Fix per-directory exclude handing for "git add"
[gitweb.git] / builtin-apply.c
index e5c29ebf35f2dc44b816e9756505c428c2e7a28a..91f8752ff7fdb588e64f594519a2e9503c516630 100644 (file)
@@ -12,7 +12,6 @@
 #include "blob.h"
 #include "delta.h"
 #include "builtin.h"
-#include "strbuf.h"
 
 /*
  *  --check turns on checking that the working tree matches the
@@ -42,7 +41,7 @@ static int apply_in_reverse;
 static int apply_with_reject;
 static int apply_verbosely;
 static int no_add;
-static int show_index_info;
+static const char *fake_ancestor;
 static int line_termination = '\n';
 static unsigned long p_context = ULONG_MAX;
 static const char apply_usage[] =
@@ -153,7 +152,7 @@ struct patch {
        unsigned int is_rename: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;
@@ -164,15 +163,14 @@ static void say_patch_name(FILE *output, const char *pre, struct patch *patch, c
        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);
+               quote_c_style(patch->old_name, NULL, output, 0);
                fputs(" => ", output);
-               write_name_quoted(NULL, 0, patch->new_name, 1, output);
-       }
-       else {
+               quote_c_style(patch->new_name, NULL, output, 0);
+       } else {
                const char *n = patch->new_name;
                if (!n)
                        n = patch->old_name;
-               write_name_quoted(NULL, 0, n, 1, output);
+               quote_c_style(n, NULL, output, 0);
        }
        fputs(post, output);
 }
@@ -180,23 +178,18 @@ static void say_patch_name(FILE *output, const char *pre, struct patch *patch, c
 #define CHUNKSIZE (8192)
 #define SLOP (16)
 
-static void *read_patch_file(int fd, unsigned long *sizep)
+static void read_patch_file(struct strbuf *sb, int fd)
 {
-       struct strbuf buf;
-
-       strbuf_init(&buf, 0);
-       if (strbuf_read(&buf, fd, 0) < 0)
+       if (strbuf_read(sb, fd, 0) < 0)
                die("git-apply: read returned %s", strerror(errno));
-       *sizep = buf.len;
 
        /*
         * 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.
         */
-       strbuf_grow(&buf, SLOP);
-       memset(buf.buf + buf.len, 0, SLOP);
-       return strbuf_detach(&buf);
+       strbuf_grow(sb, SLOP);
+       memset(sb->buf + sb->len, 0, SLOP);
 }
 
 static unsigned long linelen(const char *buffer, unsigned long size)
@@ -232,35 +225,33 @@ static char *find_name(const char *line, char *def, int p_value, int terminate)
 {
        int len;
        const char *start = line;
-       char *name;
 
        if (*line == '"') {
+               struct strbuf name;
+
                /* 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, '/');
+               strbuf_init(&name, 0);
+               if (!unquote_c_style(&name, line, NULL)) {
+                       char *cp;
+
+                       for (cp = name.buf; p_value; p_value--) {
+                               cp = strchr(cp, '/');
                                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);
+                               strbuf_remove(&name, 0, cp - name.buf);
                                free(def);
-                               return name;
-                       }
-                       else {
-                               free(name);
-                               name = NULL;
+                               return strbuf_detach(&name, NULL);
                        }
                }
+               strbuf_release(&name);
        }
 
        for (;;) {
@@ -292,13 +283,10 @@ static char *find_name(const char *line, char *def, int p_value, int terminate)
                int deflen = strlen(def);
                if (deflen < len && !strncmp(start, def, deflen))
                        return def;
+               free(def);
        }
 
-       name = xmalloc(len + 1);
-       memcpy(name, start, len);
-       name[len] = 0;
-       free(def);
-       return name;
+       return xmemdupz(start, len);
 }
 
 static int count_slashes(const char *cp)
@@ -571,29 +559,30 @@ static const char *stop_at_slash(const char *line, int llen)
  */
 static char *git_header_name(char *line, int llen)
 {
-       int len;
        const char *name;
        const char *second = NULL;
+       size_t 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;
+               struct strbuf sp;
+
+               strbuf_init(&first, 0);
+               strbuf_init(&sp, 0);
+
+               if (unquote_c_style(&first, line, &second))
+                       goto free_and_fail1;
 
