packfile: add repository argument to prepare_packed_git
[git] / builtin / fsck.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "repository.h"
4 #include "config.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "blob.h"
8 #include "tag.h"
9 #include "refs.h"
10 #include "pack.h"
11 #include "cache-tree.h"
12 #include "tree-walk.h"
13 #include "fsck.h"
14 #include "parse-options.h"
15 #include "dir.h"
16 #include "progress.h"
17 #include "streaming.h"
18 #include "decorate.h"
19 #include "packfile.h"
20 #include "object-store.h"
21
22 #define REACHABLE 0x0001
23 #define SEEN      0x0002
24 #define HAS_OBJ   0x0004
25 /* This flag is set if something points to this object. */
26 #define USED      0x0008
27
28 static int show_root;
29 static int show_tags;
30 static int show_unreachable;
31 static int include_reflogs = 1;
32 static int check_full = 1;
33 static int connectivity_only;
34 static int check_strict;
35 static int keep_cache_objects;
36 static struct fsck_options fsck_walk_options = FSCK_OPTIONS_DEFAULT;
37 static struct fsck_options fsck_obj_options = FSCK_OPTIONS_DEFAULT;
38 static struct object_id head_oid;
39 static const char *head_points_at;
40 static int errors_found;
41 static int write_lost_and_found;
42 static int verbose;
43 static int show_progress = -1;
44 static int show_dangling = 1;
45 static int name_objects;
46 #define ERROR_OBJECT 01
47 #define ERROR_REACHABLE 02
48 #define ERROR_PACK 04
49 #define ERROR_REFS 010
50
51 static const char *describe_object(struct object *obj)
52 {
53         static struct strbuf buf = STRBUF_INIT;
54         char *name = name_objects ?
55                 lookup_decoration(fsck_walk_options.object_names, obj) : NULL;
56
57         strbuf_reset(&buf);
58         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
59         if (name)
60                 strbuf_addf(&buf, " (%s)", name);
61
62         return buf.buf;
63 }
64
65 static const char *printable_type(struct object *obj)
66 {
67         const char *ret;
68
69         if (obj->type == OBJ_NONE) {
70                 enum object_type type = sha1_object_info(obj->oid.hash, NULL);
71                 if (type > 0)
72                         object_as_type(obj, type, 0);
73         }
74
75         ret = typename(obj->type);
76         if (!ret)
77                 ret = "unknown";
78
79         return ret;
80 }
81
82 static int fsck_config(const char *var, const char *value, void *cb)
83 {
84         if (strcmp(var, "fsck.skiplist") == 0) {
85                 const char *path;
86                 struct strbuf sb = STRBUF_INIT;
87
88                 if (git_config_pathname(&path, var, value))
89                         return 1;
90                 strbuf_addf(&sb, "skiplist=%s", path);
91                 free((char *)path);
92                 fsck_set_msg_types(&fsck_obj_options, sb.buf);
93                 strbuf_release(&sb);
94                 return 0;
95         }
96
97         if (skip_prefix(var, "fsck.", &var)) {
98                 fsck_set_msg_type(&fsck_obj_options, var, value);
99                 return 0;
100         }
101
102         return git_default_config(var, value, cb);
103 }
104
105 static void objreport(struct object *obj, const char *msg_type,
106                         const char *err)
107 {
108         fprintf(stderr, "%s in %s %s: %s\n",
109                 msg_type, printable_type(obj), describe_object(obj), err);
110 }
111
112 static int objerror(struct object *obj, const char *err)
113 {
114         errors_found |= ERROR_OBJECT;
115         objreport(obj, "error", err);
116         return -1;
117 }
118
119 static int fsck_error_func(struct fsck_options *o,
120         struct object *obj, int type, const char *message)
121 {
122         objreport(obj, (type == FSCK_WARN) ? "warning" : "error", message);
123         return (type == FSCK_WARN) ? 0 : 1;
124 }
125
126 static struct object_array pending;
127
128 static int mark_object(struct object *obj, int type, void *data, struct fsck_options *options)
129 {
130         struct object *parent = data;
131
132         /*
133          * The only case data is NULL or type is OBJ_ANY is when
134          * mark_object_reachable() calls us.  All the callers of
135          * that function has non-NULL obj hence ...
