git-fetch/push/pull: documentation.
[gitweb.git] / apply.c
diff --git a/apply.c b/apply.c
index e0a1549022ef4ad027c2dae369615bb4c2aec796..e5c0b7d074936507159353cb5699d17897c8b1e4 100644 (file)
--- a/apply.c
+++ b/apply.c
@@ -5,31 +5,26 @@
  *
  * This applies patches on top of some (arbitrary) version of the SCM.
  *
- * NOTE! It does all its work in the index file, and only cares about
- * the files in the working directory if you tell it to "merge" the
- * patch apply.
- *
- * Even when merging it always takes the source from the index, and
- * uses the working tree as a "branch" for a 3-way merge.
  */
-#include <ctype.h>
-
+#include <fnmatch.h>
 #include "cache.h"
+#include "quote.h"
 
-// We default to the merge behaviour, since that's what most people would
-// expect.
-//
 //  --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
-//  --show-files shows the directory changes
+//  --index-info shows the old and new index info for paths if available.
 //
-static int merge_patch = 1;
+static int check_index = 0;
+static int write_index = 0;
 static int diffstat = 0;
+static int summary = 0;
 static int check = 0;
 static int apply = 1;
-static int show_files = 0;
-static const char apply_usage[] = "git-apply [--stat] [--check] [--show-files] <patch>";
+static int show_index_info = 0;
+static int line_termination = '\n';
+static const char apply_usage[] =
+"git-apply [--stat] [--summary] [--check] [--index] [--apply] [--index-info] [-z] <patch>...";
 
 /*
  * For "diff-stat" like behaviour, we keep track of the biggest change
@@ -58,7 +53,12 @@ struct patch {
        unsigned int old_mode, new_mode;
        int is_rename, is_copy, is_new, is_delete;
        int lines_added, lines_deleted;
+       int score;
        struct fragment *fragments;
+       char *result;
+       unsigned long resultsize;
+       char old_sha1_prefix[41];
+       char new_sha1_prefix[41];
        struct patch *next;
 };
 
@@ -100,7 +100,7 @@ static void *read_patch_file(int fd, unsigned long *sizep)
        return buffer;
 }
 
-static unsigned long linelen(char *buffer, unsigned long size)
+static unsigned long linelen(const char *buffer, unsigned long size)
 {
        unsigned long len = 0;
        while (size--) {
@@ -135,6 +135,35 @@ static char * find_name(const char *line, char *def, int p_value, int terminate)
        const char *start = line;
        char *name;
 
+       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;
+                       }
+               }
+       }
+
        for (;;) {
                char c = *line;
 
@@ -224,37 +253,29 @@ static int gitdiff_hdrend(const char *line, struct patch *patch)
  */
 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
 {
-       int len;
-       const char *name;
-
        if (!orig_name && !isnull)
                return find_name(line, NULL, 1, 0);
 
-       name = "/dev/null";
-       len = 9;
        if (orig_name) {
+               int len;
+               const char *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);
-       }
-
-       if (*name == '/')
-               goto absolute_path;
-
-       for (;;) {
-               char c = *line++;
-               if (c == '\n')
-                       break;
-               if (c != '/')
-                       continue;
-absolute_path:
-               if (memcmp(line, name, len) || line[len] != '\n')
-                       break;
+               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);
+               free(another);
                return orig_name;
        }
-       die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
-       return NULL;
+       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;
+       }
 }
 
 static int gitdiff_oldname(const char *line, struct patch *patch)
@@ -325,11 +346,47 @@ static int gitdiff_renamedst(const char *line, struct patch *patch)
 
 static int gitdiff_similarity(const char *line, struct patch *patch)
 {
+       if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
+               patch->score = 0;
        return 0;
 }
 
 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 {
+       if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
+               patch->score = 0;
+       return 0;
+}
+
+static int gitdiff_index(const char *line, struct patch *patch)
+{
+       /* index line is N hexadecimal, "..", N hexadecimal,
+        * and optional space with octal mode.
+        */
+       const char *ptr, *eol;
+       int len;
+
+       ptr = strchr(line, '.');
+       if (!ptr || ptr[1] != '.' || 40 <= ptr - line)
+               return 0;
+       len = ptr - line;
+       memcpy(patch->old_sha1_prefix, line, len);
+       patch->old_sha1_prefix[len] = 0;
+
+       line = ptr + 2;
+       ptr = strchr(line, ' ');
+       eol = strchr(line, '\n');
+
+       if (!ptr || eol < ptr)
+               ptr = eol;
+       len = ptr - line;
+
+       if (40 <= len)
+               return 0;
+       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);
        return 0;
 }
 
