builtin-blame: Reencode commit messages according to git-log rules.
[gitweb.git] / fsck.c
diff --git a/fsck.c b/fsck.c
index 558f0a6b349b921802668282e8c2b71b0f03d754..0cf5f012bdfa876fae4e15ed9cb94ed304314bf6 100644 (file)
--- a/fsck.c
+++ b/fsck.c
 #include "cache.h"
-#include "commit.h"
-#include "tree.h"
+#include "object.h"
 #include "blob.h"
-#include "tag.h"
-#include "refs.h"
-#include "pack.h"
-#include "cache-tree.h"
+#include "tree.h"
 #include "tree-walk.h"
+#include "commit.h"
+#include "tag.h"
+#include "fsck.h"
 
-#define REACHABLE 0x0001
-#define SEEN      0x0002
-
-static int show_root;
-static int show_tags;
-static int show_unreachable;
-static int check_full;
-static int check_strict;
-static int keep_cache_objects;
-static unsigned char head_sha1[20];
-
-#ifdef NO_D_INO_IN_DIRENT
-#define SORT_DIRENT 0
-#define DIRENT_SORT_HINT(de) 0
-#else
-#define SORT_DIRENT 1
-#define DIRENT_SORT_HINT(de) ((de)->d_ino)
-#endif
-
-static void objreport(struct object *obj, const char *severity,
-                      const char *err, va_list params)
-{
-       fprintf(stderr, "%s in %s %s: ",
-               severity, typename(obj->type), sha1_to_hex(obj->sha1));
-       vfprintf(stderr, err, params);
-       fputs("\n", stderr);
-}
-
-static int objerror(struct object *obj, const char *err, ...)
-{
-       va_list params;
-       va_start(params, err);
-       objreport(obj, "error", err, params);
-       va_end(params);
-       return -1;
-}
-
-static int objwarning(struct object *obj, const char *err, ...)
+static int fsck_walk_tree(struct tree *tree, fsck_walk_func walk, void *data)
 {
-       va_list params;
-       va_start(params, err);
-       objreport(obj, "warning", err, params);
-       va_end(params);
-       return -1;
-}
+       struct tree_desc desc;
+       struct name_entry entry;
+       int res = 0;
 
-/*
- * Check a single reachable object
- */
-static void check_reachable_object(struct object *obj)
-{
-       const struct object_refs *refs;
+       if (parse_tree(tree))
+               return -1;
 
-       /*
-        * We obviously want the object to be parsed,
-        * except if it was in a pack-file and we didn't
-        * do a full fsck
-        */
-       if (!obj->parsed) {
-               if (has_sha1_file(obj->sha1))
-                       return; /* it is in pack - forget about it */
-               printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
-               return;
-       }
+       init_tree_desc(&desc, tree->buffer, tree->size);
+       while (tree_entry(&desc, &entry)) {
+               int result;
 
-       /*
-        * Check that everything that we try to reference is also good.
-        */
-       refs = lookup_object_refs(obj);
-       if (refs) {
-               unsigned j;
-               for (j = 0; j < refs->count; j++) {
-                       struct object *ref = refs->ref[j];
-                       if (ref->parsed ||
-                           (has_sha1_file(ref->sha1)))
-                               continue;
-                       printf("broken link from %7s %s\n",
-                              typename(obj->type), sha1_to_hex(obj->sha1));
-                       printf("              to %7s %s\n",
-                              typename(ref->type), sha1_to_hex(ref->sha1));
+               if (S_ISGITLINK(entry.mode))
+                       continue;
+               if (S_ISDIR(entry.mode))
+                       result = walk(&lookup_tree(entry.sha1)->object, OBJ_TREE, data);
+               else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
+                       result = walk(&lookup_blob(entry.sha1)->object, OBJ_BLOB, data);
+               else {
+                       result = error("in tree %s: entry %s has bad mode %.6o\n",
+                                       sha1_to_hex(tree->object.sha1), entry.path, entry.mode);
                }
+               if (result < 0)
+                       return result;
+               if (!res)
+                       res = result;
        }
+       return res;
 }
 
