Merge branch 'nd/completion-aliasfiletype-typofix'
[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 = oid_object_info(the_repository,
71                                                         &obj->oid, NULL);
72                 if (type > 0)
73                         object_as_type(obj, type, 0);
74         }
75
76         ret = type_name(obj->type);
77         if (!ret)
78                 ret = "unknown";
79
80         return ret;
81 }
82
83 static int fsck_config(const char *var, const char *value, void *cb)
84 {
85         if (strcmp(var, "fsck.skiplist") == 0) {
86                 const char *path;
87                 struct strbuf sb = STRBUF_INIT;
88
89                 if (git_config_pathname(&path, var, value))
90                         return 1;
91                 strbuf_addf(&sb, "skiplist=%s", path);
92                 free((char *)path);
93                 fsck_set_msg_types(&fsck_obj_options, sb.buf);
94                 strbuf_release(&sb);
95                 return 0;
96         }
97
98         if (skip_prefix(var, "fsck.", &var)) {
99                 fsck_set_msg_type(&fsck_obj_options, var, value);
100                 return 0;
101         }
102
103         return git_default_config(var, value, cb);
104 }
105
106 static void objreport(struct object *obj, const char *msg_type,
107                         const char *err)
108 {
109         fprintf(stderr, "%s in %s %s: %s\n",
110                 msg_type, printable_type(obj), describe_object(obj), err);
111 }
112
113 static int objerror(struct object *obj, const char *err)
114 {
115         errors_found |= ERROR_OBJECT;
116         objreport(obj, "error", err);
117         return -1;
118 }
119
120 static int fsck_error_func(struct fsck_options *o,
121         struct object *obj, int type, const char *message)
122 {
123         objreport(obj, (type == FSCK_WARN) ? "warning" : "error", message);
124         return (type == FSCK_WARN) ? 0 : 1;
125 }
126
127 static struct object_array pending;
128
129 static int mark_object(struct object *obj, int type, void *data, struct fsck_options *options)
130 {
131         struct object *parent = data;
132
133         /*
134          * The only case data is NULL or type is OBJ_ANY is when
135          * mark_object_reachable() calls us.  All the callers of
136          * that function has non-NULL obj hence ...
137          */
138         if (!obj) {
139                 /* ... these references to parent->fld are safe here */
140                 printf("broken link from %7s %s\n",
141                            printable_type(parent), describe_object(parent));
142                 printf("broken link from %7s %s\n",
143                            (type == OBJ_ANY ? "unknown" : type_name(type)), "unknown");
144                 errors_found |= ERROR_REACHABLE;
145                 return 1;
146         }
147
148         if (type != OBJ_ANY && obj->type != type)
149                 /* ... and the reference to parent is safe here */
150                 objerror(parent, "wrong object type in link");
151
152         if (obj->flags & REACHABLE)
153                 return 0;
154         obj->flags |= REACHABLE;
155
156         if (is_promisor_object(&obj->oid))
157                 /*
158                  * Further recursion does not need to be performed on this
159                  * object since it is a promisor object (so it does not need to
160                  * be added to "pending").