@@ -342,29 +399,124 @@ static int gitdiff_unrecognized(const char *line, struct patch *patch)
        return -1;
 }
 
-static char *git_header_name(char *line)
+static const char *stop_at_slash(const char *line, int llen)
+{
+       int i;
+
+       for (i = 0; i < llen; i++) {
+               int ch = line[i];
+               if (ch == '/')
+                       return line + i;
+       }
+       return NULL;
+}
+
+/* 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)
 {
        int len;
-       char *name, *second;
+       const char *name;
+       const char *second = NULL;
 
-       /*
-        * Find the first '/'
-        */
-       name = line;
-       for (;;) {
-               char c = *name++;
-               if (c == '\n')
+       line += strlen("diff --git ");
+       llen -= strlen("diff --git ");
+
+       if (*line == '"') {
+               const char *cp;
+               char *first = unquote_c_style(line, &second);
+               if (!first)
                        return NULL;
-               if (c == '/')
-                       break;
+
+               /* 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 */
+
+               /* 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;
+               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;
+                       }
+                       /* They must match, otherwise ignore */
+                       if (strcmp(cp+1, first))
+                               goto free_both_and_fail;
+                       free(sp);
+                       return first;
+               }
+
+               /* 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;
        }
 
-       /*
-        * We don't accept absolute paths (/dev/null) as possibly valid
-        */
-       if (name == line+1)
+       /* unquoted first name */
+       name = stop_at_slash(line, llen);
+       if (!name || name == line)
                return NULL;
 
+       name++;
+
+       /* 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;
+                       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 &&
+                           !strncmp(np, name, len) &&
+                           isspace(name[len])) {
+                               /* Good */
+                               memmove(sp, np, len + 1);
+                               return sp;
+                       }
+                       goto free_second_and_fail;
+               }
+       }
+
        /*
         * Accept a name only if it shows up twice, exactly the same
         * form.
@@ -376,7 +528,7 @@ static char *git_header_name(char *line)
                default:
                        continue;
                case '\n':
-                       break;
+                       return NULL;
                case '\t': case ' ':
                        second = name+len;
                        for (;;) {
@@ -412,7 +564,7 @@ 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 + strlen("diff --git "));
+       patch->def_name = git_header_name(line, len);
 
        line += len;
        size -= len;
@@ -431,10 +583,13 @@ static int parse_git_header(char *line, int len, unsigned int size, struct patch
                        { "new file mode ", gitdiff_newfile },
                        { "copy from ", gitdiff_copysrc },
                        { "copy to ", gitdiff_copydst },
+                       { "rename old ", gitdiff_renamesrc },
+                       { "rename new ", gitdiff_renamedst },
                        { "rename from ", gitdiff_renamesrc },
                        { "rename to ", gitdiff_renamedst },
                        { "similarity index ", gitdiff_similarity },
                        { "dissimilarity index ", gitdiff_dissimilarity },
+                       { "index ", gitdiff_index },
                        { "", gitdiff_unrecognized },
                };
                int i;
@@ -550,7 +705,7 @@ 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, len-1, line);
+                       error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
                }
 
                if (size < len + 6)
@@ -562,10 +717,13 @@ static int find_header(char *line, unsigned long size, int *hdrsize, struct patc
                 */
                if (!memcmp("diff --git ", line, 11)) {
                        int git_hdr_len = parse_git_header(line, len, size, patch);
-                       if (git_hdr_len < 0)
+                       if (git_hdr_len <= len)
                                continue;
-                       if (!patch->old_name && !patch->new_name)
-                               die("git diff header lacks filename information");
+                       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;
+                       }
                        *hdrsize = git_hdr_len;
                        return offset;
                }
@@ -603,7 +761,7 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
 {
        int added, deleted;
        int len = linelen(line, size), offset;
-       unsigned long pos[4], oldlines, newlines;
+       unsigned long oldlines, newlines;
 
        offset = parse_fragment_header(line, len, fragment);
        if (offset < 0)
@@ -611,10 +769,24 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
        oldlines = fragment->oldlines;
        newlines = fragment->newlines;
 