-/*
- * Check a single unreachable object
- */
-static void check_unreachable_object(struct object *obj)
+static int fsck_walk_commit(struct commit *commit, fsck_walk_func walk, void *data)
 {
-       /*
-        * Missing unreachable object? Ignore it. It's not like
-        * we miss it (since it can't be reached), nor do we want
-        * to complain about it being unreachable (since it does
-        * not exist).
-        */
-       if (!obj->parsed)
-               return;
-
-       /*
-        * Unreachable object that exists? Show it if asked to,
-        * since this is something that is prunable.
-        */
-       if (show_unreachable) {
-               printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
-               return;
-       }
-
-       /*
-        * "!used" means that nothing at all points to it, including
-        * other unreacahble objects. In other words, it's the "tip"
-        * of some set of unreachable objects, usually a commit that
-        * got dropped.
-        *
-        * Such starting points are more interesting than some random
-        * set of unreachable objects, so we show them even if the user
-        * hasn't asked for _all_ unreachable objects. If you have
-        * deleted a branch by mistake, this is a prime candidate to
-        * start looking at, for example.
-        */
-       if (!obj->used) {
-               printf("dangling %s %s\n", typename(obj->type),
-                      sha1_to_hex(obj->sha1));
-               return;
+       struct commit_list *parents;
+       int res;
+       int result;
+
+       if (parse_commit(commit))
+               return -1;
+
+       result = walk((struct object *)commit->tree, OBJ_TREE, data);
+       if (result < 0)
+               return result;
+       res = result;
+
+       parents = commit->parents;
+       while (parents) {
+               result = walk((struct object *)parents->item, OBJ_COMMIT, data);
+               if (result < 0)
+                       return result;
+               if (!res)
+                       res = result;
+               parents = parents->next;
        }
-
-       /*
-        * Otherwise? It's there, it's unreachable, and some other unreachable
-        * object points to it. Ignore it - it's not interesting, and we showed
-        * all the interesting cases above.
-        */
+       return res;
 }
 
-static void check_object(struct object *obj)
+static int fsck_walk_tag(struct tag *tag, fsck_walk_func walk, void *data)
 {
-       if (obj->flags & REACHABLE)
-               check_reachable_object(obj);
-       else
-               check_unreachable_object(obj);
+       if (parse_tag(tag))
+               return -1;
+       return walk(tag->tagged, OBJ_ANY, data);
 }
 
-static void check_connectivity(void)
+int fsck_walk(struct object *obj, fsck_walk_func walk, void *data)
 {
-       int i, max;
-
-       /* Look up all the requirements, warn about missing objects.. */
-       max = get_max_object_index();
-       for (i = 0; i < max; i++) {
-               struct object *obj = get_indexed_object(i);
-
-               if (obj)
-                       check_object(obj);
+       if (!obj)
+               return -1;
+       switch (obj->type) {
+       case OBJ_BLOB:
+               return 0;
+       case OBJ_TREE:
+               return fsck_walk_tree((struct tree *)obj, walk, data);
+       case OBJ_COMMIT:
+               return fsck_walk_commit((struct commit *)obj, walk, data);
+       case OBJ_TAG:
+               return fsck_walk_tag((struct tag *)obj, walk, data);
+       default:
+               error("Unknown object type for %s", sha1_to_hex(obj->sha1));
+               return -1;
        }
 }
 
@@ -208,10 +136,11 @@ static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, con
        return c1 < c2 ? 0 : TREE_UNORDERED;
 }
 
-static int fsck_tree(struct tree *item)
+static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
 {
        int retval;
        int has_full_path = 0;
+       int has_empty_name = 0;
        int has_zero_pad = 0;
        int has_bad_modes = 0;
        int has_dup_entries = 0;
@@ -221,12 +150,12 @@ static int fsck_tree(struct tree *item)
        const char *o_name;
        const unsigned char *o_sha1;
 
