        return offset;
 }
 
-static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
+/*
+ * We have seen "diff --git a/... b/..." header (or a traditional patch
+ * header).  Read hunks that belong to this patch into fragments and hang
+ * them to the given patch structure.
+ *
+ * The (fragment->patch, fragment->size) pair points into the memory given
+ * by the caller, not a copy, when we return.
+ *
+ * Returns:
+ *   -1 in case of error,
+ *   the number of bytes in the patch otherwise.
+ */
+static int parse_single_patch(struct apply_state *state,
+                             const char *line,
+                             unsigned long size,
+                             struct patch *patch)
 {
        unsigned long offset = 0;
+       unsigned long oldlines = 0, newlines = 0, context = 0;
        struct fragment **fragp = &patch->fragments;
 
        while (size > 4 && !memcmp(line, "@@ -", 4)) {
@@ -947,12 +1788,17 @@ static int parse_single_patch(char *line, unsigned long size, struct patch *patc
                int len;
 
                fragment = xcalloc(1, sizeof(*fragment));
-               len = parse_fragment(line, size, patch, fragment);
-               if (len <= 0)
-                       die("corrupt patch at line %d", linenr);
-
+               fragment->linenr = state->linenr;
+               len = parse_fragment(state, line, size, patch, fragment);
+               if (len <= 0) {
+                       free(fragment);
+                       return error(_("corrupt patch at line %d"), state->linenr);
+               }
                fragment->patch = line;
                fragment->size = len;
+               oldlines += fragment->oldlines;
+               newlines += fragment->newlines;
+               context += fragment->leading + fragment->trailing;
 
                *fragp = fragment;
                fragp = &fragment->next;
@@ -961,6 +1807,37 @@ static int parse_single_patch(char *line, unsigned long size, struct patch *patc
                line += len;
                size -= len;
        }
+
+       /*
+        * If something was removed (i.e. we have old-lines) it cannot
+        * be creation, and if something was added it cannot be
+        * deletion.  However, the reverse is not true; --unified=0
+        * patches that only add are not necessarily creation even
+        * though they do not have any old lines, and ones that only
+        * delete are not necessarily deletion.
+        *
+        * Unfortunately, a real creation/deletion patch do _not_ have
+        * any context line by definition, so we cannot safely tell it
+        * apart with --unified=0 insanity.  At least if the patch has
+        * more than one hunk it is not creation or deletion.
+        */
+       if (patch->is_new < 0 &&
+           (oldlines || (patch->fragments && patch->fragments->next)))
+               patch->is_new = 0;
+       if (patch->is_delete < 0 &&
+           (newlines || (patch->fragments && patch->fragments->next)))
+               patch->is_delete = 0;
+
+       if (0 < patch->is_new && oldlines)
+               return error(_("new file %s depends on old contents"), patch->new_name);
+       if (0 < patch->is_delete && newlines)
+               return error(_("deleted file %s still has contents"), patch->old_name);
+       if (!patch->is_delete && !newlines && context && state->apply_verbosity > verbosity_silent)
+               fprintf_ln(stderr,
+                          _("** warning: "
+                            "file %s becomes empty but is not deleted"),
+                          patch->new_name);
+
        return offset;
 }
 
@@ -974,52 +1851,92 @@ static inline int metadata_changes(struct patch *patch)
                 patch->old_mode != patch->new_mode);
 }
 
-static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
+static char *inflate_it(const void *data, unsigned long size,
+                       unsigned long inflated_size)
+{
+       git_zstream stream;
+       void *out;
+       int st;
+
+       memset(&stream, 0, sizeof(stream));
+
+       stream.next_in = (unsigned char *)data;
+       stream.avail_in = size;
+       stream.next_out = out = xmalloc(inflated_size);
+       stream.avail_out = inflated_size;
+       git_inflate_init(&stream);
+       st = git_inflate(&stream, Z_FINISH);
+       git_inflate_end(&stream);
+       if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
+               free(out);
+               return NULL;
+       }
+       return out;
+}
+
+/*
+ * Read a binary hunk and return a new fragment; fragment->patch
+ * points at an allocated memory that the caller must free, so
+ * it is marked as "->free_patch = 1".
+ */
+static struct fragment *parse_binary_hunk(struct apply_state *state,
+                                         char **buf_p,
+                                         unsigned long *sz_p,
+                                         int *status_p,
+                                         int *used_p)
 {
-       /* We have read "GIT binary patch\n"; what follows is a line
-        * that says the patch method (currently, either "deflated
-        * literal" or "deflated delta") and the length of data before
-        * deflating; a sequence of 'length-byte' followed by base-85
-        * encoded data follows.
+       /*
+        * Expect a line that begins with binary patch method ("literal"
+        * or "delta"), followed by the length of data before deflating.
+        * a sequence of 'length-byte' followed by base-85 encoded data
+        * should follow, terminated by a newline.
         *
         * Each 5-byte sequence of base-85 encodes up to 4 bytes,
         * and we would limit the patch line to 66 characters,
         * so one line can fit up to 13 groups that would decode
         * to 52 bytes max.  The length byte 'A'-'Z' corresponds
         * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
-        * The end of binary is signalled with an empty line.
         */
        int llen, used;
-       struct fragment *fragment;
+       unsigned long size = *sz_p;
+       char *buffer = *buf_p;
+       int patch_method;
+       unsigned long origlen;
        char *data = NULL;
+       int hunk_size = 0;
+       struct fragment *frag;
 
-       patch->fragments = fragment = xcalloc(1, sizeof(*fragment));
-
-       /* Grab the type of patch */
        llen = linelen(buffer, size);
        used = llen;
-       linenr++;
 
-       if (!strncmp(buffer, "delta ", 6)) {
-               patch->is_binary = BINARY_DELTA_DEFLATED;
-               patch->deflate_origlen = strtoul(buffer + 6, NULL, 10);
+       *status_p = 0;
+
+       if (starts_with(buffer, "delta ")) {
+               patch_method = BINARY_DELTA_DEFLATED;
+               origlen = strtoul(buffer + 6, NULL, 10);
        }
-       else if (!strncmp(buffer, "literal ", 8)) {
-               patch->is_binary = BINARY_LITERAL_DEFLATED;
-               patch->deflate_origlen = strtoul(buffer + 8, NULL, 10);
+       else if (starts_with(buffer, "literal ")) {
+               patch_method = BINARY_LITERAL_DEFLATED;
+               origlen = strtoul(buffer + 8, NULL, 10);
        }
        else
-               return error("unrecognized binary patch at line %d: %.*s",
-                            linenr-1, llen-1, buffer);
+               return NULL;
+
+       state->linenr++;
        buffer += llen;
        while (1) {
                int byte_length, max_byte_length, newsize;
                llen = linelen(buffer, size);
                used += llen;
-               linenr++;
-               if (llen == 1)
+               state->linenr++;
+               if (llen == 1) {
+                       /* consume the blank line */
+                       buffer++;
+                       size--;
                        break;
-               /* Minimum line is "A00000\n" which is 7-byte long,
+               }
+               /*
+                * Minimum line is "A00000\n" which is 7-byte long,
                 * and the line length must be multiple of 5 plus 2.
                 */
                if ((llen < 7) || (llen-2) % 5)
@@ -1039,61 +1956,216 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
                if (max_byte_length < byte_length ||
                    byte_length <= max_byte_length - 4)
                        goto corrupt;
-               newsize = fragment->size + byte_length;
+               newsize = hunk_size + byte_length;
                data = xrealloc(data, newsize);
-               if (decode_85(data + fragment->size,
-                             buffer + 1,
-                             byte_length))
+               if (decode_85(data + hunk_size, buffer + 1, byte_length))
                        goto corrupt;
-               fragment->size = newsize;
+               hunk_size = newsize;
                buffer += llen;
                size -= llen;
        }
-       fragment->patch = data;
-       return used;
+
+       frag = xcalloc(1, sizeof(*frag));
+       frag->patch = inflate_it(data, hunk_size, origlen);
+       frag->free_patch = 1;
+       if (!frag->patch)
+               goto corrupt;
+       free(data);
+       frag->size = origlen;
+       *buf_p = buffer;
+       *sz_p = size;
+       *used_p = used;
+       frag->binary_patch_method = patch_method;
+       return frag;
+
  corrupt:
-       return error("corrupt binary patch at line %d: %.*s",
-                    linenr-1, llen-1, buffer);
+       free(data);
+       *status_p = -1;
+       error(_("corrupt binary patch at line %d: %.*s"),
+             state->linenr-1, llen-1, buffer);
+       return NULL;
 }
 
-static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
+/*
+ * Returns:
+ *   -1 in case of error,
+ *   the length of the parsed binary patch otherwise
+ */
+static int parse_binary(struct apply_state *state,
+                       char *buffer,
+                       unsigned long size,
+                       struct patch *patch)
 {
-       int hdrsize, patchsize;
-       int offset = find_header(buffer, size, &hdrsize, patch);
+       /*
+        * We have read "GIT binary patch\n"; what follows is a line
+        * that says the patch method (currently, either "literal" or
+        * "delta") and the length of data before deflating; a
+        * sequence of 'length-byte' followed by base-85 encoded data
+        * follows.
+        *
+        * When a binary patch is reversible, there is another binary
+        * hunk in the same format, starting with patch method (either
+        * "literal" or "delta") with the length of data, and a sequence
+        * of length-byte + base-85 encoded data, terminated with another
+        * empty line.  This data, when applied to the postimage, produces
+        * the preimage.
+        */
+       struct fragment *forward;
+       struct fragment *reverse;
+       int status;
+       int used, used_1;
+
+       forward = parse_binary_hunk(state, &buffer, &size, &status, &used);
+       if (!forward && !status)
+               /* there has to be one hunk (forward hunk) */
+               return error(_("unrecognized binary patch at line %d"), state->linenr-1);
+       if (status)
+               /* otherwise we already gave an error message */
+               return status;
+
+       reverse = parse_binary_hunk(state, &buffer, &size, &status, &used_1);
+       if (reverse)
+               used += used_1;
+       else if (status) {
+               /*
+                * Not having reverse hunk is not an error, but having
+                * a corrupt reverse hunk is.
+                */
+               free((void*) forward->patch);
+               free(forward);
+               return status;
+       }
+       forward->next = reverse;
+       patch->fragments = forward;
+       patch->is_binary = 1;
+       return used;
+}
 
-       if (offset < 0)
-               return offset;
+static void prefix_one(struct apply_state *state, char **name)
+{
+       char *old_name = *name;
+       if (!old_name)
+               return;
+       *name = xstrdup(prefix_filename(state->prefix, state->prefix_length, *name));
+       free(old_name);
+}
 
-       patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
+static void prefix_patch(struct apply_state *state, struct patch *p)
+{
+       if (!state->prefix || p->is_toplevel_relative)
+               return;
+       prefix_one(state, &p->new_name);
+       prefix_one(state, &p->old_name);
+}
 
-       if (!patchsize) {
-               static const char *binhdr[] = {
-                       "Binary files ",
-                       "Files ",
-                       NULL,
-               };
-               static const char git_binary[] = "GIT binary patch\n";
-               int i;
+/*
+ * include/exclude
+ */
+
+static void add_name_limit(struct apply_state *state,
+                          const char *name,
+                          int exclude)
+{
+       struct string_list_item *it;
+
+       it = string_list_append(&state->limit_by_name, name);
+       it->util = exclude ? NULL : (void *) 1;
+}
+
+static int use_patch(struct apply_state *state, struct patch *p)
+{
+       const char *pathname = p->new_name ? p->new_name : p->old_name;
+       int i;
+
+       /* Paths outside are not touched regardless of "--include" */
+       if (0 < state->prefix_length) {
+               int pathlen = strlen(pathname);
+               if (pathlen <= state->prefix_length ||
+                   memcmp(state->prefix, pathname, state->prefix_length))
+                       return 0;
+       }
+
+       /* See if it matches any of exclude/include rule */
+       for (i = 0; i < state->limit_by_name.nr; i++) {
+               struct string_list_item *it = &state->limit_by_name.items[i];
+               if (!wildmatch(it->string, pathname, 0, NULL))
+                       return (it->util != NULL);
+       }
+
+       /*
+        * If we had any include, a path that does not match any rule is
+        * not used.  Otherwise, we saw bunch of exclude rules (or none)
+        * and such a path is used.
+        */
+       return !state->has_include;
+}
+
+/*
+ * Read the patch text in "buffer" that extends for "size" bytes; stop
+ * reading after seeing a single patch (i.e. changes to a single file).
+ * Create fragments (i.e. patch hunks) and hang them to the given patch.
+ *
+ * Returns:
+ *   -1 if no header was found or parse_binary() failed,
+ *   -128 on another error,
+ *   the number of bytes consumed otherwise,
+ *     so that the caller can call us again for the next patch.
+ */
+static int parse_chunk(struct apply_state *state, char *buffer, unsigned long size, struct patch *patch)
+{
+       int hdrsize, patchsize;
+       int offset = find_header(state, buffer, size, &hdrsize, patch);
+
+       if (offset < 0)
+               return offset;
+
+       prefix_patch(state, patch);
+
+       if (!use_patch(state, patch))
+               patch->ws_rule = 0;
+       else
+               patch->ws_rule = whitespace_rule(patch->new_name
+                                                ? patch->new_name
+                                                : patch->old_name);
+
+       patchsize = parse_single_patch(state,
+                                      buffer + offset + hdrsize,
+                                      size - offset - hdrsize,
+                                      patch);
+
+       if (patchsize < 0)
+               return -128;
+
+       if (!patchsize) {
+               static const char git_binary[] = "GIT binary patch\n";
                int hd = hdrsize + offset;
                unsigned long llen = linelen(buffer + hd, size - hd);
 
                if (llen == sizeof(git_binary) - 1 &&
                    !memcmp(git_binary, buffer + hd, llen)) {
                        int used;
-                       linenr++;
-                       used = parse_binary(buffer + hd + llen,
+                       state->linenr++;
+                       used = parse_binary(state, buffer + hd + llen,
                                            size - hd - llen, patch);
+                       if (used < 0)
+                               return -1;
                        if (used)
                                patchsize = used + llen;
                        else
                                patchsize = 0;
                }
                else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
+                       static const char *binhdr[] = {
+                               "Binary files ",
+                               "Files ",
+                               NULL,
+                       };
+                       int i;
                        for (i = 0; binhdr[i]; i++) {
                                int len = strlen(binhdr[i]);
                                if (len < size - hd &&
                                    !memcmp(binhdr[i], buffer + hd, len)) {
-                                       linenr++;
+                                       state->linenr++;
                                        patch->is_binary = 1;
                                        patchsize = llen;
                                        break;
@@ -1101,251 +2173,689 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
                        }
                }
 
-               /* Empty patch cannot be applied if:
-                * - it is a binary patch and we do not do binary_replace, or
-                * - text patch without metadata change
+               /* Empty patch cannot be applied if it is a text patch
+                * without metadata change.  A binary patch appears
+                * empty to us here.
                 */
-               if ((apply || check) &&
-                   (patch->is_binary
-                    ? !allow_binary_replacement
-                    : !metadata_changes(patch)))
-                       die("patch with only garbage at line %d", linenr);
+               if ((state->apply || state->check) &&
+                   (!patch->is_binary && !metadata_changes(patch))) {
+                       error(_("patch with only garbage at line %d"), state->linenr);
+                       return -128;
+               }
        }
 
        return offset + hdrsize + patchsize;
 }
 
-static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
-static const char minuses[]= "----------------------------------------------------------------------";
+#define swap(a,b) myswap((a),(b),sizeof(a))
 