                /* 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 */
+               cp = stop_at_slash(first.buf, first.len);
+               /* we do not accept absolute paths */
+               if (!cp || cp == first.buf)
+                       goto free_and_fail1;
+               strbuf_remove(&first, 0, cp + 1 - first.buf);
 
                /* second points at one past closing dq of name.
                 * find the second name.
@@ -602,40 +591,40 @@ static char *git_header_name(char *line, int llen)
                        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 = stop_at_slash(sp.buf, sp.len);
+                       if (!cp || cp == sp.buf)
+                               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 + 1, 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;
+                       goto free_and_fail1;
                cp++;
-               if (line + llen - cp != len + 1 ||
-                   memcmp(first, cp, len))
-                       goto free_first_and_fail;
-               return first;
+               if (line + llen - cp != first.len + 1 ||
+                   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)
                return NULL;
-
        name++;
 
        /* since the first name is unquoted, a dq if exists must be
@@ -643,28 +632,30 @@ static char *git_header_name(char *line, int llen)
         */
        for (second = name; second < line + llen; second++) {
                if (*second == '"') {
-                       const char *cp = second;
+                       struct strbuf sp;
                        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;
-                       }
+
+                       strbuf_init(&sp, 0);
+                       if (unquote_c_style(&sp, second, NULL))
+                               goto free_and_fail2;
+
+                       np = stop_at_slash(sp.buf, sp.len);
+                       if (!np || np == sp.buf)
+                               goto free_and_fail2;
                        np++;
-                       len = strlen(np);
-                       if (len < cp - name &&
+
+                       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;
                }
        }
 
@@ -688,14 +679,10 @@ static char *git_header_name(char *line, int llen)
                                        break;
                        }
                        if (second[len] == '\n' && !memcmp(name, second, len)) {
-                               char *ret = xmalloc(len + 1);
-                               memcpy(ret, name, len);
-                               ret[len] = 0;
-                               return ret;
+                               return xmemdupz(name, len);
                        }
                }
        }
-       return NULL;
 }
 
 /* Verify that we recognize the lines following a git header */
@@ -1385,94 +1372,66 @@ static const char minuses[]= "--------------------------------------------------
 
 static void show_stats(struct patch *patch)
 {
-       const char *prefix = "";
-       char *name = patch->new_name;
-       char *qname = NULL;
-       int len, max, add, del, total;
-
-       if (!name)
-               name = patch->old_name;
+       struct strbuf qname;
+       char *cp = patch->new_name ? patch->new_name : patch->old_name;
+       int max, add, del;
 
-       if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
-               qname = xmalloc(len + 1);
-               quote_c_style(name, qname, NULL, 0);
-               name = qname;
-       }
+       strbuf_init(&qname, 0);
+       quote_c_style(cp, &qname, NULL, 0);
 
        /*
         * "scale" the filename
         */
-       len = strlen(name);
        max = 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);
        }
-       len = max;
+
+       if (patch->is_binary) {
+               printf(" %-*s |  Bin\n", max, qname.buf);
+               strbuf_release(&qname);
+               return;
+       }
+
+       printf(" %-*s |", max, qname.buf);
+       strbuf_release(&qname);
 
