Merge git://git.kernel.org/pub/scm/gitk/gitk
[gitweb.git] / builtin-apply.c
index e9ead002d38368f6de6ba75f25542fe61258cfb9..1a1deaf78c61547a53bf0c3f7f1e7f37464610c5 100644 (file)
 #include "delta.h"
 #include "builtin.h"
 
-//  --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.
-//
+/*
+ *  --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 allow_binary_replacement;
+static int check_index;
+static int write_index;
+static int cached;
+static int diffstat;
+static int numstat;
+static int summary;
+static int check;
 static int apply = 1;
-static int no_add = 0;
-static int show_index_info = 0;
+static int apply_in_reverse;
+static int apply_with_reject;
+static int apply_verbosely;
+static int no_add;
+static int show_index_info;
 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>...";
+"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--cached] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [--reverse] [--reject] [--verbose] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
 
 static enum whitespace_eol {
        nowarn_whitespace,
@@ -49,10 +53,10 @@ static enum whitespace_eol {
        error_on_whitespace,
        strip_whitespace,
 } new_whitespace = warn_on_whitespace;
-static int whitespace_error = 0;
+static int whitespace_error;
 static int squelch_whitespace_errors = 5;
-static int applied_after_stripping = 0;
-static const char *patch_input_file = NULL;
+static int applied_after_stripping;
+static const char *patch_input_file;
 
 static void parse_whitespace_option(const char *option)
 {
@@ -107,21 +111,37 @@ static int max_change, max_len;
  */
 static int linenr = 1;
 
+/*
+ * 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.
+ */
 struct fragment {
        unsigned long leading, trailing;
        unsigned long oldpos, oldlines;
        unsigned long newpos, newlines;
        const char *patch;
        int size;
+       int rejected;
        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
+
 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
+       int rejected;
        unsigned long deflate_origlen;
        int lines_added, lines_deleted;
        int score;
@@ -134,6 +154,24 @@ struct patch {
        struct patch *next;
 };
 
+static void say_patch_name(FILE *output, const char *pre, struct patch *patch, const char *post)
+{
+       fputs(pre, output);
+       if (patch->old_name && patch->new_name &&
+           strcmp(patch->old_name, patch->new_name)) {
+               write_name_quoted(NULL, 0, patch->old_name, 1, output);
+               fputs(" => ", output);
+               write_name_quoted(NULL, 0, patch->new_name, 1, output);
+       }
+       else {
+               const char *n = patch->new_name;
+               if (!n)
+                       n = patch->old_name;
+               write_name_quoted(NULL, 0, n, 1, output);
+       }
+       fputs(post, output);
+}
+
 #define CHUNKSIZE (8192)
 #define SLOP (16)
 
@@ -284,8 +322,8 @@ static void parse_traditional_patch(const char *first, const char *second, struc
 {
        char *name;
 
-       first += 4;     // skip "--- "
-       second += 4;    // skip "+++ "
+       first += 4;     /* skip "--- " */
+       second += 4;    /* skip "+++ " */
        if (is_dev_null(first)) {
                patch->is_new = 1;
                patch->is_delete = 0;
@@ -590,9 +628,7 @@ static char *git_header_name(char *line, int llen)
         * form.
         */
        for (len = 0 ; ; len++) {
-               char c = name[len];
-
-               switch (c) {
+               switch (name[len]) {
                default:
                        continue;
                case '\n':
@@ -765,7 +801,7 @@ 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.
                 */
@@ -977,51 +1013,82 @@ 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)
 {
-       /* 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.
+       z_stream 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;
+       inflateInit(&stream);
+       st = inflate(&stream, Z_FINISH);
+       if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
+               free(out);
+               return NULL;
+       }
+       return out;
+}
+
+static struct fragment *parse_binary_hunk(char **buf_p,
+                                         unsigned long *sz_p,
+                                         int *status_p,
+                                         int *used_p)
+{
+       /* 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++;
+
+       *status_p = 0;
 