161                  */
162                 return 0;
163
164         if (!(obj->flags & HAS_OBJ)) {
165                 if (parent && !has_object_file(&obj->oid)) {
166                         printf("broken link from %7s %s\n",
167                                  printable_type(parent), describe_object(parent));
168                         printf("              to %7s %s\n",
169                                  printable_type(obj), describe_object(obj));
170                         errors_found |= ERROR_REACHABLE;
171                 }
172                 return 1;
173         }
174
175         add_object_array(obj, NULL, &pending);
176         return 0;
177 }
178
179 static void mark_object_reachable(struct object *obj)
180 {
181         mark_object(obj, OBJ_ANY, NULL, NULL);
182 }
183
184 static int traverse_one_object(struct object *obj)
185 {
186         int result = fsck_walk(obj, obj, &fsck_walk_options);
187
188         if (obj->type == OBJ_TREE) {
189                 struct tree *tree = (struct tree *)obj;
190                 free_tree_buffer(tree);
191         }
192         return result;
193 }
194
195 static int traverse_reachable(void)
196 {
197         struct progress *progress = NULL;
198         unsigned int nr = 0;
199         int result = 0;
200         if (show_progress)
201                 progress = start_delayed_progress(_("Checking connectivity"), 0);
202         while (pending.nr) {
203                 result |= traverse_one_object(object_array_pop(&pending));
204                 display_progress(progress, ++nr);
205         }
206         stop_progress(&progress);
207         return !!result;
208 }
209
210 static int mark_used(struct object *obj, int type, void *data, struct fsck_options *options)
211 {
212         if (!obj)
213                 return 1;
214         obj->flags |= USED;
215         return 0;
216 }
217
218 /*
219  * Check a single reachable object
220  */
221 static void check_reachable_object(struct object *obj)
222 {
223         /*
224          * We obviously want the object to be parsed,
225          * except if it was in a pack-file and we didn't
226          * do a full fsck
227          */
228         if (!(obj->flags & HAS_OBJ)) {
229                 if (is_promisor_object(&obj->oid))
230                         return;
231                 if (has_sha1_pack(obj->oid.hash))
232                         return; /* it is in pack - forget about it */
233                 printf("missing %s %s\n", printable_type(obj),
234                         describe_object(obj));
235                 errors_found |= ERROR_REACHABLE;
236                 return;
237         }
238 }
239
240 /*
241  * Check a single unreachable object
242  */
243 static void check_unreachable_object(struct object *obj)
244 {
245         /*
246          * Missing unreachable object? Ignore it. It's not like
247          * we miss it (since it can't be reached), nor do we want
248          * to complain about it being unreachable (since it does
249          * not exist).
250          */
251         if (!(obj->flags & HAS_OBJ))
252                 return;
253
254         /*
255          * Unreachable object that exists? Show it if asked to,
256          * since this is something that is prunable.
257          */
258         if (show_unreachable) {
259                 printf("unreachable %s %s\n", printable_type(obj),
260                         describe_object(obj));
261                 return;
262         }
263
264         /*
265          * "!USED" means that nothing at all points to it, including
266          * other unreachable objects. In other words, it's the "tip"
267          * of some set of unreachable objects, usually a commit that
268          * got dropped.
269          *
270          * Such starting points are more interesting than some random
271          * set of unreachable objects, so we show them even if the user
272          * hasn't asked for _all_ unreachable objects. If you have
273          * deleted a branch by mistake, this is a prime candidate to
274          * start looking at, for example.
275          */
276         if (!(obj->flags & USED)) {
277                 if (show_dangling)
278                         printf("dangling %s %s\n", printable_type(obj),
279                                describe_object(obj));
280                 if (write_lost_and_found) {
281                         char *filename = git_pathdup("lost-found/%s/%s",
282                                 obj->type == OBJ_COMMIT ? "commit" : "other",
283                                 describe_object(obj));
284                         FILE *f;
285
286                         if (safe_create_leading_directories_const(filename)) {
287                                 error("Could not create lost-found");
288                                 free(filename);
289                                 return;
290                         }
291                         f = xfopen(filename, "w");
292                         if (obj->type == OBJ_BLOB) {
293                                 if (stream_blob_to_fd(fileno(f), &obj->oid, NULL, 1))
294                                         die_errno("Could not write '%s'", filename);
295                         } else
296                                 fprintf(f, "%s\n", describe_object(obj));
297                         if (fclose(f))
298                                 die_errno("Could not finish '%s'",
299                                           filename);
300                         free(filename);
301                 }
302                 return;
303         }
304
305         /*
306          * Otherwise? It's there, it's unreachable, and some other unreachable
307          * object points to it. Ignore it - it's not interesting, and we showed
308          * all the interesting cases above.