-static void show_stats(struct patch *patch)
+#define myswap(a, b, size) do {                \
+       unsigned char mytmp[size];      \
+       memcpy(mytmp, &a, size);                \
+       memcpy(&a, &b, size);           \
+       memcpy(&b, mytmp, size);                \
+} while (0)
+
+static void reverse_patches(struct patch *p)
 {
-       const char *prefix = "";
-       char *name = patch->new_name;
-       char *qname = NULL;
-       int len, max, add, del, total;
+       for (; p; p = p->next) {
+               struct fragment *frag = p->fragments;
+
+               swap(p->new_name, p->old_name);
+               swap(p->new_mode, p->old_mode);
+               swap(p->is_new, p->is_delete);
+               swap(p->lines_added, p->lines_deleted);
+               swap(p->old_sha1_prefix, p->new_sha1_prefix);
+
+               for (; frag; frag = frag->next) {
+                       swap(frag->newpos, frag->oldpos);
+                       swap(frag->newlines, frag->oldlines);
+               }
+       }
+}
 
-       if (!name)
-               name = patch->old_name;
+static const char pluses[] =
+"++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
+static const char minuses[]=
+"----------------------------------------------------------------------";
 
-       if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
-               qname = xmalloc(len + 1);
-               quote_c_style(name, qname, NULL, 0);
-               name = qname;
-       }
+static void show_stats(struct apply_state *state, struct patch *patch)
+{
+       struct strbuf qname = STRBUF_INIT;
+       char *cp = patch->new_name ? patch->new_name : patch->old_name;
+       int max, add, del;
+
+       quote_c_style(cp, &qname, NULL, 0);
 
        /*
         * "scale" the filename
         */
-       len = strlen(name);
-       max = max_len;
+       max = state->max_len;
        if (max > 50)
                max = 50;
-       if (len > max) {
-               char *slash;
-               prefix = "...";
-               max -= 3;
-               name += len - max;
-               slash = strchr(name, '/');
-               if (slash)
-                       name = slash;
+
+       if (qname.len > max) {
+               cp = strchr(qname.buf + qname.len + 3 - max, '/');
+               if (!cp)
+                       cp = qname.buf + qname.len + 3 - max;
+               strbuf_splice(&qname, 0, cp - qname.buf, "...", 3);
+       }
+
+       if (patch->is_binary) {
+               printf(" %-*s |  Bin\n", max, qname.buf);
+               strbuf_release(&qname);
+               return;
        }
-       len = max;
+
+       printf(" %-*s |", max, qname.buf);
+       strbuf_release(&qname);
 
        /*
         * scale the add/delete
         */
-       max = max_change;
-       if (max + len > 70)
-               max = 70 - len;
-
+       max = max + state->max_change > 70 ? 70 - max : state->max_change;
        add = patch->lines_added;
        del = patch->lines_deleted;
-       total = add + del;
 
-       if (max_change > 0) {
-               total = (total * max + max_change / 2) / max_change;
-               add = (add * max + max_change / 2) / max_change;
+       if (state->max_change > 0) {
+               int total = ((add + del) * max + state->max_change / 2) / state->max_change;
+               add = (add * max + state->max_change / 2) / state->max_change;
                del = total - add;
        }
-       if (patch->is_binary)
-               printf(" %s%-*s |  Bin\n", prefix, len, name);
-       else
-               printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
-                      len, name, patch->lines_added + patch->lines_deleted,
-                      add, pluses, del, minuses);
-       if (qname)
-               free(qname);
+       printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
+               add, pluses, del, minuses);
 }
 
-static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
+static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
 {
-       int fd;
-       unsigned long got;
-
        switch (st->st_mode & S_IFMT) {
        case S_IFLNK:
-               return readlink(path, buf, size);
+               if (strbuf_readlink(buf, path, st->st_size) < 0)
+                       return error(_("unable to read symlink %s"), path);
+               return 0;
        case S_IFREG:
-               fd = open(path, O_RDONLY);
-               if (fd < 0)
-                       return error("unable to open %s", path);
-               got = 0;
-               for (;;) {
-                       int ret = xread(fd, buf + got, size - got);
-                       if (ret <= 0)
-                               break;
-                       got += ret;
-               }
-               close(fd);
-               return got;
-
+               if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
+                       return error(_("unable to open or read %s"), path);
+               convert_to_git(path, buf->buf, buf->len, buf, 0);
+               return 0;
        default:
                return -1;
        }
 }
 
-static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line, int *lines)
+/*
+ * Update the preimage, and the common lines in postimage,
+ * from buffer buf of length len. If postlen is 0 the postimage
+ * is updated in place, otherwise it's updated on a new buffer
+ * of length postlen
+ */
+
+static void update_pre_post_images(struct image *preimage,
+                                  struct image *postimage,
+                                  char *buf,
+                                  size_t len, size_t postlen)
 {
-       int i;
-       unsigned long start, backwards, forwards;
+       int i, ctx, reduced;
+       char *new, *old, *fixed;
+       struct image fixed_preimage;
 
-       if (fragsize > size)
-               return -1;
+       /*
+        * Update the preimage with whitespace fixes.  Note that we
+        * are not losing preimage->buf -- apply_one_fragment() will
+        * free "oldlines".
+        */
+       prepare_image(&fixed_preimage, buf, len, 1);
+       assert(postlen
+              ? fixed_preimage.nr == preimage->nr
+              : fixed_preimage.nr <= preimage->nr);
+       for (i = 0; i < fixed_preimage.nr; i++)
+               fixed_preimage.line[i].flag = preimage->line[i].flag;
+       free(preimage->line_allocated);
+       *preimage = fixed_preimage;
 
-       start = 0;
-       if (line > 1) {
-               unsigned long offset = 0;
-               i = line-1;
-               while (offset + fragsize <= size) {
-                       if (buf[offset++] == '\n') {
-                               start = offset;
-                               if (!--i)
-                                       break;
-                       }
+       /*
+        * Adjust the common context lines in postimage. This can be
+        * done in-place when we are shrinking it with whitespace
+        * fixing, but needs a new buffer when ignoring whitespace or
+        * expanding leading tabs to spaces.
+        *
+        * We trust the caller to tell us if the update can be done
+        * in place (postlen==0) or not.
+        */
+       old = postimage->buf;
+       if (postlen)
+               new = postimage->buf = xmalloc(postlen);
+       else
+               new = old;
+       fixed = preimage->buf;
+
+       for (i = reduced = ctx = 0; i < postimage->nr; i++) {
+               size_t l_len = postimage->line[i].len;
+               if (!(postimage->line[i].flag & LINE_COMMON)) {
+                       /* an added line -- no counterparts in preimage */
+                       memmove(new, old, l_len);
+                       old += l_len;
+                       new += l_len;
+                       continue;
                }
+
+               /* a common context -- skip it in the original postimage */
+               old += l_len;
+
+               /* and find the corresponding one in the fixed preimage */
+               while (ctx < preimage->nr &&
+                      !(preimage->line[ctx].flag & LINE_COMMON)) {
+                       fixed += preimage->line[ctx].len;
+                       ctx++;
+               }
+
+               /*
+                * preimage is expected to run out, if the caller
+                * fixed addition of trailing blank lines.
+                */
+               if (preimage->nr <= ctx) {
+                       reduced++;
+                       continue;
+               }
+
+               /* and copy it in, while fixing the line length */
+               l_len = preimage->line[ctx].len;
+               memcpy(new, fixed, l_len);
+               new += l_len;
+               fixed += l_len;
+               postimage->line[i].len = l_len;
+               ctx++;
+       }
+
+       if (postlen
+           ? postlen < new - postimage->buf
+           : postimage->len < new - postimage->buf)
+               die("BUG: caller miscounted postlen: asked %d, orig = %d, used = %d",
+                   (int)postlen, (int) postimage->len, (int)(new - postimage->buf));
+
+       /* Fix the length of the whole thing */
+       postimage->len = new - postimage->buf;
+       postimage->nr -= reduced;
+}
+
+static int line_by_line_fuzzy_match(struct image *img,
+                                   struct image *preimage,
+                                   struct image *postimage,
+                                   unsigned long try,
+                                   int try_lno,
+                                   int preimage_limit)
+{
+       int i;
+       size_t imgoff = 0;
+       size_t preoff = 0;
+       size_t postlen = postimage->len;
+       size_t extra_chars;
+       char *buf;
+       char *preimage_eof;
+       char *preimage_end;
+       struct strbuf fixed;
+       char *fixed_buf;
+       size_t fixed_len;
+
+       for (i = 0; i < preimage_limit; i++) {
+               size_t prelen = preimage->line[i].len;
+               size_t imglen = img->line[try_lno+i].len;
+
+               if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
+                                     preimage->buf + preoff, prelen))
+                       return 0;
+               if (preimage->line[i].flag & LINE_COMMON)
+                       postlen += imglen - prelen;
+               imgoff += imglen;
+               preoff += prelen;
        }
 
-       /* Exact line number? */
-       if (!memcmp(buf + start, fragment, fragsize))
-               return start;
+       /*
+        * Ok, the preimage matches with whitespace fuzz.
+        *
+        * imgoff now holds the true length of the target that
+        * matches the preimage before the end of the file.
+        *
+        * Count the number of characters in the preimage that fall
+        * beyond the end of the file and make sure that all of them
+        * are whitespace characters. (This can only happen if
+        * we are removing blank lines at the end of the file.)
+        */
+       buf = preimage_eof = preimage->buf + preoff;
+       for ( ; i < preimage->nr; i++)
+               preoff += preimage->line[i].len;
+       preimage_end = preimage->buf + preoff;
+       for ( ; buf < preimage_end; buf++)
+               if (!isspace(*buf))
+                       return 0;
+
+       /*
+        * Update the preimage and the common postimage context
+        * lines to use the same whitespace as the target.
+        * If whitespace is missing in the target (i.e.
+        * if the preimage extends beyond the end of the file),
+        * use the whitespace from the preimage.
+        */
+       extra_chars = preimage_end - preimage_eof;
+       strbuf_init(&fixed, imgoff + extra_chars);
+       strbuf_add(&fixed, img->buf + try, imgoff);
+       strbuf_add(&fixed, preimage_eof, extra_chars);
+       fixed_buf = strbuf_detach(&fixed, &fixed_len);
+       update_pre_post_images(preimage, postimage,
+                              fixed_buf, fixed_len, postlen);
+       return 1;
+}
+
+static int match_fragment(struct apply_state *state,
+                         struct image *img,
+                         struct image *preimage,
+                         struct image *postimage,
+                         unsigned long try,
+                         int try_lno,
+                         unsigned ws_rule,
+                         int match_beginning, int match_end)
+{
+       int i;
+       char *fixed_buf, *buf, *orig, *target;
+       struct strbuf fixed;
+       size_t fixed_len, postlen;
+       int preimage_limit;
+
+       if (preimage->nr + try_lno <= img->nr) {
+               /*
+                * The hunk falls within the boundaries of img.
+                */
+               preimage_limit = preimage->nr;
+               if (match_end && (preimage->nr + try_lno != img->nr))
+                       return 0;
+       } else if (state->ws_error_action == correct_ws_error &&
+                  (ws_rule & WS_BLANK_AT_EOF)) {
+               /*
+                * This hunk extends beyond the end of img, and we are
+                * removing blank lines at the end of the file.  This
+                * many lines from the beginning of the preimage must
+                * match with img, and the remainder of the preimage
+                * must be blank.
+                */
+               preimage_limit = img->nr - try_lno;
+       } else {
+               /*
+                * The hunk extends beyond the end of the img and
+                * we are not removing blanks at the end, so we
+                * should reject the hunk at this position.
+                */
+               return 0;
+       }
+
+       if (match_beginning && try_lno)
+               return 0;
+
+       /* Quick hash check */
+       for (i = 0; i < preimage_limit; i++)
+               if ((img->line[try_lno + i].flag & LINE_PATCHED) ||
+                   (preimage->line[i].hash != img->line[try_lno + i].hash))
+                       return 0;
+
+       if (preimage_limit == preimage->nr) {
+               /*
+                * Do we have an exact match?  If we were told to match
+                * at the end, size must be exactly at try+fragsize,
+                * otherwise try+fragsize must be still within the preimage,
+                * and either case, the old piece should match the preimage
+                * exactly.
+                */
+               if ((match_end
+                    ? (try + preimage->len == img->len)
+                    : (try + preimage->len <= img->len)) &&
+                   !memcmp(img->buf + try, preimage->buf, preimage->len))
+                       return 1;
+       } else {
+               /*
+                * The preimage extends beyond the end of img, so
+                * there cannot be an exact match.
+                *
+                * There must be one non-blank context line that match
+                * a line before the end of img.
+                */
+               char *buf_end;
+
+               buf = preimage->buf;
+               buf_end = buf;
+               for (i = 0; i < preimage_limit; i++)
+                       buf_end += preimage->line[i].len;
+
+               for ( ; buf < buf_end; buf++)
+                       if (!isspace(*buf))
+                               break;
+               if (buf == buf_end)
+                       return 0;
+       }
+
+       /*
+        * No exact match. If we are ignoring whitespace, run a line-by-line
+        * fuzzy matching. We collect all the line length information because
+        * we need it to adjust whitespace if we match.
+        */
+       if (state->ws_ignore_action == ignore_ws_change)
+               return line_by_line_fuzzy_match(img, preimage, postimage,
+                                               try, try_lno, preimage_limit);
+
+       if (state->ws_error_action != correct_ws_error)
+               return 0;
+
+       /*
+        * The hunk does not apply byte-by-byte, but the hash says
+        * it might with whitespace fuzz. We weren't asked to
+        * ignore whitespace, we were asked to correct whitespace
+        * errors, so let's try matching after whitespace correction.
+        *
+        * While checking the preimage against the target, whitespace
+        * errors in both fixed, we count how large the corresponding
+        * postimage needs to be.  The postimage prepared by
+        * apply_one_fragment() has whitespace errors fixed on added
+        * lines already, but the common lines were propagated as-is,
+        * which may become longer when their whitespace errors are
+        * fixed.
+        */
+
+       /* First count added lines in postimage */
+       postlen = 0;
+       for (i = 0; i < postimage->nr; i++) {
+               if (!(postimage->line[i].flag & LINE_COMMON))
+                       postlen += postimage->line[i].len;
+       }
+
+       /*
+        * The preimage may extend beyond the end of the file,
+        * but in this loop we will only handle the part of the
+        * preimage that falls within the file.
+        */
+       strbuf_init(&fixed, preimage->len + 1);
+       orig = preimage->buf;
+       target = img->buf + try;
+       for (i = 0; i < preimage_limit; i++) {
+               size_t oldlen = preimage->line[i].len;
+               size_t tgtlen = img->line[try_lno + i].len;
+               size_t fixstart = fixed.len;
+               struct strbuf tgtfix;
+               int match;
+
+               /* Try fixing the line in the preimage */
+               ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
+
+               /* Try fixing the line in the target */
+               strbuf_init(&tgtfix, tgtlen);
+               ws_fix_copy(&tgtfix, target, tgtlen, ws_rule, NULL);
+
+               /*
+                * If they match, either the preimage was based on
+                * a version before our tree fixed whitespace breakage,
+                * or we are lacking a whitespace-fix patch the tree
+                * the preimage was based on already had (i.e. target
+                * has whitespace breakage, the preimage doesn't).
+                * In either case, we are fixing the whitespace breakages
+                * so we might as well take the fix together with their
+                * real change.
+                */
+               match = (tgtfix.len == fixed.len - fixstart &&
+                        !memcmp(tgtfix.buf, fixed.buf + fixstart,
+                                            fixed.len - fixstart));
+
+               /* Add the length if this is common with the postimage */
+               if (preimage->line[i].flag & LINE_COMMON)
+                       postlen += tgtfix.len;
+
+               strbuf_release(&tgtfix);
+               if (!match)
+                       goto unmatch_exit;
+
+               orig += oldlen;
+               target += tgtlen;
+       }
+
+
+       /*
+        * Now handle the lines in the preimage that falls beyond the
+        * end of the file (if any). They will only match if they are
+        * empty or only contain whitespace (if WS_BLANK_AT_EOL is
+        * false).
+        */
+       for ( ; i < preimage->nr; i++) {
+               size_t fixstart = fixed.len; /* start of the fixed preimage */
+               size_t oldlen = preimage->line[i].len;
+               int j;
+
+               /* Try fixing the line in the preimage */
+               ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
+
+               for (j = fixstart; j < fixed.len; j++)
+                       if (!isspace(fixed.buf[j]))
+                               goto unmatch_exit;
+
+               orig += oldlen;
+       }
+
+       /*
+        * Yes, the preimage is based on an older version that still
+        * has whitespace breakages unfixed, and fixing them makes the
+        * hunk match.  Update the context lines in the postimage.
+        */
+       fixed_buf = strbuf_detach(&fixed, &fixed_len);
+       if (postlen < postimage->len)
+               postlen = 0;
+       update_pre_post_images(preimage, postimage,
+                              fixed_buf, fixed_len, postlen);
+       return 1;
+
+ unmatch_exit:
+       strbuf_release(&fixed);
+       return 0;
+}
+
+static int find_pos(struct apply_state *state,
+                   struct image *img,
+                   struct image *preimage,
+                   struct image *postimage,
+                   int line,
+                   unsigned ws_rule,
+                   int match_beginning, int match_end)
+{
+       int i;
+       unsigned long backwards, forwards, try;
+       int backwards_lno, forwards_lno, try_lno;
+
+       /*
+        * If match_beginning or match_end is specified, there is no
+        * point starting from a wrong line that will never match and
+        * wander around and wait for a match at the specified end.
+        */
+       if (match_beginning)
+               line = 0;
+       else if (match_end)
+               line = img->nr - preimage->nr;
+
+       /*
+        * Because the comparison is unsigned, the following test
+        * will also take care of a negative line number that can
+        * result when match_end and preimage is larger than the target.
+        */
+       if ((size_t) line > img->nr)
+               line = img->nr;
+
+       try = 0;
+       for (i = 0; i < line; i++)
+               try += img->line[i].len;
 