        /*
         * scale the add/delete
         */
-       max = max_change;
-       if (max + len > 70)
-               max = 70 - len;
-
+       max = max + max_change > 70 ? 70 - max : 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;
+               int total = ((add + del) * max + max_change / 2) / max_change;
                add = (add * max + max_change / 2) / 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);
-       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, char **buf_p, unsigned long *alloc_p, unsigned long *size_p)
+static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
 {
-       int fd;
-       unsigned long got;
-       struct strbuf nbuf;
-       unsigned long size = *size_p;
-       char *buf = *buf_p;
-
        switch (st->st_mode & S_IFMT) {
        case S_IFLNK:
-               return readlink(path, buf, size) != size;
+               strbuf_grow(buf, st->st_size);
+               if (readlink(path, buf->buf, st->st_size) != st->st_size)
+                       return -1;
+               strbuf_setlen(buf, st->st_size);
+               return 0;
        case S_IFREG:
-               fd = open(path, O_RDONLY);
-               if (fd < 0)
-                       return error("unable to open %s", path);
-               got = 0;
-               for (;;) {
-                       ssize_t ret = xread(fd, buf + got, size - got);
-                       if (ret <= 0)
-                               break;
-                       got += ret;
-               }
-               close(fd);
-               strbuf_init(&nbuf, 0);
-               if (convert_to_git(path, buf, size, &nbuf)) {
-                       free(buf);
-                       *buf_p = nbuf.buf;
-                       *alloc_p = nbuf.alloc;
-                       *size_p = nbuf.len;
-               }
-               return got != size;
+               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);
+               return 0;
        default:
                return -1;
        }
@@ -1577,12 +1536,6 @@ static void remove_last_line(const char **rbuf, int *rsize)
        *rsize = offset + 1;
 }
 
-struct buffer_desc {
-       char *buffer;
-       unsigned long size;
-       unsigned long alloc;
-};
-
 static int apply_line(char *output, const char *patch, int plen)
 {
        /* plen is number of bytes to be copied from patch,
@@ -1628,15 +1581,22 @@ static int apply_line(char *output, const char *patch, int plen)
 
        buf = output;
        if (need_fix_leading_space) {
+               int consecutive_spaces = 0;
                /* between patch[1..last_tab_in_indent] strip the
                 * funny spaces, updating them to tab as needed.
                 */
                for (i = 1; i < last_tab_in_indent; i++, plen--) {
                        char ch = patch[i];
-                       if (ch != ' ')
+                       if (ch != ' ') {
+                               consecutive_spaces = 0;
                                *output++ = ch;
-                       else if ((i % 8) == 0)
-                               *output++ = '\t';
+                       } else {
+                               consecutive_spaces++;
+                               if (consecutive_spaces == 8) {
+                                       *output++ = '\t';
+                                       consecutive_spaces = 0;
+                               }
+                       }
                }
                fixed = 1;
                i = last_tab_in_indent;
@@ -1652,10 +1612,9 @@ static int apply_line(char *output, const char *patch, int plen)
        return output + plen - buf;
 }
 
-static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, int inaccurate_eof)
+static int apply_one_fragment(struct strbuf *buf, struct fragment *frag, int inaccurate_eof)
 {
        int match_beginning, match_end;
-       char *buf = desc->buffer;
        const char *patch = frag->patch;
        int offset, size = frag->size;
        char *old = xmalloc(size);
@@ -1766,24 +1725,17 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, i
        lines = 0;
        pos = frag->newpos;
        for (;;) {
-               offset = find_offset(buf, desc->size,
+               offset = find_offset(buf->buf, buf->len,
                                     oldlines, oldsize, pos, &lines);
-               if (match_end && offset + oldsize != desc->size)
+               if (match_end && offset + oldsize != buf->len)
                        offset = -1;
                if (match_beginning && offset)
                        offset = -1;
                if (offset >= 0) {
-                       int diff;
-                       unsigned long size, alloc;
-
                        if (new_whitespace == strip_whitespace &&
-                           (desc->size - oldsize - offset == 0)) /* end of file? */
+                           (buf->len - oldsize - offset == 0)) /* end of file? */
                                newsize -= new_blank_lines_at_end;
 
-                       diff = newsize - oldsize;
-                       size = desc->size + diff;
-                       alloc = desc->alloc;
-
                        /* Warn if it was necessary to reduce the number
                         * of context lines.
                         */
@@ -1793,19 +1745,8 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, i
                                        " 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);
+                       strbuf_splice(buf, offset, oldsize, newlines, newsize);
                        offset = 0;
-
                        break;
                }
 