136          */
137         if (!obj) {
138                 /* ... these references to parent->fld are safe here */
139                 printf("broken link from %7s %s\n",
140                            printable_type(parent), describe_object(parent));
141                 printf("broken link from %7s %s\n",
142                            (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
143                 errors_found |= ERROR_REACHABLE;
144                 return 1;
145         }
146
147         if (type != OBJ_ANY && obj->type != type)
148                 /* ... and the reference to parent is safe here */
149                 objerror(parent, "wrong object type in link");
150
151         if (obj->flags & REACHABLE)
152                 return 0;
153         obj->flags |= REACHABLE;
154
155         if (is_promisor_object(&obj->oid))
156                 /*
157                  * Further recursion does not need to be performed on this
158                  * object since it is a promisor object (so it does not need to
159                  * be added to "pending").
160                  */
161                 return 0;
162
163         if (!(obj->flags & HAS_OBJ)) {
164                 if (parent && !has_object_file(&obj->oid)) {
165                         printf("broken link from %7s %s\n",
166                                  printable_type(parent), describe_object(parent));
167                         printf("              to %7s %s\n",
168                                  printable_type(obj), describe_object(obj));
169                         errors_found |= ERROR_REACHABLE;
170                 }
171                 return 1;
172         }
173
174         add_object_array(obj, NULL, &pending);
175         return 0;
176 }
177
178 static void mark_object_reachable(struct object *obj)
179 {
180         mark_object(obj, OBJ_ANY, NULL, NULL);
181 }
182
183 static int traverse_one_object(struct object *obj)
184 {
185         return fsck_walk(obj, obj, &fsck_walk_options);
186 }
187
188 static int traverse_reachable(void)
189 {
190         struct progress *progress = NULL;
191         unsigned int nr = 0;
192         int result = 0;
193         if (show_progress)
194                 progress = start_delayed_progress(_("Checking connectivity"), 0);
195         while (pending.nr) {
196                 result |= traverse_one_object(object_array_pop(&pending));
197                 display_progress(progress, ++nr);
198         }
199         stop_progress(&progress);
200         return !!result;
201 }
202
203 static int mark_used(struct object *obj, int type, void *data, struct fsck_options *options)
204 {
205         if (!obj)
206                 return 1;
207         obj->flags |= USED;
208         return 0;
209 }
210
211 /*
212  * Check a single reachable object
213  */
214 static void check_reachable_object(struct object *obj)
215 {
216         /*
217          * We obviously want the object to be parsed,
218          * except if it was in a pack-file and we didn't
219          * do a full fsck
220          */
221         if (!(obj->flags & HAS_OBJ)) {
222                 if (is_promisor_object(&obj->oid))
223                         return;
224                 if (has_sha1_pack(obj->oid.hash))
225                         return; /* it is in pack - forget about it */
226                 printf("missing %s %s\n", printable_type(obj),
227                         describe_object(obj));
228                 errors_found |= ERROR_REACHABLE;
229                 return;
230         }
231 }
232
233 /*
234  * Check a single unreachable object
235  */
236 static void check_unreachable_object(struct object *obj)
237 {
238         /*
239          * Missing unreachable object? Ignore it. It's not like
240          * we miss it (since it can't be reached), nor do we want
241          * to complain about it being unreachable (since it does
242          * not exist).
243          */
244         if (!(obj->flags & HAS_OBJ))
245                 return;
246
247         /*
248          * Unreachable object that exists? Show it if asked to,
249          * since this is something that is prunable.
250          */
251         if (show_unreachable) {
252                 printf("unreachable %s %s\n", printable_type(obj),
253                         describe_object(obj));
254                 return;
255         }
256
257         /*
258          * "!USED" means that nothing at all points to it, including
259          * other unreachable objects. In other words, it's the "tip"
260          * of some set of unreachable objects, usually a commit that
261          * got dropped.
262          *
263          * Such starting points are more interesting than some random
264          * set of unreachable objects, so we show them even if the user
265          * hasn't asked for _all_ unreachable objects. If you have
266          * deleted a branch by mistake, this is a prime candidate to
267          * start looking at, for example.
