Merge branch 'en/status-multiple-renames-to-the-same-target-fix' into maint
[git] / fsck.c
1 #include "cache.h"
2 #include "object-store.h"
3 #include "repository.h"
4 #include "object.h"
5 #include "blob.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "commit.h"
9 #include "tag.h"
10 #include "fsck.h"
11 #include "refs.h"
12 #include "utf8.h"
13 #include "sha1-array.h"
14 #include "decorate.h"
15 #include "oidset.h"
16 #include "packfile.h"
17 #include "submodule-config.h"
18 #include "config.h"
19 #include "help.h"
20
21 static struct oidset gitmodules_found = OIDSET_INIT;
22 static struct oidset gitmodules_done = OIDSET_INIT;
23
24 #define FSCK_FATAL -1
25 #define FSCK_INFO -2
26
27 #define FOREACH_MSG_ID(FUNC) \
28         /* fatal errors */ \
29         FUNC(NUL_IN_HEADER, FATAL) \
30         FUNC(UNTERMINATED_HEADER, FATAL) \
31         /* errors */ \
32         FUNC(BAD_DATE, ERROR) \
33         FUNC(BAD_DATE_OVERFLOW, ERROR) \
34         FUNC(BAD_EMAIL, ERROR) \
35         FUNC(BAD_NAME, ERROR) \
36         FUNC(BAD_OBJECT_SHA1, ERROR) \
37         FUNC(BAD_PARENT_SHA1, ERROR) \
38         FUNC(BAD_TAG_OBJECT, ERROR) \
39         FUNC(BAD_TIMEZONE, ERROR) \
40         FUNC(BAD_TREE, ERROR) \
41         FUNC(BAD_TREE_SHA1, ERROR) \
42         FUNC(BAD_TYPE, ERROR) \
43         FUNC(DUPLICATE_ENTRIES, ERROR) \
44         FUNC(MISSING_AUTHOR, ERROR) \
45         FUNC(MISSING_COMMITTER, ERROR) \
46         FUNC(MISSING_EMAIL, ERROR) \
47         FUNC(MISSING_GRAFT, ERROR) \
48         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
49         FUNC(MISSING_OBJECT, ERROR) \
50         FUNC(MISSING_PARENT, ERROR) \
51         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
52         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
53         FUNC(MISSING_TAG, ERROR) \
54         FUNC(MISSING_TAG_ENTRY, ERROR) \
55         FUNC(MISSING_TAG_OBJECT, ERROR) \
56         FUNC(MISSING_TREE, ERROR) \
57         FUNC(MISSING_TREE_OBJECT, ERROR) \
58         FUNC(MISSING_TYPE, ERROR) \
59         FUNC(MISSING_TYPE_ENTRY, ERROR) \
60         FUNC(MULTIPLE_AUTHORS, ERROR) \
61         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
62         FUNC(TREE_NOT_SORTED, ERROR) \
63         FUNC(UNKNOWN_TYPE, ERROR) \
64         FUNC(ZERO_PADDED_DATE, ERROR) \
65         FUNC(GITMODULES_MISSING, ERROR) \
66         FUNC(GITMODULES_BLOB, ERROR) \
67         FUNC(GITMODULES_LARGE, ERROR) \
68         FUNC(GITMODULES_NAME, ERROR) \
69         FUNC(GITMODULES_SYMLINK, ERROR) \
70         FUNC(GITMODULES_URL, ERROR) \
71         FUNC(GITMODULES_PATH, ERROR) \
72         /* warnings */ \
73         FUNC(BAD_FILEMODE, WARN) \
74         FUNC(EMPTY_NAME, WARN) \
75         FUNC(FULL_PATHNAME, WARN) \
76         FUNC(HAS_DOT, WARN) \
77         FUNC(HAS_DOTDOT, WARN) \
78         FUNC(HAS_DOTGIT, WARN) \
79         FUNC(NULL_SHA1, WARN) \
80         FUNC(ZERO_PADDED_FILEMODE, WARN) \
81         FUNC(NUL_IN_COMMIT, WARN) \
82         /* infos (reported as warnings, but ignored by default) */ \
83         FUNC(GITMODULES_PARSE, INFO) \
84         FUNC(BAD_TAG_NAME, INFO) \
85         FUNC(MISSING_TAGGER_ENTRY, INFO)
86
87 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
88 enum fsck_msg_id {
89         FOREACH_MSG_ID(MSG_ID)
90         FSCK_MSG_MAX
91 };
92 #undef MSG_ID
93
94 #define STR(x) #x
95 #define MSG_ID(id, msg_type) { STR(id), NULL, NULL, FSCK_##msg_type },
96 static struct {
97         const char *id_string;
98         const char *downcased;
99         const char *camelcased;
100         int msg_type;
101 } msg_id_info[FSCK_MSG_MAX + 1] = {
102         FOREACH_MSG_ID(MSG_ID)
103         { NULL, NULL, NULL, -1 }
104 };
105 #undef MSG_ID
106
107 static void prepare_msg_ids(void)
108 {
109         int i;
110
111         if (msg_id_info[0].downcased)
112                 return;
113
114         /* convert id_string to lower case, without underscores. */
115         for (i = 0; i < FSCK_MSG_MAX; i++) {
116                 const char *p = msg_id_info[i].id_string;
117                 int len = strlen(p);
118                 char *q = xmalloc(len);