-       if (patch->is_new < 0 && (pos[0] || oldlines))
-               patch->is_new = 0;
-       if (patch->is_delete < 0 && (pos[1] || newlines))
-               patch->is_delete = 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;
@@ -642,11 +814,27 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
                        added++;
                        newlines--;
                        break;
-               /* We allow "\ No newline at end of file" */
+
+                /* 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.
+                */
                case '\\':
+                       if (len < 12 || memcmp(line, "\\ ", 2))
+                               return -1;
                        break;
                }
        }
+       /* 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.
+        */
+       if (12 < size && !memcmp(line, "\\ ", 2))
+               offset += linelen(line, size);
+
        patch->lines_added += added;
        patch->lines_deleted += deleted;
        return offset;
@@ -680,6 +868,16 @@ static int parse_single_patch(char *line, unsigned long size, struct patch *patc
        return offset;
 }
 
+static inline int metadata_changes(struct patch *patch)
+{
+       return  patch->is_rename > 0 ||
+               patch->is_copy > 0 ||
+               patch->is_new > 0 ||
+               patch->is_delete ||
+               (patch->old_mode && patch->new_mode &&
+                patch->old_mode != patch->new_mode);
+}
+
 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 {
        int hdrsize, patchsize;
@@ -690,19 +888,30 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 
        patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
 
+       if (!patchsize && !metadata_changes(patch))
+               die("patch with only garbage at line %d", linenr);
+
        return offset + hdrsize + patchsize;
 }
 
-const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
-const char minuses[]= "----------------------------------------------------------------------";
+static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
+static const char minuses[]= "----------------------------------------------------------------------";
 
 static void show_stats(struct patch *patch)
 {
-       char *name = patch->old_name;
+       const char *prefix = "";
+       char *name = patch->new_name;
+       char *qname = NULL;
        int len, max, add, del, total;
 
        if (!name)
-               name = patch->new_name;
+               name = patch->old_name;
+
+       if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
+               qname = xmalloc(len + 1);
+               quote_c_style(name, qname, NULL, 0);
+               name = qname;
+       }
 
        /*
         * "scale" the filename
@@ -711,8 +920,15 @@ static void show_stats(struct patch *patch)
        max = max_len;
        if (max > 50)
                max = 50;
-       if (len > max)
+       if (len > max) {
+               char *slash;
+               prefix = "...";
+               max -= 3;
                name += len - max;
+               slash = strchr(name, '/');
+               if (slash)
+                       name = slash;
+       }
        len = max;
 
        /*
@@ -726,12 +942,238 @@ static void show_stats(struct patch *patch)
        del = patch->lines_deleted;
        total = add + del;
 