309          */
310 }
311
312 static void check_object(struct object *obj)
313 {
314         if (verbose)
315                 fprintf(stderr, "Checking %s\n", describe_object(obj));
316
317         if (obj->flags & REACHABLE)
318                 check_reachable_object(obj);
319         else
320                 check_unreachable_object(obj);
321 }
322
323 static void check_connectivity(void)
324 {
325         int i, max;
326
327         /* Traverse the pending reachable objects */
328         traverse_reachable();
329
330         /* Look up all the requirements, warn about missing objects.. */
331         max = get_max_object_index();
332         if (verbose)
333                 fprintf(stderr, "Checking connectivity (%d objects)\n", max);
334
335         for (i = 0; i < max; i++) {
336                 struct object *obj = get_indexed_object(i);
337
338                 if (obj)
339                         check_object(obj);
340         }
341 }
342
343 static int fsck_obj(struct object *obj)
344 {
345         int err;
346
347         if (obj->flags & SEEN)
348                 return 0;
349         obj->flags |= SEEN;
350
351         if (verbose)
352                 fprintf(stderr, "Checking %s %s\n",
353                         printable_type(obj), describe_object(obj));
354
355         if (fsck_walk(obj, NULL, &fsck_obj_options))
356                 objerror(obj, "broken links");
357         err = fsck_object(obj, NULL, 0, &fsck_obj_options);
358         if (err)
359                 goto out;
360
361         if (obj->type == OBJ_COMMIT) {
362                 struct commit *commit = (struct commit *) obj;
363
364                 if (!commit->parents && show_root)
365                         printf("root %s\n", describe_object(&commit->object));
366         }
367
368         if (obj->type == OBJ_TAG) {
369                 struct tag *tag = (struct tag *) obj;
370
371                 if (show_tags && tag->tagged) {
372                         printf("tagged %s %s", printable_type(tag->tagged),
373                                 describe_object(tag->tagged));
374                         printf(" (%s) in %s\n", tag->tag,
375                                 describe_object(&tag->object));
376                 }
377         }
378
379 out:
380         if (obj->type == OBJ_TREE)
381                 free_tree_buffer((struct tree *)obj);
382         if (obj->type == OBJ_COMMIT)
383                 free_commit_buffer((struct commit *)obj);
384         return err;
385 }
386
387 static int fsck_obj_buffer(const struct object_id *oid, enum object_type type,
388                            unsigned long size, void *buffer, int *eaten)
389 {
390         /*
391          * Note, buffer may be NULL if type is OBJ_BLOB. See
392          * verify_packfile(), data_valid variable for details.
393          */
394         struct object *obj;
395         obj = parse_object_buffer(oid, type, size, buffer, eaten);
396         if (!obj) {
397                 errors_found |= ERROR_OBJECT;
398                 return error("%s: object corrupt or missing", oid_to_hex(oid));
399         }
400         obj->flags &= ~(REACHABLE | SEEN);
401         obj->flags |= HAS_OBJ;
402         return fsck_obj(obj);
403 }
404
405 static int default_refs;
406
407 static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
408         timestamp_t timestamp)
409 {
410         struct object *obj;
411
412         if (!is_null_oid(oid)) {
413                 obj = lookup_object(oid->hash);
414                 if (obj && (obj->flags & HAS_OBJ)) {
415                         if (timestamp && name_objects)
416                                 add_decoration(fsck_walk_options.object_names,
417                                         obj,
418                                         xstrfmt("%s@{%"PRItime"}", refname, timestamp));
419                         obj->flags |= USED;
420                         mark_object_reachable(obj);
421                 } else if (!is_promisor_object(oid)) {
422                         error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
423                         errors_found |= ERROR_REACHABLE;
424                 }
425         }
426 }
427
428 static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid,
429                 const char *email, timestamp_t timestamp, int tz,
430                 const char *message, void *cb_data)
431 {
432         const char *refname = cb_data;
433
434         if (verbose)
435                 fprintf(stderr, "Checking reflog %s->%s\n",
436                         oid_to_hex(ooid), oid_to_hex(noid));
437
438         fsck_handle_reflog_oid(refname, ooid, 0);
439         fsck_handle_reflog_oid(refname, noid, timestamp);
440         return 0;
441 }
442
443 static int fsck_handle_reflog(const char *logname, const struct object_id *oid,
444                               int flag, void *cb_data)
445 {
446         for_each_reflog_ent(logname, fsck_handle_reflog_ent, (void *)logname);
447         return 0;
448 }
449
450 static int fsck_handle_ref(const char *refname, const struct object_id *oid,
451                            int flag, void *cb_data)
452 {
453         struct object *obj;
454
455         obj = parse_object(oid);
456         if (!obj) {
457                 if (is_promisor_object(oid)) {
458                         /*
459                          * Increment default_refs anyway, because this is a
460                          * valid ref.