119
120                 msg_id_info[i].downcased = q;
121                 while (*p)
122                         if (*p == '_')
123                                 p++;
124                         else
125                                 *(q)++ = tolower(*(p)++);
126                 *q = '\0';
127
128                 p = msg_id_info[i].id_string;
129                 q = xmalloc(len);
130                 msg_id_info[i].camelcased = q;
131                 while (*p) {
132                         if (*p == '_') {
133                                 p++;
134                                 if (*p)
135                                         *q++ = *p++;
136                         } else {
137                                 *q++ = tolower(*p++);
138                         }
139                 }
140                 *q = '\0';
141         }
142 }
143
144 static int parse_msg_id(const char *text)
145 {
146         int i;
147
148         prepare_msg_ids();
149
150         for (i = 0; i < FSCK_MSG_MAX; i++)
151                 if (!strcmp(text, msg_id_info[i].downcased))
152                         return i;
153
154         return -1;
155 }
156
157 void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
158 {
159         int i;
160
161         prepare_msg_ids();
162
163         for (i = 0; i < FSCK_MSG_MAX; i++)
164                 list_config_item(list, prefix, msg_id_info[i].camelcased);
165 }
166
167 static int fsck_msg_type(enum fsck_msg_id msg_id,
168         struct fsck_options *options)
169 {
170         int msg_type;
171
172         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
173
174         if (options->msg_type)
175                 msg_type = options->msg_type[msg_id];
176         else {
177                 msg_type = msg_id_info[msg_id].msg_type;
178                 if (options->strict && msg_type == FSCK_WARN)
179                         msg_type = FSCK_ERROR;
180         }
181
182         return msg_type;
183 }
184
185 static void init_skiplist(struct fsck_options *options, const char *path)
186 {
187         static struct oid_array skiplist = OID_ARRAY_INIT;
188         int sorted, fd;
189         char buffer[GIT_MAX_HEXSZ + 1];
190         struct object_id oid;
191
192         if (options->skiplist)
193                 sorted = options->skiplist->sorted;
194         else {
195                 sorted = 1;
196                 options->skiplist = &skiplist;
197         }
198
199         fd = open(path, O_RDONLY);
200         if (fd < 0)
201                 die("Could not open skip list: %s", path);
202         for (;;) {
203                 const char *p;
204                 int result = read_in_full(fd, buffer, sizeof(buffer));
205                 if (result < 0)
206                         die_errno("Could not read '%s'", path);
207                 if (!result)
208                         break;
209                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n')
210                         die("Invalid SHA-1: %s", buffer);
211                 oid_array_append(&skiplist, &oid);
212                 if (sorted && skiplist.nr > 1 &&
213                                 oidcmp(&skiplist.oid[skiplist.nr - 2],
214                                        &oid) > 0)
215                         sorted = 0;
216         }
217         close(fd);
218
219         if (sorted)
220                 skiplist.sorted = 1;
221 }
222
223 static int parse_msg_type(const char *str)
224 {
225         if (!strcmp(str, "error"))
226                 return FSCK_ERROR;
227         else if (!strcmp(str, "warn"))
228                 return FSCK_WARN;
229         else if (!strcmp(str, "ignore"))
230                 return FSCK_IGNORE;
231         else
232                 die("Unknown fsck message type: '%s'", str);
233 }
234
235 int is_valid_msg_type(const char *msg_id, const char *msg_type)
236 {
237         if (parse_msg_id(msg_id) < 0)
238                 return 0;
239         parse_msg_type(msg_type);
240         return 1;
241 }
242
243 void fsck_set_msg_type(struct fsck_options *options,
244                 const char *msg_id, const char *msg_type)
245 {