-       desc.buf = item->buffer;
-       desc.size = item->size;
+       init_tree_desc(&desc, item->buffer, item->size);
 
        o_mode = 0;
        o_name = NULL;
        o_sha1 = NULL;
+
        while (desc.size) {
                unsigned mode;
                const char *name;
@@ -236,7 +165,9 @@ static int fsck_tree(struct tree *item)
 
                if (strchr(name, '/'))
                        has_full_path = 1;
-               has_zero_pad |= *(char *)desc.buf == '0';
+               if (!*name)
+                       has_empty_name = 1;
+               has_zero_pad |= *(char *)desc.buffer == '0';
                update_tree_entry(&desc);
 
                switch (mode) {
@@ -247,6 +178,7 @@ static int fsck_tree(struct tree *item)
                case S_IFREG | 0644:
                case S_IFLNK:
                case S_IFDIR:
+               case S_IFGITLINK:
                        break;
                /*
                 * This is nonstandard, but we had a few of these
@@ -254,7 +186,7 @@ static int fsck_tree(struct tree *item)
                 * bits..
                 */
                case S_IFREG | 0664:
-                       if (!check_strict)
+                       if (!strict)
                                break;
                default:
                        has_bad_modes = 1;
@@ -277,414 +209,124 @@ static int fsck_tree(struct tree *item)
                o_name = name;
                o_sha1 = sha1;
        }
-       free(item->buffer);
-       item->buffer = NULL;
 
        retval = 0;
-       if (has_full_path) {
-               objwarning(&item->object, "contains full pathnames");
-       }
-       if (has_zero_pad) {
-               objwarning(&item->object, "contains zero-padded file modes");
-       }
-       if (has_bad_modes) {
-               objwarning(&item->object, "contains bad file modes");
-       }
-       if (has_dup_entries) {
-               retval = objerror(&item->object, "contains duplicate file entries");
-       }
-       if (not_properly_sorted) {
-               retval = objerror(&item->object, "not properly sorted");
-       }
+       if (has_full_path)
+               retval += error_func(&item->object, FSCK_WARN, "contains full pathnames");
+       if (has_empty_name)
+               retval += error_func(&item->object, FSCK_WARN, "contains empty pathname");
+       if (has_zero_pad)
+               retval += error_func(&item->object, FSCK_WARN, "contains zero-padded file modes");
+       if (has_bad_modes)
+               retval += error_func(&item->object, FSCK_WARN, "contains bad file modes");
+       if (has_dup_entries)
+               retval += error_func(&item->object, FSCK_ERROR, "contains duplicate file entries");
+       if (not_properly_sorted)
+               retval += error_func(&item->object, FSCK_ERROR, "not properly sorted");
        return retval;
 }
 
-static int fsck_commit(struct commit *commit)
+static int fsck_commit(struct commit *commit, fsck_error error_func)
 {
        char *buffer = commit->buffer;
        unsigned char tree_sha1[20], sha1[20];
+       struct commit_graft *graft;
+       int parents = 0;
+
+       if (!commit->date)
+               return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
 
        if (memcmp(buffer, "tree ", 5))
-               return objerror(&commit->object, "invalid format - expected 'tree' line");
+               return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
        if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
-               return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
+               return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
        buffer += 46;
        while (!memcmp(buffer, "parent ", 7)) {
                if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
-                       return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
+                       return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
                buffer += 48;
+               parents++;
+       }
+       graft = lookup_commit_graft(commit->object.sha1);
+       if (graft) {
+               struct commit_list *p = commit->parents;
+               parents = 0;
+               while (p) {
+                       p = p->next;
+                       parents++;
+               }
+               if (graft->nr_parent == -1 && !parents)
+                       ; /* shallow commit */
+               else if (graft->nr_parent != parents)
+                       return error_func(&commit->object, FSCK_ERROR, "graft objects missing");
+       } else {
+               struct commit_list *p = commit->parents;
+               while (p && parents) {
+                       p = p->next;
+                       parents--;
+               }
+               if (p || parents)
+                       return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
        }
        if (memcmp(buffer, "author ", 7))
-               return objerror(&commit->object, "invalid format - expected 'author' line");
-       free(commit->buffer);
-       commit->buffer = NULL;
+               return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
        if (!commit->tree)
-               return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
-       if (!commit->parents && show_root)
-               printf("root %s\n", sha1_to_hex(commit->object.sha1));
-       if (!commit->date)
-               printf("bad commit date in %s\n", 
-                      sha1_to_hex(commit->object.sha1));
+               return error_func(&commit->object, FSCK_ERROR, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
+
        return 0;
 }
 