        /*
         * There's probably some smart way to do this, but I'll leave
         * that to the smart and beautiful people. I'm simple and stupid.
         */
-       backwards = start;
-       forwards = start;
+       backwards = try;
+       backwards_lno = line;
+       forwards = try;
+       forwards_lno = line;
+       try_lno = line;
+
        for (i = 0; ; i++) {
-               unsigned long try;
-               int n;
+               if (match_fragment(state, img, preimage, postimage,
+                                  try, try_lno, ws_rule,
+                                  match_beginning, match_end))
+                       return try_lno;
+
+       again:
+               if (backwards_lno == 0 && forwards_lno == img->nr)
+                       break;
 
-               /* "backward" */
                if (i & 1) {
-                       if (!backwards) {
-                               if (forwards + fragsize > size)
-                                       break;
-                               continue;
+                       if (backwards_lno == 0) {
+                               i++;
+                               goto again;
                        }
-                       do {
-                               --backwards;
-                       } while (backwards && buf[backwards-1] != '\n');
+                       backwards_lno--;
+                       backwards -= img->line[backwards_lno].len;
                        try = backwards;
+                       try_lno = backwards_lno;
                } else {
-                       while (forwards + fragsize <= size) {
-                               if (buf[forwards++] == '\n')
-                                       break;
+                       if (forwards_lno == img->nr) {
+                               i++;
+                               goto again;
                        }
+                       forwards += img->line[forwards_lno].len;
+                       forwards_lno++;
                        try = forwards;
+                       try_lno = forwards_lno;
                }
 
-               if (try + fragsize > size)
-                       continue;
-               if (memcmp(buf + try, fragment, fragsize))
-                       continue;
-               n = (i >> 1)+1;
-               if (i & 1)
-                       n = -n;
-               *lines = n;
-               return try;
        }
-
-       /*
-        * We should start searching forward and backward.
-        */
        return -1;
 }
 
-static void remove_first_line(const char **rbuf, int *rsize)
+static void remove_first_line(struct image *img)
 {
-       const char *buf = *rbuf;
-       int size = *rsize;
-       unsigned long offset;
-       offset = 0;
-       while (offset <= size) {
-               if (buf[offset++] == '\n')
-                       break;
-       }
-       *rsize = size - offset;
-       *rbuf = buf + offset;
+       img->buf += img->line[0].len;
+       img->len -= img->line[0].len;
+       img->line++;
+       img->nr--;
 }
 
-static void remove_last_line(const char **rbuf, int *rsize)
+static void remove_last_line(struct image *img)
 {
-       const char *buf = *rbuf;
-       int size = *rsize;
-       unsigned long offset;
-       offset = size - 1;
-       while (offset > 0) {
-               if (buf[--offset] == '\n')
-                       break;
-       }
-       *rsize = offset + 1;
+       img->len -= img->line[--img->nr].len;
 }
 
-struct buffer_desc {
-       char *buffer;
-       unsigned long size;
-       unsigned long alloc;
-};
-
-static int apply_line(char *output, const char *patch, int plen)
+/*
+ * The change from "preimage" and "postimage" has been found to
+ * apply at applied_pos (counts in line numbers) in "img".
+ * Update "img" to remove "preimage" and replace it with "postimage".
+ */
+static void update_image(struct apply_state *state,
+                        struct image *img,
+                        int applied_pos,
+                        struct image *preimage,
+                        struct image *postimage)
 {
-       /* plen is number of bytes to be copied from patch,
-        * starting at patch+1 (patch[0] is '+').  Typically
-        * patch[plen] is '\n'.
+       /*
+        * remove the copy of preimage at offset in img
+        * and replace it with postimage
         */
-       int add_nl_to_tail = 0;
-       if ((new_whitespace == strip_whitespace) &&
-           1 < plen && isspace(patch[plen-1])) {
-               if (patch[plen] == '\n')
-                       add_nl_to_tail = 1;
-               plen--;
-               while (0 < plen && isspace(patch[plen]))
-                       plen--;
-               applied_after_stripping++;
+       int i, nr;
+       size_t remove_count, insert_count, applied_at = 0;
+       char *result;
+       int preimage_limit;
+
+       /*
+        * If we are removing blank lines at the end of img,
+        * the preimage may extend beyond the end.
+        * If that is the case, we must be careful only to
+        * remove the part of the preimage that falls within
+        * the boundaries of img. Initialize preimage_limit
+        * to the number of lines in the preimage that falls
+        * within the boundaries.
+        */
+       preimage_limit = preimage->nr;
+       if (preimage_limit > img->nr - applied_pos)
+               preimage_limit = img->nr - applied_pos;
+
+       for (i = 0; i < applied_pos; i++)
+               applied_at += img->line[i].len;
+
+       remove_count = 0;
+       for (i = 0; i < preimage_limit; i++)
+               remove_count += img->line[applied_pos + i].len;
+       insert_count = postimage->len;
+
+       /* Adjust the contents */
+       result = xmalloc(st_add3(st_sub(img->len, remove_count), insert_count, 1));
+       memcpy(result, img->buf, applied_at);
+       memcpy(result + applied_at, postimage->buf, postimage->len);
+       memcpy(result + applied_at + postimage->len,
+              img->buf + (applied_at + remove_count),
+              img->len - (applied_at + remove_count));
+       free(img->buf);
+       img->buf = result;
+       img->len += insert_count - remove_count;
+       result[img->len] = '\0';
+
+       /* Adjust the line table */
+       nr = img->nr + postimage->nr - preimage_limit;
+       if (preimage_limit < postimage->nr) {
+               /*
+                * NOTE: this knows that we never call remove_first_line()
+                * on anything other than pre/post image.
+                */
+               REALLOC_ARRAY(img->line, nr);
+               img->line_allocated = img->line;
        }
-       memcpy(output, patch + 1, plen);
-       if (add_nl_to_tail)
-               output[plen++] = '\n';
-       return plen;
+       if (preimage_limit != postimage->nr)
+               memmove(img->line + applied_pos + postimage->nr,
+                       img->line + applied_pos + preimage_limit,
+                       (img->nr - (applied_pos + preimage_limit)) *
+                       sizeof(*img->line));
+       memcpy(img->line + applied_pos,
+              postimage->line,
+              postimage->nr * sizeof(*img->line));
+       if (!state->allow_overlap)
+               for (i = 0; i < postimage->nr; i++)
+                       img->line[applied_pos + i].flag |= LINE_PATCHED;
+       img->nr = nr;
 }
 
-static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
+/*
+ * Use the patch-hunk text in "frag" to prepare two images (preimage and
+ * postimage) for the hunk.  Find lines that match "preimage" in "img" and
+ * replace the part of "img" with "postimage" text.
+ */
+static int apply_one_fragment(struct apply_state *state,
+                             struct image *img, struct fragment *frag,
+                             int inaccurate_eof, unsigned ws_rule,
+                             int nth_fragment)
 {
-       char *buf = desc->buffer;
+       int match_beginning, match_end;
        const char *patch = frag->patch;
-       int offset, size = frag->size;
-       char *old = xmalloc(size);
-       char *new = xmalloc(size);
-       const char *oldlines, *newlines;
-       int oldsize = 0, newsize = 0;
+       int size = frag->size;
+       char *old, *oldlines;
+       struct strbuf newlines;
+       int new_blank_lines_at_end = 0;
+       int found_new_blank_lines_at_end = 0;
+       int hunk_linenr = frag->linenr;
        unsigned long leading, trailing;
-       int pos, lines;
+       int pos, applied_pos;
+       struct image preimage;
+       struct image postimage;
+
+       memset(&preimage, 0, sizeof(preimage));
+       memset(&postimage, 0, sizeof(postimage));
+       oldlines = xmalloc(size);
+       strbuf_init(&newlines, size);
 
+       old = oldlines;
        while (size > 0) {
+               char first;
                int len = linelen(patch, size);
                int plen;
+               int added_blank_line = 0;
+               int is_blank_context = 0;
+               size_t start;
 
                if (!len)
                        break;
@@ -1357,167 +2867,274 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
                 * followed by "\ No newline", then we also remove the
                 * last one (which is the newline, of course).
                 */
-               plen = len-1;
+               plen = len - 1;
                if (len < size && patch[len] == '\\')
                        plen--;
-               switch (*patch) {
+               first = *patch;
+               if (state->apply_in_reverse) {
+                       if (first == '-')
+                               first = '+';
+                       else if (first == '+')
+                               first = '-';
+               }
+
+               switch (first) {
+               case '\n':
+                       /* Newer GNU diff, empty context line */
+                       if (plen < 0)
+                               /* ... followed by '\No newline'; nothing */
+                               break;
+                       *old++ = '\n';
+                       strbuf_addch(&newlines, '\n');
+                       add_line_info(&preimage, "\n", 1, LINE_COMMON);
+                       add_line_info(&postimage, "\n", 1, LINE_COMMON);
+                       is_blank_context = 1;
+                       break;
                case ' ':
+                       if (plen && (ws_rule & WS_BLANK_AT_EOF) &&
+                           ws_blank_line(patch + 1, plen, ws_rule))
+                               is_blank_context = 1;
                case '-':
-                       memcpy(old + oldsize, patch + 1, plen);
-                       oldsize += plen;
-                       if (*patch == '-')
+                       memcpy(old, patch + 1, plen);
+                       add_line_info(&preimage, old, plen,
+                                     (first == ' ' ? LINE_COMMON : 0));
+                       old += plen;
+                       if (first == '-')
                                break;
                /* Fall-through for ' ' */
                case '+':
-                       if (*patch != '+' || !no_add)
-                               newsize += apply_line(new + newsize, patch,
-                                                     plen);
+                       /* --no-add does not add new lines */
+                       if (first == '+' && state->no_add)
+                               break;
+
+                       start = newlines.len;
+                       if (first != '+' ||
+                           !state->whitespace_error ||
+                           state->ws_error_action != correct_ws_error) {
+                               strbuf_add(&newlines, patch + 1, plen);
+                       }
+                       else {
+                               ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &state->applied_after_fixing_ws);
+                       }
+                       add_line_info(&postimage, newlines.buf + start, newlines.len - start,
+                                     (first == '+' ? 0 : LINE_COMMON));
+                       if (first == '+' &&
+                           (ws_rule & WS_BLANK_AT_EOF) &&
+                           ws_blank_line(patch + 1, plen, ws_rule))
+                               added_blank_line = 1;
                        break;
                case '@': case '\\':
                        /* Ignore it, we already handled it */
                        break;
                default:
-                       return -1;
+                       if (state->apply_verbosity > verbosity_normal)
+                               error(_("invalid start of line: '%c'"), first);
+                       applied_pos = -1;
+                       goto out;
                }
+               if (added_blank_line) {
+                       if (!new_blank_lines_at_end)
+                               found_new_blank_lines_at_end = hunk_linenr;
+                       new_blank_lines_at_end++;
+               }
+               else if (is_blank_context)
+                       ;
+               else
+                       new_blank_lines_at_end = 0;
                patch += len;
                size -= len;
+               hunk_linenr++;
        }
-
-#ifdef NO_ACCURATE_DIFF
-       if (oldsize > 0 && old[oldsize - 1] == '\n' &&
-                       newsize > 0 && new[newsize - 1] == '\n') {
-               oldsize--;
-               newsize--;
+       if (inaccurate_eof &&
+           old > oldlines && old[-1] == '\n' &&
+           newlines.len > 0 && newlines.buf[newlines.len - 1] == '\n') {
+               old--;
+               strbuf_setlen(&newlines, newlines.len - 1);
        }
-#endif
 
-       oldlines = old;
-       newlines = new;
        leading = frag->leading;
        trailing = frag->trailing;
-       lines = 0;
-       pos = frag->newpos;
+
+       /*
+        * A hunk to change lines at the beginning would begin with
+        * @@ -1,L +N,M @@
+        * but we need to be careful.  -U0 that inserts before the second
+        * line also has this pattern.
+        *
+        * And a hunk to add to an empty file would begin with
+        * @@ -0,0 +N,M @@
+        *
+        * In other words, a hunk that is (frag->oldpos <= 1) with or
+        * without leading context must match at the beginning.
+        */
+       match_beginning = (!frag->oldpos ||
+                          (frag->oldpos == 1 && !state->unidiff_zero));
+
+       /*
+        * A hunk without trailing lines must match at the end.
+        * However, we simply cannot tell if a hunk must match end
+        * from the lack of trailing lines if the patch was generated
+        * with unidiff without any context.
+        */
+       match_end = !state->unidiff_zero && !trailing;
+
+       pos = frag->newpos ? (frag->newpos - 1) : 0;
+       preimage.buf = oldlines;
+       preimage.len = old - oldlines;
+       postimage.buf = newlines.buf;
+       postimage.len = newlines.len;
+       preimage.line = preimage.line_allocated;
+       postimage.line = postimage.line_allocated;
+
        for (;;) {
-               offset = find_offset(buf, desc->size, oldlines, oldsize, pos, &lines);
-               if (offset >= 0) {
-                       int diff = newsize - oldsize;
-                       unsigned long size = desc->size + diff;
-                       unsigned long alloc = desc->alloc;
-
-                       /* Warn if it was necessary to reduce the number
-                        * of context lines.
-                        */
-                       if ((leading != frag->leading) || (trailing != frag->trailing))
-                               fprintf(stderr, "Context reduced to (%ld/%ld) to apply fragment at %d\n",
-                                       leading, trailing, pos + lines);
-
-                       if (size > alloc) {
-                               alloc = size + 8192;
-                               desc->alloc = alloc;
-                               buf = xrealloc(buf, alloc);
-                               desc->buffer = buf;
-                       }
-                       desc->size = size;
-                       memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
-                       memcpy(buf + offset, newlines, newsize);
-                       offset = 0;
 