461                          */
462                          default_refs++;
463                          return 0;
464                 }
465                 error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
466                 errors_found |= ERROR_REACHABLE;
467                 /* We'll continue with the rest despite the error.. */
468                 return 0;
469         }
470         if (obj->type != OBJ_COMMIT && is_branch(refname)) {
471                 error("%s: not a commit", refname);
472                 errors_found |= ERROR_REFS;
473         }
474         default_refs++;
475         obj->flags |= USED;
476         if (name_objects)
477                 add_decoration(fsck_walk_options.object_names,
478                         obj, xstrdup(refname));
479         mark_object_reachable(obj);
480
481         return 0;
482 }
483
484 static void get_default_heads(void)
485 {
486         if (head_points_at && !is_null_oid(&head_oid))
487                 fsck_handle_ref("HEAD", &head_oid, 0, NULL);
488         for_each_rawref(fsck_handle_ref, NULL);
489         if (include_reflogs)
490                 for_each_reflog(fsck_handle_reflog, NULL);
491
492         /*
493          * Not having any default heads isn't really fatal, but
494          * it does mean that "--unreachable" no longer makes any
495          * sense (since in this case everything will obviously
496          * be unreachable by definition.
497          *
498          * Showing dangling objects is valid, though (as those
499          * dangling objects are likely lost heads).
500          *
501          * So we just print a warning about it, and clear the
502          * "show_unreachable" flag.
503          */
504         if (!default_refs) {
505                 fprintf(stderr, "notice: No default references\n");
506                 show_unreachable = 0;
507         }
508 }
509
510 static struct object *parse_loose_object(const struct object_id *oid,
511                                          const char *path)
512 {
513         struct object *obj;
514         void *contents;
515         enum object_type type;
516         unsigned long size;
517         int eaten;
518
519         if (read_loose_object(path, oid, &type, &size, &contents) < 0)
520                 return NULL;
521
522         if (!contents && type != OBJ_BLOB)
523                 die("BUG: read_loose_object streamed a non-blob");
524
525         obj = parse_object_buffer(oid, type, size, contents, &eaten);
526
527         if (!eaten)
528                 free(contents);
529         return obj;
530 }
531
532 static int fsck_loose(const struct object_id *oid, const char *path, void *data)
533 {
534         struct object *obj = parse_loose_object(oid, path);
535
536         if (!obj) {
537                 errors_found |= ERROR_OBJECT;
538                 error("%s: object corrupt or missing: %s",
539                       oid_to_hex(oid), path);
540                 return 0; /* keep checking other objects */
541         }
542
543         obj->flags &= ~(REACHABLE | SEEN);
544         obj->flags |= HAS_OBJ;
545         if (fsck_obj(obj))
546                 errors_found |= ERROR_OBJECT;
547         return 0;
548 }
549
550 static int fsck_cruft(const char *basename, const char *path, void *data)
551 {
552         if (!starts_with(basename, "tmp_obj_"))
553                 fprintf(stderr, "bad sha1 file: %s\n", path);
554         return 0;
555 }
556
557 static int fsck_subdir(unsigned int nr, const char *path, void *progress)
558 {
559         display_progress(progress, nr + 1);
560         return 0;
561 }
562
563 static void fsck_object_dir(const char *path)
564 {
565         struct progress *progress = NULL;
566
567         if (verbose)
568                 fprintf(stderr, "Checking object directory\n");
569
570         if (show_progress)
571                 progress = start_progress(_("Checking object directories"), 256);
572
573         for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
574                                       progress);
575         display_progress(progress, 256);
576         stop_progress(&progress);
577 }
578
579 static int fsck_head_link(void)
580 {
581         int null_is_error = 0;
582
583         if (verbose)
584                 fprintf(stderr, "Checking HEAD link\n");
585
586         head_points_at = resolve_ref_unsafe("HEAD", 0, &head_oid, NULL);
587         if (!head_points_at) {
588                 errors_found |= ERROR_REFS;
589                 return error("Invalid HEAD");
590         }
591         if (!strcmp(head_points_at, "HEAD"))
592                 /* detached HEAD */
593                 null_is_error = 1;
594         else if (!starts_with(head_points_at, "refs/heads/")) {
595                 errors_found |= ERROR_REFS;
596                 return error("HEAD points to something strange (%s)",