268          */
269         if (!(obj->flags & USED)) {
270                 if (show_dangling)
271                         printf("dangling %s %s\n", printable_type(obj),
272                                describe_object(obj));
273                 if (write_lost_and_found) {
274                         char *filename = git_pathdup("lost-found/%s/%s",
275                                 obj->type == OBJ_COMMIT ? "commit" : "other",
276                                 describe_object(obj));
277                         FILE *f;
278
279                         if (safe_create_leading_directories_const(filename)) {
280                                 error("Could not create lost-found");
281                                 free(filename);
282                                 return;
283                         }
284                         f = xfopen(filename, "w");
285                         if (obj->type == OBJ_BLOB) {
286                                 if (stream_blob_to_fd(fileno(f), &obj->oid, NULL, 1))
287                                         die_errno("Could not write '%s'", filename);
288                         } else
289                                 fprintf(f, "%s\n", describe_object(obj));
290                         if (fclose(f))
291                                 die_errno("Could not finish '%s'",
292                                           filename);
293                         free(filename);
294                 }
295                 return;
296         }
297
298         /*
299          * Otherwise? It's there, it's unreachable, and some other unreachable
300          * object points to it. Ignore it - it's not interesting, and we showed
301          * all the interesting cases above.
302          */
303 }
304
305 static void check_object(struct object *obj)
306 {
307         if (verbose)
308                 fprintf(stderr, "Checking %s\n", describe_object(obj));
309
310         if (obj->flags & REACHABLE)
311                 check_reachable_object(obj);
312         else
313                 check_unreachable_object(obj);
314 }
315
316 static void check_connectivity(void)
317 {
318         int i, max;
319
320         /* Traverse the pending reachable objects */
321         traverse_reachable();
322
323         /* Look up all the requirements, warn about missing objects.. */
324         max = get_max_object_index();
325         if (verbose)
326                 fprintf(stderr, "Checking connectivity (%d objects)\n", max);
327
328         for (i = 0; i < max; i++) {
329                 struct object *obj = get_indexed_object(i);
330
331                 if (obj)
332                         check_object(obj);
333         }
334 }
335
336 static int fsck_obj(struct object *obj)
337 {
338         int err;
339
340         if (obj->flags & SEEN)
341                 return 0;
342         obj->flags |= SEEN;
343
344         if (verbose)
345                 fprintf(stderr, "Checking %s %s\n",
346                         printable_type(obj), describe_object(obj));
347
348         if (fsck_walk(obj, NULL, &fsck_obj_options))
349                 objerror(obj, "broken links");
350         err = fsck_object(obj, NULL, 0, &fsck_obj_options);
351         if (err)
352                 goto out;
353
354         if (obj->type == OBJ_COMMIT) {
355                 struct commit *commit = (struct commit *) obj;
356
357                 if (!commit->parents && show_root)
358                         printf("root %s\n", describe_object(&commit->object));
359         }
360
361         if (obj->type == OBJ_TAG) {
362                 struct tag *tag = (struct tag *) obj;
363
364                 if (show_tags && tag->tagged) {
365                         printf("tagged %s %s", printable_type(tag->tagged),
366                                 describe_object(tag->tagged));
367                         printf(" (%s) in %s\n", tag->tag,
368                                 describe_object(&tag->object));
369                 }
370         }
371
372 out:
373         if (obj->type == OBJ_TREE)
374                 free_tree_buffer((struct tree *)obj);
375         if (obj->type == OBJ_COMMIT)
376                 free_commit_buffer((struct commit *)obj);
377         return err;
378 }
379
380 static int fsck_obj_buffer(const struct object_id *oid, enum object_type type,
381                            unsigned long size, void *buffer, int *eaten)
382 {
383         /*
384          * Note, buffer may be NULL if type is OBJ_BLOB. See
385          * verify_packfile(), data_valid variable for details.
386          */
387         struct object *obj;
388         obj = parse_object_buffer(oid, type, size, buffer, eaten);
389         if (!obj) {
390                 errors_found |= ERROR_OBJECT;
391                 return error("%s: object corrupt or missing", oid_to_hex(oid));
392         }
393         obj->flags &= ~(REACHABLE | SEEN);
394         obj->flags |= HAS_OBJ;
395         return fsck_obj(obj);
396 }
397
398 static int default_refs;
399
400 static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
401         timestamp_t timestamp)
402 {
403         struct object *obj;
404
405         if (!is_null_oid(oid)) {
406                 obj = lookup_object(oid->hash);
407                 if (obj && (obj->flags & HAS_OBJ)) {
408                         if (timestamp && name_objects)
409                                 add_decoration(fsck_walk_options.object_names,
410                                         obj,
411                                         xstrfmt("%s@{%"PRItime"}", refname, timestamp));
412                         obj->flags |= USED;
413                         mark_object_reachable(obj);
414                 } else if (!is_promisor_object(oid)) {
415                         error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
416                         errors_found |= ERROR_REACHABLE;
417                 }
418         }
419 }
420
421 static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid,
422                 const char *email, timestamp_t timestamp, int tz,
423                 const char *message, void *cb_data)
424 {
425         const char *refname = cb_data;
426
427         if (verbose)
428                 fprintf(stderr, "Checking reflog %s->%s\n",
429                         oid_to_hex(ooid), oid_to_hex(noid));
430
431         fsck_handle_reflog_oid(refname, ooid, 0);
432         fsck_handle_reflog_oid(refname, noid, timestamp);
433         return 0;
434 }
435
436 static int fsck_handle_reflog(const char *logname, const struct object_id *oid,
437                               int flag, void *cb_data)
438 {
439         for_each_reflog_ent(logname, fsck_handle_reflog_ent, (void *)logname);
440         return 0;
441 }
442
443 static int fsck_handle_ref(const char *refname, const struct object_id *oid,
444                            int flag, void *cb_data)
445 {
446         struct object *obj;
447
448         obj = parse_object(oid);
449         if (!obj) {
450                 if (is_promisor_object(oid)) {
451                         /*
452                          * Increment default_refs anyway, because this is a
453                          * valid ref.