+               applied_pos = find_pos(state, img, &preimage, &postimage, pos,
+                                      ws_rule, match_beginning, match_end);
+
+               if (applied_pos >= 0)
                        break;
-               }
 
                /* Am I at my context limits? */
-               if ((leading <= p_context) && (trailing <= p_context))
+               if ((leading <= state->p_context) && (trailing <= state->p_context))
                        break;
-               /* Reduce the number of context lines
-                * Reduce both leading and trailing if they are equal
-                * otherwise just reduce the larger context.
+               if (match_beginning || match_end) {
+                       match_beginning = match_end = 0;
+                       continue;
+               }
+
+               /*
+                * Reduce the number of context lines; reduce both
+                * leading and trailing if they are equal otherwise
+                * just reduce the larger context.
                 */
                if (leading >= trailing) {
-                       remove_first_line(&oldlines, &oldsize);
-                       remove_first_line(&newlines, &newsize);
+                       remove_first_line(&preimage);
+                       remove_first_line(&postimage);
                        pos--;
                        leading--;
                }
                if (trailing > leading) {
-                       remove_last_line(&oldlines, &oldsize);
-                       remove_last_line(&newlines, &newsize);
+                       remove_last_line(&preimage);
+                       remove_last_line(&postimage);
                        trailing--;
                }
        }
 
-       free(old);
-       free(new);
-       return offset;
-}
-
-static char *inflate_it(const void *data, unsigned long size,
-                       unsigned long inflated_size)
-{
-       z_stream stream;
-       void *out;
-       int st;
+       if (applied_pos >= 0) {
+               if (new_blank_lines_at_end &&
+                   preimage.nr + applied_pos >= img->nr &&
+                   (ws_rule & WS_BLANK_AT_EOF) &&
+                   state->ws_error_action != nowarn_ws_error) {
+                       record_ws_error(state, WS_BLANK_AT_EOF, "+", 1,
+                                       found_new_blank_lines_at_end);
+                       if (state->ws_error_action == correct_ws_error) {
+                               while (new_blank_lines_at_end--)
+                                       remove_last_line(&postimage);
+                       }
+                       /*
+                        * We would want to prevent write_out_results()
+                        * from taking place in apply_patch() that follows
+                        * the callchain led us here, which is:
+                        * apply_patch->check_patch_list->check_patch->
+                        * apply_data->apply_fragments->apply_one_fragment
+                        */
+                       if (state->ws_error_action == die_on_ws_error)
+                               state->apply = 0;
+               }
 
-       memset(&stream, 0, sizeof(stream));
+               if (state->apply_verbosity > verbosity_normal && applied_pos != pos) {
+                       int offset = applied_pos - pos;
+                       if (state->apply_in_reverse)
+                               offset = 0 - offset;
+                       fprintf_ln(stderr,
+                                  Q_("Hunk #%d succeeded at %d (offset %d line).",
+                                     "Hunk #%d succeeded at %d (offset %d lines).",
+                                     offset),
+                                  nth_fragment, applied_pos + 1, offset);
+               }
 
-       stream.next_in = (unsigned char *)data;
-       stream.avail_in = size;
-       stream.next_out = out = xmalloc(inflated_size);
-       stream.avail_out = inflated_size;
-       inflateInit(&stream);
-       st = inflate(&stream, Z_FINISH);
-       if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
-               free(out);
-               return NULL;
+               /*
+                * Warn if it was necessary to reduce the number
+                * of context lines.
+                */
+               if ((leading != frag->leading ||
+                    trailing != frag->trailing) && state->apply_verbosity > verbosity_silent)
+                       fprintf_ln(stderr, _("Context reduced to (%ld/%ld)"
+                                            " to apply fragment at %d"),
+                                  leading, trailing, applied_pos+1);
+               update_image(state, img, applied_pos, &preimage, &postimage);
+       } else {
+               if (state->apply_verbosity > verbosity_normal)
+                       error(_("while searching for:\n%.*s"),
+                             (int)(old - oldlines), oldlines);
        }
-       return out;
+
+out:
+       free(oldlines);
+       strbuf_release(&newlines);
+       free(preimage.line_allocated);
+       free(postimage.line_allocated);
+
+       return (applied_pos < 0);
 }
 
-static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
+static int apply_binary_fragment(struct apply_state *state,
+                                struct image *img,
+                                struct patch *patch)
 {
-       unsigned long dst_size;
        struct fragment *fragment = patch->fragments;
-       void *data;
-       void *result;
-
-       data = inflate_it(fragment->patch, fragment->size,
-                         patch->deflate_origlen);
-       if (!data)
-               return error("corrupt patch data");
-       switch (patch->is_binary) {
+       unsigned long len;
+       void *dst;
+
+       if (!fragment)
+               return error(_("missing binary patch data for '%s'"),
+                            patch->new_name ?
+                            patch->new_name :
+                            patch->old_name);
+
+       /* Binary patch is irreversible without the optional second hunk */
+       if (state->apply_in_reverse) {
+               if (!fragment->next)
+                       return error("cannot reverse-apply a binary patch "
+                                    "without the reverse hunk to '%s'",
+                                    patch->new_name
+                                    ? patch->new_name : patch->old_name);
+               fragment = fragment->next;
+       }
+       switch (fragment->binary_patch_method) {
        case BINARY_DELTA_DEFLATED:
-               result = patch_delta(desc->buffer, desc->size,
-                                    data,
-                                    patch->deflate_origlen,
-                                    &dst_size);
-               free(desc->buffer);
-               desc->buffer = result;
-               free(data);
-               break;
+               dst = patch_delta(img->buf, img->len, fragment->patch,
+                                 fragment->size, &len);
+               if (!dst)
+                       return -1;
+               clear_image(img);
+               img->buf = dst;
+               img->len = len;
+               return 0;
        case BINARY_LITERAL_DEFLATED:
-               free(desc->buffer);
-               desc->buffer = data;
-               dst_size = patch->deflate_origlen;
-               break;
+               clear_image(img);
+               img->len = fragment->size;
+               img->buf = xmemdupz(fragment->patch, img->len);
+               return 0;
        }
-       if (!desc->buffer)
-               return -1;
-       desc->size = desc->alloc = dst_size;
-       return 0;
+       return -1;
 }
 
-static int apply_binary(struct buffer_desc *desc, struct patch *patch)
+/*
+ * Replace "img" with the result of applying the binary patch.
+ * The binary patch data itself in patch->fragment is still kept
+ * but the preimage prepared by the caller in "img" is freed here
+ * or in the helper function apply_binary_fragment() this calls.
+ */
+static int apply_binary(struct apply_state *state,
+                       struct image *img,
+                       struct patch *patch)
 {
        const char *name = patch->old_name ? patch->old_name : patch->new_name;
        unsigned char sha1[20];
-       unsigned char hdr[50];
-       int hdrlen;
-
-       if (!allow_binary_replacement)
-               return error("cannot apply binary patch to '%s' "
-                            "without --allow-binary-replacement",
-                            name);
 
-       /* For safety, we require patch index line to contain
+       /*
+        * For safety, we require patch index line to contain
         * full 40-byte textual SHA1 for old and new, at least for now.
         */
        if (strlen(patch->old_sha1_prefix) != 40 ||
@@ -1528,11 +3145,11 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
                             "without full index line", name);
 
        if (patch->old_name) {
-               /* See if the old one matches what the patch
+               /*
+                * See if the old one matches what the patch
                 * applies to.
                 */
-               write_sha1_file_prepare(desc->buffer, desc->size,
-                                       blob_type, sha1, hdr, &hdrlen);
+               hash_sha1_file(img->buf, img->len, blob_type, sha1);
                if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
                        return error("the patch applies to '%s' (%s), "
                                     "which does not match the "
@@ -1541,184 +3158,775 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
        }
        else {
                /* Otherwise, the old one must be empty. */
-               if (desc->size)
+               if (img->len)
                        return error("the patch applies to an empty "
                                     "'%s' but it is not empty", name);
        }
 
        get_sha1_hex(patch->new_sha1_prefix, sha1);
-       if (!memcmp(sha1, null_sha1, 20)) {
-               free(desc->buffer);
-               desc->alloc = desc->size = 0;
-               desc->buffer = NULL;
+       if (is_null_sha1(sha1)) {
+               clear_image(img);
                return 0; /* deletion patch */
        }
 
        if (has_sha1_file(sha1)) {
                /* We already have the postimage */
-               char type[10];
+               enum object_type type;
                unsigned long size;
+               char *result;
 
-               free(desc->buffer);
-               desc->buffer = read_sha1_file(sha1, type, &size);
-               if (!desc->buffer)
+               result = read_sha1_file(sha1, &type, &size);
+               if (!result)
                        return error("the necessary postimage %s for "
                                     "'%s' cannot be read",
                                     patch->new_sha1_prefix, name);
-               desc->alloc = desc->size = size;
-       }
-       else {
-               /* We have verified desc matches the preimage;
+               clear_image(img);
+               img->buf = result;
+               img->len = size;
+       } else {
+               /*
+                * We have verified buf matches the preimage;
                 * apply the patch data to it, which is stored
                 * in the patch->fragments->{patch,size}.
                 */
-               if (apply_binary_fragment(desc, patch))
-                       return error("binary patch does not apply to '%s'",
+               if (apply_binary_fragment(state, img, patch))
+                       return error(_("binary patch does not apply to '%s'"),
                                     name);
 