        if (!strncmp(buffer, "delta ", 6)) {
-               patch->is_binary = BINARY_DELTA_DEFLATED;
-               patch->deflate_origlen = strtoul(buffer + 6, NULL, 10);
+               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);
+               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;
+
+       linenr++;
        buffer += llen;
        while (1) {
                int byte_length, max_byte_length, newsize;
                llen = linelen(buffer, size);
                used += llen;
                linenr++;
-               if (llen == 1)
+               if (llen == 1) {
+                       /* consume the blank line */
+                       buffer++;
+                       size--;
                        break;
+               }
                /* Minimum line is "A00000\n" which is 7-byte long,
                 * and the line length must be multiple of 5 plus 2.
                 */
@@ -1042,21 +1109,78 @@ 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);
+       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",
+             linenr-1, llen-1, buffer);
+       return NULL;
+}
+
+static int parse_binary(char *buffer, unsigned long size, struct patch *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(&buffer, &size, &status, &used);
+       if (!forward && !status)
+               /* there has to be one hunk (forward hunk) */
+               return error("unrecognized binary patch at line %d", linenr-1);
+       if (status)
+               /* otherwise we already gave an error message */
+               return status;
+
+       reverse = parse_binary_hunk(&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;
 }
 
 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
@@ -1118,6 +1242,33 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
        return offset + hdrsize + patchsize;
 }
 
+#define swap(a,b) myswap((a),(b),sizeof(a))
+
+#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)
+{
+       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);
+               }
+       }
+}
+
 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 static const char minuses[]= "----------------------------------------------------------------------";
 
@@ -1177,8 +1328,7 @@ static void show_stats(struct patch *patch)
                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
                       len, name, patch->lines_added + patch->lines_deleted,
                       add, pluses, del, minuses);
-       if (qname)
-               free(qname);
+       free(qname);
 }
 
 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
@@ -1334,8 +1484,7 @@ static int apply_line(char *output, const char *patch, int plen)
        return plen;
 }
 
-static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
-       int inaccurate_eof)
+static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, int inaccurate_eof)
 {
        int match_beginning, match_end;
        char *buf = desc->buffer;
@@ -1349,6 +1498,7 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
        int pos, lines;
 
        while (size > 0) {
+               char first;
                int len = linelen(patch, size);
                int plen;
 
@@ -1365,16 +1515,23 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
                plen = len-1;
                if (len < size && patch[len] == '\\')
                        plen--;
-               switch (*patch) {
+               first = *patch;
+               if (apply_in_reverse) {
+                       if (first == '-')
+                               first = '+';
+                       else if (first == '+')
+                               first = '-';
+               }
+               switch (first) {
                case ' ':
                case '-':
                        memcpy(old + oldsize, patch + 1, plen);
                        oldsize += plen;
-                       if (*patch == '-')
+                       if (first == '-')
                                break;
                /* Fall-through for ' ' */
                case '+':
-                       if (*patch != '+' || !no_add)
+                       if (first != '+' || !no_add)
                                newsize += apply_line(new + newsize, patch,
                                                      plen);
                        break;
@@ -1409,7 +1566,8 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
        lines = 0;
        pos = frag->newpos;
        for (;;) {
-               offset = find_offset(buf, desc->size, oldlines, oldsize, pos, &lines);
+               offset = find_offset(buf, desc->size,
+                                    oldlines, oldsize, pos, &lines);
                if (match_end && offset + oldsize != desc->size)
                        offset = -1;
                if (match_beginning && offset)
@@ -1422,8 +1580,10 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
                        /* 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",
+                       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) {
@@ -1433,7 +1593,9 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
                                desc->buffer = buf;
                        }
                        desc->size = size;
-                       memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
+                       memmove(buf + offset + newsize,
+                               buf + offset + oldsize,
+                               size - offset - newsize);
                        memcpy(buf + offset, newlines, newsize);
                        offset = 0;
 
@@ -1469,28 +1631,6 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
        return offset;
 }
 