246         int id = parse_msg_id(msg_id), type;
247
248         if (id < 0)
249                 die("Unhandled message id: %s", msg_id);
250         type = parse_msg_type(msg_type);
251
252         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
253                 die("Cannot demote %s to %s", msg_id, msg_type);
254
255         if (!options->msg_type) {
256                 int i;
257                 int *msg_type;
258                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
259                 for (i = 0; i < FSCK_MSG_MAX; i++)
260                         msg_type[i] = fsck_msg_type(i, options);
261                 options->msg_type = msg_type;
262         }
263
264         options->msg_type[id] = type;
265 }
266
267 void fsck_set_msg_types(struct fsck_options *options, const char *values)
268 {
269         char *buf = xstrdup(values), *to_free = buf;
270         int done = 0;
271
272         while (!done) {
273                 int len = strcspn(buf, " ,|"), equal;
274
275                 done = !buf[len];
276                 if (!len) {
277                         buf++;
278                         continue;
279                 }
280                 buf[len] = '\0';
281
282                 for (equal = 0;
283                      equal < len && buf[equal] != '=' && buf[equal] != ':';
284                      equal++)
285                         buf[equal] = tolower(buf[equal]);
286                 buf[equal] = '\0';
287
288                 if (!strcmp(buf, "skiplist")) {
289                         if (equal == len)
290                                 die("skiplist requires a path");
291                         init_skiplist(options, buf + equal + 1);
292                         buf += len + 1;
293                         continue;
294                 }
295
296                 if (equal == len)
297                         die("Missing '=': '%s'", buf);
298
299                 fsck_set_msg_type(options, buf, buf + equal + 1);
300                 buf += len + 1;
301         }
302         free(to_free);
303 }
304
305 static void append_msg_id(struct strbuf *sb, const char *msg_id)
306 {
307         for (;;) {
308                 char c = *(msg_id)++;
309
310                 if (!c)
311                         break;
312                 if (c != '_')
313                         strbuf_addch(sb, tolower(c));
314                 else {
315                         assert(*msg_id);
316                         strbuf_addch(sb, *(msg_id)++);
317                 }
318         }
319
320         strbuf_addstr(sb, ": ");
321 }
322
323 static int object_on_skiplist(struct fsck_options *opts, struct object *obj)
324 {
325         if (opts && opts->skiplist && obj)
326                 return oid_array_lookup(opts->skiplist, &obj->oid) >= 0;
327         return 0;
328 }
329
330 __attribute__((format (printf, 4, 5)))
331 static int report(struct fsck_options *options, struct object *object,
332         enum fsck_msg_id id, const char *fmt, ...)
333 {
334         va_list ap;
335         struct strbuf sb = STRBUF_INIT;
336         int msg_type = fsck_msg_type(id, options), result;
337
338         if (msg_type == FSCK_IGNORE)
339                 return 0;
340
341         if (object_on_skiplist(options, object))
342                 return 0;
343
344         if (msg_type == FSCK_FATAL)
345                 msg_type = FSCK_ERROR;
346         else if (msg_type == FSCK_INFO)
347                 msg_type = FSCK_WARN;
348
349         append_msg_id(&sb, msg_id_info[id].id_string);
350
351         va_start(ap, fmt);
352         strbuf_vaddf(&sb, fmt, ap);
353         result = options->error_func(options, object, msg_type, sb.buf);
354         strbuf_release(&sb);
355         va_end(ap);
356
357         return result;
358 }
359
360 static char *get_object_name(struct fsck_options *options, struct object *obj)
361 {
362         if (!options->object_names)
363                 return NULL;
364         return lookup_decoration(options->object_names, obj);
365 }
366
367 static void put_object_name(struct fsck_options *options, struct object *obj,
368         const char *fmt, ...)