-               /* verify that the result matches */
-               write_sha1_file_prepare(desc->buffer, desc->size, blob_type,
-                                       sha1, hdr, &hdrlen);
-               if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
-                       return error("binary patch to '%s' creates incorrect result", name);
-       }
+               /* verify that the result matches */
+               hash_sha1_file(img->buf, img->len, blob_type, sha1);
+               if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
+                       return error(_("binary patch to '%s' creates incorrect result (expecting %s, got %s)"),
+                               name, patch->new_sha1_prefix, sha1_to_hex(sha1));
+       }
+
+       return 0;
+}
+
+static int apply_fragments(struct apply_state *state, struct image *img, struct patch *patch)
+{
+       struct fragment *frag = patch->fragments;
+       const char *name = patch->old_name ? patch->old_name : patch->new_name;
+       unsigned ws_rule = patch->ws_rule;
+       unsigned inaccurate_eof = patch->inaccurate_eof;
+       int nth = 0;
+
+       if (patch->is_binary)
+               return apply_binary(state, img, patch);
+
+       while (frag) {
+               nth++;
+               if (apply_one_fragment(state, img, frag, inaccurate_eof, ws_rule, nth)) {
+                       error(_("patch failed: %s:%ld"), name, frag->oldpos);
+                       if (!state->apply_with_reject)
+                               return -1;
+                       frag->rejected = 1;
+               }
+               frag = frag->next;
+       }
+       return 0;
+}
+
+static int read_blob_object(struct strbuf *buf, const unsigned char *sha1, unsigned mode)
+{
+       if (S_ISGITLINK(mode)) {
+               strbuf_grow(buf, 100);
+               strbuf_addf(buf, "Subproject commit %s\n", sha1_to_hex(sha1));
+       } else {
+               enum object_type type;
+               unsigned long sz;
+               char *result;
+
+               result = read_sha1_file(sha1, &type, &sz);
+               if (!result)
+                       return -1;
+               /* XXX read_sha1_file NUL-terminates */
+               strbuf_attach(buf, result, sz, sz + 1);
+       }
+       return 0;
+}
+
+static int read_file_or_gitlink(const struct cache_entry *ce, struct strbuf *buf)
+{
+       if (!ce)
+               return 0;
+       return read_blob_object(buf, ce->sha1, ce->ce_mode);
+}
+
+static struct patch *in_fn_table(struct apply_state *state, const char *name)
+{
+       struct string_list_item *item;
+
+       if (name == NULL)
+               return NULL;
+
+       item = string_list_lookup(&state->fn_table, name);
+       if (item != NULL)
+               return (struct patch *)item->util;
+
+       return NULL;
+}
+
+/*
+ * item->util in the filename table records the status of the path.
+ * Usually it points at a patch (whose result records the contents
+ * of it after applying it), but it could be PATH_WAS_DELETED for a
+ * path that a previously applied patch has already removed, or
+ * PATH_TO_BE_DELETED for a path that a later patch would remove.
+ *
+ * The latter is needed to deal with a case where two paths A and B
+ * are swapped by first renaming A to B and then renaming B to A;
+ * moving A to B should not be prevented due to presence of B as we
+ * will remove it in a later patch.
+ */
+#define PATH_TO_BE_DELETED ((struct patch *) -2)
+#define PATH_WAS_DELETED ((struct patch *) -1)
+
+static int to_be_deleted(struct patch *patch)
+{
+       return patch == PATH_TO_BE_DELETED;
+}
+
+static int was_deleted(struct patch *patch)
+{
+       return patch == PATH_WAS_DELETED;
+}
+
+static void add_to_fn_table(struct apply_state *state, struct patch *patch)
+{
+       struct string_list_item *item;
+
+       /*
+        * Always add new_name unless patch is a deletion
+        * This should cover the cases for normal diffs,
+        * file creations and copies
+        */
+       if (patch->new_name != NULL) {
+               item = string_list_insert(&state->fn_table, patch->new_name);
+               item->util = patch;
+       }
+
+       /*
+        * store a failure on rename/deletion cases because
+        * later chunks shouldn't patch old names
+        */
+       if ((patch->new_name == NULL) || (patch->is_rename)) {
+               item = string_list_insert(&state->fn_table, patch->old_name);
+               item->util = PATH_WAS_DELETED;
+       }
+}
+
+static void prepare_fn_table(struct apply_state *state, struct patch *patch)
+{
+       /*
+        * store information about incoming file deletion
+        */
+       while (patch) {
+               if ((patch->new_name == NULL) || (patch->is_rename)) {
+                       struct string_list_item *item;
+                       item = string_list_insert(&state->fn_table, patch->old_name);
+                       item->util = PATH_TO_BE_DELETED;
+               }
+               patch = patch->next;
+       }
+}
+
+static int checkout_target(struct index_state *istate,
+                          struct cache_entry *ce, struct stat *st)
+{
+       struct checkout costate;
+
+       memset(&costate, 0, sizeof(costate));
+       costate.base_dir = "";
+       costate.refresh_cache = 1;
+       costate.istate = istate;
+       if (checkout_entry(ce, &costate, NULL) || lstat(ce->name, st))
+               return error(_("cannot checkout %s"), ce->name);
+       return 0;
+}
+
+static struct patch *previous_patch(struct apply_state *state,
+                                   struct patch *patch,
+                                   int *gone)
+{
+       struct patch *previous;
+
+       *gone = 0;
+       if (patch->is_copy || patch->is_rename)
+               return NULL; /* "git" patches do not depend on the order */
+
+       previous = in_fn_table(state, patch->old_name);
+       if (!previous)
+               return NULL;
+
+       if (to_be_deleted(previous))
+               return NULL; /* the deletion hasn't happened yet */
+
+       if (was_deleted(previous))
+               *gone = 1;
+
+       return previous;
+}
+
+static int verify_index_match(const struct cache_entry *ce, struct stat *st)
+{
+       if (S_ISGITLINK(ce->ce_mode)) {
+               if (!S_ISDIR(st->st_mode))
+                       return -1;
+               return 0;
+       }
+       return ce_match_stat(ce, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
+}
+
+#define SUBMODULE_PATCH_WITHOUT_INDEX 1
+
+static int load_patch_target(struct apply_state *state,
+                            struct strbuf *buf,
+                            const struct cache_entry *ce,
+                            struct stat *st,
+                            const char *name,
+                            unsigned expected_mode)
+{
+       if (state->cached || state->check_index) {
+               if (read_file_or_gitlink(ce, buf))
+                       return error(_("failed to read %s"), name);
+       } else if (name) {
+               if (S_ISGITLINK(expected_mode)) {
+                       if (ce)
+                               return read_file_or_gitlink(ce, buf);
+                       else
+                               return SUBMODULE_PATCH_WITHOUT_INDEX;
+               } else if (has_symlink_leading_path(name, strlen(name))) {
+                       return error(_("reading from '%s' beyond a symbolic link"), name);
+               } else {
+                       if (read_old_data(st, name, buf))
+                               return error(_("failed to read %s"), name);
+               }
+       }
+       return 0;
+}
+
+/*
+ * We are about to apply "patch"; populate the "image" with the
+ * current version we have, from the working tree or from the index,
+ * depending on the situation e.g. --cached/--index.  If we are
+ * applying a non-git patch that incrementally updates the tree,
+ * we read from the result of a previous diff.
+ */
+static int load_preimage(struct apply_state *state,
+                        struct image *image,
+                        struct patch *patch, struct stat *st,
+                        const struct cache_entry *ce)
+{
+       struct strbuf buf = STRBUF_INIT;
+       size_t len;
+       char *img;
+       struct patch *previous;
+       int status;
+
+       previous = previous_patch(state, patch, &status);
+       if (status)
+               return error(_("path %s has been renamed/deleted"),
+                            patch->old_name);
+       if (previous) {
+               /* We have a patched copy in memory; use that. */
+               strbuf_add(&buf, previous->result, previous->resultsize);
+       } else {
+               status = load_patch_target(state, &buf, ce, st,
+                                          patch->old_name, patch->old_mode);
+               if (status < 0)
+                       return status;
+               else if (status == SUBMODULE_PATCH_WITHOUT_INDEX) {
+                       /*
+                        * There is no way to apply subproject
+                        * patch without looking at the index.
+                        * NEEDSWORK: shouldn't this be flagged
+                        * as an error???
+                        */
+                       free_fragment_list(patch->fragments);
+                       patch->fragments = NULL;
+               } else if (status) {
+                       return error(_("failed to read %s"), patch->old_name);
+               }
+       }
+
+       img = strbuf_detach(&buf, &len);
+       prepare_image(image, img, len, !patch->is_binary);
+       return 0;
+}
+
+static int three_way_merge(struct image *image,
+                          char *path,
+                          const unsigned char *base,
+                          const unsigned char *ours,
+                          const unsigned char *theirs)
+{
+       mmfile_t base_file, our_file, their_file;
+       mmbuffer_t result = { NULL };
+       int status;
+
+       read_mmblob(&base_file, base);
+       read_mmblob(&our_file, ours);
+       read_mmblob(&their_file, theirs);
+       status = ll_merge(&result, path,
+                         &base_file, "base",
+                         &our_file, "ours",
+                         &their_file, "theirs", NULL);
+       free(base_file.ptr);
+       free(our_file.ptr);
+       free(their_file.ptr);
+       if (status < 0 || !result.ptr) {
+               free(result.ptr);
+               return -1;
+       }
+       clear_image(image);
+       image->buf = result.ptr;
+       image->len = result.size;
+
+       return status;
+}
+
+/*
+ * When directly falling back to add/add three-way merge, we read from
+ * the current contents of the new_name.  In no cases other than that
+ * this function will be called.
+ */
+static int load_current(struct apply_state *state,
+                       struct image *image,
+                       struct patch *patch)
+{
+       struct strbuf buf = STRBUF_INIT;
+       int status, pos;
+       size_t len;
+       char *img;
+       struct stat st;
+       struct cache_entry *ce;
+       char *name = patch->new_name;
+       unsigned mode = patch->new_mode;
+
+       if (!patch->is_new)
+               die("BUG: patch to %s is not a creation", patch->old_name);
+
+       pos = cache_name_pos(name, strlen(name));
+       if (pos < 0)
+               return error(_("%s: does not exist in index"), name);
+       ce = active_cache[pos];
+       if (lstat(name, &st)) {
+               if (errno != ENOENT)
+                       return error_errno("%s", name);
+               if (checkout_target(&the_index, ce, &st))
+                       return -1;
+       }
+       if (verify_index_match(ce, &st))
+               return error(_("%s: does not match index"), name);
+
+       status = load_patch_target(state, &buf, ce, &st, name, mode);
+       if (status < 0)
+               return status;
+       else if (status)
+               return -1;
+       img = strbuf_detach(&buf, &len);
+       prepare_image(image, img, len, !patch->is_binary);
+       return 0;
+}
+
+static int try_threeway(struct apply_state *state,
+                       struct image *image,
+                       struct patch *patch,
+                       struct stat *st,
+                       const struct cache_entry *ce)
+{
+       unsigned char pre_sha1[20], post_sha1[20], our_sha1[20];
+       struct strbuf buf = STRBUF_INIT;
+       size_t len;
+       int status;
+       char *img;
+       struct image tmp_image;
+
+       /* No point falling back to 3-way merge in these cases */
+       if (patch->is_delete ||
+           S_ISGITLINK(patch->old_mode) || S_ISGITLINK(patch->new_mode))
+               return -1;
+
+       /* Preimage the patch was prepared for */
+       if (patch->is_new)
+               write_sha1_file("", 0, blob_type, pre_sha1);
+       else if (get_sha1(patch->old_sha1_prefix, pre_sha1) ||
+                read_blob_object(&buf, pre_sha1, patch->old_mode))
+               return error("repository lacks the necessary blob to fall back on 3-way merge.");
+
+       if (state->apply_verbosity > verbosity_silent)
+               fprintf(stderr, "Falling back to three-way merge...\n");
+
+       img = strbuf_detach(&buf, &len);
+       prepare_image(&tmp_image, img, len, 1);
+       /* Apply the patch to get the post image */
+       if (apply_fragments(state, &tmp_image, patch) < 0) {
+               clear_image(&tmp_image);
+               return -1;
+       }
+       /* post_sha1[] is theirs */
+       write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, post_sha1);
+       clear_image(&tmp_image);
+
+       /* our_sha1[] is ours */
+       if (patch->is_new) {
+               if (load_current(state, &tmp_image, patch))
+                       return error("cannot read the current contents of '%s'",
+                                    patch->new_name);
+       } else {
+               if (load_preimage(state, &tmp_image, patch, st, ce))
+                       return error("cannot read the current contents of '%s'",
+                                    patch->old_name);
+       }
+       write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, our_sha1);
+       clear_image(&tmp_image);
+
+       /* in-core three-way merge between post and our using pre as base */
+       status = three_way_merge(image, patch->new_name,
+                                pre_sha1, our_sha1, post_sha1);
+       if (status < 0) {
+               if (state->apply_verbosity > verbosity_silent)
+                       fprintf(stderr,
+                               "Failed to fall back on three-way merge...\n");
+               return status;
+       }
+
+       if (status) {
+               patch->conflicted_threeway = 1;
+               if (patch->is_new)
+                       oidclr(&patch->threeway_stage[0]);
+               else
+                       hashcpy(patch->threeway_stage[0].hash, pre_sha1);
+               hashcpy(patch->threeway_stage[1].hash, our_sha1);
+               hashcpy(patch->threeway_stage[2].hash, post_sha1);
+               if (state->apply_verbosity > verbosity_silent)
+                       fprintf(stderr,
+                               "Applied patch to '%s' with conflicts.\n",
+                               patch->new_name);
+       } else {
+               if (state->apply_verbosity > verbosity_silent)
+                       fprintf(stderr,
+                               "Applied patch to '%s' cleanly.\n",
+                               patch->new_name);
+       }
+       return 0;
+}
+
+static int apply_data(struct apply_state *state, struct patch *patch,
+                     struct stat *st, const struct cache_entry *ce)
+{
+       struct image image;
+
+       if (load_preimage(state, &image, patch, st, ce) < 0)
+               return -1;
+
+       if (patch->direct_to_threeway ||
+           apply_fragments(state, &image, patch) < 0) {
+               /* Note: with --reject, apply_fragments() returns 0 */
+               if (!state->threeway || try_threeway(state, &image, patch, st, ce) < 0)
+                       return -1;
+       }
+       patch->result = image.buf;
+       patch->resultsize = image.len;
+       add_to_fn_table(state, patch);
+       free(image.line_allocated);
+
+       if (0 < patch->is_delete && patch->resultsize)
+               return error(_("removal patch leaves file contents"));
+
+       return 0;
+}
+
+/*
+ * If "patch" that we are looking at modifies or deletes what we have,
+ * we would want it not to lose any local modification we have, either
+ * in the working tree or in the index.
+ *
+ * This also decides if a non-git patch is a creation patch or a
+ * modification to an existing empty file.  We do not check the state
+ * of the current tree for a creation patch in this function; the caller
+ * check_patch() separately makes sure (and errors out otherwise) that
+ * the path the patch creates does not exist in the current tree.
+ */
+static int check_preimage(struct apply_state *state,
+                         struct patch *patch,
+                         struct cache_entry **ce,
+                         struct stat *st)
+{
+       const char *old_name = patch->old_name;
+       struct patch *previous = NULL;
+       int stat_ret = 0, status;
+       unsigned st_mode = 0;
+
+       if (!old_name)
+               return 0;
+
+       assert(patch->is_new <= 0);
+       previous = previous_patch(state, patch, &status);
+
+       if (status)
+               return error(_("path %s has been renamed/deleted"), old_name);
+       if (previous) {
+               st_mode = previous->new_mode;
+       } else if (!state->cached) {
+               stat_ret = lstat(old_name, st);
+               if (stat_ret && errno != ENOENT)
+                       return error_errno("%s", old_name);
+       }
+
+       if (state->check_index && !previous) {
+               int pos = cache_name_pos(old_name, strlen(old_name));
+               if (pos < 0) {
+                       if (patch->is_new < 0)
+                               goto is_new;
+                       return error(_("%s: does not exist in index"), old_name);
+               }
+               *ce = active_cache[pos];
+               if (stat_ret < 0) {
+                       if (checkout_target(&the_index, *ce, st))
+                               return -1;
+               }
+               if (!state->cached && verify_index_match(*ce, st))
+                       return error(_("%s: does not match index"), old_name);
+               if (state->cached)
+                       st_mode = (*ce)->ce_mode;
+       } else if (stat_ret < 0) {
+               if (patch->is_new < 0)
+                       goto is_new;
+               return error_errno("%s", old_name);
+       }
+
+       if (!state->cached && !previous)
+               st_mode = ce_mode_from_stat(*ce, st->st_mode);
+
+       if (patch->is_new < 0)
+               patch->is_new = 0;
+       if (!patch->old_mode)
+               patch->old_mode = st_mode;
+       if ((st_mode ^ patch->old_mode) & S_IFMT)
+               return error(_("%s: wrong type"), old_name);
+       if (st_mode != patch->old_mode)
+               warning(_("%s has type %o, expected %o"),
+                       old_name, st_mode, patch->old_mode);
+       if (!patch->new_mode && !patch->is_delete)
+               patch->new_mode = st_mode;
+       return 0;
+
+ is_new:
+       patch->is_new = 1;
+       patch->is_delete = 0;
+       free(patch->old_name);
+       patch->old_name = NULL;
+       return 0;
+}
+
+
+#define EXISTS_IN_INDEX 1
+#define EXISTS_IN_WORKTREE 2
+
+static int check_to_create(struct apply_state *state,
+                          const char *new_name,
+                          int ok_if_exists)
+{
+       struct stat nst;
+
+       if (state->check_index &&
+           cache_name_pos(new_name, strlen(new_name)) >= 0 &&
+           !ok_if_exists)
+               return EXISTS_IN_INDEX;
+       if (state->cached)
+               return 0;
+
+       if (!lstat(new_name, &nst)) {
+               if (S_ISDIR(nst.st_mode) || ok_if_exists)
+                       return 0;
+               /*
+                * A leading component of new_name might be a symlink
+                * that is going to be removed with this patch, but
+                * still pointing at somewhere that has the path.
+                * In such a case, path "new_name" does not exist as
+                * far as git is concerned.
+                */
+               if (has_symlink_leading_path(new_name, strlen(new_name)))
+                       return 0;
+
+               return EXISTS_IN_WORKTREE;
+       } else if ((errno != ENOENT) && (errno != ENOTDIR)) {
+               return error_errno("%s", new_name);
+       }
+       return 0;
+}
+
+static uintptr_t register_symlink_changes(struct apply_state *state,
+                                         const char *path,
+                                         uintptr_t what)
+{
+       struct string_list_item *ent;
+
+       ent = string_list_lookup(&state->symlink_changes, path);
+       if (!ent) {
+               ent = string_list_insert(&state->symlink_changes, path);
+               ent->util = (void *)0;
+       }
+       ent->util = (void *)(what | ((uintptr_t)ent->util));
+       return (uintptr_t)ent->util;
+}
+
+static uintptr_t check_symlink_changes(struct apply_state *state, const char *path)
+{
+       struct string_list_item *ent;
+
+       ent = string_list_lookup(&state->symlink_changes, path);
+       if (!ent)
+               return 0;
+       return (uintptr_t)ent->util;
+}
 
-       return 0;
+static void prepare_symlink_changes(struct apply_state *state, struct patch *patch)
+{
+       for ( ; patch; patch = patch->next) {
+               if ((patch->old_name && S_ISLNK(patch->old_mode)) &&
+                   (patch->is_rename || patch->is_delete))
+                       /* the symlink at patch->old_name is removed */
+                       register_symlink_changes(state, patch->old_name, APPLY_SYMLINK_GOES_AWAY);
+
+               if (patch->new_name && S_ISLNK(patch->new_mode))
+                       /* the symlink at patch->new_name is created or remains */
+                       register_symlink_changes(state, patch->new_name, APPLY_SYMLINK_IN_RESULT);
+       }
 }
 
-static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
+static int path_is_beyond_symlink_1(struct apply_state *state, struct strbuf *name)
 {
-       struct fragment *frag = patch->fragments;
-       const char *name = patch->old_name ? patch->old_name : patch->new_name;
+       do {
+               unsigned int change;
 
-       if (patch->is_binary)
-               return apply_binary(desc, patch);
+               while (--name->len && name->buf[name->len] != '/')
+                       ; /* scan backwards */
+               if (!name->len)
+                       break;
+               name->buf[name->len] = '\0';
+               change = check_symlink_changes(state, name->buf);
+               if (change & APPLY_SYMLINK_IN_RESULT)
+                       return 1;
+               if (change & APPLY_SYMLINK_GOES_AWAY)
+                       /*
+                        * This cannot be "return 0", because we may
+                        * see a new one created at a higher level.
+                        */
+                       continue;
 
-       while (frag) {
-               if (apply_one_fragment(desc, frag) < 0)
-                       return error("patch failed: %s:%ld",
-                                    name, frag->oldpos);
-               frag = frag->next;
-       }
+               /* otherwise, check the preimage */
+               if (state->check_index) {
+                       struct cache_entry *ce;
+
+                       ce = cache_file_exists(name->buf, name->len, ignore_case);
+                       if (ce && S_ISLNK(ce->ce_mode))
+                               return 1;
+               } else {
+                       struct stat st;
+                       if (!lstat(name->buf, &st) && S_ISLNK(st.st_mode))
+                               return 1;
+               }
+       } while (1);
        return 0;
 }
 