454                          */
455                          default_refs++;
456                          return 0;
457                 }
458                 error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
459                 errors_found |= ERROR_REACHABLE;
460                 /* We'll continue with the rest despite the error.. */
461                 return 0;
462         }
463         if (obj->type != OBJ_COMMIT && is_branch(refname)) {
464                 error("%s: not a commit", refname);
465                 errors_found |= ERROR_REFS;
466         }
467         default_refs++;
468         obj->flags |= USED;
469         if (name_objects)
470                 add_decoration(fsck_walk_options.object_names,
471                         obj, xstrdup(refname));
472         mark_object_reachable(obj);
473
474         return 0;
475 }
476
477 static void get_default_heads(void)
478 {
479         if (head_points_at && !is_null_oid(&head_oid))
480                 fsck_handle_ref("HEAD", &head_oid, 0, NULL);
481         for_each_rawref(fsck_handle_ref, NULL);
482         if (include_reflogs)
483                 for_each_reflog(fsck_handle_reflog, NULL);
484
485         /*
486          * Not having any default heads isn't really fatal, but
487          * it does mean that "--unreachable" no longer makes any
488          * sense (since in this case everything will obviously
489          * be unreachable by definition.
490          *
491          * Showing dangling objects is valid, though (as those
492          * dangling objects are likely lost heads).
493          *
494          * So we just print a warning about it, and clear the
495          * "show_unreachable" flag.
496          */
497         if (!default_refs) {
498                 fprintf(stderr, "notice: No default references\n");
499                 show_unreachable = 0;
500         }
501 }
502
503 static struct object *parse_loose_object(const struct object_id *oid,
504                                          const char *path)
505 {
506         struct object *obj;
507         void *contents;
508         enum object_type type;
509         unsigned long size;
510         int eaten;
511
512         if (read_loose_object(path, oid->hash, &type, &size, &contents) < 0)
513                 return NULL;
514
515         if (!contents && type != OBJ_BLOB)
516                 die("BUG: read_loose_object streamed a non-blob");
517
518         obj = parse_object_buffer(oid, type, size, contents, &eaten);
519
520         if (!eaten)
521                 free(contents);
522         return obj;
523 }
524
525 static int fsck_loose(const struct object_id *oid, const char *path, void *data)
526 {
527         struct object *obj = parse_loose_object(oid, path);
528
529         if (!obj) {
530                 errors_found |= ERROR_OBJECT;
531                 error("%s: object corrupt or missing: %s",
532                       oid_to_hex(oid), path);
533                 return 0; /* keep checking other objects */
534         }
535
536         obj->flags &= ~(REACHABLE | SEEN);
537         obj->flags |= HAS_OBJ;
538         if (fsck_obj(obj))
539                 errors_found |= ERROR_OBJECT;
540         return 0;
541 }
542
543 static int fsck_cruft(const char *basename, const char *path, void *data)
544 {
545         if (!starts_with(basename, "tmp_obj_"))
546                 fprintf(stderr, "bad sha1 file: %s\n", path);
547         return 0;
548 }
549
550 static int fsck_subdir(unsigned int nr, const char *path, void *progress)
551 {
552         display_progress(progress, nr + 1);
553         return 0;
554 }
555
556 static void fsck_object_dir(const char *path)
557 {
558         struct progress *progress = NULL;
559
560         if (verbose)
561                 fprintf(stderr, "Checking object directory\n");
562
563         if (show_progress)
564                 progress = start_progress(_("Checking object directories"), 256);
565
566         for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
567                                       progress);
568         display_progress(progress, 256);
569         stop_progress(&progress);
570 }
571
572 static int fsck_head_link(void)
573 {
574         int null_is_error = 0;
575
576         if (verbose)
577                 fprintf(stderr, "Checking HEAD link\n");
578
579         head_points_at = resolve_ref_unsafe("HEAD", 0, &head_oid, NULL);
580         if (!head_points_at) {
581                 errors_found |= ERROR_REFS;
582                 return error("Invalid HEAD");
583         }
584         if (!strcmp(head_points_at, "HEAD"))
585                 /* detached HEAD */
586                 null_is_error = 1;
587         else if (!starts_with(head_points_at, "refs/heads/")) {
588                 errors_found |= ERROR_REFS;
589                 return error("HEAD points to something strange (%s)",