-       total = (total * max + max_change / 2) / max_change;
-       add = (add * max + max_change / 2) / max_change;
-       del = total - add;
-       printf(" %-*s |%5d %.*s%.*s\n",
+       if (max_change > 0) {
+               total = (total * max + max_change / 2) / max_change;
+               add = (add * max + max_change / 2) / max_change;
+               del = total - add;
+       }
+       printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
                len, name, patch->lines_added + patch->lines_deleted,
                add, pluses, del, minuses);
+       if (qname)
+               free(qname);
+}
+
+static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
+{
+       int fd;
+       unsigned long got;
+
+       switch (st->st_mode & S_IFMT) {
+       case S_IFLNK:
+               return readlink(path, buf, size);
+       case S_IFREG:
+               fd = open(path, O_RDONLY);
+               if (fd < 0)
+                       return error("unable to open %s", path);
+               got = 0;
+               for (;;) {
+                       int ret = read(fd, buf + got, size - got);
+                       if (ret < 0) {
+                               if (errno == EAGAIN)
+                                       continue;
+                               break;
+                       }
+                       if (!ret)
+                               break;
+                       got += ret;
+               }
+               close(fd);
+               return got;
+
+       default:
+               return -1;
+       }
+}
+
+static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
+{
+       int i;
+       unsigned long start, backwards, forwards;
+
+       if (fragsize > size)
+               return -1;
+
+       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;
+                       }
+               }
+       }
+
+       /* Exact line number? */
+       if (!memcmp(buf + start, fragment, fragsize))
+               return start;
+
+       /*
+        * 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;
+       for (i = 0; ; i++) {
+               unsigned long try;
+               int n;
+
+               /* "backward" */
+               if (i & 1) {
+                       if (!backwards) {
+                               if (forwards + fragsize > size)
+                                       break;
+                               continue;
+                       }
+                       do {
+                               --backwards;
+                       } while (backwards && buf[backwards-1] != '\n');
+                       try = backwards;
+               } else {
+                       while (forwards + fragsize <= size) {
+                               if (buf[forwards++] == '\n')
+                                       break;
+                       }
+                       try = forwards;
+               }
+
+               if (try + fragsize > size)
+                       continue;
+               if (memcmp(buf + try, fragment, fragsize))
+                       continue;
+               n = (i >> 1)+1;
+               if (i & 1)
+                       n = -n;
+               return try;
+       }
+
+       /*
+        * We should start searching forward and backward.
+        */
+       return -1;
+}
+
+struct buffer_desc {
+       char *buffer;
+       unsigned long size;
+       unsigned long alloc;
+};
+
+static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
+{
+       char *buf = desc->buffer;
+       const char *patch = frag->patch;
+       int offset, size = frag->size;
+       char *old = xmalloc(size);
+       char *new = xmalloc(size);
+       int oldsize = 0, newsize = 0;
+
+       while (size > 0) {
+               int len = linelen(patch, size);
+               int plen;
+
+               if (!len)
+                       break;
+
+               /*
+                * "plen" is how much of the line we should use for
+                * the actual patch data. Normally we just remove the
+                * first character on the line, but if the line is
+                * followed by "\ No newline", then we also remove the
+                * last one (which is the newline, of course).
+                */
+               plen = len-1;
+               if (len < size && patch[len] == '\\')
+                       plen--;
+               switch (*patch) {
+               case ' ':
+               case '-':
+                       memcpy(old + oldsize, patch + 1, plen);
+                       oldsize += plen;
+                       if (*patch == '-')
+                               break;
+               /* Fall-through for ' ' */
+               case '+':
+                       memcpy(new + newsize, patch + 1, plen);
+                       newsize += plen;
+                       break;
+               case '@': case '\\':
+                       /* Ignore it, we already handled it */
+                       break;
+               default:
+                       return -1;
+               }
+               patch += len;
+               size -= len;
+       }
+
+       offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
+       if (offset >= 0) {
+               int diff = newsize - oldsize;
+               unsigned long size = desc->size + diff;
+               unsigned long alloc = desc->alloc;
+
+               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, new, newsize);
+               offset = 0;
+       }
+
+       free(old);
+       free(new);
+       return offset;
+}
+
+static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
+{
+       struct fragment *frag = patch->fragments;
+
+       while (frag) {
+               if (apply_one_fragment(desc, frag) < 0)
+                       return error("patch failed: %s:%ld", patch->old_name, frag->oldpos);
+               frag = frag->next;
+       }
+       return 0;
+}
+
+static int apply_data(struct patch *patch, struct stat *st)
+{
+       char *buf;
+       unsigned long size, alloc;
+       struct buffer_desc desc;
+
+       size = 0;
+       alloc = 0;
+       buf = NULL;
+       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;
+
+       if (patch->is_delete && patch->resultsize)
+               return error("removal patch leaves file contents");
+
+       return 0;
 }
 
 static int check_patch(struct patch *patch)
@@ -741,30 +1183,79 @@ static int check_patch(struct patch *patch)
        const char *new_name = patch->new_name;
 
        if (old_name) {
-               int pos = cache_name_pos(old_name, strlen(old_name));
                int changed;
+               int 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);
+                       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(active_cache[pos],
+                                                  &costate) ||
+                                   lstat(old_name, &st))
+                                       return -1;
+                       }
+
+                       changed = ce_match_stat(active_cache[pos], &st);
+                       if (changed)
+                               return error("%s: does not match index",
+                                            old_name);
+               }
+               else if (stat_ret < 0)
+                       return error("%s: %s", old_name, strerror(errno));
 