-static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
+static int path_is_beyond_symlink(struct apply_state *state, const char *name_)
 {
-       char *buf;
-       unsigned long size, alloc;
-       struct buffer_desc desc;
-
-       size = 0;
-       alloc = 0;
-       buf = NULL;
-       if (cached) {
-               if (ce) {
-                       char type[20];
-                       buf = read_sha1_file(ce->sha1, type, &size);
-                       if (!buf)
-                               return error("read of %s failed",
-                                            patch->old_name);
-                       alloc = size;
-               }
-       }
-       else if (patch->old_name) {
-               size = st->st_size;
-               alloc = size + 8192;
-               buf = xmalloc(alloc);
-               if (read_old_data(st, patch->old_name, buf, alloc) != size)
-                       return error("read of %s failed", patch->old_name);
-       }
-
-       desc.size = size;
-       desc.alloc = alloc;
-       desc.buffer = buf;
-       if (apply_fragments(&desc, patch) < 0)
-               return -1;
-       patch->result = desc.buffer;
-       patch->resultsize = desc.size;
+       int ret;
+       struct strbuf name = STRBUF_INIT;
 
-       if (patch->is_delete && patch->resultsize)
-               return error("removal patch leaves file contents");
+       assert(*name_ != '\0');
+       strbuf_addstr(&name, name_);
+       ret = path_is_beyond_symlink_1(state, &name);
+       strbuf_release(&name);
 
+       return ret;
+}
+
+static int check_unsafe_path(struct patch *patch)
+{
+       const char *old_name = NULL;
+       const char *new_name = NULL;
+       if (patch->is_delete)
+               old_name = patch->old_name;
+       else if (!patch->is_new && !patch->is_copy)
+               old_name = patch->old_name;
+       if (!patch->is_delete)
+               new_name = patch->new_name;
+
+       if (old_name && !verify_path(old_name))
+               return error(_("invalid path '%s'"), old_name);
+       if (new_name && !verify_path(new_name))
+               return error(_("invalid path '%s'"), new_name);
        return 0;
 }
 
-static int check_patch(struct patch *patch)
+/*
+ * Check and apply the patch in-core; leave the result in patch->result
+ * for the caller to write it out to the final destination.
+ */
+static int check_patch(struct apply_state *state, struct patch *patch)
 {
        struct stat st;
        const char *old_name = patch->old_name;
        const char *new_name = patch->new_name;
        const char *name = old_name ? old_name : new_name;
        struct cache_entry *ce = NULL;
+       struct patch *tpatch;
+       int ok_if_exists;
+       int status;
 
-       if (old_name) {
-               int changed = 0;
-               int stat_ret = 0;
-               unsigned st_mode = 0;
-
-               if (!cached)
-                       stat_ret = lstat(old_name, &st);
-               if (check_index) {
-                       int pos = cache_name_pos(old_name, strlen(old_name));
-                       if (pos < 0)
-                               return error("%s: does not exist in index",
-                                            old_name);
-                       ce = active_cache[pos];
-                       if (stat_ret < 0) {
-                               struct checkout costate;
-                               if (errno != ENOENT)
-                                       return error("%s: %s", old_name,
-                                                    strerror(errno));
-                               /* checkout */
-                               costate.base_dir = "";
-                               costate.base_dir_len = 0;
-                               costate.force = 0;
-                               costate.quiet = 0;
-                               costate.not_new = 0;
-                               costate.refresh_cache = 1;
-                               if (checkout_entry(ce,
-                                                  &costate,
-                                                  NULL) ||
-                                   lstat(old_name, &st))
-                                       return -1;
-                       }
-                       if (!cached)
-                               changed = ce_match_stat(ce, &st, 1);
-                       if (changed)
-                               return error("%s: does not match index",
-                                            old_name);
-                       if (cached)
-                               st_mode = ntohl(ce->ce_mode);
-               }
-               else if (stat_ret < 0)
-                       return error("%s: %s", old_name, strerror(errno));
+       patch->rejected = 1; /* we will drop this after we succeed */
 
-               if (!cached)
-                       st_mode = ntohl(create_ce_mode(st.st_mode));
+       status = check_preimage(state, patch, &ce, &st);
+       if (status)
+               return status;
+       old_name = patch->old_name;
 
-               if (patch->is_new < 0)
-                       patch->is_new = 0;
-               if (!patch->old_mode)
-                       patch->old_mode = st_mode;
-               if ((st_mode ^ patch->old_mode) & S_IFMT)
-                       return error("%s: wrong type", old_name);
-               if (st_mode != patch->old_mode)
-                       fprintf(stderr, "warning: %s has type %o, expected %o\n",
-                               old_name, st_mode, patch->old_mode);
-       }
-
-       if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
-               if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
-                       return error("%s: already exists in index", new_name);
-               if (!cached) {
-                       if (!lstat(new_name, &st))
-                               return error("%s: already exists in working directory", new_name);
-                       if (errno != ENOENT)
-                               return error("%s: %s", new_name, strerror(errno));
+       /*
+        * A type-change diff is always split into a patch to delete
+        * old, immediately followed by a patch to create new (see
+        * diff.c::run_diff()); in such a case it is Ok that the entry
+        * to be deleted by the previous patch is still in the working
+        * tree and in the index.
+        *
+        * A patch to swap-rename between A and B would first rename A
+        * to B and then rename B to A.  While applying the first one,
+        * the presence of B should not stop A from getting renamed to
+        * B; ask to_be_deleted() about the later rename.  Removal of
+        * B and rename from A to B is handled the same way by asking
+        * was_deleted().
+        */
+       if ((tpatch = in_fn_table(state, new_name)) &&
+           (was_deleted(tpatch) || to_be_deleted(tpatch)))
+               ok_if_exists = 1;
+       else
+               ok_if_exists = 0;
+
+       if (new_name &&
+           ((0 < patch->is_new) || patch->is_rename || patch->is_copy)) {
+               int err = check_to_create(state, new_name, ok_if_exists);
+
+               if (err && state->threeway) {
+                       patch->direct_to_threeway = 1;
+               } else switch (err) {
+               case 0:
+                       break; /* happy */
+               case EXISTS_IN_INDEX:
+                       return error(_("%s: already exists in index"), new_name);
+                       break;
+               case EXISTS_IN_WORKTREE:
+                       return error(_("%s: already exists in working directory"),
+                                    new_name);
+               default:
+                       return err;
                }
+
                if (!patch->new_mode) {
-                       if (patch->is_new)
+                       if (0 < patch->is_new)
                                patch->new_mode = S_IFREG | 0644;
                        else
                                patch->new_mode = patch->old_mode;
@@ -1729,62 +3937,170 @@ static int check_patch(struct patch *patch)
                int same = !strcmp(old_name, new_name);
                if (!patch->new_mode)
                        patch->new_mode = patch->old_mode;
-               if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
-                       return error("new mode (%o) of %s does not match old mode (%o)%s%s",
-                               patch->new_mode, new_name, patch->old_mode,
-                               same ? "" : " of ", same ? "" : old_name);
+               if ((patch->old_mode ^ patch->new_mode) & S_IFMT) {
+                       if (same)
+                               return error(_("new mode (%o) of %s does not "
+                                              "match old mode (%o)"),
+                                       patch->new_mode, new_name,
+                                       patch->old_mode);
+                       else
+                               return error(_("new mode (%o) of %s does not "
+                                              "match old mode (%o) of %s"),
+                                       patch->new_mode, new_name,
+                                       patch->old_mode, old_name);
+               }
        }
 
-       if (apply_data(patch, &st, ce) < 0)
-               return error("%s: patch does not apply", name);
+       if (!state->unsafe_paths && check_unsafe_path(patch))
+               return -128;
+
+       /*
+        * An attempt to read from or delete a path that is beyond a
+        * symbolic link will be prevented by load_patch_target() that
+        * is called at the beginning of apply_data() so we do not
+        * have to worry about a patch marked with "is_delete" bit
+        * here.  We however need to make sure that the patch result
+        * is not deposited to a path that is beyond a symbolic link
+        * here.
+        */
+       if (!patch->is_delete && path_is_beyond_symlink(state, patch->new_name))
+               return error(_("affected file '%s' is beyond a symbolic link"),
+                            patch->new_name);
+
+       if (apply_data(state, patch, &st, ce) < 0)
+               return error(_("%s: patch does not apply"), name);
+       patch->rejected = 0;
        return 0;
 }
 
-static int check_patch_list(struct patch *patch)
+static int check_patch_list(struct apply_state *state, struct patch *patch)
+{
+       int err = 0;
+
+       prepare_symlink_changes(state, patch);
+       prepare_fn_table(state, patch);
+       while (patch) {
+               int res;
+               if (state->apply_verbosity > verbosity_normal)
+                       say_patch_name(stderr,
+                                      _("Checking patch %s..."), patch);
+               res = check_patch(state, patch);
+               if (res == -128)
+                       return -128;
+               err |= res;
+               patch = patch->next;
+       }
+       return err;
+}
+
+/* This function tries to read the sha1 from the current index */
+static int get_current_sha1(const char *path, unsigned char *sha1)
 {
-       int error = 0;
+       int pos;
 
-       for (;patch ; patch = patch->next)
-               error |= check_patch(patch);
-       return error;
+       if (read_cache() < 0)
+               return -1;
+       pos = cache_name_pos(path, strlen(path));
+       if (pos < 0)
+               return -1;
+       hashcpy(sha1, active_cache[pos]->sha1);
+       return 0;
 }
 
-static inline int is_null_sha1(const unsigned char *sha1)
+static int preimage_sha1_in_gitlink_patch(struct patch *p, unsigned char sha1[20])
 {
-       return !memcmp(sha1, null_sha1, 20);
+       /*
+        * A usable gitlink patch has only one fragment (hunk) that looks like:
+        * @@ -1 +1 @@
+        * -Subproject commit <old sha1>
+        * +Subproject commit <new sha1>
+        * or
+        * @@ -1 +0,0 @@
+        * -Subproject commit <old sha1>
+        * for a removal patch.
+        */
+       struct fragment *hunk = p->fragments;
+       static const char heading[] = "-Subproject commit ";
+       char *preimage;
+
+       if (/* does the patch have only one hunk? */
+           hunk && !hunk->next &&
+           /* is its preimage one line? */
+           hunk->oldpos == 1 && hunk->oldlines == 1 &&
+           /* does preimage begin with the heading? */
+           (preimage = memchr(hunk->patch, '\n', hunk->size)) != NULL &&
+           starts_with(++preimage, heading) &&
+           /* does it record full SHA-1? */
+           !get_sha1_hex(preimage + sizeof(heading) - 1, sha1) &&
+           preimage[sizeof(heading) + 40 - 1] == '\n' &&
+           /* does the abbreviated name on the index line agree with it? */
+           starts_with(preimage + sizeof(heading) - 1, p->old_sha1_prefix))
+               return 0; /* it all looks fine */
+
+       /* we may have full object name on the index line */
+       return get_sha1_hex(p->old_sha1_prefix, sha1);
 }
 
-static void show_index_list(struct patch *list)
+/* Build an index that contains the just the files needed for a 3way merge */
+static int build_fake_ancestor(struct apply_state *state, struct patch *list)
 {
        struct patch *patch;
+       struct index_state result = { NULL };
+       static struct lock_file lock;
+       int res;
 
        /* Once we start supporting the reverse patch, it may be
         * worth showing the new sha1 prefix, but until then...
         */
        for (patch = list; patch; patch = patch->next) {
-               const unsigned char *sha1_ptr;
                unsigned char sha1[20];
+               struct cache_entry *ce;
                const char *name;
 
                name = patch->old_name ? patch->old_name : patch->new_name;
-               if (patch->is_new)
-                       sha1_ptr = null_sha1;
-               else if (get_sha1(patch->old_sha1_prefix, sha1))
-                       die("sha1 information is lacking or useless (%s).",
-                           name);
-               else
-                       sha1_ptr = sha1;
+               if (0 < patch->is_new)
+                       continue;
 
-               printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
-               if (line_termination && quote_c_style(name, NULL, NULL, 0))
-                       quote_c_style(name, NULL, stdout, 0);
-               else
-                       fputs(name, stdout);
-               putchar(line_termination);
+               if (S_ISGITLINK(patch->old_mode)) {
+                       if (!preimage_sha1_in_gitlink_patch(patch, sha1))
+                               ; /* ok, the textual part looks sane */
+                       else
+                               return error("sha1 information is lacking or "
+                                            "useless for submodule %s", name);
+               } else if (!get_sha1_blob(patch->old_sha1_prefix, sha1)) {
+                       ; /* ok */
+               } else if (!patch->lines_added && !patch->lines_deleted) {
+                       /* mode-only change: update the current */
+                       if (get_current_sha1(patch->old_name, sha1))
+                               return error("mode change for %s, which is not "
+                                            "in current HEAD", name);
+               } else
+                       return error("sha1 information is lacking or useless "
+                                    "(%s).", name);
+
+               ce = make_cache_entry(patch->old_mode, sha1, name, 0, 0);
+               if (!ce)
+                       return error(_("make_cache_entry failed for path '%s'"),
+                                    name);
+               if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD)) {
+                       free(ce);
+                       return error("Could not add %s to temporary index",
+                                    name);
+               }
        }
+
+       hold_lock_file_for_update(&lock, state->fake_ancestor, LOCK_DIE_ON_ERROR);
+       res = write_locked_index(&result, &lock, COMMIT_LOCK);
+       discard_index(&result);
+
+       if (res)
+               return error("Could not write temporary index to %s",
+                            state->fake_ancestor);
+
+       return 0;
 }
 
-static void stat_patch_list(struct patch *patch)
+static void stat_patch_list(struct apply_state *state, struct patch *patch)
 {
        int files, adds, dels;
 
@@ -1792,23 +4108,23 @@ static void stat_patch_list(struct patch *patch)
                files++;
                adds += patch->lines_added;
                dels += patch->lines_deleted;
-               show_stats(patch);
+               show_stats(state, patch);
        }
 
-       printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
+       print_stat_summary(stdout, files, adds, dels);
 }
 
-static void numstat_patch_list(struct patch *patch)
+static void numstat_patch_list(struct apply_state *state,
+                              struct patch *patch)
 {
        for ( ; patch; patch = patch->next) {
                const char *name;
                name = patch->new_name ? patch->new_name : patch->old_name;
-               printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
-               if (line_termination && quote_c_style(name, NULL, NULL, 0))
-                       quote_c_style(name, NULL, stdout, 0);
+               if (patch->is_binary)
+                       printf("-\t-\t");
                else
-                       fputs(name, stdout);
-               putchar('\n');
+                       printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
+               write_name_quoted(name, stdout, state->line_termination);
        }
 }
 
@@ -1890,115 +4206,195 @@ static void summary_patch_list(struct patch *patch)
        }
 }
 
-static void patch_stats(struct patch *patch)
+static void patch_stats(struct apply_state *state, struct patch *patch)
 {
        int lines = patch->lines_added + patch->lines_deleted;
 
-       if (lines > max_change)
-               max_change = lines;
+       if (lines > state->max_change)
+               state->max_change = lines;
        if (patch->old_name) {
                int len = quote_c_style(patch->old_name, NULL, NULL, 0);
                if (!len)
                        len = strlen(patch->old_name);
-               if (len > max_len)
-                       max_len = len;
+               if (len > state->max_len)
+                       state->max_len = len;
        }
        if (patch->new_name) {
                int len = quote_c_style(patch->new_name, NULL, NULL, 0);
                if (!len)
                        len = strlen(patch->new_name);
-               if (len > max_len)
-                       max_len = len;
+               if (len > state->max_len)
+                       state->max_len = len;
        }
 }
 