@@ -1841,12 +1782,11 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, i
        return offset;
 }
 
-static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
+static int apply_binary_fragment(struct strbuf *buf, struct patch *patch)
 {
-       unsigned long dst_size;
        struct fragment *fragment = patch->fragments;
-       void *data;
-       void *result;
+       unsigned long len;
+       void *dst;
 
        /* Binary patch is irreversible without the optional second hunk */
        if (apply_in_reverse) {
@@ -1857,29 +1797,24 @@ static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
                                     ? 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,
-                                    fragment->size,
-                                    &dst_size);
-               free(desc->buffer);
-               desc->buffer = result;
-               break;
+               dst = patch_delta(buf->buf, buf->len, fragment->patch,
+                                 fragment->size, &len);
+               if (!dst)
+                       return -1;
+               /* XXX patch_delta NUL-terminates */
+               strbuf_attach(buf, dst, len, len + 1);
+               return 0;
        case BINARY_LITERAL_DEFLATED:
-               free(desc->buffer);
-               desc->buffer = data;
-               dst_size = fragment->size;
-               break;
+               strbuf_reset(buf);
+               strbuf_add(buf, fragment->patch, fragment->size);
+               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)
+static int apply_binary(struct strbuf *buf, struct patch *patch)
 {
        const char *name = patch->old_name ? patch->old_name : patch->new_name;
        unsigned char sha1[20];
@@ -1898,7 +1833,7 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
                /* See if the old one matches what the patch
                 * applies to.
                 */
-               hash_sha1_file(desc->buffer, desc->size, blob_type, sha1);
+               hash_sha1_file(buf->buf, buf->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 "
@@ -1907,16 +1842,14 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
        }
        else {
                /* Otherwise, the old one must be empty. */
-               if (desc->size)
+               if (buf->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 (is_null_sha1(sha1)) {
-               free(desc->buffer);
-               desc->alloc = desc->size = 0;
-               desc->buffer = NULL;
+               strbuf_release(buf);
                return 0; /* deletion patch */
        }
 
@@ -1924,43 +1857,44 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
                /* We already have the postimage */
                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;
+               /* XXX read_sha1_file NUL-terminates */
+               strbuf_attach(buf, result, size, size + 1);
+       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))
+               if (apply_binary_fragment(buf, patch))
                        return error("binary patch does not apply to '%s'",
                                     name);
 
                /* verify that the result matches */
-               hash_sha1_file(desc->buffer, desc->size, blob_type, sha1);
+               hash_sha1_file(buf->buf, buf->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 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 buffer_desc *desc, struct patch *patch)
+static int apply_fragments(struct strbuf *buf, struct patch *patch)
 {
        struct fragment *frag = patch->fragments;
        const char *name = patch->old_name ? patch->old_name : patch->new_name;
 
        if (patch->is_binary)
-               return apply_binary(desc, patch);
+               return apply_binary(buf, patch);
 
        while (frag) {
-               if (apply_one_fragment(desc, frag, patch->inaccurate_eof)) {
+               if (apply_one_fragment(buf, frag, patch->inaccurate_eof)) {
                        error("patch failed: %s:%ld", name, frag->oldpos);
                        if (!apply_with_reject)
                                return -1;
@@ -1971,76 +1905,56 @@ static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
        return 0;
 }
 