-static char *inflate_it(const void *data, unsigned long size,
-                       unsigned long inflated_size)
-{
-       z_stream 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;
-       inflateInit(&stream);
-       st = inflate(&stream, Z_FINISH);
-       if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
-               free(out);
-               return NULL;
-       }
-       return out;
-}
-
 static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
 {
        unsigned long dst_size;
@@ -1498,24 +1638,29 @@ static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
        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) {
+       /* Binary patch is irreversible without the optional second hunk */
+       if (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;
+       }
+       data = (void*) fragment->patch;
+       switch (fragment->binary_patch_method) {
        case BINARY_DELTA_DEFLATED:
                result = patch_delta(desc->buffer, desc->size,
                                     data,
-                                    patch->deflate_origlen,
+                                    fragment->size,
                                     &dst_size);
                free(desc->buffer);
                desc->buffer = result;
-               free(data);
                break;
        case BINARY_LITERAL_DEFLATED:
                free(desc->buffer);
                desc->buffer = data;
-               dst_size = patch->deflate_origlen;
+               dst_size = fragment->size;
                break;
        }
        if (!desc->buffer)
@@ -1566,7 +1711,7 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
        }
 
        get_sha1_hex(patch->new_sha1_prefix, sha1);
-       if (!memcmp(sha1, null_sha1, 20)) {
+       if (is_null_sha1(sha1)) {
                free(desc->buffer);
                desc->alloc = desc->size = 0;
                desc->buffer = NULL;
@@ -1599,7 +1744,7 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
                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);
+                       return error("binary patch to '%s' creates incorrect result (expecting %s, got %s)", name, patch->new_sha1_prefix, sha1_to_hex(sha1));
        }
 
        return 0;
@@ -1614,9 +1759,12 @@ static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
                return apply_binary(desc, patch);
 
        while (frag) {
-               if (apply_one_fragment(desc, frag, patch->inaccurate_eof) < 0)
-                       return error("patch failed: %s:%ld",
-                                    name, frag->oldpos);
+               if (apply_one_fragment(desc, frag, patch->inaccurate_eof)) {
+                       error("patch failed: %s:%ld", name, frag->oldpos);
+                       if (!apply_with_reject)
+                               return -1;
+                       frag->rejected = 1;
+               }
                frag = frag->next;
        }
        return 0;
@@ -1652,8 +1800,15 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
        desc.size = size;
        desc.alloc = alloc;
        desc.buffer = buf;
+
        if (apply_fragments(&desc, patch) < 0)
-               return -1;
+               return -1; /* note with --reject this succeeds. */
+
+       /* NUL terminate the result */
+       if (desc.alloc <= desc.size)
+               desc.buffer = xrealloc(desc.buffer, desc.size + 1);
+       desc.buffer[desc.size] = 0;
+
        patch->result = desc.buffer;
        patch->resultsize = desc.size;
 
@@ -1663,14 +1818,16 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
        return 0;
 }
 
-static int check_patch(struct patch *patch)
+static int check_patch(struct patch *patch, struct patch *prev_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;
+       int ok_if_exists;
 
+       patch->rejected = 1; /* we will drop this after we succeed */
        if (old_name) {
                int changed = 0;
                int stat_ret = 0;
@@ -1727,13 +1884,33 @@ static int check_patch(struct patch *patch)
                                old_name, st_mode, patch->old_mode);
        }
 
+       if (new_name && prev_patch && prev_patch->is_delete &&
+           !strcmp(prev_patch->old_name, new_name))
+               /* 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.
+                */
+               ok_if_exists = 1;
+       else
+               ok_if_exists = 0;
+
        if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
-               if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
+               if (check_index &&
+                   cache_name_pos(new_name, strlen(new_name)) >= 0 &&
+                   !ok_if_exists)
                        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)
+                       struct stat nst;
+                       if (!lstat(new_name, &nst)) {
+                               if (S_ISDIR(nst.st_mode) || ok_if_exists)
+                                       ; /* ok */
+                               else
+                                       return error("%s: already exists in working directory", new_name);
+                       }
+                       else if ((errno != ENOENT) && (errno != ENOTDIR))
                                return error("%s: %s", new_name, strerror(errno));
                }
                if (!patch->new_mode) {
@@ -1756,21 +1933,23 @@ static int check_patch(struct patch *patch)
 
        if (apply_data(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)
 {
-       int error = 0;
+       struct patch *prev_patch = NULL;
+       int err = 0;
 