-static void remove_file(struct patch *patch)
+static int remove_file(struct apply_state *state, struct patch *patch, int rmdir_empty)
 {
-       if (write_index) {
+       if (state->update_index) {
                if (remove_file_from_cache(patch->old_name) < 0)
-                       die("unable to remove %s from index", patch->old_name);
+                       return error(_("unable to remove %s from index"), patch->old_name);
        }
-       if (!cached)
-               unlink(patch->old_name);
+       if (!state->cached) {
+               if (!remove_or_warn(patch->old_mode, patch->old_name) && rmdir_empty) {
+                       remove_path(patch->old_name);
+               }
+       }
+       return 0;
 }
 
-static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
+static int add_index_file(struct apply_state *state,
+                         const char *path,
+                         unsigned mode,
+                         void *buf,
+                         unsigned long size)
 {
        struct stat st;
        struct cache_entry *ce;
        int namelen = strlen(path);
        unsigned ce_size = cache_entry_size(namelen);
 
-       if (!write_index)
-               return;
+       if (!state->update_index)
+               return 0;
 
        ce = xcalloc(1, ce_size);
        memcpy(ce->name, path, namelen);
        ce->ce_mode = create_ce_mode(mode);
-       ce->ce_flags = htons(namelen);
-       if (!cached) {
-               if (lstat(path, &st) < 0)
-                       die("unable to stat newly created file %s", path);
-               fill_stat_cache_info(ce, &st);
+       ce->ce_flags = create_ce_flags(0);
+       ce->ce_namelen = namelen;
+       if (S_ISGITLINK(mode)) {
+               const char *s;
+
+               if (!skip_prefix(buf, "Subproject commit ", &s) ||
+                   get_sha1_hex(s, ce->sha1)) {
+                       free(ce);
+                       return error(_("corrupt patch for submodule %s"), path);
+               }
+       } else {
+               if (!state->cached) {
+                       if (lstat(path, &st) < 0) {
+                               free(ce);
+                               return error_errno(_("unable to stat newly "
+                                                    "created file '%s'"),
+                                                  path);
+                       }
+                       fill_stat_cache_info(ce, &st);
+               }
+               if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0) {
+                       free(ce);
+                       return error(_("unable to create backing store "
+                                      "for newly created file %s"), path);
+               }
        }
-       if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
-               die("unable to create backing store for newly created file %s", path);
-       if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
-               die("unable to add cache entry for %s", path);
+       if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0) {
+               free(ce);
+               return error(_("unable to add cache entry for %s"), path);
+       }
+
+       return 0;
 }
 
+/*
+ * Returns:
+ *  -1 if an unrecoverable error happened
+ *   0 if everything went well
+ *   1 if a recoverable error happened
+ */
 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
 {
-       int fd;
+       int fd, res;
+       struct strbuf nbuf = STRBUF_INIT;
+
+       if (S_ISGITLINK(mode)) {
+               struct stat st;
+               if (!lstat(path, &st) && S_ISDIR(st.st_mode))
+                       return 0;
+               return !!mkdir(path, 0777);
+       }
+
+       if (has_symlinks && S_ISLNK(mode))
+               /* Although buf:size is counted string, it also is NUL
+                * terminated.
+                */
+               return !!symlink(buf, path);
 
-       if (S_ISLNK(mode))
-               return symlink(buf, path);
        fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
        if (fd < 0)
-               return -1;
-       while (size) {
-               int written = xwrite(fd, buf, size);
-               if (written < 0)
-                       die("writing file %s: %s", path, strerror(errno));
-               if (!written)
-                       die("out of space writing file %s", path);
-               buf += written;
-               size -= written;
-       }
-       if (close(fd) < 0)
-               die("closing file %s: %s", path, strerror(errno));
-       return 0;
+               return 1;
+
+       if (convert_to_working_tree(path, buf, size, &nbuf)) {
+               size = nbuf.len;
+               buf  = nbuf.buf;
+       }
+
+       res = write_in_full(fd, buf, size) < 0;
+       if (res)
+               error_errno(_("failed to write to '%s'"), path);
+       strbuf_release(&nbuf);
+
+       if (close(fd) < 0 && !res)
+               return error_errno(_("closing file '%s'"), path);
+
+       return res ? -1 : 0;
 }
 
 /*
  * We optimistically assume that the directories exist,
  * which is true 99% of the time anyway. If they don't,
  * we create them and try again.
+ *
+ * Returns:
+ *   -1 on error
+ *   0 otherwise
  */
-static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
+static int create_one_file(struct apply_state *state,
+                          char *path,
+                          unsigned mode,
+                          const char *buf,
+                          unsigned long size)
 {
-       if (cached)
-               return;
-       if (!try_create_file(path, mode, buf, size))
-               return;
+       int res;
+
+       if (state->cached)
+               return 0;
+
+       res = try_create_file(path, mode, buf, size);
+       if (res < 0)
+               return -1;
+       if (!res)
+               return 0;
 
        if (errno == ENOENT) {
                if (safe_create_leading_directories(path))
-                       return;
-               if (!try_create_file(path, mode, buf, size))
-                       return;
+                       return 0;
+               res = try_create_file(path, mode, buf, size);
+               if (res < 0)
+                       return -1;
+               if (!res)
+                       return 0;
+       }
+
+       if (errno == EEXIST || errno == EACCES) {
+               /* We may be trying to create a file where a directory
+                * used to be.
+                */
+               struct stat st;
+               if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
+                       errno = EEXIST;
        }
 
        if (errno == EEXIST) {
                unsigned int nr = getpid();
 
                for (;;) {
-                       const char *newpath;
-                       newpath = mkpath("%s~%u", path, nr);
-                       if (!try_create_file(newpath, mode, buf, size)) {
+                       char newpath[PATH_MAX];
+                       mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
+                       res = try_create_file(newpath, mode, buf, size);
+                       if (res < 0)
+                               return -1;
+                       if (!res) {
                                if (!rename(newpath, path))
-                                       return;
-                               unlink(newpath);
+                                       return 0;
+                               unlink_or_warn(newpath);
                                break;
                        }
                        if (errno != EEXIST)
@@ -2006,10 +4402,44 @@ static void create_one_file(char *path, unsigned mode, const char *buf, unsigned
                        ++nr;
                }
        }
-       die("unable to write file %s mode %o", path, mode);
+       return error_errno(_("unable to write file '%s' mode %o"),
+                          path, mode);
 }
 
-static void create_file(struct patch *patch)
+static int add_conflicted_stages_file(struct apply_state *state,
+                                      struct patch *patch)
+{
+       int stage, namelen;
+       unsigned ce_size, mode;
+       struct cache_entry *ce;
+
+       if (!state->update_index)
+               return 0;
+       namelen = strlen(patch->new_name);
+       ce_size = cache_entry_size(namelen);
+       mode = patch->new_mode ? patch->new_mode : (S_IFREG | 0644);
+
+       remove_file_from_cache(patch->new_name);
+       for (stage = 1; stage < 4; stage++) {
+               if (is_null_oid(&patch->threeway_stage[stage - 1]))
+                       continue;
+               ce = xcalloc(1, ce_size);
+               memcpy(ce->name, patch->new_name, namelen);
+               ce->ce_mode = create_ce_mode(mode);
+               ce->ce_flags = create_ce_flags(stage);
+               ce->ce_namelen = namelen;
+               hashcpy(ce->sha1, patch->threeway_stage[stage - 1].hash);
+               if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0) {
+                       free(ce);
+                       return error(_("unable to add cache entry for %s"),
+                                    patch->new_name);
+               }
+       }
+
+       return 0;
+}
+
+static int create_file(struct apply_state *state, struct patch *patch)
 {
        char *path = patch->new_name;
        unsigned mode = patch->new_mode;
@@ -2018,282 +4448,526 @@ static void create_file(struct patch *patch)
 
        if (!mode)
                mode = S_IFREG | 0644;
-       create_one_file(path, mode, buf, size); 
-       add_index_file(path, mode, buf, size);
+       if (create_one_file(state, path, mode, buf, size))
+               return -1;
+
+       if (patch->conflicted_threeway)
+               return add_conflicted_stages_file(state, patch);
+       else
+               return add_index_file(state, path, mode, buf, size);
 }
 
-static void write_out_one_result(struct patch *patch)
+/* phase zero is to remove, phase one is to create */
+static int write_out_one_result(struct apply_state *state,
+                               struct patch *patch,
+                               int phase)
 {
        if (patch->is_delete > 0) {
-               remove_file(patch);
-               return;
+               if (phase == 0)
+                       return remove_file(state, patch, 1);
+               return 0;
        }
        if (patch->is_new > 0 || patch->is_copy) {
-               create_file(patch);
-               return;
+               if (phase == 1)
+                       return create_file(state, patch);
+               return 0;
        }
        /*
         * Rename or modification boils down to the same
         * thing: remove the old, write the new
         */
-       remove_file(patch);
-       create_file(patch);
+       if (phase == 0)
+               return remove_file(state, patch, patch->is_rename);
+       if (phase == 1)
+               return create_file(state, patch);
+       return 0;
 }
 
-static void write_out_results(struct patch *list, int skipped_patch)
+static int write_out_one_reject(struct apply_state *state, struct patch *patch)
 {
-       if (!list && !skipped_patch)
-               die("No changes");
+       FILE *rej;
+       char namebuf[PATH_MAX];
+       struct fragment *frag;
+       int cnt = 0;
+       struct strbuf sb = STRBUF_INIT;
+
+       for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
+               if (!frag->rejected)
+                       continue;
+               cnt++;
+       }
 
-       while (list) {
-               write_out_one_result(list);
-               list = list->next;
+       if (!cnt) {
+               if (state->apply_verbosity > verbosity_normal)
+                       say_patch_name(stderr,
+                                      _("Applied patch %s cleanly."), patch);
+               return 0;
        }
-}
 
-static struct cache_file cache_file;
+       /* This should not happen, because a removal patch that leaves
+        * contents are marked "rejected" at the patch level.
+        */
+       if (!patch->new_name)
+               die(_("internal error"));
+
+       /* Say this even without --verbose */
+       strbuf_addf(&sb, Q_("Applying patch %%s with %d reject...",
+                           "Applying patch %%s with %d rejects...",
+                           cnt),
+                   cnt);
+       if (state->apply_verbosity > verbosity_silent)
+               say_patch_name(stderr, sb.buf, patch);
+       strbuf_release(&sb);
+
+       cnt = strlen(patch->new_name);
+       if (ARRAY_SIZE(namebuf) <= cnt + 5) {
+               cnt = ARRAY_SIZE(namebuf) - 5;
+               warning(_("truncating .rej filename to %.*s.rej"),
+                       cnt - 1, patch->new_name);
+       }
+       memcpy(namebuf, patch->new_name, cnt);
+       memcpy(namebuf + cnt, ".rej", 5);
+
+       rej = fopen(namebuf, "w");
+       if (!rej)
+               return error_errno(_("cannot open %s"), namebuf);
 
-static struct excludes {
-       struct excludes *next;
-       const char *path;
-} *excludes;
+       /* Normal git tools never deal with .rej, so do not pretend
+        * this is a git patch by saying --git or giving extended
+        * headers.  While at it, maybe please "kompare" that wants
+        * the trailing TAB and some garbage at the end of line ;-).
+        */
+       fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
+               patch->new_name, patch->new_name);
+       for (cnt = 1, frag = patch->fragments;
+            frag;
+            cnt++, frag = frag->next) {
+               if (!frag->rejected) {
+                       if (state->apply_verbosity > verbosity_silent)
+                               fprintf_ln(stderr, _("Hunk #%d applied cleanly."), cnt);
+                       continue;
+               }
+               if (state->apply_verbosity > verbosity_silent)
+                       fprintf_ln(stderr, _("Rejected hunk #%d."), cnt);
+               fprintf(rej, "%.*s", frag->size, frag->patch);
+               if (frag->patch[frag->size-1] != '\n')
+                       fputc('\n', rej);
+       }
+       fclose(rej);
+       return -1;
+}
 
-static int use_patch(struct patch *p)
+/*
+ * Returns:
+ *  -1 if an error happened
+ *   0 if the patch applied cleanly
+ *   1 if the patch did not apply cleanly
+ */
+static int write_out_results(struct apply_state *state, struct patch *list)
 {
-       const char *pathname = p->new_name ? p->new_name : p->old_name;
-       struct excludes *x = excludes;
-       while (x) {
-               if (fnmatch(x->path, pathname, 0) == 0)
-                       return 0;
-               x = x->next;
+       int phase;
+       int errs = 0;
+       struct patch *l;
+       struct string_list cpath = STRING_LIST_INIT_DUP;
+
+       for (phase = 0; phase < 2; phase++) {
+               l = list;
+               while (l) {
+                       if (l->rejected)
+                               errs = 1;
+                       else {
+                               if (write_out_one_result(state, l, phase)) {
+                                       string_list_clear(&cpath, 0);
+                                       return -1;
+                               }
+                               if (phase == 1) {
+                                       if (write_out_one_reject(state, l))
+                                               errs = 1;
+                                       if (l->conflicted_threeway) {
+                                               string_list_append(&cpath, l->new_name);
+                                               errs = 1;
+                                       }
+                               }
+                       }
+                       l = l->next;
+               }
        }
-       if (0 < prefix_length) {
-               int pathlen = strlen(pathname);
-               if (pathlen <= prefix_length ||
-                   memcmp(prefix, pathname, prefix_length))
-                       return 0;
+
+       if (cpath.nr) {
+               struct string_list_item *item;
+
+               string_list_sort(&cpath);
+               if (state->apply_verbosity > verbosity_silent) {
+                       for_each_string_list_item(item, &cpath)
+                               fprintf(stderr, "U %s\n", item->string);
+               }
+               string_list_clear(&cpath, 0);
+
+               rerere(0);
        }
-       return 1;
+
+       return errs;
 }
 
-static int apply_patch(int fd, const char *filename)
+/*
+ * Try to apply a patch.
+ *
+ * Returns:
+ *  -128 if a bad error happened (like patch unreadable)
+ *  -1 if patch did not apply and user cannot deal with it
+ *   0 if the patch applied
+ *   1 if the patch did not apply but user might fix it
+ */
+static int apply_patch(struct apply_state *state,
+                      int fd,
+                      const char *filename,
+                      int options)
 {
-       unsigned long offset, size;
-       char *buffer = read_patch_file(fd, &size);
+       size_t offset;
+       struct strbuf buf = STRBUF_INIT; /* owns the patch text */
        struct patch *list = NULL, **listp = &list;
        int skipped_patch = 0;
+       int res = 0;
 
-       patch_input_file = filename;
-       if (!buffer)
-               return -1;
+       state->patch_input_file = filename;
+       if (read_patch_file(&buf, fd) < 0)
+               return -128;
        offset = 0;
-       while (size > 0) {
+       while (offset < buf.len) {
                struct patch *patch;
                int nr;
 
                patch = xcalloc(1, sizeof(*patch));
-               nr = parse_chunk(buffer + offset, size, patch);
-               if (nr < 0)
+               patch->inaccurate_eof = !!(options & APPLY_OPT_INACCURATE_EOF);
+               patch->recount =  !!(options & APPLY_OPT_RECOUNT);
+               nr = parse_chunk(state, buf.buf + offset, buf.len - offset, patch);
+               if (nr < 0) {
+                       free_patch(patch);
+                       if (nr == -128) {
+                               res = -128;
+                               goto end;
+                       }
                        break;
-               if (use_patch(patch)) {
-                       patch_stats(patch);
+               }
+               if (state->apply_in_reverse)
+                       reverse_patches(patch);
+               if (use_patch(state, patch)) {
+                       patch_stats(state, patch);
                        *listp = patch;
                        listp = &patch->next;
-               } else {
-                       /* perhaps free it a bit better? */
-                       free(patch);
+               }
+               else {
+                       if (state->apply_verbosity > verbosity_normal)
+                               say_patch_name(stderr, _("Skipped patch '%s'."), patch);
+                       free_patch(patch);
                        skipped_patch++;
                }
                offset += nr;
-               size -= nr;
        }
 