369 {
370         va_list ap;
371         struct strbuf buf = STRBUF_INIT;
372         char *existing;
373
374         if (!options->object_names)
375                 return;
376         existing = lookup_decoration(options->object_names, obj);
377         if (existing)
378                 return;
379         va_start(ap, fmt);
380         strbuf_vaddf(&buf, fmt, ap);
381         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
382         va_end(ap);
383 }
384
385 static const char *describe_object(struct fsck_options *o, struct object *obj)
386 {
387         static struct strbuf buf = STRBUF_INIT;
388         char *name;
389
390         strbuf_reset(&buf);
391         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
392         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
393                 strbuf_addf(&buf, " (%s)", name);
394
395         return buf.buf;
396 }
397
398 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
399 {
400         struct tree_desc desc;
401         struct name_entry entry;
402         int res = 0;
403         const char *name;
404
405         if (parse_tree(tree))
406                 return -1;
407
408         name = get_object_name(options, &tree->object);
409         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
410                 return -1;
411         while (tree_entry_gently(&desc, &entry)) {
412                 struct object *obj;
413                 int result;
414
415                 if (S_ISGITLINK(entry.mode))
416                         continue;
417
418                 if (S_ISDIR(entry.mode)) {
419                         obj = (struct object *)lookup_tree(the_repository, entry.oid);
420                         if (name && obj)
421                                 put_object_name(options, obj, "%s%s/", name,
422                                         entry.path);
423                         result = options->walk(obj, OBJ_TREE, data, options);
424                 }
425                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
426                         obj = (struct object *)lookup_blob(the_repository, entry.oid);
427                         if (name && obj)
428                                 put_object_name(options, obj, "%s%s", name,
429                                         entry.path);
430                         result = options->walk(obj, OBJ_BLOB, data, options);
431                 }
432                 else {
433                         result = error("in tree %s: entry %s has bad mode %.6o",
434                                         describe_object(options, &tree->object), entry.path, entry.mode);
435                 }
436                 if (result < 0)
437                         return result;
438                 if (!res)
439                         res = result;
440         }
441         return res;
442 }
443
444 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
445 {
446         int counter = 0, generation = 0, name_prefix_len = 0;
447         struct commit_list *parents;
448         int res;
449         int result;
450         const char *name;
451
452         if (parse_commit(commit))
453                 return -1;
454
455         name = get_object_name(options, &commit->object);
456         if (name)
457                 put_object_name(options, &get_commit_tree(commit)->object,
458                                 "%s:", name);
459
460         result = options->walk((struct object *)get_commit_tree(commit),
461                                OBJ_TREE, data, options);
462         if (result < 0)
463                 return result;
464         res = result;
465
466         parents = commit->parents;
467         if (name && parents) {
468                 int len = strlen(name), power;
469
470                 if (len && name[len - 1] == '^') {
471                         generation = 1;
472                         name_prefix_len = len - 1;
473                 }
474                 else { /* parse ~<generation> suffix */
475                         for (generation = 0, power = 1;
476                              len && isdigit(name[len - 1]);
477                              power *= 10)
478                                 generation += power * (name[--len] - '0');
479                         if (power > 1 && len && name[len - 1] == '~')
480                                 name_prefix_len = len - 1;
481                 }
482         }
483
484         while (parents) {
485                 if (name) {
486                         struct object *obj = &parents->item->object;
487
488                         if (++counter > 1)
489                                 put_object_name(options, obj, "%s^%d",
490                                         name, counter);
491                         else if (generation > 0)
492                                 put_object_name(options, obj, "%.*s~%d",
493                                         name_prefix_len, name, generation + 1);
494                         else
495                                 put_object_name(options, obj, "%s^", name);
496                 }
497                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
498                 if (result < 0)
499                         return result;
500                 if (!res)
501                         res = result;
502                 parents = parents->next;
503         }
504         return res;
505 }
506
507 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
508 {
509         char *name = get_object_name(options, &tag->object);
510
511         if (parse_tag(tag))
512                 return -1;
513         if (name)
514                 put_object_name(options, tag->tagged, "%s", name);
515         return options->walk(tag->tagged, OBJ_ANY, data, options);
516 }
517
518 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
519 {
520         if (!obj)
521                 return -1;
522
523         if (obj->type == OBJ_NONE)
524                 parse_object(the_repository, &obj->oid);
525
526         switch (obj->type) {
527         case OBJ_BLOB:
528                 return 0;
529         case OBJ_TREE:
530                 return fsck_walk_tree((struct tree *)obj, data, options);
531         case OBJ_COMMIT:
532                 return fsck_walk_commit((struct commit *)obj, data, options);
533         case OBJ_TAG:
534                 return fsck_walk_tag((struct tag *)obj, data, options);
535         default:
536                 error("Unknown object type for %s", describe_object(options, obj));
537                 return -1;
538         }
539 }
540
541 /*
542  * The entries in a tree are ordered in the _path_ order,
543  * which means that a directory entry is ordered by adding
544  * a slash to the end of it.