-       for (;patch ; patch = patch->next)
-               error |= check_patch(patch);
-       return error;
-}
-
-static inline int is_null_sha1(const unsigned char *sha1)
-{
-       return !memcmp(sha1, null_sha1, 20);
+       for (prev_patch = NULL; patch ; patch = patch->next) {
+               if (apply_verbosely)
+                       say_patch_name(stderr,
+                                      "Checking patch ", patch, "...\n");
+               err |= check_patch(patch, prev_patch);
+               prev_patch = patch;
+       }
+       return err;
 }
 
 static void show_index_list(struct patch *list)
@@ -1972,6 +2151,9 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
        int fd;
 
        if (S_ISLNK(mode))
+               /* Although buf:size is counted string, it also is NUL
+                * terminated.
+                */
                return symlink(buf, path);
        fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
        if (fd < 0)
@@ -2009,6 +2191,16 @@ static void create_one_file(char *path, unsigned mode, const char *buf, unsigned
                        return;
        }
 
+       if (errno == EEXIST || errno == EACCES) {
+               /* We may be trying to create a file where a directory
+                * used to be.
+                */
+               struct stat st;
+               errno = 0;
+               if (!lstat(path, &st) && S_ISDIR(st.st_mode) && !rmdir(path))
+                       errno = EEXIST;
+       }
+
        if (errno == EEXIST) {
                unsigned int nr = getpid();
 
@@ -2043,33 +2235,119 @@ static void create_file(struct patch *patch)
        cache_tree_invalidate_path(active_cache_tree, path);
 }
 
-static void write_out_one_result(struct patch *patch)
+/* phase zero is to remove, phase one is to create */
+static void write_out_one_result(struct patch *patch, int phase)
 {
        if (patch->is_delete > 0) {
-               remove_file(patch);
+               if (phase == 0)
+                       remove_file(patch);
                return;
        }
        if (patch->is_new > 0 || patch->is_copy) {
-               create_file(patch);
+               if (phase == 1)
+                       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);
+       if (phase == 0)
+               remove_file(patch);
+       if (phase == 1)
+               create_file(patch);
+}
+
+static int write_out_one_reject(struct patch *patch)
+{
+       FILE *rej;
+       char namebuf[PATH_MAX];
+       struct fragment *frag;
+       int cnt = 0;
+
+       for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
+               if (!frag->rejected)
+                       continue;
+               cnt++;
+       }
+
+       if (!cnt) {
+               if (apply_verbosely)
+                       say_patch_name(stderr,
+                                      "Applied patch ", patch, " cleanly.\n");
+               return 0;
+       }
+
+       /* 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 */
+       say_patch_name(stderr, "Applying patch ", patch, " with");
+       fprintf(stderr, " %d rejects...\n", cnt);
+
+       cnt = strlen(patch->new_name);
+       if (ARRAY_SIZE(namebuf) <= cnt + 5) {
+               cnt = ARRAY_SIZE(namebuf) - 5;
+               fprintf(stderr,
+                       "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("cannot open %s: %s", namebuf, strerror(errno));
+
+       /* Normal git tools never deal with .rej, so do not pretend
+        * this is a git patch by saying --git nor give 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) {
+                       fprintf(stderr, "Hunk #%d applied cleanly.\n", cnt);
+                       continue;
+               }
+               fprintf(stderr, "Rejected hunk #%d.\n", cnt);
+               fprintf(rej, "%.*s", frag->size, frag->patch);
+               if (frag->patch[frag->size-1] != '\n')
+                       fputc('\n', rej);
+       }
+       fclose(rej);
+       return -1;
 }
 
-static void write_out_results(struct patch *list, int skipped_patch)
+static int write_out_results(struct patch *list, int skipped_patch)
 {
+       int phase;
+       int errs = 0;
+       struct patch *l;
+
        if (!list && !skipped_patch)
-               die("No changes");
+               return error("No changes");
 