-static int fsck_tag(struct tag *tag)
+static int fsck_tag(struct tag *tag, fsck_error error_func)
 {
        struct object *tagged = tag->tagged;
 
-       if (!tagged) {
-               return objerror(&tag->object, "could not load tagged object");
-       }
-       if (!show_tags)
-               return 0;
-
-       printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1));
-       printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
+       if (!tagged)
+               return error_func(&tag->object, FSCK_ERROR, "could not load tagged object");
        return 0;
 }
 
-static int fsck_sha1(unsigned char *sha1)
+int fsck_object(struct object *obj, int strict, fsck_error error_func)
 {
-       struct object *obj = parse_object(sha1);
        if (!obj)
-               return error("%s: object corrupt or missing", sha1_to_hex(sha1));
-       if (obj->flags & SEEN)
-               return 0;
-       obj->flags |= SEEN;
+               return error_func(obj, FSCK_ERROR, "no valid object to fsck");
+
        if (obj->type == OBJ_BLOB)
                return 0;
        if (obj->type == OBJ_TREE)
-               return fsck_tree((struct tree *) obj);
+               return fsck_tree((struct tree *) obj, strict, error_func);
        if (obj->type == OBJ_COMMIT)
-               return fsck_commit((struct commit *) obj);
+               return fsck_commit((struct commit *) obj, error_func);
        if (obj->type == OBJ_TAG)
-               return fsck_tag((struct tag *) obj);
-       /* By now, parse_object() would've returned NULL instead. */
-       return objerror(obj, "unknown type '%d' (internal fsck error)", obj->type);
-}
+               return fsck_tag((struct tag *) obj, error_func);
 
-/*
- * This is the sorting chunk size: make it reasonably
- * big so that we can sort well..
- */
-#define MAX_SHA1_ENTRIES (1024)
-
-struct sha1_entry {
-       unsigned long ino;
-       unsigned char sha1[20];
-};
-
-static struct {
-       unsigned long nr;
-       struct sha1_entry *entry[MAX_SHA1_ENTRIES];
-} sha1_list;
-
-static int ino_compare(const void *_a, const void *_b)
-{
-       const struct sha1_entry *a = _a, *b = _b;
-       unsigned long ino1 = a->ino, ino2 = b->ino;
-       return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
-}
-
-static void fsck_sha1_list(void)
-{
-       int i, nr = sha1_list.nr;
-
-       if (SORT_DIRENT)
-               qsort(sha1_list.entry, nr,
-                     sizeof(struct sha1_entry *), ino_compare);
-       for (i = 0; i < nr; i++) {
-               struct sha1_entry *entry = sha1_list.entry[i];
-               unsigned char *sha1 = entry->sha1;
-
-               sha1_list.entry[i] = NULL;
-               fsck_sha1(sha1);
-               free(entry);
-       }
-       sha1_list.nr = 0;
+       return error_func(obj, FSCK_ERROR, "unknown type '%d' (internal fsck error)",
+                         obj->type);
 }
 