545  *
546  * So a directory called "a" is ordered _after_ a file
547  * called "a.c", because "a/" sorts after "a.c".
548  */
549 #define TREE_UNORDERED (-1)
550 #define TREE_HAS_DUPS  (-2)
551
552 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
553 {
554         int len1 = strlen(name1);
555         int len2 = strlen(name2);
556         int len = len1 < len2 ? len1 : len2;
557         unsigned char c1, c2;
558         int cmp;
559
560         cmp = memcmp(name1, name2, len);
561         if (cmp < 0)
562                 return 0;
563         if (cmp > 0)
564                 return TREE_UNORDERED;
565
566         /*
567          * Ok, the first <len> characters are the same.
568          * Now we need to order the next one, but turn
569          * a '\0' into a '/' for a directory entry.
570          */
571         c1 = name1[len];
572         c2 = name2[len];
573         if (!c1 && !c2)
574                 /*
575                  * git-write-tree used to write out a nonsense tree that has
576                  * entries with the same name, one blob and one tree.  Make
577                  * sure we do not have duplicate entries.
578                  */
579                 return TREE_HAS_DUPS;
580         if (!c1 && S_ISDIR(mode1))
581                 c1 = '/';
582         if (!c2 && S_ISDIR(mode2))
583                 c2 = '/';
584         return c1 < c2 ? 0 : TREE_UNORDERED;
585 }
586
587 static int fsck_tree(struct tree *item, struct fsck_options *options)
588 {
589         int retval = 0;
590         int has_null_sha1 = 0;
591         int has_full_path = 0;
592         int has_empty_name = 0;
593         int has_dot = 0;
594         int has_dotdot = 0;
595         int has_dotgit = 0;
596         int has_zero_pad = 0;
597         int has_bad_modes = 0;
598         int has_dup_entries = 0;
599         int not_properly_sorted = 0;
600         struct tree_desc desc;
601         unsigned o_mode;
602         const char *o_name;
603
604         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
605                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
606                 return retval;
607         }
608
609         o_mode = 0;
610         o_name = NULL;
611
612         while (desc.size) {
613                 unsigned mode;
614                 const char *name;
615                 const struct object_id *oid;
616
617                 oid = tree_entry_extract(&desc, &name, &mode);
618
619                 has_null_sha1 |= is_null_oid(oid);
620                 has_full_path |= !!strchr(name, '/');
621                 has_empty_name |= !*name;
622                 has_dot |= !strcmp(name, ".");
623                 has_dotdot |= !strcmp(name, "..");
624                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
625                 has_zero_pad |= *(char *)desc.buffer == '0';
626
627                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
628                         if (!S_ISLNK(mode))
629                                 oidset_insert(&gitmodules_found, oid);
630                         else
631                                 retval += report(options, &item->object,
632                                                  FSCK_MSG_GITMODULES_SYMLINK,
633                                                  ".gitmodules is a symbolic link");
634                 }
635
636                 if (update_tree_entry_gently(&desc)) {
637                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
638                         break;
639                 }
640
641                 switch (mode) {
642                 /*
643                  * Standard modes..
644                  */
645                 case S_IFREG | 0755:
646                 case S_IFREG | 0644:
647                 case S_IFLNK:
648                 case S_IFDIR:
649                 case S_IFGITLINK:
650                         break;
651                 /*
652                  * This is nonstandard, but we had a few of these
653                  * early on when we honored the full set of mode
654                  * bits..