-               if (pos < 0)
-                       return error("%s: does not exist in index", old_name);
                if (patch->is_new < 0)
                        patch->is_new = 0;
-               if (lstat(old_name, &st) < 0)
-                       return error("%s: %s\n", strerror(errno));
-               changed = ce_match_stat(active_cache[pos], &st);
-               if (changed)
-                       return error("%s: does not match index", old_name);
+               st.st_mode = ntohl(create_ce_mode(st.st_mode));
                if (!patch->old_mode)
                        patch->old_mode = st.st_mode;
+               if ((st.st_mode ^ patch->old_mode) & S_IFMT)
+                       return error("%s: wrong type", old_name);
+               if (st.st_mode != patch->old_mode)
+                       fprintf(stderr, "warning: %s has type %o, expected %o\n",
+                               old_name, st.st_mode, patch->old_mode);
        }
 
        if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
-               if (cache_name_pos(new_name, strlen(new_name)) >= 0)
+               if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
                        return error("%s: already exists in index", new_name);
                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));
+               if (!patch->new_mode) {
+                       if (patch->is_new)
+                               patch->new_mode = S_IFREG | 0644;
+                       else
+                               patch->new_mode = patch->old_mode;
+               }
        }
+
+       if (new_name && old_name) {
+               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 (apply_data(patch, &st) < 0)
+               return error("%s: patch does not apply", old_name);
        return 0;
 }
 
@@ -777,32 +1268,38 @@ static int check_patch_list(struct patch *patch)
        return error;
 }
 
-static void show_file(int c, unsigned int mode, const char *name)
+static inline int is_null_sha1(const unsigned char *sha1)
 {
-       printf("%c %o %s\n", c, mode, name);
+       return !memcmp(sha1, null_sha1, 20);
 }
 
-static void show_file_list(struct patch *patch)
+static void show_index_list(struct patch *list)
 {
-       for (;patch ; patch = patch->next) {
-               if (patch->is_rename) {
-                       show_file('-', patch->old_mode, patch->old_name);
-                       show_file('+', patch->new_mode, patch->new_name);
-                       continue;
-               }
-               if (patch->is_copy || patch->is_new) {
-                       show_file('+', patch->new_mode, patch->new_name);
-                       continue;
-               }
-               if (patch->is_delete) {
-                       show_file('-', patch->old_mode, patch->old_name);
-                       continue;
-               }
-               if (patch->old_mode && patch->new_mode && patch->old_mode != patch->new_mode) {
-                       printf("M %o:%o %s\n", patch->old_mode, patch->new_mode, patch->old_name);
-                       continue;
-               }
-               printf("M %o %s\n", patch->old_mode, patch->old_name);
+       struct patch *patch;
+
+       /* 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];
+               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;
+
+               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);
        }
 }
 
@@ -820,6 +1317,84 @@ static void stat_patch_list(struct patch *patch)
        printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
 }
 
