commit: add repository argument to lookup_commit_graft
[git] / fsck.c
1 #include "cache.h"
2 #include "object-store.h"
3 #include "object.h"
4 #include "blob.h"
5 #include "tree.h"
6 #include "tree-walk.h"
7 #include "commit.h"
8 #include "tag.h"
9 #include "fsck.h"
10 #include "refs.h"
11 #include "utf8.h"
12 #include "sha1-array.h"
13 #include "decorate.h"
14
15 #define FSCK_FATAL -1
16 #define FSCK_INFO -2
17
18 #define FOREACH_MSG_ID(FUNC) \
19         /* fatal errors */ \
20         FUNC(NUL_IN_HEADER, FATAL) \
21         FUNC(UNTERMINATED_HEADER, FATAL) \
22         /* errors */ \
23         FUNC(BAD_DATE, ERROR) \
24         FUNC(BAD_DATE_OVERFLOW, ERROR) \
25         FUNC(BAD_EMAIL, ERROR) \
26         FUNC(BAD_NAME, ERROR) \
27         FUNC(BAD_OBJECT_SHA1, ERROR) \
28         FUNC(BAD_PARENT_SHA1, ERROR) \
29         FUNC(BAD_TAG_OBJECT, ERROR) \
30         FUNC(BAD_TIMEZONE, ERROR) \
31         FUNC(BAD_TREE, ERROR) \
32         FUNC(BAD_TREE_SHA1, ERROR) \
33         FUNC(BAD_TYPE, ERROR) \
34         FUNC(DUPLICATE_ENTRIES, ERROR) \
35         FUNC(MISSING_AUTHOR, ERROR) \
36         FUNC(MISSING_COMMITTER, ERROR) \
37         FUNC(MISSING_EMAIL, ERROR) \
38         FUNC(MISSING_GRAFT, ERROR) \
39         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
40         FUNC(MISSING_OBJECT, ERROR) \
41         FUNC(MISSING_PARENT, ERROR) \
42         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
43         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
44         FUNC(MISSING_TAG, ERROR) \
45         FUNC(MISSING_TAG_ENTRY, ERROR) \
46         FUNC(MISSING_TAG_OBJECT, ERROR) \
47         FUNC(MISSING_TREE, ERROR) \
48         FUNC(MISSING_TYPE, ERROR) \
49         FUNC(MISSING_TYPE_ENTRY, ERROR) \
50         FUNC(MULTIPLE_AUTHORS, ERROR) \
51         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
52         FUNC(TREE_NOT_SORTED, ERROR) \
53         FUNC(UNKNOWN_TYPE, ERROR) \
54         FUNC(ZERO_PADDED_DATE, ERROR) \
55         /* warnings */ \
56         FUNC(BAD_FILEMODE, WARN) \
57         FUNC(EMPTY_NAME, WARN) \
58         FUNC(FULL_PATHNAME, WARN) \
59         FUNC(HAS_DOT, WARN) \
60         FUNC(HAS_DOTDOT, WARN) \
61         FUNC(HAS_DOTGIT, WARN) \
62         FUNC(NULL_SHA1, WARN) \
63         FUNC(ZERO_PADDED_FILEMODE, WARN) \
64         FUNC(NUL_IN_COMMIT, WARN) \
65         /* infos (reported as warnings, but ignored by default) */ \
66         FUNC(BAD_TAG_NAME, INFO) \
67         FUNC(MISSING_TAGGER_ENTRY, INFO)
68
69 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
70 enum fsck_msg_id {
71         FOREACH_MSG_ID(MSG_ID)
72         FSCK_MSG_MAX
73 };
74 #undef MSG_ID
75
76 #define STR(x) #x
77 #define MSG_ID(id, msg_type) { STR(id), NULL, FSCK_##msg_type },
78 static struct {
79         const char *id_string;
80         const char *downcased;
81         int msg_type;
82 } msg_id_info[FSCK_MSG_MAX + 1] = {
83         FOREACH_MSG_ID(MSG_ID)
84         { NULL, NULL, -1 }
85 };
86 #undef MSG_ID
87
88 static int parse_msg_id(const char *text)
89 {
90         int i;
91
92         if (!msg_id_info[0].downcased) {
93                 /* convert id_string to lower case, without underscores. */
94                 for (i = 0; i < FSCK_MSG_MAX; i++) {
95                         const char *p = msg_id_info[i].id_string;
96                         int len = strlen(p);
97                         char *q = xmalloc(len);
98
99                         msg_id_info[i].downcased = q;
100                         while (*p)
101                                 if (*p == '_')
