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