597                              head_points_at);
598         }
599         if (is_null_oid(&head_oid)) {
600                 if (null_is_error) {
601                         errors_found |= ERROR_REFS;
602                         return error("HEAD: detached HEAD points at nothing");
603                 }
604                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
605                         head_points_at + 11);
606         }
607         return 0;
608 }
609
610 static int fsck_cache_tree(struct cache_tree *it)
611 {
612         int i;
613         int err = 0;
614
615         if (verbose)
616                 fprintf(stderr, "Checking cache tree\n");
617
618         if (0 <= it->entry_count) {
619                 struct object *obj = parse_object(&it->oid);
620                 if (!obj) {
621                         error("%s: invalid sha1 pointer in cache-tree",
622                               oid_to_hex(&it->oid));
623                         errors_found |= ERROR_REFS;
624                         return 1;
625                 }
626                 obj->flags |= USED;
627                 if (name_objects)
628                         add_decoration(fsck_walk_options.object_names,
629                                 obj, xstrdup(":"));
630                 mark_object_reachable(obj);
631                 if (obj->type != OBJ_TREE)
632                         err |= objerror(obj, "non-tree in cache-tree");
633         }
634         for (i = 0; i < it->subtree_nr; i++)
635                 err |= fsck_cache_tree(it->down[i]->cache_tree);
636         return err;
637 }
638
639 static void mark_object_for_connectivity(const struct object_id *oid)
640 {
641         struct object *obj = lookup_unknown_object(oid->hash);
642         obj->flags |= HAS_OBJ;
643 }
644
645 static int mark_loose_for_connectivity(const struct object_id *oid,
646                                        const char *path,
647                                        void *data)
648 {
649         mark_object_for_connectivity(oid);
650         return 0;
651 }
652
653 static int mark_packed_for_connectivity(const struct object_id *oid,
654                                         struct packed_git *pack,
655                                         uint32_t pos,
656                                         void *data)
657 {
658         mark_object_for_connectivity(oid);
659         return 0;
660 }
661
662 static char const * const fsck_usage[] = {
663         N_("git fsck [<options>] [<object>...]"),
664         NULL
665 };
666
667 static struct option fsck_opts[] = {
668         OPT__VERBOSE(&verbose, N_("be verbose")),
669         OPT_BOOL(0, "unreachable", &show_unreachable, N_("show unreachable objects")),
670         OPT_BOOL(0, "dangling", &show_dangling, N_("show dangling objects")),
671         OPT_BOOL(0, "tags", &show_tags, N_("report tags")),
672         OPT_BOOL(0, "root", &show_root, N_("report root nodes")),
673         OPT_BOOL(0, "cache", &keep_cache_objects, N_("make index objects head nodes")),
674         OPT_BOOL(0, "reflogs", &include_reflogs, N_("make reflogs head nodes (default)")),
675         OPT_BOOL(0, "full", &check_full, N_("also consider packs and alternate objects")),
676         OPT_BOOL(0, "connectivity-only", &connectivity_only, N_("check only connectivity")),
677         OPT_BOOL(0, "strict", &check_strict, N_("enable more strict checking")),
678         OPT_BOOL(0, "lost-found", &write_lost_and_found,
679                                 N_("write dangling objects in .git/lost-found")),
680         OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
681         OPT_BOOL(0, "name-objects", &name_objects, N_("show verbose names for reachable objects")),
682         OPT_END(),
683 };
684
685 int cmd_fsck(int argc, const char **argv, const char *prefix)
686 {
687         int i;
688         struct alternate_object_database *alt;
689
690         /* fsck knows how to handle missing promisor objects */
691         fetch_if_missing = 0;
692
693         errors_found = 0;
694         check_replace_refs = 0;
695
696         argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
697
698         fsck_walk_options.walk = mark_object;
699         fsck_obj_options.walk = mark_used;
700         fsck_obj_options.error_func = fsck_error_func;
701         if (check_strict)
702                 fsck_obj_options.strict = 1;
703
704         if (show_progress == -1)
705                 show_progress = isatty(2);
706         if (verbose)
707                 show_progress = 0;
708
709         if (write_lost_and_found) {
710                 check_full = 1;
711                 include_reflogs = 0;
712         }
713
714         if (name_objects)
715                 fsck_walk_options.object_names =
716                         xcalloc(1, sizeof(struct decoration));
717
718         git_config(fsck_config, NULL);