655                  */
656                 case S_IFREG | 0664:
657                         if (!options->strict)
658                                 break;
659                         /* fallthrough */
660                 default:
661                         has_bad_modes = 1;
662                 }
663
664                 if (o_name) {
665                         switch (verify_ordered(o_mode, o_name, mode, name)) {
666                         case TREE_UNORDERED:
667                                 not_properly_sorted = 1;
668                                 break;
669                         case TREE_HAS_DUPS:
670                                 has_dup_entries = 1;
671                                 break;
672                         default:
673                                 break;
674                         }
675                 }
676
677                 o_mode = mode;
678                 o_name = name;
679         }
680
681         if (has_null_sha1)
682                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
683         if (has_full_path)
684                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
685         if (has_empty_name)
686                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
687         if (has_dot)
688                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
689         if (has_dotdot)
690                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
691         if (has_dotgit)
692                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
693         if (has_zero_pad)
694                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
695         if (has_bad_modes)
696                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
697         if (has_dup_entries)
698                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
699         if (not_properly_sorted)
700                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
701         return retval;
702 }
703
704 static int verify_headers(const void *data, unsigned long size,
705                           struct object *obj, struct fsck_options *options)
706 {
707         const char *buffer = (const char *)data;
708         unsigned long i;
709
710         for (i = 0; i < size; i++) {
711                 switch (buffer[i]) {
712                 case '\0':
713                         return report(options, obj,
714                                 FSCK_MSG_NUL_IN_HEADER,
715                                 "unterminated header: NUL at offset %ld", i);
716                 case '\n':
717                         if (i + 1 < size && buffer[i + 1] == '\n')
718                                 return 0;
719                 }
720         }
721
722         /*
723          * We did not find double-LF that separates the header
724          * and the body.  Not having a body is not a crime but
725          * we do want to see the terminating LF for the last header
726          * line.
727          */
728         if (size && buffer[size - 1] == '\n')
729                 return 0;
730
731         return report(options, obj,
732                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
733 }
734
735 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
736 {
737         const char *p = *ident;
738         char *end;
739
740         *ident = strchrnul(*ident, '\n');
741         if (**ident == '\n')
742                 (*ident)++;
743
744         if (*p == '<')
745                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
746         p += strcspn(p, "<>\n");
747         if (*p == '>')
748                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
749         if (*p != '<')
750                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
751         if (p[-1] != ' ')
752                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
753         p++;
754         p += strcspn(p, "<>\n");
755         if (*p != '>')
756                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
757         p++;
758         if (*p != ' ')
759                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
760         p++;
761         if (*p == '0' && p[1] != ' ')
762                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
763         if (date_overflows(parse_timestamp(p, &end, 10)))
764                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
765         if ((end == p || *end != ' '))
766                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
767         p = end + 1;
768         if ((*p != '+' && *p != '-') ||
769             !isdigit(p[1]) ||
770             !isdigit(p[2]) ||
771             !isdigit(p[3]) ||
772             !isdigit(p[4]) ||
773             (p[5] != '\n'))
774                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
775         p += 6;
776         return 0;
777 }
778
779 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
780         unsigned long size, struct fsck_options *options)
781 {
782         struct object_id tree_oid, oid;
783         struct commit_graft *graft;
784         unsigned parent_count, parent_line_count = 0, author_count;
785         int err;
786         const char *buffer_begin = buffer;
787         const char *p;
788
789         if (verify_headers(buffer, size, &commit->object, options))
790                 return -1;
791
792         if (!skip_prefix(buffer, "tree ", &buffer))
793                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
794         if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
795                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
796                 if (err)
797                         return err;
798         }
799         buffer = p + 1;
800         while (skip_prefix(buffer, "parent ", &buffer)) {
801                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
802                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
803                         if (err)
804                                 return err;
805                 }
806                 buffer = p + 1;
807                 parent_line_count++;
808         }
809         graft = lookup_commit_graft(the_repository, &commit->object.oid);
810         parent_count = commit_list_count(commit->parents);
811         if (graft) {
812                 if (graft->nr_parent == -1 && !parent_count)
813                         ; /* shallow commit */
814                 else if (graft->nr_parent != parent_count) {
815                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
816                         if (err)
817                                 return err;
818                 }
819         } else {
820                 if (parent_count != parent_line_count) {
821                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
822                         if (err)
823                                 return err;
824                 }
825         }
826         author_count = 0;
827         while (skip_prefix(buffer, "author ", &buffer)) {
828                 author_count++;
829                 err = fsck_ident(&buffer, &commit->object, options);
830                 if (err)
831                         return err;
832         }
833         if (author_count < 1)
834                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
835         else if (author_count > 1)
836                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
837         if (err)
838                 return err;