+static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
+{
+       if (mode)
+               printf(" %s mode %06o %s\n", newdelete, mode, name);
+       else
+               printf(" %s %s\n", newdelete, name);
+}
+
+static void show_mode_change(struct patch *p, int show_name)
+{
+       if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
+               if (show_name)
+                       printf(" mode change %06o => %06o %s\n",
+                              p->old_mode, p->new_mode, p->new_name);
+               else
+                       printf(" mode change %06o => %06o\n",
+                              p->old_mode, p->new_mode);
+       }
+}
+
+static void show_rename_copy(struct patch *p)
+{
+       const char *renamecopy = p->is_rename ? "rename" : "copy";
+       const char *old, *new;
+
+       /* Find common prefix */
+       old = p->old_name;
+       new = p->new_name;
+       while (1) {
+               const char *slash_old, *slash_new;
+               slash_old = strchr(old, '/');
+               slash_new = strchr(new, '/');
+               if (!slash_old ||
+                   !slash_new ||
+                   slash_old - old != slash_new - new ||
+                   memcmp(old, new, slash_new - new))
+                       break;
+               old = slash_old + 1;
+               new = slash_new + 1;
+       }
+       /* p->old_name thru old is the common prefix, and old and new
+        * through the end of names are renames
+        */
+       if (old != p->old_name)
+               printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
+                      (int)(old - p->old_name), p->old_name,
+                      old, new, p->score);
+       else
+               printf(" %s %s => %s (%d%%)\n", renamecopy,
+                      p->old_name, p->new_name, p->score);
+       show_mode_change(p, 0);
+}
+
+static void summary_patch_list(struct patch *patch)
+{
+       struct patch *p;
+
+       for (p = patch; p; p = p->next) {
+               if (p->is_new)
+                       show_file_mode_name("create", p->new_mode, p->new_name);
+               else if (p->is_delete)
+                       show_file_mode_name("delete", p->old_mode, p->old_name);
+               else {
+                       if (p->is_rename || p->is_copy)
+                               show_rename_copy(p);
+                       else {
+                               if (p->score) {
+                                       printf(" rewrite %s (%d%%)\n",
+                                              p->new_name, p->score);
+                                       show_mode_change(p, 0);
+                               }
+                               else
+                                       show_mode_change(p, 1);
+                       }
+               }
+       }
+}
+
 static void patch_stats(struct patch *patch)
 {
        int lines = patch->lines_added + patch->lines_deleted;
@@ -827,22 +1402,201 @@ static void patch_stats(struct patch *patch)
        if (lines > max_change)
                max_change = lines;
        if (patch->old_name) {
-               int len = strlen(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 (patch->new_name) {
-               int len = strlen(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;
        }
 }
 
+static void remove_file(struct patch *patch)
+{
+       if (write_index) {
+               if (remove_file_from_cache(patch->old_name) < 0)
+                       die("unable to remove %s from index", patch->old_name);
+       }
+       unlink(patch->old_name);
+}
+
+static void add_index_file(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;
+
+       ce = xmalloc(ce_size);
+       memset(ce, 0, ce_size);
+       memcpy(ce->name, path, namelen);
+       ce->ce_mode = create_ce_mode(mode);
+       ce->ce_flags = htons(namelen);
+       if (lstat(path, &st) < 0)
+               die("unable to stat newly created file %s", path);
+       fill_stat_cache_info(ce, &st);
+       if (write_sha1_file(buf, size, "blob", 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);
+}
+
+static void create_subdirectories(const char *path)
+{
+       int len = strlen(path);
+       char *buf = xmalloc(len + 1);
+       const char *slash = path;
+
+       while ((slash = strchr(slash+1, '/')) != NULL) {
+               len = slash - path;
+               memcpy(buf, path, len);
+               buf[len] = 0;
+               if (mkdir(buf, 0777) < 0) {
+                       if (errno != EEXIST)
+                               break;
+               }
+       }
+       free(buf);
+}
+
+static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
+{
+       int fd;
+
+       if (S_ISLNK(mode))
+               return symlink(buf, path);
+       fd = open(path, O_CREAT | O_EXCL | O_WRONLY | O_TRUNC, (mode & 0100) ? 0777 : 0666);
+       if (fd < 0)
+               return -1;
+       while (size) {
+               int written = write(fd, buf, size);
+               if (written < 0) {
+                       if (errno == EINTR || errno == EAGAIN)
+                               continue;
+                       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;
+}
+
+/*
+ * 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.
+ */
+static void create_one_file(const char *path, unsigned mode, const char *buf, unsigned long size)
+{
+       if (!try_create_file(path, mode, buf, size))
+               return;
+
+       if (errno == ENOENT) {
+               create_subdirectories(path);
+               if (!try_create_file(path, mode, buf, size))
+                       return;
+       }
+
+       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)) {
+                               if (!rename(newpath, path))
+                                       return;
+                               unlink(newpath);
+                               break;
+                       }
+                       if (errno != EEXIST)
+                               break;
+               }                       
+       }
+       die("unable to write file %s mode %o", path, mode);
+}
+
+static void create_file(struct patch *patch)
+{
+       const char *path = patch->new_name;
+       unsigned mode = patch->new_mode;
+       unsigned long size = patch->resultsize;
+       char *buf = patch->result;
+
+       if (!mode)
+               mode = S_IFREG | 0644;
+       create_one_file(path, mode, buf, size); 
+       add_index_file(path, mode, buf, size);
+}
+
+static void write_out_one_result(struct patch *patch)
+{
+       if (patch->is_delete > 0) {
+               remove_file(patch);
+               return;
+       }
+       if (patch->is_new > 0 || patch->is_copy) {
+               create_file(patch);
+               return;
+       }
+       /*
+        * Rename or modification boils down to the same
+        * thing: remove the old, write the new
+        */
+       remove_file(patch);
+       create_file(patch);
+}
+
+static void write_out_results(struct patch *list, int skipped_patch)
+{
+       if (!list && !skipped_patch)
+               die("No changes");
+
+       while (list) {
+               write_out_one_result(list);
+               list = list->next;
+       }
+}
+
+static struct cache_file cache_file;
+
+static struct excludes {
+       struct excludes *next;
+       const char *path;
+} *excludes;
+
+static int use_patch(struct patch *p)
+{
+       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;
+       }
+       return 1;
+}
+
 static int apply_patch(int fd)
 {
+       int newfd;
        unsigned long offset, size;
        char *buffer = read_patch_file(fd, &size);
        struct patch *list = NULL, **listp = &list;
+       int skipped_patch = 0;
 