590                              head_points_at);
591         }
592         if (is_null_oid(&head_oid)) {
593                 if (null_is_error) {
594                         errors_found |= ERROR_REFS;
595                         return error("HEAD: detached HEAD points at nothing");
596                 }
597                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
598                         head_points_at + 11);
599         }
600         return 0;
601 }
602
603 static int fsck_cache_tree(struct cache_tree *it)
604 {
605         int i;
606         int err = 0;
607
608         if (verbose)
609                 fprintf(stderr, "Checking cache tree\n");
610
611         if (0 <= it->entry_count) {
612                 struct object *obj = parse_object(&it->oid);
613                 if (!obj) {
614                         error("%s: invalid sha1 pointer in cache-tree",
615                               oid_to_hex(&it->oid));
616                         errors_found |= ERROR_REFS;
617                         return 1;
618                 }
619                 obj->flags |= USED;
620                 if (name_objects)
621                         add_decoration(fsck_walk_options.object_names,
622                                 obj, xstrdup(":"));
623                 mark_object_reachable(obj);
624                 if (obj->type != OBJ_TREE)
625                         err |= objerror(obj, "non-tree in cache-tree");
626         }
627         for (i = 0; i < it->subtree_nr; i++)
628                 err |= fsck_cache_tree(it->down[i]->cache_tree);
629         return err;
630 }
631
632 static void mark_object_for_connectivity(const struct object_id *oid)
633 {
634         struct object *obj = lookup_unknown_object(oid->hash);
635         obj->flags |= HAS_OBJ;
636 }
637
638 static int mark_loose_for_connectivity(const struct object_id *oid,
639                                        const char *path,
640                                        void *data)
641 {
642         mark_object_for_connectivity(oid);
643         return 0;
644 }
645
646 static int mark_packed_for_connectivity(const struct object_id *oid,
647                                         struct packed_git *pack,
648                                         uint32_t pos,
649                                         void *data)
650 {
651         mark_object_for_connectivity(oid);
652         return 0;
653 }
654
655 static char const * const fsck_usage[] = {
656         N_("git fsck [<options>] [<object>...]"),
657         NULL
658 };
659
660 static struct option fsck_opts[] = {
661         OPT__VERBOSE(&verbose, N_("be verbose")),
662         OPT_BOOL(0, "unreachable", &show_unreachable, N_("show unreachable objects")),
663         OPT_BOOL(0, "dangling", &show_dangling, N_("show dangling objects")),
664         OPT_BOOL(0, "tags", &show_tags, N_("report tags")),
665         OPT_BOOL(0, "root", &show_root, N_("report root nodes")),
666         OPT_BOOL(0, "cache", &keep_cache_objects, N_("make index objects head nodes")),
667         OPT_BOOL(0, "reflogs", &include_reflogs, N_("make reflogs head nodes (default)")),
668         OPT_BOOL(0, "full", &check_full, N_("also consider packs and alternate objects")),
669         OPT_BOOL(0, "connectivity-only", &connectivity_only, N_("check only connectivity")),
670         OPT_BOOL(0, "strict", &check_strict, N_("enable more strict checking")),
671         OPT_BOOL(0, "lost-found", &write_lost_and_found,
672                                 N_("write dangling objects in .git/lost-found")),
673         OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
674         OPT_BOOL(0, "name-objects", &name_objects, N_("show verbose names for reachable objects")),
675         OPT_END(),
676 };
677
678 int cmd_fsck(int argc, const char **argv, const char *prefix)
679 {
680         int i;
681         struct alternate_object_database *alt;
682
683         /* fsck knows how to handle missing promisor objects */
684         fetch_if_missing = 0;
685
686         errors_found = 0;
687         check_replace_refs = 0;
688
689         argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
690
691         fsck_walk_options.walk = mark_object;
692         fsck_obj_options.walk = mark_used;
693         fsck_obj_options.error_func = fsck_error_func;
694         if (check_strict)
695                 fsck_obj_options.strict = 1;
696
697         if (show_progress == -1)
698                 show_progress = isatty(2);
699         if (verbose)
700                 show_progress = 0;
701
702         if (write_lost_and_found) {
703                 check_full = 1;
704                 include_reflogs = 0;
705         }
706
707         if (name_objects)
708                 fsck_walk_options.object_names =
709                         xcalloc(1, sizeof(struct decoration));
710
711         git_config(fsck_config, NULL);
712
713         fsck_head_link();
