Add "git checkout" that does what the name suggests
[gitweb.git] / apply.c
diff --git a/apply.c b/apply.c
index e0a1549022ef4ad027c2dae369615bb4c2aec796..8a3ead6c949ecc0a493f9525580fd90d6bc6ebcd 100644 (file)
--- a/apply.c
+++ b/apply.c
@@ -25,6 +25,8 @@
 //  --show-files shows the directory changes
 //
 static int merge_patch = 1;
+static int check_index = 0;
+static int write_index = 0;
 static int diffstat = 0;
 static int check = 0;
 static int apply = 1;
@@ -59,6 +61,8 @@ struct patch {
        int is_rename, is_copy, is_new, is_delete;
        int lines_added, lines_deleted;
        struct fragment *fragments;
+       char *result;
+       unsigned long resultsize;
        struct patch *next;
 };
 
@@ -100,7 +104,7 @@ 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--) {
@@ -431,6 +435,8 @@ 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 },
@@ -562,10 +568,13 @@ 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 +612,7 @@ 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 +620,24 @@ 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;
@@ -644,6 +667,8 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
                        break;
                /* We allow "\ No newline at end of file" */
                case '\\':
+                       if (len < 12 || memcmp(line, "\\ No newline", 12))
+                               return -1;
                        break;
                }
        }
@@ -726,14 +751,239 @@ 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;
+       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 |%5d %.*s%.*s\n",
                len, name, patch->lines_added + patch->lines_deleted,
                add, pluses, del, minuses);
 }
 
+static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
+{
+       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;
+               fprintf(stderr, "Fragment applied at offset %d\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:%d", 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)
 {
        struct stat st;
@@ -741,30 +991,53 @@ 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;
 
-               if (pos < 0)
-                       return error("%s: does not exist in index", old_name);
+               if (lstat(old_name, &st) < 0)
+                       return error("%s: %s", old_name, strerror(errno));
+               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);
+                       changed = ce_match_stat(active_cache[pos], &st);
+                       if (changed)
+                               return error("%s: does not match 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)
+                       patch->new_mode = S_IFREG | 0644;
        }
+
+       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;
 }
 
@@ -838,8 +1111,106 @@ static void patch_stats(struct patch *patch)
        }
 }
 
+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_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;
+       if (S_ISREG(mode)) {
+               int fd;
+               mode = (mode & 0100) ? 0777 : 0666;
+               fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, mode);
+               if (fd < 0)
+                       die("unable to create file %s (%s)", path, strerror(errno));
+               if (write(fd, buf, size) != size)
+                       die("unable to write file %s", path);
+               close(fd);
+               add_index_file(path, mode, buf, size);
+               return;
+       }
+       if (S_ISLNK(mode)) {
+               if (size && buf[size-1] == '\n')
+                       size--;
+               buf[size] = 0;
+               if (symlink(buf, path) < 0)
+                       die("unable to write symlink %s", path);
+               add_index_file(path, mode, buf, size);
+               return;
+       }
+       die("unable to write file mode %o", mode);
+}
+
+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)
+{
+       if (!list)
+               die("No changes");
+
+       while (list) {
+               write_out_one_result(list);
+               list = list->next;
+       }
+}
+
+static struct cache_file cache_file;
+
 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;
@@ -863,9 +1234,27 @@ static int apply_patch(int fd)
                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 (apply)
+               write_out_results(list);
+
+       if (write_index) {
+               if (write_cache(newfd, active_cache, active_nr) ||
+                   commit_index_file(&cache_file))
+                       die("Unable to write new cachefile");
+       }
+
        if (show_files)
                show_file_list(list);
 
@@ -881,9 +1270,6 @@ 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;
@@ -907,6 +1293,10 @@ int main(int argc, char **argv)
                        check = 1;
                        continue;
                }
+               if (!strcmp(arg, "--index")) {
+                       check_index = 1;
+                       continue;
+               }
                if (!strcmp(arg, "--show-files")) {
                        show_files = 1;
                        continue;