-static void add_sha1_list(unsigned char *sha1, unsigned long ino)
+int fsck_error_function(struct object *obj, int type, const char *fmt, ...)
 {
-       struct sha1_entry *entry = xmalloc(sizeof(*entry));
-       int nr;
-
-       entry->ino = ino;
-       hashcpy(entry->sha1, sha1);
-       nr = sha1_list.nr;
-       if (nr == MAX_SHA1_ENTRIES) {
-               fsck_sha1_list();
-               nr = 0;
+       va_list ap;
+       int len;
+       struct strbuf sb = STRBUF_INIT;
+
+       strbuf_addf(&sb, "object %s:", obj->sha1?sha1_to_hex(obj->sha1):"(null)");
+
+       va_start(ap, fmt);
+       len = vsnprintf(sb.buf + sb.len, strbuf_avail(&sb), fmt, ap);
+       va_end(ap);
+
+       if (len < 0)
+               len = 0;
+       if (len >= strbuf_avail(&sb)) {
+               strbuf_grow(&sb, len + 2);
+               va_start(ap, fmt);
+               len = vsnprintf(sb.buf + sb.len, strbuf_avail(&sb), fmt, ap);
+               va_end(ap);
+               if (len >= strbuf_avail(&sb))
+                       die("this should not happen, your snprintf is broken");
        }
-       sha1_list.entry[nr] = entry;
-       sha1_list.nr = ++nr;
-}
-
-static void fsck_dir(int i, char *path)
-{
-       DIR *dir = opendir(path);
-       struct dirent *de;
-
-       if (!dir)
-               return;
-
-       while ((de = readdir(dir)) != NULL) {
-               char name[100];
-               unsigned char sha1[20];
-               int len = strlen(de->d_name);
 