719
720         fsck_head_link();
721         if (connectivity_only) {
722                 for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
723                 for_each_packed_object(mark_packed_for_connectivity, NULL, 0);
724         } else {
725                 struct alternate_object_database *alt_odb_list;
726
727                 fsck_object_dir(get_object_directory());
728
729                 prepare_alt_odb(the_repository);
730                 alt_odb_list = the_repository->objects->alt_odb_list;
731                 for (alt = alt_odb_list; alt; alt = alt->next)
732                         fsck_object_dir(alt->path);
733
734                 if (check_full) {
735                         struct packed_git *p;
736                         uint32_t total = 0, count = 0;
737                         struct progress *progress = NULL;
738
739                         if (show_progress) {
740                                 for (p = get_packed_git(the_repository); p;
741                                      p = p->next) {
742                                         if (open_pack_index(p))
743                                                 continue;
744                                         total += p->num_objects;
745                                 }
746
747                                 progress = start_progress(_("Checking objects"), total);
748                         }
749                         for (p = get_packed_git(the_repository); p;
750                              p = p->next) {
751                                 /* verify gives error messages itself */
752                                 if (verify_pack(p, fsck_obj_buffer,
753                                                 progress, count))
754                                         errors_found |= ERROR_PACK;
755                                 count += p->num_objects;
756                         }
757                         stop_progress(&progress);
758                 }
759         }
760
761         for (i = 0; i < argc; i++) {
762                 const char *arg = argv[i];
763                 struct object_id oid;
764                 if (!get_oid(arg, &oid)) {
765                         struct object *obj = lookup_object(oid.hash);
766
767                         if (!obj || !(obj->flags & HAS_OBJ)) {
768                                 if (is_promisor_object(&oid))
769                                         continue;
770                                 error("%s: object missing", oid_to_hex(&oid));
771                                 errors_found |= ERROR_OBJECT;
772                                 continue;
773                         }
774
775                         obj->flags |= USED;
776                         if (name_objects)
777                                 add_decoration(fsck_walk_options.object_names,
778                                         obj, xstrdup(arg));
779                         mark_object_reachable(obj);
780                         continue;
781                 }
782                 error("invalid parameter: expected sha1, got '%s'", arg);
783                 errors_found |= ERROR_OBJECT;
784         }
785
786         /*
787          * If we've not been given any explicit head information, do the
788          * default ones from .git/refs. We also consider the index file
789          * in this case (ie this implies --cache).
790          */
791         if (!argc) {
792                 get_default_heads();
793                 keep_cache_objects = 1;
794         }
795
796         if (keep_cache_objects) {
797                 verify_index_checksum = 1;
798                 verify_ce_order = 1;
799                 read_cache();
800                 for (i = 0; i < active_nr; i++) {
801                         unsigned int mode;
802                         struct blob *blob;
803                         struct object *obj;
804
805                         mode = active_cache[i]->ce_mode;
806                         if (S_ISGITLINK(mode))
807                                 continue;
808                         blob = lookup_blob(&active_cache[i]->oid);
809                         if (!blob)
810                                 continue;
811                         obj = &blob->object;
812                         obj->flags |= USED;
813                         if (name_objects)
814                                 add_decoration(fsck_walk_options.object_names,
815                                         obj,
816                                         xstrfmt(":%s", active_cache[i]->name));
817                         mark_object_reachable(obj);
818                 }
819                 if (active_cache_tree)
820                         fsck_cache_tree(active_cache_tree);
821         }
822
823         check_connectivity();
824         return errors_found;
825 }