102                                         p++;
103                                 else
104                                         *(q)++ = tolower(*(p)++);
105                         *q = '\0';
106                 }
107         }
108
109         for (i = 0; i < FSCK_MSG_MAX; i++)
110                 if (!strcmp(text, msg_id_info[i].downcased))
111                         return i;
112
113         return -1;
114 }
115
116 static int fsck_msg_type(enum fsck_msg_id msg_id,
117         struct fsck_options *options)
118 {
119         int msg_type;
120
121         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
122
123         if (options->msg_type)
124                 msg_type = options->msg_type[msg_id];
125         else {
126                 msg_type = msg_id_info[msg_id].msg_type;
127                 if (options->strict && msg_type == FSCK_WARN)
128                         msg_type = FSCK_ERROR;
129         }
130
131         return msg_type;
132 }
133
134 static void init_skiplist(struct fsck_options *options, const char *path)
135 {
136         static struct oid_array skiplist = OID_ARRAY_INIT;
137         int sorted, fd;
138         char buffer[GIT_MAX_HEXSZ + 1];
139         struct object_id oid;
140
141         if (options->skiplist)
142                 sorted = options->skiplist->sorted;
143         else {
144                 sorted = 1;
145                 options->skiplist = &skiplist;
146         }
147
148         fd = open(path, O_RDONLY);
149         if (fd < 0)
150                 die("Could not open skip list: %s", path);
151         for (;;) {
152                 const char *p;
153                 int result = read_in_full(fd, buffer, sizeof(buffer));
154                 if (result < 0)
155                         die_errno("Could not read '%s'", path);
156                 if (!result)
157                         break;
158                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n')
159                         die("Invalid SHA-1: %s", buffer);
160                 oid_array_append(&skiplist, &oid);
161                 if (sorted && skiplist.nr > 1 &&
162                                 oidcmp(&skiplist.oid[skiplist.nr - 2],
163                                        &oid) > 0)
164                         sorted = 0;
165         }
166         close(fd);
167
168         if (sorted)
169                 skiplist.sorted = 1;
170 }
171
172 static int parse_msg_type(const char *str)
173 {
174         if (!strcmp(str, "error"))
175                 return FSCK_ERROR;
176         else if (!strcmp(str, "warn"))
177                 return FSCK_WARN;
178         else if (!strcmp(str, "ignore"))
179                 return FSCK_IGNORE;
180         else
181                 die("Unknown fsck message type: '%s'", str);
182 }
183
184 int is_valid_msg_type(const char *msg_id, const char *msg_type)
185 {
186         if (parse_msg_id(msg_id) < 0)
187                 return 0;
188         parse_msg_type(msg_type);
189         return 1;
190 }
191
192 void fsck_set_msg_type(struct fsck_options *options,
193                 const char *msg_id, const char *msg_type)
194 {
195         int id = parse_msg_id(msg_id), type;
196
197         if (id < 0)
198                 die("Unhandled message id: %s", msg_id);
199         type = parse_msg_type(msg_type);
200
201         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
202                 die("Cannot demote %s to %s", msg_id, msg_type);
203
204         if (!options->msg_type) {
205                 int i;
206                 int *msg_type;