839         if (!skip_prefix(buffer, "committer ", &buffer))
840                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
841         err = fsck_ident(&buffer, &commit->object, options);
842         if (err)
843                 return err;
844         if (!get_commit_tree(commit)) {
845                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", oid_to_hex(&tree_oid));
846                 if (err)
847                         return err;
848         }
849         if (memchr(buffer_begin, '\0', size)) {
850                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
851                              "NUL byte in the commit object body");
852                 if (err)
853                         return err;
854         }
855         return 0;
856 }
857
858 static int fsck_commit(struct commit *commit, const char *data,
859         unsigned long size, struct fsck_options *options)
860 {
861         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
862         int ret = fsck_commit_buffer(commit, buffer, size, options);
863         if (!data)
864                 unuse_commit_buffer(commit, buffer);
865         return ret;
866 }
867
868 static int fsck_tag_buffer(struct tag *tag, const char *data,
869         unsigned long size, struct fsck_options *options)
870 {
871         struct object_id oid;
872         int ret = 0;
873         const char *buffer;
874         char *to_free = NULL, *eol;
875         struct strbuf sb = STRBUF_INIT;
876         const char *p;
877
878         if (data)
879                 buffer = data;
880         else {
881                 enum object_type type;
882
883                 buffer = to_free =
884                         read_object_file(&tag->object.oid, &type, &size);
885                 if (!buffer)
886                         return report(options, &tag->object,
887                                 FSCK_MSG_MISSING_TAG_OBJECT,
888                                 "cannot read tag object");
889
890                 if (type != OBJ_TAG) {
891                         ret = report(options, &tag->object,
892                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
893                                 "expected tag got %s",
894                             type_name(type));
895                         goto done;
896                 }
897         }
898
899         ret = verify_headers(buffer, size, &tag->object, options);
900         if (ret)
901                 goto done;
902
903         if (!skip_prefix(buffer, "object ", &buffer)) {
904                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
905                 goto done;
906         }
907         if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
908                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
909                 if (ret)
910                         goto done;
911         }
912         buffer = p + 1;
913
914         if (!skip_prefix(buffer, "type ", &buffer)) {
915                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
916                 goto done;
917         }
918         eol = strchr(buffer, '\n');
919         if (!eol) {
920                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
921                 goto done;
922         }
923         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
924                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
925         if (ret)
926                 goto done;
927         buffer = eol + 1;
928
929         if (!skip_prefix(buffer, "tag ", &buffer)) {
930                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
931                 goto done;
932         }
933         eol = strchr(buffer, '\n');
934         if (!eol) {
935                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
936                 goto done;
937         }
938         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
939         if (check_refname_format(sb.buf, 0)) {
940                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
941                            "invalid 'tag' name: %.*s",
942                            (int)(eol - buffer), buffer);
943                 if (ret)
944                         goto done;
945         }
946         buffer = eol + 1;
947
948         if (!skip_prefix(buffer, "tagger ", &buffer)) {
949                 /* early tags do not contain 'tagger' lines; warn only */
950                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
951                 if (ret)
952                         goto done;
953         }
954         else
955                 ret = fsck_ident(&buffer, &tag->object, options);
956
957 done:
958         strbuf_release(&sb);
959         free(to_free);
960         return ret;
961 }
962
963 static int fsck_tag(struct tag *tag, const char *data,
964         unsigned long size, struct fsck_options *options)
965 {
966         struct object *tagged = tag->tagged;
967
968         if (!tagged)
969                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
970
971         return fsck_tag_buffer(tag, data, size, options);
972 }
973
974 struct fsck_gitmodules_data {
975         struct object *obj;
976         struct fsck_options *options;
977         int ret;
978 };
979
980 static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
981 {
982         struct fsck_gitmodules_data *data = vdata;
983         const char *subsection, *key;
984         int subsection_len;
985         char *name;
986
987         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
988             !subsection)
989                 return 0;
990
991         name = xmemdupz(subsection, subsection_len);
992         if (check_submodule_name(name) < 0)
993                 data->ret |= report(data->options, data->obj,
994                                     FSCK_MSG_GITMODULES_NAME,
995                                     "disallowed submodule name: %s",
996                                     name);
997         if (!strcmp(key, "url") && value &&
998             looks_like_command_line_option(value))
999                 data->ret |= report(data->options, data->obj,
1000                                     FSCK_MSG_GITMODULES_URL,
1001                                     "disallowed submodule url: %s",
1002                                     value);
1003         if (!strcmp(key, "path") && value &&
1004             looks_like_command_line_option(value))
1005                 data->ret |= report(data->options, data->obj,
1006                                     FSCK_MSG_GITMODULES_PATH,
1007                                     "disallowed submodule path: %s",
1008                                     value);
1009         free(name);
1010
1011         return 0;
1012 }
1013
1014 static int fsck_blob(struct blob *blob, const char *buf,
1015                      unsigned long size, struct fsck_options *options)
1016 {
1017         struct fsck_gitmodules_data data;
1018         struct config_options config_opts = { 0 };
1019
1020         if (!oidset_contains(&gitmodules_found, &blob->object.oid))
1021                 return 0;
1022         oidset_insert(&gitmodules_done, &blob->object.oid);
1023
1024         if (object_on_skiplist(options, &blob->object))
1025                 return 0;
1026
1027         if (!buf) {
1028                 /*
1029                  * A missing buffer here is a sign that the caller found the
1030                  * blob too gigantic to load into memory. Let's just consider
1031                  * that an error.