-               switch (len) {
-               case 2:
-                       if (de->d_name[1] != '.')
-                               break;
-               case 1:
-                       if (de->d_name[0] != '.')
-                               break;
-                       continue;
-               case 38:
-                       sprintf(name, "%02x", i);
-                       memcpy(name+2, de->d_name, len+1);
-                       if (get_sha1_hex(name, sha1) < 0)
-                               break;
-                       add_sha1_list(sha1, DIRENT_SORT_HINT(de));
-                       continue;
-               }
-               fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
-       }
-       closedir(dir);
-}
-
-static int default_refs;
-
-static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
-               const char *email, unsigned long timestamp, int tz,
-               const char *message, void *cb_data)
-{
-       struct object *obj;
-
-       if (!is_null_sha1(osha1)) {
-               obj = lookup_object(osha1);
-               if (obj) {
-                       obj->used = 1;
-                       mark_reachable(obj, REACHABLE);
-               }
-       }
-       obj = lookup_object(nsha1);
-       if (obj) {
-               obj->used = 1;
-               mark_reachable(obj, REACHABLE);
-       }
-       return 0;
-}
-
-static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
-{
-       struct object *obj;
-
-       obj = lookup_object(sha1);
-       if (!obj) {
-               if (has_sha1_file(sha1)) {
-                       default_refs++;
-                       return 0; /* it is in a pack */
-               }
-               error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
-               /* We'll continue with the rest despite the error.. */
-               return 0;
-       }
-       default_refs++;
-       obj->used = 1;
-       mark_reachable(obj, REACHABLE);
-
-       for_each_reflog_ent(refname, fsck_handle_reflog_ent, NULL);
-
-       return 0;
-}
-
-static void get_default_heads(void)
-{
-       for_each_ref(fsck_handle_ref, NULL);
-
-       /*
-        * Not having any default heads isn't really fatal, but
-        * it does mean that "--unreachable" no longer makes any
-        * sense (since in this case everything will obviously
-        * be unreachable by definition.
-        *
-        * Showing dangling objects is valid, though (as those
-        * dangling objects are likely lost heads).
-        *
-        * So we just print a warning about it, and clear the
-        * "show_unreachable" flag.
-        */
-       if (!default_refs) {
-               error("No default references");
-               show_unreachable = 0;
-       }
-}
-
-static void fsck_object_dir(const char *path)
-{
-       int i;
-       for (i = 0; i < 256; i++) {
-               static char dir[4096];
-               sprintf(dir, "%s/%02x", path, i);
-               fsck_dir(i, dir);
-       }
-       fsck_sha1_list();
-}
-
-static int fsck_head_link(void)
-{
-       unsigned char sha1[20];
-       int flag;
-       const char *head_points_at = resolve_ref("HEAD", sha1, 1, &flag);
-
-       if (!head_points_at || !(flag & REF_ISSYMREF))
-               return error("HEAD is not a symbolic ref");
-       if (strncmp(head_points_at, "refs/heads/", 11))
-               return error("HEAD points to something strange (%s)",
-                            head_points_at);
-       if (is_null_sha1(sha1))
-               return error("HEAD: not a valid git pointer");
-       return 0;
-}
-
-static int fsck_cache_tree(struct cache_tree *it)
-{
-       int i;
-       int err = 0;
-
-       if (0 <= it->entry_count) {
-               struct object *obj = parse_object(it->sha1);
-               if (!obj) {
-                       error("%s: invalid sha1 pointer in cache-tree",
-                             sha1_to_hex(it->sha1));
-                       return 1;
-               }
-               mark_reachable(obj, REACHABLE);
-               obj->used = 1;
-               if (obj->type != OBJ_TREE)
-                       err |= objerror(obj, "non-tree in cache-tree");
-       }
-       for (i = 0; i < it->subtree_nr; i++)
-               err |= fsck_cache_tree(it->down[i]->cache_tree);
-       return err;
-}
-
-int main(int argc, char **argv)
-{
-       int i, heads;
-
-       track_object_refs = 1;
-       setup_git_directory();
-
-       for (i = 1; i < argc; i++) {
-               const char *arg = argv[i];
-
-               if (!strcmp(arg, "--unreachable")) {
-                       show_unreachable = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--tags")) {
-                       show_tags = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--root")) {
-                       show_root = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--cache")) {
-                       keep_cache_objects = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--full")) {
-                       check_full = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--strict")) {
-                       check_strict = 1;
-                       continue;
-               }
-               if (*arg == '-')
-                       usage("git-fsck [--tags] [--root] [[--unreachable] [--cache] [--full] [--strict] <head-sha1>*]");
-       }
-
-       fsck_head_link();
-       fsck_object_dir(get_object_directory());
-       if (check_full) {
-               struct alternate_object_database *alt;
-               struct packed_git *p;
-               prepare_alt_odb();
-               for (alt = alt_odb_list; alt; alt = alt->next) {
-                       char namebuf[PATH_MAX];
-                       int namelen = alt->name - alt->base;
-                       memcpy(namebuf, alt->base, namelen);
-                       namebuf[namelen - 1] = 0;
-                       fsck_object_dir(namebuf);
-               }
-               prepare_packed_git();
-               for (p = packed_git; p; p = p->next)
-                       /* verify gives error messages itself */
-                       verify_pack(p, 0);
-
-               for (p = packed_git; p; p = p->next) {
-                       int num = num_packed_objects(p);
-                       for (i = 0; i < num; i++) {
-                               unsigned char sha1[20];
-                               nth_packed_object_sha1(p, i, sha1);
-                               fsck_sha1(sha1);
-                       }
-               }
-       }
-
-       heads = 0;
-       for (i = 1; i < argc; i++) {
-               const char *arg = argv[i]; 
-
-               if (*arg == '-')
-                       continue;
-
-               if (!get_sha1(arg, head_sha1)) {
-                       struct object *obj = lookup_object(head_sha1);
-
-                       /* Error is printed by lookup_object(). */
-                       if (!obj)
-                               continue;
-
-                       obj->used = 1;
-                       mark_reachable(obj, REACHABLE);
-                       heads++;
-                       continue;
-               }
-               error("invalid parameter: expected sha1, got '%s'", arg);
-       }
-
-       /*
-        * If we've not been given any explicit head information, do the
-        * default ones from .git/refs. We also consider the index file
-        * in this case (ie this implies --cache).
-        */
-       if (!heads) {
-               get_default_heads();
-               keep_cache_objects = 1;
-       }
-
-       if (keep_cache_objects) {
-               int i;
-               read_cache();
-               for (i = 0; i < active_nr; i++) {
-                       struct blob *blob = lookup_blob(active_cache[i]->sha1);
-                       struct object *obj;
-                       if (!blob)
-                               continue;
-                       obj = &blob->object;
-                       obj->used = 1;
-                       mark_reachable(obj, REACHABLE);
-               }
-               if (active_cache_tree)
-                       fsck_cache_tree(active_cache_tree);
-       }
-
-       check_connectivity();
-       return 0;
+       error(sb.buf);
+       strbuf_release(&sb);
+       return 1;
 }