        if (!buffer)
                return -1;
@@ -856,22 +1610,49 @@ static int apply_patch(int fd)
                nr = parse_chunk(buffer + offset, size, patch);
                if (nr < 0)
                        break;
-               patch_stats(patch);
-               *listp = patch;
-               listp = &patch->next;
+               if (use_patch(patch)) {
+                       patch_stats(patch);
+                       *listp = patch;
+                       listp = &patch->next;
+               } else {
+                       /* perhaps free it a bit better? */
+                       free(patch);
+                       skipped_patch++;
+               }
                offset += nr;
                size -= nr;
        }
 
+       newfd = -1;
+       write_index = check_index && apply;
+       if (write_index)
+               newfd = hold_index_file_for_update(&cache_file, get_index_file());
+       if (check_index) {
+               if (read_cache() < 0)
+                       die("unable to read index file");
+       }
+
        if ((check || apply) && check_patch_list(list) < 0)
                exit(1);
 
-       if (show_files)
-               show_file_list(list);
+       if (apply)
+               write_out_results(list, skipped_patch);
+
+       if (write_index) {
+               if (write_cache(newfd, active_cache, active_nr) ||
+                   commit_index_file(&cache_file))
+                       die("Unable to write new cachefile");
+       }
+
+       if (show_index_info)
+               show_index_list(list);
 
        if (diffstat)
                stat_patch_list(list);
 
+       if (summary)
+               summary_patch_list(list);
+
        free(buffer);
        return 0;
 }
@@ -881,9 +1662,6 @@ int main(int argc, char **argv)
        int i;
        int read_stdin = 1;
 
-       if (read_cache() < 0)
-               die("unable to read index file");
-
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
                int fd;
@@ -893,8 +1671,11 @@ int main(int argc, char **argv)
                        read_stdin = 0;
                        continue;
                }
-               if (!strcmp(arg, "--no-merge")) {
-                       merge_patch = 0;
+               if (!strncmp(arg, "--exclude=", 10)) {
+                       struct excludes *x = xmalloc(sizeof(*x));
+                       x->path = arg + 10;
+                       x->next = excludes;
+                       excludes = x;
                        continue;
                }
                if (!strcmp(arg, "--stat")) {
@@ -902,13 +1683,31 @@ int main(int argc, char **argv)
                        diffstat = 1;
                        continue;
                }
+               if (!strcmp(arg, "--summary")) {
+                       apply = 0;
+                       summary = 1;
+                       continue;
+               }
                if (!strcmp(arg, "--check")) {
                        apply = 0;
                        check = 1;
                        continue;
                }
-               if (!strcmp(arg, "--show-files")) {
-                       show_files = 1;
+               if (!strcmp(arg, "--index")) {
+                       check_index = 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;
                }
                fd = open(arg, O_RDONLY);