-static int read_file_or_gitlink(struct cache_entry *ce, char **buf_p,
-                               unsigned long *size_p)
+static int read_file_or_gitlink(struct cache_entry *ce, struct strbuf *buf)
 {
        if (!ce)
                return 0;
 
        if (S_ISGITLINK(ntohl(ce->ce_mode))) {
-               *buf_p = xmalloc(100);
-               *size_p = snprintf(*buf_p, 100,
-                       "Subproject commit %s\n", sha1_to_hex(ce->sha1));
+               strbuf_grow(buf, 100);
+               strbuf_addf(buf, "Subproject commit %s\n", sha1_to_hex(ce->sha1));
        } else {
                enum object_type type;
-               *buf_p = read_sha1_file(ce->sha1, &type, size_p);
-               if (!*buf_p)
+               unsigned long sz;
+               char *result;
+
+               result = read_sha1_file(ce->sha1, &type, &sz);
+               if (!result)
                        return -1;
+               /* XXX read_sha1_file NUL-terminates */
+               strbuf_attach(buf, result, sz, sz + 1);
        }
        return 0;
 }
 
 static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
 {
-       char *buf;
-       unsigned long size, alloc;
-       struct buffer_desc desc;
+       struct strbuf buf;
 
-       size = 0;
-       alloc = 0;
-       buf = NULL;
+       strbuf_init(&buf, 0);
        if (cached) {
-               if (read_file_or_gitlink(ce, &buf, &size))
+               if (read_file_or_gitlink(ce, &buf))
                        return error("read of %s failed", patch->old_name);
-               alloc = size;
        } else if (patch->old_name) {
                if (S_ISGITLINK(patch->old_mode)) {
-                       if (ce)
-                               read_file_or_gitlink(ce, &buf, &size);
-                       else {
+                       if (ce) {
+                               read_file_or_gitlink(ce, &buf);
+                       else {
                                /*
                                 * There is no way to apply subproject
                                 * patch without looking at the index.
                                 */
                                patch->fragments = NULL;
-                               size = 0;
                        }
-               }
-               else {
-                       size = xsize_t(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);
+               } else {
+                       if (read_old_data(st, patch->old_name, &buf))
+                               return error("read of %s failed", patch->old_name);
                }
        }
 
-       desc.size = size;
-       desc.alloc = alloc;
-       desc.buffer = buf;
-
-       if (apply_fragments(&desc, patch) < 0)
+       if (apply_fragments(&buf, patch) < 0)
                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;
+       patch->result = strbuf_detach(&buf, &patch->resultsize);
 
        if (0 < patch->is_delete && patch->resultsize)
                return error("removal patch leaves file contents");
@@ -2078,7 +1992,7 @@ static int verify_index_match(struct cache_entry *ce, struct stat *st)
                        return -1;
                return 0;
        }
-       return ce_match_stat(ce, st, 1);
+       return ce_match_stat(ce, st, CE_MATCH_IGNORE_VALID);
 }
 
 static int check_patch(struct patch *patch, struct patch *prev_patch)
@@ -2213,9 +2127,26 @@ static int check_patch_list(struct patch *patch)
        return err;
 }
 
-static void show_index_list(struct patch *list)
+/* This function tries to read the sha1 from the current index */
+static int get_current_sha1(const char *path, unsigned char *sha1)
+{
+       int pos;
+
+       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;
+}
+
+/* Build an index that contains the just the files needed for a 3way merge */
+static void build_fake_ancestor(struct patch *list, const char *filename)
 {
        struct patch *patch;
+       struct index_state result = { 0 };
+       int fd;
 
        /* Once we start supporting the reverse patch, it may be
         * worth showing the new sha1 prefix, but until then...
@@ -2223,24 +2154,36 @@ static void show_index_list(struct patch *list)
        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 (0 < patch->is_new)
-                       sha1_ptr = null_sha1;
+                       continue;
                else if (get_sha1(patch->old_sha1_prefix, sha1))
-                       die("sha1 information is lacking or useless (%s).",
-                           name);
+                       /* git diff has no index line for mode/type changes */
+                       if (!patch->lines_added && !patch->lines_deleted) {
+                               if (get_current_sha1(patch->new_name, sha1) ||
+                                   get_current_sha1(patch->old_name, sha1))
+                                       die("mode change for %s, which is not "
+                                               "in current HEAD", name);
+                               sha1_ptr = sha1;
+                       } else
+                               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);
+               ce = make_cache_entry(patch->old_mode, sha1_ptr, name, 0, 0);
+               if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD))
+                       die ("Could not add %s to temporary index", name);
        }
+
+       fd = open(filename, O_WRONLY | O_CREAT, 0666);
+       if (fd < 0 || write_index(&result, fd) || close(fd))
+               die ("Could not write temporary index to %s", filename);
+
+       discard_index(&result);
 }
 