-       while (list) {
-               write_out_one_result(list);
-               list = list->next;
+       for (phase = 0; phase < 2; phase++) {
+               l = list;
+               while (l) {
+                       if (l->rejected)
+                               errs = 1;
+                       else {
+                               write_out_one_result(l, phase);
+                               if (phase == 1 && write_out_one_reject(l))
+                                       errs = 1;
+                       }
+                       l = l->next;
+               }
        }
+       return errs;
 }
 
 static struct lock_file lock_file;
@@ -2117,6 +2395,8 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
                nr = parse_chunk(buffer + offset, size, patch);
                if (nr < 0)
                        break;
+               if (apply_in_reverse)
+                       reverse_patches(patch);
                if (use_patch(patch)) {
                        patch_stats(patch);
                        *listp = patch;
@@ -2134,22 +2414,21 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
                apply = 0;
 
        write_index = check_index && apply;
-       if (write_index && newfd < 0) {
+       if (write_index && newfd < 0)
                newfd = hold_lock_file_for_update(&lock_file,
-                                                 get_index_file());
-               if (newfd < 0)
-                       die("unable to create new index file");
-       }
+                                                 get_index_file(), 1);
        if (check_index) {
                if (read_cache() < 0)
                        die("unable to read index file");
        }
 
-       if ((check || apply) && check_patch_list(list) < 0)
+       if ((check || apply) &&
+           check_patch_list(list) < 0 &&
+           !apply_with_reject)
                exit(1);
 
-       if (apply)
-               write_out_results(list, skipped_patch);
+       if (apply && write_out_results(list, skipped_patch))
+               exit(1);
 
        if (show_index_info)
                show_index_list(list);
@@ -2177,11 +2456,12 @@ static int git_apply_config(const char *var, const char *value)
 }
 
 
-int cmd_apply(int argc, const char **argv, char **envp)
+int cmd_apply(int argc, const char **argv, const char *prefix)
 {
        int i;
        int read_stdin = 1;
        int inaccurate_eof = 0;
+       int errs = 0;
 
        const char *whitespace_option = NULL;
 
@@ -2191,7 +2471,7 @@ int cmd_apply(int argc, const char **argv, char **envp)
                int fd;
 
                if (!strcmp(arg, "-")) {
-                       apply_patch(0, "<stdin>", inaccurate_eof);
+                       errs |= apply_patch(0, "<stdin>", inaccurate_eof);
                        read_stdin = 0;
                        continue;
                }
@@ -2268,6 +2548,18 @@ int cmd_apply(int argc, const char **argv, char **envp)
                        parse_whitespace_option(arg + 13);
                        continue;
                }
+               if (!strcmp(arg, "-R") || !strcmp(arg, "--reverse")) {
+                       apply_in_reverse = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--reject")) {
+                       apply = apply_with_reject = apply_verbosely = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--verbose")) {
+                       apply_verbosely = 1;
+                       continue;
+               }
                if (!strcmp(arg, "--inaccurate-eof")) {
                        inaccurate_eof = 1;
                        continue;
@@ -2288,18 +2580,19 @@ int cmd_apply(int argc, const char **argv, char **envp)
                        usage(apply_usage);
                read_stdin = 0;
                set_default_whitespace_mode(whitespace_option);
-               apply_patch(fd, arg, inaccurate_eof);
+               errs |= apply_patch(fd, arg, inaccurate_eof);
                close(fd);
        }
        set_default_whitespace_mode(whitespace_option);
        if (read_stdin)
-               apply_patch(0, "<stdin>", inaccurate_eof);
+               errs |= apply_patch(0, "<stdin>", inaccurate_eof);
        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",
+                       fprintf(stderr, "warning: squelched %d "
+                               "whitespace error%s\n",
                                squelched,
                                squelched == 1 ? "" : "s");
                }
@@ -2323,9 +2616,9 @@ int cmd_apply(int argc, const char **argv, char **envp)
 
        if (write_index) {
                if (write_cache(newfd, active_cache, active_nr) ||
-                   commit_lock_file(&lock_file))
+                   close(newfd) || commit_lock_file(&lock_file))
                        die("Unable to write new index file");
        }
 
-       return 0;
+       return !!errs;
 }