207                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
208                 for (i = 0; i < FSCK_MSG_MAX; i++)
209                         msg_type[i] = fsck_msg_type(i, options);
210                 options->msg_type = msg_type;
211         }
212
213         options->msg_type[id] = type;
214 }
215
216 void fsck_set_msg_types(struct fsck_options *options, const char *values)
217 {
218         char *buf = xstrdup(values), *to_free = buf;
219         int done = 0;
220
221         while (!done) {
222                 int len = strcspn(buf, " ,|"), equal;
223
224                 done = !buf[len];
225                 if (!len) {
226                         buf++;
227                         continue;
228                 }
229                 buf[len] = '\0';
230
231                 for (equal = 0;
232                      equal < len && buf[equal] != '=' && buf[equal] != ':';
233                      equal++)
234                         buf[equal] = tolower(buf[equal]);
235                 buf[equal] = '\0';
236
237                 if (!strcmp(buf, "skiplist")) {
238                         if (equal == len)
239                                 die("skiplist requires a path");
240                         init_skiplist(options, buf + equal + 1);
241                         buf += len + 1;
242                         continue;
243                 }
244
245                 if (equal == len)
246                         die("Missing '=': '%s'", buf);
247
248                 fsck_set_msg_type(options, buf, buf + equal + 1);
249                 buf += len + 1;
250         }
251         free(to_free);
252 }
253
254 static void append_msg_id(struct strbuf *sb, const char *msg_id)
255 {
256         for (;;) {
257                 char c = *(msg_id)++;
258
259                 if (!c)
260                         break;
261                 if (c != '_')
262                         strbuf_addch(sb, tolower(c));
263                 else {
264                         assert(*msg_id);
265                         strbuf_addch(sb, *(msg_id)++);
266                 }
267         }
268
269         strbuf_addstr(sb, ": ");
270 }
271
272 __attribute__((format (printf, 4, 5)))
273 static int report(struct fsck_options *options, struct object *object,
274         enum fsck_msg_id id, const char *fmt, ...)
275 {
276         va_list ap;
277         struct strbuf sb = STRBUF_INIT;
278         int msg_type = fsck_msg_type(id, options), result;
279
280         if (msg_type == FSCK_IGNORE)
281                 return 0;
282
283         if (options->skiplist && object &&
284                         oid_array_lookup(options->skiplist, &object->oid) >= 0)
285                 return 0;
286
287         if (msg_type == FSCK_FATAL)
288                 msg_type = FSCK_ERROR;
289         else if (msg_type == FSCK_INFO)
290                 msg_type = FSCK_WARN;
291
292         append_msg_id(&sb, msg_id_info[id].id_string);
293
294         va_start(ap, fmt);
295         strbuf_vaddf(&sb, fmt, ap);
296         result = options->error_func(options, object, msg_type, sb.buf);
297         strbuf_release(&sb);
298         va_end(ap);
299
300         return result;
301 }
302
303 static char *get_object_name(struct fsck_options *options, struct object *obj)
304 {
305         if (!options->object_names)
306                 return NULL;
307         return lookup_decoration(options->object_names, obj);
308 }
309
310 static void put_object_name(struct fsck_options *options, struct object *obj,
311         const char *fmt, ...)