-       if (whitespace_error && (new_whitespace == error_on_whitespace))
-               apply = 0;
+       if (!list && !skipped_patch) {
+               error(_("unrecognized input"));
+               res = -128;
+               goto end;
+       }
+
+       if (state->whitespace_error && (state->ws_error_action == die_on_ws_error))
+               state->apply = 0;
 
-       write_index = check_index && apply;
-       if (write_index && newfd < 0)
-               newfd = hold_index_file_for_update(&cache_file, get_index_file());
-       if (check_index) {
-               if (read_cache() < 0)
-                       die("unable to read index file");
+       state->update_index = state->check_index && state->apply;
+       if (state->update_index && state->newfd < 0)
+               state->newfd = hold_locked_index(state->lock_file, 1);
+
+       if (state->check_index && read_cache() < 0) {
+               error(_("unable to read index file"));
+               res = -128;
+               goto end;
        }
 
-       if ((check || apply) && check_patch_list(list) < 0)
-               exit(1);
+       if (state->check || state->apply) {
+               int r = check_patch_list(state, list);
+               if (r == -128) {
+                       res = -128;
+                       goto end;
+               }
+               if (r < 0 && !state->apply_with_reject) {
+                       res = -1;
+                       goto end;
+               }
+       }
 
-       if (apply)
-               write_out_results(list, skipped_patch);
+       if (state->apply) {
+               int write_res = write_out_results(state, list);
+               if (write_res < 0) {
+                       res = -128;
+                       goto end;
+               }
+               if (write_res > 0) {
+                       /* with --3way, we still need to write the index out */
+                       res = state->apply_with_reject ? -1 : 1;
+                       goto end;
+               }
+       }
 
-       if (show_index_info)
-               show_index_list(list);
+       if (state->fake_ancestor &&
+           build_fake_ancestor(state, list)) {
+               res = -128;
+               goto end;
+       }
 
-       if (diffstat)
-               stat_patch_list(list);
+       if (state->diffstat && state->apply_verbosity > verbosity_silent)
+               stat_patch_list(state, list);
 
-       if (numstat)
-               numstat_patch_list(list);
+       if (state->numstat && state->apply_verbosity > verbosity_silent)
+               numstat_patch_list(state, list);
 
-       if (summary)
+       if (state->summary && state->apply_verbosity > verbosity_silent)
                summary_patch_list(list);
 
-       free(buffer);
+end:
+       free_patch_list(list);
+       strbuf_release(&buf);
+       string_list_clear(&state->fn_table, 0);
+       return res;
+}
+
+static int apply_option_parse_exclude(const struct option *opt,
+                                     const char *arg, int unset)
+{
+       struct apply_state *state = opt->value;
+       add_name_limit(state, arg, 1);
        return 0;
 }
 
-static int git_apply_config(const char *var, const char *value)
+static int apply_option_parse_include(const struct option *opt,
+                                     const char *arg, int unset)
 {
-       if (!strcmp(var, "apply.whitespace")) {
-               apply_default_whitespace = strdup(value);
-               return 0;
-       }
-       return git_default_config(var, value);
+       struct apply_state *state = opt->value;
+       add_name_limit(state, arg, 0);
+       state->has_include = 1;
+       return 0;
+}
+
+static int apply_option_parse_p(const struct option *opt,
+                               const char *arg,
+                               int unset)
+{
+       struct apply_state *state = opt->value;
+       state->p_value = atoi(arg);
+       state->p_value_known = 1;
+       return 0;
+}
+
+static int apply_option_parse_space_change(const struct option *opt,
+                                          const char *arg, int unset)
+{
+       struct apply_state *state = opt->value;
+       if (unset)
+               state->ws_ignore_action = ignore_ws_none;
+       else
+               state->ws_ignore_action = ignore_ws_change;
+       return 0;
 }
 
+static int apply_option_parse_whitespace(const struct option *opt,
+                                        const char *arg, int unset)
+{
+       struct apply_state *state = opt->value;
+       state->whitespace_option = arg;
+       if (parse_whitespace_option(state, arg))
+               exit(1);
+       return 0;
+}
+
+static int apply_option_parse_directory(const struct option *opt,
+                                       const char *arg, int unset)
+{
+       struct apply_state *state = opt->value;
+       strbuf_reset(&state->root);
+       strbuf_addstr(&state->root, arg);
+       strbuf_complete(&state->root, '/');
+       return 0;
+}
 
-int main(int argc, char **argv)
+int apply_all_patches(struct apply_state *state,
+                     int argc,
+                     const char **argv,
+                     int options)
 {
        int i;
+       int res;
+       int errs = 0;
        int read_stdin = 1;
-       const char *whitespace_option = NULL;
 
-       for (i = 1; i < argc; i++) {
+       for (i = 0; i < argc; i++) {
                const char *arg = argv[i];
-               char *end;
                int fd;
 
                if (!strcmp(arg, "-")) {
-                       apply_patch(0, "<stdin>");
+                       res = apply_patch(state, 0, "<stdin>", options);
+                       if (res < 0)
+                               goto end;
+                       errs |= res;
                        read_stdin = 0;
                        continue;
+               } else if (0 < state->prefix_length)
+                       arg = prefix_filename(state->prefix,
+                                             state->prefix_length,
+                                             arg);
+
+               fd = open(arg, O_RDONLY);
+               if (fd < 0) {
+                       error(_("can't open patch '%s': %s"), arg, strerror(errno));
+                       res = -128;
+                       goto end;
                }
-               if (!strncmp(arg, "--exclude=", 10)) {
-                       struct excludes *x = xmalloc(sizeof(*x));
-                       x->path = arg + 10;
-                       x->next = excludes;
-                       excludes = x;
-                       continue;
-               }
-               if (!strncmp(arg, "-p", 2)) {
-                       p_value = atoi(arg + 2);
-                       continue;
-               }
-               if (!strcmp(arg, "--no-add")) {
-                       no_add = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--stat")) {
-                       apply = 0;
-                       diffstat = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--allow-binary-replacement") ||
-                   !strcmp(arg, "--binary")) {
-                       allow_binary_replacement = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--numstat")) {
-                       apply = 0;
-                       numstat = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--summary")) {
-                       apply = 0;
-                       summary = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--check")) {
-                       apply = 0;
-                       check = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--index")) {
-                       check_index = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--cached")) {
-                       check_index = 1;
-                       cached = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--apply")) {
-                       apply = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--index-info")) {
-                       apply = 0;
-                       show_index_info = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "-z")) {
-                       line_termination = 0;
-                       continue;
-               }
-               if (!strncmp(arg, "-C", 2)) {
-                       p_context = strtoul(arg + 2, &end, 0);
-                       if (*end != '\0')
-                               die("unrecognized context count '%s'", arg + 2);
-                       continue;
+               read_stdin = 0;
+               set_default_whitespace_mode(state);
+               res = apply_patch(state, fd, arg, options);
+               close(fd);
+               if (res < 0)
+                       goto end;
+               errs |= res;
+       }
+       set_default_whitespace_mode(state);
+       if (read_stdin) {
+               res = apply_patch(state, 0, "<stdin>", options);
+               if (res < 0)
+                       goto end;
+               errs |= res;
+       }
+
+       if (state->whitespace_error) {
+               if (state->squelch_whitespace_errors &&
+                   state->squelch_whitespace_errors < state->whitespace_error) {
+                       int squelched =
+                               state->whitespace_error - state->squelch_whitespace_errors;
+                       warning(Q_("squelched %d whitespace error",
+                                  "squelched %d whitespace errors",
+                                  squelched),
+                               squelched);
                }
-               if (!strncmp(arg, "--whitespace=", 13)) {
-                       whitespace_option = arg + 13;
-                       parse_whitespace_option(arg + 13);
-                       continue;
+               if (state->ws_error_action == die_on_ws_error) {
+                       error(Q_("%d line adds whitespace errors.",
+                                "%d lines add whitespace errors.",
+                                state->whitespace_error),
+                             state->whitespace_error);
+                       res = -128;
+                       goto end;
                }
+               if (state->applied_after_fixing_ws && state->apply)
+                       warning("%d line%s applied after"
+                               " fixing whitespace errors.",
+                               state->applied_after_fixing_ws,
+                               state->applied_after_fixing_ws == 1 ? "" : "s");
+               else if (state->whitespace_error)
+                       warning(Q_("%d line adds whitespace errors.",
+                                  "%d lines add whitespace errors.",
+                                  state->whitespace_error),
+                               state->whitespace_error);
+       }
 
-               if (check_index && prefix_length < 0) {
-                       prefix = setup_git_directory();
-                       prefix_length = prefix ? strlen(prefix) : 0;
-                       git_config(git_apply_config);
-                       if (!whitespace_option && apply_default_whitespace)
-                               parse_whitespace_option(apply_default_whitespace);
+       if (state->update_index) {
+               res = write_locked_index(&the_index, state->lock_file, COMMIT_LOCK);
+               if (res) {
+                       error(_("Unable to write new index file"));
+                       res = -128;
+                       goto end;
                }
-               if (0 < prefix_length)
-                       arg = prefix_filename(prefix, prefix_length, arg);
+               state->newfd = -1;
+       }
 
-               fd = open(arg, O_RDONLY);
-               if (fd < 0)
-                       usage(apply_usage);
-               read_stdin = 0;
-               set_default_whitespace_mode(whitespace_option);
-               apply_patch(fd, arg);
-               close(fd);
+       res = !!errs;
+
+end:
+       if (state->newfd >= 0) {
+               rollback_lock_file(state->lock_file);
+               state->newfd = -1;
        }
-       set_default_whitespace_mode(whitespace_option);
-       if (read_stdin)
-               apply_patch(0, "<stdin>");
-       if (whitespace_error) {
-               if (squelch_whitespace_errors &&
-                   squelch_whitespace_errors < whitespace_error) {
-                       int squelched =
-                               whitespace_error - squelch_whitespace_errors;
-                       fprintf(stderr, "warning: squelched %d whitespace error%s\n",
-                               squelched,
-                               squelched == 1 ? "" : "s");
-               }
-               if (new_whitespace == error_on_whitespace)
-                       die("%d line%s add%s trailing whitespaces.",
-                           whitespace_error,
-                           whitespace_error == 1 ? "" : "s",
-                           whitespace_error == 1 ? "s" : "");
-               if (applied_after_stripping)
-                       fprintf(stderr, "warning: %d line%s applied after"
-                               " stripping trailing whitespaces.\n",
-                               applied_after_stripping,
-                               applied_after_stripping == 1 ? "" : "s");
-               else if (whitespace_error)
-                       fprintf(stderr, "warning: %d line%s add%s trailing"
-                               " whitespaces.\n",
-                               whitespace_error,
-                               whitespace_error == 1 ? "" : "s",
-                               whitespace_error == 1 ? "s" : "");
-       }
-
-       if (write_index) {
-               if (write_cache(newfd, active_cache, active_nr) ||
-                   commit_index_file(&cache_file))
-                       die("Unable to write new cachefile");
+
+       if (state->apply_verbosity <= verbosity_silent) {
+               set_error_routine(state->saved_error_routine);
+               set_warn_routine(state->saved_warn_routine);
        }
 
-       return 0;
+       if (res > -1)
+               return res;
+       return (res == -1 ? 1 : 128);
+}
+
+int apply_parse_options(int argc, const char **argv,
+                       struct apply_state *state,
+                       int *force_apply, int *options,
+                       const char * const *apply_usage)
+{
+       struct option builtin_apply_options[] = {
+               { OPTION_CALLBACK, 0, "exclude", state, N_("path"),
+                       N_("don't apply changes matching the given path"),
+                       0, apply_option_parse_exclude },
+               { OPTION_CALLBACK, 0, "include", state, N_("path"),
+                       N_("apply changes matching the given path"),
+                       0, apply_option_parse_include },
+               { OPTION_CALLBACK, 'p', NULL, state, N_("num"),
+                       N_("remove <num> leading slashes from traditional diff paths"),
+                       0, apply_option_parse_p },
+               OPT_BOOL(0, "no-add", &state->no_add,
+                       N_("ignore additions made by the patch")),
+               OPT_BOOL(0, "stat", &state->diffstat,
+                       N_("instead of applying the patch, output diffstat for the input")),
+               OPT_NOOP_NOARG(0, "allow-binary-replacement"),
+               OPT_NOOP_NOARG(0, "binary"),
+               OPT_BOOL(0, "numstat", &state->numstat,
+                       N_("show number of added and deleted lines in decimal notation")),
+               OPT_BOOL(0, "summary", &state->summary,
+                       N_("instead of applying the patch, output a summary for the input")),
+               OPT_BOOL(0, "check", &state->check,
+                       N_("instead of applying the patch, see if the patch is applicable")),
+               OPT_BOOL(0, "index", &state->check_index,
+                       N_("make sure the patch is applicable to the current index")),
+               OPT_BOOL(0, "cached", &state->cached,
+                       N_("apply a patch without touching the working tree")),
+               OPT_BOOL(0, "unsafe-paths", &state->unsafe_paths,
+                       N_("accept a patch that touches outside the working area")),
+               OPT_BOOL(0, "apply", force_apply,
+                       N_("also apply the patch (use with --stat/--summary/--check)")),
+               OPT_BOOL('3', "3way", &state->threeway,
+                        N_( "attempt three-way merge if a patch does not apply")),
+               OPT_FILENAME(0, "build-fake-ancestor", &state->fake_ancestor,
+                       N_("build a temporary index based on embedded index information")),
+               /* Think twice before adding "--nul" synonym to this */
+               OPT_SET_INT('z', NULL, &state->line_termination,
+                       N_("paths are separated with NUL character"), '\0'),
+               OPT_INTEGER('C', NULL, &state->p_context,
+                               N_("ensure at least <n> lines of context match")),
+               { OPTION_CALLBACK, 0, "whitespace", state, N_("action"),
+                       N_("detect new or modified lines that have whitespace errors"),
+                       0, apply_option_parse_whitespace },
+               { OPTION_CALLBACK, 0, "ignore-space-change", state, NULL,
+                       N_("ignore changes in whitespace when finding context"),
+                       PARSE_OPT_NOARG, apply_option_parse_space_change },
+               { OPTION_CALLBACK, 0, "ignore-whitespace", state, NULL,
+                       N_("ignore changes in whitespace when finding context"),
+                       PARSE_OPT_NOARG, apply_option_parse_space_change },
+               OPT_BOOL('R', "reverse", &state->apply_in_reverse,
+                       N_("apply the patch in reverse")),
+               OPT_BOOL(0, "unidiff-zero", &state->unidiff_zero,
+                       N_("don't expect at least one line of context")),
+               OPT_BOOL(0, "reject", &state->apply_with_reject,
+                       N_("leave the rejected hunks in corresponding *.rej files")),
+               OPT_BOOL(0, "allow-overlap", &state->allow_overlap,
+                       N_("allow overlapping hunks")),
+               OPT__VERBOSE(&state->apply_verbosity, N_("be verbose")),
+               OPT_BIT(0, "inaccurate-eof", options,
+                       N_("tolerate incorrectly detected missing new-line at the end of file"),
+                       APPLY_OPT_INACCURATE_EOF),
+               OPT_BIT(0, "recount", options,
+                       N_("do not trust the line counts in the hunk headers"),
+                       APPLY_OPT_RECOUNT),
+               { OPTION_CALLBACK, 0, "directory", state, N_("root"),
+                       N_("prepend <root> to all filenames"),
+                       0, apply_option_parse_directory },
+               OPT_END()
+       };
+
+       return parse_options(argc, argv, state->prefix, builtin_apply_options, apply_usage, 0);
 }