714         if (connectivity_only) {
715                 for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
716                 for_each_packed_object(mark_packed_for_connectivity, NULL, 0);
717         } else {
718                 struct alternate_object_database *alt_odb_list;
719
720                 fsck_object_dir(get_object_directory());
721
722                 prepare_alt_odb(the_repository);
723                 alt_odb_list = the_repository->objects->alt_odb_list;
724                 for (alt = alt_odb_list; alt; alt = alt->next)
725                         fsck_object_dir(alt->path);
726
727                 if (check_full) {
728                         struct packed_git *p;
729                         uint32_t total = 0, count = 0;
730                         struct progress *progress = NULL;
731
732                         prepare_packed_git(the_repository);
733
734                         if (show_progress) {
735                                 for (p = get_packed_git(the_repository); p;
736                                      p = p->next) {
737                                         if (open_pack_index(p))
738                                                 continue;
739                                         total += p->num_objects;
740                                 }
741
742                                 progress = start_progress(_("Checking objects"), total);
743                         }
744                         for (p = get_packed_git(the_repository); p;
745                              p = p->next) {
746                                 /* verify gives error messages itself */
747                                 if (verify_pack(p, fsck_obj_buffer,
748                                                 progress, count))
749                                         errors_found |= ERROR_PACK;
750                                 count += p->num_objects;
751                         }
752                         stop_progress(&progress);
753                 }
754         }
755
756         for (i = 0; i < argc; i++) {
757                 const char *arg = argv[i];
758                 struct object_id oid;
759                 if (!get_oid(arg, &oid)) {
760                         struct object *obj = lookup_object(oid.hash);
761
762                         if (!obj || !(obj->flags & HAS_OBJ)) {
763                                 if (is_promisor_object(&oid))
764                                         continue;
765                                 error("%s: object missing", oid_to_hex(&oid));
766                                 errors_found |= ERROR_OBJECT;
767                                 continue;
768                         }
769
770                         obj->flags |= USED;
771                         if (name_objects)
772                                 add_decoration(fsck_walk_options.object_names,
773                                         obj, xstrdup(arg));
774                         mark_object_reachable(obj);
775                         continue;
776                 }
777                 error("invalid parameter: expected sha1, got '%s'", arg);
778                 errors_found |= ERROR_OBJECT;
779         }
780
781         /*
782          * If we've not been given any explicit head information, do the
783          * default ones from .git/refs. We also consider the index file
784          * in this case (ie this implies --cache).
785          */
786         if (!argc) {
787                 get_default_heads();
788                 keep_cache_objects = 1;
789         }
790
791         if (keep_cache_objects) {
792                 verify_index_checksum = 1;
793                 verify_ce_order = 1;
794                 read_cache();
795                 for (i = 0; i < active_nr; i++) {
796                         unsigned int mode;
797                         struct blob *blob;
798                         struct object *obj;
799
800                         mode = active_cache[i]->ce_mode;
801                         if (S_ISGITLINK(mode))
802                                 continue;
803                         blob = lookup_blob(&active_cache[i]->oid);
804                         if (!blob)
805                                 continue;
806                         obj = &blob->object;
807                         obj->flags |= USED;
808                         if (name_objects)
809                                 add_decoration(fsck_walk_options.object_names,
810                                         obj,
811                                         xstrfmt(":%s", active_cache[i]->name));
812                         mark_object_reachable(obj);
813                 }
814                 if (active_cache_tree)
815                         fsck_cache_tree(active_cache_tree);
816         }
817
818         check_connectivity();
819         return errors_found;
820 }