312 {
313         va_list ap;
314         struct strbuf buf = STRBUF_INIT;
315         char *existing;
316
317         if (!options->object_names)
318                 return;
319         existing = lookup_decoration(options->object_names, obj);
320         if (existing)
321                 return;
322         va_start(ap, fmt);
323         strbuf_vaddf(&buf, fmt, ap);
324         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
325         va_end(ap);
326 }
327
328 static const char *describe_object(struct fsck_options *o, struct object *obj)
329 {
330         static struct strbuf buf = STRBUF_INIT;
331         char *name;
332
333         strbuf_reset(&buf);
334         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
335         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
336                 strbuf_addf(&buf, " (%s)", name);
337
338         return buf.buf;
339 }
340
341 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
342 {
343         struct tree_desc desc;
344         struct name_entry entry;
345         int res = 0;
346         const char *name;
347
348         if (parse_tree(tree))
349                 return -1;
350
351         name = get_object_name(options, &tree->object);
352         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
353                 return -1;
354         while (tree_entry_gently(&desc, &entry)) {
355                 struct object *obj;
356                 int result;
357
358                 if (S_ISGITLINK(entry.mode))
359                         continue;
360
361                 if (S_ISDIR(entry.mode)) {
362                         obj = (struct object *)lookup_tree(entry.oid);
363                         if (name && obj)
364                                 put_object_name(options, obj, "%s%s/", name,
365                                         entry.path);
366                         result = options->walk(obj, OBJ_TREE, data, options);
367                 }
368                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
369                         obj = (struct object *)lookup_blob(entry.oid);
370                         if (name && obj)
371                                 put_object_name(options, obj, "%s%s", name,
372                                         entry.path);
373                         result = options->walk(obj, OBJ_BLOB, data, options);
374                 }
375                 else {
376                         result = error("in tree %s: entry %s has bad mode %.6o",
377                                         describe_object(options, &tree->object), entry.path, entry.mode);
378                 }
379                 if (result < 0)
380                         return result;
381                 if (!res)
382                         res = result;
383         }
384         return res;
385 }
386
387 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
388 {
389         int counter = 0, generation = 0, name_prefix_len = 0;
390         struct commit_list *parents;
391         int res;
392         int result;
393         const char *name;
394
395         if (parse_commit(commit))
396                 return -1;
397
398         name = get_object_name(options, &commit->object);
399         if (name)
400                 put_object_name(options, &commit->tree->object, "%s:", name);
401
402         result = options->walk((struct object *)commit->tree, OBJ_TREE, data, options);
403         if (result < 0)
404                 return result;
405         res = result;
406
407         parents = commit->parents;
408         if (name && parents) {
409                 int len = strlen(name), power;
410
411                 if (len && name[len - 1] == '^') {
412                         generation = 1;
413                         name_prefix_len = len - 1;
414                 }
415                 else { /* parse ~<generation> suffix */
416                         for (generation = 0, power = 1;
417                              len && isdigit(name[len - 1]);
418                              power *= 10)
419                                 generation += power * (name[--len] - '0');
420                         if (power > 1 && len && name[len - 1] == '~')
421                                 name_prefix_len = len - 1;
422                 }
423         }
424
425         while (parents) {
426                 if (name) {
427                         struct object *obj = &parents->item->object;
428
429                         if (++counter > 1)
430                                 put_object_name(options, obj, "%s^%d",
431                                         name, counter);
432                         else if (generation > 0)
433                                 put_object_name(options, obj, "%.*s~%d",
434                                         name_prefix_len, name, generation + 1);
435                         else
436                                 put_object_name(options, obj, "%s^", name);
437                 }
438                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
439                 if (result < 0)
440                         return result;
441                 if (!res)
442                         res = result;
443                 parents = parents->next;
444         }
445         return res;
446 }
447
448 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
449 {
450         char *name = get_object_name(options, &tag->object);
451
452         if (parse_tag(tag))
453                 return -1;
454         if (name)
455                 put_object_name(options, tag->tagged, "%s", name);
456         return options->walk(tag->tagged, OBJ_ANY, data, options);
457 }
458
459 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
460 {
461         if (!obj)
462                 return -1;
463
464         if (obj->type == OBJ_NONE)
465                 parse_object(&obj->oid);
466
467         switch (obj->type) {
468         case OBJ_BLOB:
469                 return 0;
470         case OBJ_TREE:
471                 return fsck_walk_tree((struct tree *)obj, data, options);
472         case OBJ_COMMIT:
473                 return fsck_walk_commit((struct commit *)obj, data, options);
474         case OBJ_TAG:
475                 return fsck_walk_tag((struct tag *)obj, data, options);
476         default:
477                 error("Unknown object type for %s", describe_object(options, obj));
478                 return -1;
479         }
480 }
481
482 /*
483  * The entries in a tree are ordered in the _path_ order,
484  * which means that a directory entry is ordered by adding
485  * a slash to the end of it.
486  *
487  * So a directory called "a" is ordered _after_ a file
488  * called "a.c", because "a/" sorts after "a.c".