1032                  */
1033                 return report(options, &blob->object,
1034                               FSCK_MSG_GITMODULES_LARGE,
1035                               ".gitmodules too large to parse");
1036         }
1037
1038         data.obj = &blob->object;
1039         data.options = options;
1040         data.ret = 0;
1041         config_opts.error_action = CONFIG_ERROR_SILENT;
1042         if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1043                                 ".gitmodules", buf, size, &data, &config_opts))
1044                 data.ret |= report(options, &blob->object,
1045                                    FSCK_MSG_GITMODULES_PARSE,
1046                                    "could not parse gitmodules blob");
1047
1048         return data.ret;
1049 }
1050
1051 int fsck_object(struct object *obj, void *data, unsigned long size,
1052         struct fsck_options *options)
1053 {
1054         if (!obj)
1055                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1056
1057         if (obj->type == OBJ_BLOB)
1058                 return fsck_blob((struct blob *)obj, data, size, options);
1059         if (obj->type == OBJ_TREE)
1060                 return fsck_tree((struct tree *) obj, options);
1061         if (obj->type == OBJ_COMMIT)
1062                 return fsck_commit((struct commit *) obj, (const char *) data,
1063                         size, options);
1064         if (obj->type == OBJ_TAG)
1065                 return fsck_tag((struct tag *) obj, (const char *) data,
1066                         size, options);
1067
1068         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
1069                           obj->type);
1070 }
1071
1072 int fsck_error_function(struct fsck_options *o,
1073         struct object *obj, int msg_type, const char *message)
1074 {
1075         if (msg_type == FSCK_WARN) {
1076                 warning("object %s: %s", describe_object(o, obj), message);
1077                 return 0;
1078         }
1079         error("object %s: %s", describe_object(o, obj), message);
1080         return 1;
1081 }
1082
1083 int fsck_finish(struct fsck_options *options)
1084 {
1085         int ret = 0;
1086         struct oidset_iter iter;
1087         const struct object_id *oid;
1088
1089         oidset_iter_init(&gitmodules_found, &iter);
1090         while ((oid = oidset_iter_next(&iter))) {
1091                 struct blob *blob;
1092                 enum object_type type;
1093                 unsigned long size;
1094                 char *buf;
1095
1096                 if (oidset_contains(&gitmodules_done, oid))
1097                         continue;
1098
1099                 blob = lookup_blob(the_repository, oid);
1100                 if (!blob) {
1101                         struct object *obj = lookup_unknown_object(oid->hash);
1102                         ret |= report(options, obj,
1103                                       FSCK_MSG_GITMODULES_BLOB,
1104                                       "non-blob found at .gitmodules");
1105                         continue;
1106                 }
1107
1108                 buf = read_object_file(oid, &type, &size);
1109                 if (!buf) {
1110                         if (is_promisor_object(&blob->object.oid))
1111                                 continue;
1112                         ret |= report(options, &blob->object,
1113                                       FSCK_MSG_GITMODULES_MISSING,
1114                                       "unable to read .gitmodules blob");
1115                         continue;
1116                 }
1117
1118                 if (type == OBJ_BLOB)
1119                         ret |= fsck_blob(blob, buf, size, options);
1120                 else
1121                         ret |= report(options, &blob->object,
1122                                       FSCK_MSG_GITMODULES_BLOB,
1123                                       "non-blob found at .gitmodules");
1124                 free(buf);
1125         }
1126
1127
1128         oidset_clear(&gitmodules_found);
1129         oidset_clear(&gitmodules_done);
1130         return ret;
1131 }