 static void stat_patch_list(struct patch *patch)
@@ -2265,13 +2208,8 @@ static void numstat_patch_list(struct patch *patch)
                if (patch->is_binary)
                        printf("-\t-\t");
                else
-                       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);
-               else
-                       fputs(name, stdout);
-               putchar(line_termination);
+                       printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
+               write_name_quoted(name, stdout, line_termination);
        }
 }
 
@@ -2380,7 +2318,6 @@ static void remove_file(struct patch *patch, int rmdir_empty)
        if (update_index) {
                if (remove_file_from_cache(patch->old_name) < 0)
                        die("unable to remove %s from index", patch->old_name);
-               cache_tree_invalidate_path(active_cache_tree, patch->old_name);
        }
        if (!cached) {
                if (S_ISGITLINK(patch->old_mode)) {
@@ -2461,19 +2398,11 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
                size = nbuf.len;
                buf  = nbuf.buf;
        }
+       write_or_die(fd, buf, size);
+       strbuf_release(&nbuf);
 
-       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));
-       strbuf_release(&nbuf);
        return 0;
 }
 
@@ -2536,7 +2465,6 @@ static void create_file(struct patch *patch)
                mode = S_IFREG | 0644;
        create_one_file(path, mode, buf, size);
        add_index_file(path, mode, buf, size);
-       cache_tree_invalidate_path(active_cache_tree, path);
 }
 
 /* phase zero is to remove, phase one is to create */
@@ -2707,22 +2635,22 @@ static void prefix_patches(struct patch *p)
 
 static int apply_patch(int fd, const char *filename, int inaccurate_eof)
 {
-       unsigned long offset, size;
-       char *buffer = read_patch_file(fd, &size);
+       size_t offset;
+       struct strbuf buf;
        struct patch *list = NULL, **listp = &list;
        int skipped_patch = 0;
 
+       strbuf_init(&buf, 0);
        patch_input_file = filename;
-       if (!buffer)
-               return -1;
+       read_patch_file(&buf, fd);
        offset = 0;
-       while (size > 0) {
+       while (offset < buf.len) {
                struct patch *patch;
                int nr;
 
                patch = xcalloc(1, sizeof(*patch));
                patch->inaccurate_eof = inaccurate_eof;
-               nr = parse_chunk(buffer + offset, size, patch);
+               nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
                if (nr < 0)
                        break;
                if (apply_in_reverse)
@@ -2740,7 +2668,6 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
                        skipped_patch++;
                }
                offset += nr;
-               size -= nr;
        }
 
        if (whitespace_error && (new_whitespace == error_on_whitespace))
@@ -2763,8 +2690,8 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
        if (apply && write_out_results(list, skipped_patch))
                exit(1);
 
-       if (show_index_info)
-               show_index_list(list);
+       if (fake_ancestor)
+               build_fake_ancestor(list, fake_ancestor);
 
        if (diffstat)
                stat_patch_list(list);
@@ -2775,7 +2702,7 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
        if (summary)
                summary_patch_list(list);
 
-       free(buffer);
+       strbuf_release(&buf);
        return 0;
 }
 
@@ -2872,9 +2799,11 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
                        apply = 1;
                        continue;
                }
-               if (!strcmp(arg, "--index-info")) {
+               if (!strcmp(arg, "--build-fake-ancestor")) {
                        apply = 0;
-                       show_index_info = 1;
+                       if (++i >= argc)
+                               die ("need a filename");
+                       fake_ancestor = argv[i];
                        continue;
                }
                if (!strcmp(arg, "-z")) {