489  */
490 #define TREE_UNORDERED (-1)
491 #define TREE_HAS_DUPS  (-2)
492
493 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
494 {
495         int len1 = strlen(name1);
496         int len2 = strlen(name2);
497         int len = len1 < len2 ? len1 : len2;
498         unsigned char c1, c2;
499         int cmp;
500
501         cmp = memcmp(name1, name2, len);
502         if (cmp < 0)
503                 return 0;
504         if (cmp > 0)
505                 return TREE_UNORDERED;
506
507         /*
508          * Ok, the first <len> characters are the same.
509          * Now we need to order the next one, but turn
510          * a '\0' into a '/' for a directory entry.
511          */
512         c1 = name1[len];
513         c2 = name2[len];
514         if (!c1 && !c2)
515                 /*
516                  * git-write-tree used to write out a nonsense tree that has
517                  * entries with the same name, one blob and one tree.  Make
518                  * sure we do not have duplicate entries.
519                  */
520                 return TREE_HAS_DUPS;
521         if (!c1 && S_ISDIR(mode1))
522                 c1 = '/';
523         if (!c2 && S_ISDIR(mode2))
524                 c2 = '/';
525         return c1 < c2 ? 0 : TREE_UNORDERED;
526 }
527
528 static int fsck_tree(struct tree *item, struct fsck_options *options)
529 {
530         int retval = 0;
531         int has_null_sha1 = 0;
532         int has_full_path = 0;
533         int has_empty_name = 0;
534         int has_dot = 0;
535         int has_dotdot = 0;
536         int has_dotgit = 0;
537         int has_zero_pad = 0;
538         int has_bad_modes = 0;
539         int has_dup_entries = 0;
540         int not_properly_sorted = 0;
541         struct tree_desc desc;
542         unsigned o_mode;
543         const char *o_name;
544
545         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
546                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
547                 return retval;
548         }
549
550         o_mode = 0;
551         o_name = NULL;
552
553         while (desc.size) {
554                 unsigned mode;
555                 const char *name;
556                 const struct object_id *oid;
557
558                 oid = tree_entry_extract(&desc, &name, &mode);
559
560                 has_null_sha1 |= is_null_oid(oid);
561                 has_full_path |= !!strchr(name, '/');
562                 has_empty_name |= !*name;
563                 has_dot |= !strcmp(name, ".");
564                 has_dotdot |= !strcmp(name, "..");
565                 has_dotgit |= (!strcmp(name, ".git") ||
566                                is_hfs_dotgit(name) ||
567                                is_ntfs_dotgit(name));
568                 has_zero_pad |= *(char *)desc.buffer == '0';
569                 if (update_tree_entry_gently(&desc)) {
570                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
571                         break;
572                 }
573
574                 switch (mode) {
575                 /*
576                  * Standard modes..
577                  */
578                 case S_IFREG | 0755:
579                 case S_IFREG | 0644:
580                 case S_IFLNK:
581                 case S_IFDIR:
582                 case S_IFGITLINK:
583                         break;
584                 /*
585                  * This is nonstandard, but we had a few of these
586                  * early on when we honored the full set of mode
587                  * bits..
588                  */
589                 case S_IFREG | 0664:
590                         if (!options->strict)
591                                 break;
592                         /* fallthrough */
593                 default:
594                         has_bad_modes = 1;
595                 }
596
597                 if (o_name) {
598                         switch (verify_ordered(o_mode, o_name, mode, name)) {
599                         case TREE_UNORDERED:
600                                 not_properly_sorted = 1;
601                                 break;
602                         case TREE_HAS_DUPS:
603                                 has_dup_entries = 1;
604                                 break;
605                         default:
606                                 break;
607                         }
608                 }
609
610                 o_mode = mode;
611                 o_name = name;
612         }
613
614         if (has_null_sha1)
615                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
616         if (has_full_path)
617                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
618         if (has_empty_name)
619                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
620         if (has_dot)
621                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
622         if (has_dotdot)
623                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
624         if (has_dotgit)
625                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
626         if (has_zero_pad)
627                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
628         if (has_bad_modes)
629                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
630         if (has_dup_entries)
631                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
632         if (not_properly_sorted)
633                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
634         return retval;
635 }
636
637 static int verify_headers(const void *data, unsigned long size,
638                           struct object *obj, struct fsck_options *options)
639 {
640         const char *buffer = (const char *)data;
641         unsigned long i;
642
643         for (i = 0; i < size; i++) {
644                 switch (buffer[i]) {
645                 case '\0':
646                         return report(options, obj,
647                                 FSCK_MSG_NUL_IN_HEADER,
648                                 "unterminated header: NUL at offset %ld", i);
649                 case '\n':
650                         if (i + 1 < size && buffer[i + 1] == '\n')
651                                 return 0;
652                 }
653         }
654
655         /*
656          * We did not find double-LF that separates the header
657          * and the body.  Not having a body is not a crime but
658          * we do want to see the terminating LF for the last header
659          * line.
660          */
661         if (size && buffer[size - 1] == '\n')
662                 return 0;
663
664         return report(options, obj,
665                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
666 }
667
668 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
669 {
670         const char *p = *ident;
671         char *end;
672
673         *ident = strchrnul(*ident, '\n');
674         if (**ident == '\n')
675                 (*ident)++;
676
677         if (*p == '<')
678                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
679         p += strcspn(p, "<>\n");
680         if (*p == '>')
681                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
682         if (*p != '<')
683                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
684         if (p[-1] != ' ')
685                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
686         p++;
687         p += strcspn(p, "<>\n");
688         if (*p != '>')
689                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
690         p++;
691         if (*p != ' ')
692                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
693         p++;
694         if (*p == '0' && p[1] != ' ')
695                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
696         if (date_overflows(parse_timestamp(p, &end, 10)))
697                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
698         if ((end == p || *end != ' '))
699                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
700         p = end + 1;
701         if ((*p != '+' && *p != '-') ||
702             !isdigit(p[1]) ||
703             !isdigit(p[2]) ||
704             !isdigit(p[3]) ||
705             !isdigit(p[4]) ||
706             (p[5] != '\n'))
707                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
708         p += 6;
709         return 0;
710 }
711
712 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
713         unsigned long size, struct fsck_options *options)
714 {
715         unsigned char tree_sha1[20], sha1[20];
716         struct commit_graft *graft;
717         unsigned parent_count, parent_line_count = 0, author_count;
718         int err;
719         const char *buffer_begin = buffer;
720
721         if (verify_headers(buffer, size, &commit->object, options))
722                 return -1;
723
724         if (!skip_prefix(buffer, "tree ", &buffer))
725                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
726         if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n') {
727                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
728                 if (err)
729                         return err;
730         }
731         buffer += 41;
732         while (skip_prefix(buffer, "parent ", &buffer)) {
733                 if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
734                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
735                         if (err)
736                                 return err;
737                 }
738                 buffer += 41;
739                 parent_line_count++;
740         }
741         graft = lookup_commit_graft(the_repository, &commit->object.oid);
742         parent_count = commit_list_count(commit->parents);
743         if (graft) {
744                 if (graft->nr_parent == -1 && !parent_count)
745                         ; /* shallow commit */
746                 else if (graft->nr_parent != parent_count) {
747                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
748                         if (err)
749                                 return err;
750                 }
751         } else {
752                 if (parent_count != parent_line_count) {
753                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
754                         if (err)
755                                 return err;
756                 }
757         }
758         author_count = 0;
759         while (skip_prefix(buffer, "author ", &buffer)) {
760                 author_count++;
761                 err = fsck_ident(&buffer, &commit->object, options);
762                 if (err)
763                         return err;
764         }
765         if (author_count < 1)
766                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
767         else if (author_count > 1)
768                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
769         if (err)
770                 return err;
771         if (!skip_prefix(buffer, "committer ", &buffer))
772                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
773         err = fsck_ident(&buffer, &commit->object, options);
774         if (err)
775                 return err;
776         if (!commit->tree) {
777                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
778                 if (err)
779                         return err;
780         }
781         if (memchr(buffer_begin, '\0', size)) {
782                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
783                              "NUL byte in the commit object body");
784                 if (err)
785                         return err;
786         }
787         return 0;
788 }
789
790 static int fsck_commit(struct commit *commit, const char *data,
791         unsigned long size, struct fsck_options *options)
792 {
793         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
794         int ret = fsck_commit_buffer(commit, buffer, size, options);
795         if (!data)
796                 unuse_commit_buffer(commit, buffer);
797         return ret;
798 }
799
800 static int fsck_tag_buffer(struct tag *tag, const char *data,
801         unsigned long size, struct fsck_options *options)
802 {
803         unsigned char sha1[20];
804         int ret = 0;
805         const char *buffer;
806         char *to_free = NULL, *eol;
807         struct strbuf sb = STRBUF_INIT;
808
809         if (data)
810                 buffer = data;
811         else {
812                 enum object_type type;
813
814                 buffer = to_free =
815                         read_object_file(&tag->object.oid, &type, &size);
816                 if (!buffer)
817                         return report(options, &tag->object,
818                                 FSCK_MSG_MISSING_TAG_OBJECT,
819                                 "cannot read tag object");
820
821                 if (type != OBJ_TAG) {
822                         ret = report(options, &tag->object,
823                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
824                                 "expected tag got %s",
825                             type_name(type));
826                         goto done;
827                 }
828         }
829
830         ret = verify_headers(buffer, size, &tag->object, options);
831         if (ret)
832                 goto done;
833
834         if (!skip_prefix(buffer, "object ", &buffer)) {
835                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
836                 goto done;
837         }
838         if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
839                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
840                 if (ret)
841                         goto done;
842         }
843         buffer += 41;
844
845         if (!skip_prefix(buffer, "type ", &buffer)) {
846                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
847                 goto done;
848         }
849         eol = strchr(buffer, '\n');
850         if (!eol) {
851                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
852                 goto done;
853         }
854         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
855                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
856         if (ret)
857                 goto done;
858         buffer = eol + 1;
859
860         if (!skip_prefix(buffer, "tag ", &buffer)) {
861                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
862                 goto done;
863         }
864         eol = strchr(buffer, '\n');
865         if (!eol) {
866                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
867                 goto done;
868         }
869         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
870         if (check_refname_format(sb.buf, 0)) {
871                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
872                            "invalid 'tag' name: %.*s",
873                            (int)(eol - buffer), buffer);
874                 if (ret)
875                         goto done;
876         }
877         buffer = eol + 1;
878
879         if (!skip_prefix(buffer, "tagger ", &buffer)) {
880                 /* early tags do not contain 'tagger' lines; warn only */
881                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
882                 if (ret)
883                         goto done;
884         }
885         else
886                 ret = fsck_ident(&buffer, &tag->object, options);
887
888 done:
889         strbuf_release(&sb);
890         free(to_free);
891         return ret;
892 }
893
894 static int fsck_tag(struct tag *tag, const char *data,
895         unsigned long size, struct fsck_options *options)
896 {
897         struct object *tagged = tag->tagged;
898
899         if (!tagged)
900                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
901
902         return fsck_tag_buffer(tag, data, size, options);
903 }
904
905 int fsck_object(struct object *obj, void *data, unsigned long size,
906         struct fsck_options *options)
907 {
908         if (!obj)
909                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
910
911         if (obj->type == OBJ_BLOB)
912                 return 0;
913         if (obj->type == OBJ_TREE)
914                 return fsck_tree((struct tree *) obj, options);
915         if (obj->type == OBJ_COMMIT)
916                 return fsck_commit((struct commit *) obj, (const char *) data,
917                         size, options);
918         if (obj->type == OBJ_TAG)
919                 return fsck_tag((struct tag *) obj, (const char *) data,
920                         size, options);
921
922         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
923                           obj->type);
924 }
925
926 int fsck_error_function(struct fsck_options *o,
927         struct object *obj, int msg_type, const char *message)
928 {
929         if (msg_type == FSCK_WARN) {
930                 warning("object %s: %s", describe_object(o, obj), message);
931                 return 0;
932         }
933         error("object %s: %s", describe_object(o, obj), message);
934         return 1;
935 }