Merge branch 'jh/resize-convert-scratch-buffer'
[git] / builtin / fast-export.c
1 /*
2  * "git fast-export" builtin command
3  *
4  * Copyright (C) 2007 Johannes E. Schindelin
5  */
6 #include "builtin.h"
7 #include "cache.h"
8 #include "config.h"
9 #include "refs.h"
10 #include "refspec.h"
11 #include "object-store.h"
12 #include "commit.h"
13 #include "object.h"
14 #include "tag.h"
15 #include "diff.h"
16 #include "diffcore.h"
17 #include "log-tree.h"
18 #include "revision.h"
19 #include "decorate.h"
20 #include "string-list.h"
21 #include "utf8.h"
22 #include "parse-options.h"
23 #include "quote.h"
24 #include "remote.h"
25 #include "blob.h"
26 #include "commit-slab.h"
27
28 static const char *fast_export_usage[] = {
29         N_("git fast-export [rev-list-opts]"),
30         NULL
31 };
32
33 static int progress;
34 static enum { SIGNED_TAG_ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = SIGNED_TAG_ABORT;
35 static enum { TAG_FILTERING_ABORT, DROP, REWRITE } tag_of_filtered_mode = TAG_FILTERING_ABORT;
36 static int fake_missing_tagger;
37 static int use_done_feature;
38 static int no_data;
39 static int full_tree;
40 static int reference_excluded_commits;
41 static int show_original_ids;
42 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
43 static struct string_list tag_refs = STRING_LIST_INIT_NODUP;
44 static struct refspec refspecs = REFSPEC_INIT_FETCH;
45 static int anonymize;
46 static struct revision_sources revision_sources;
47
48 static int parse_opt_signed_tag_mode(const struct option *opt,
49                                      const char *arg, int unset)
50 {
51         if (unset || !strcmp(arg, "abort"))
52                 signed_tag_mode = SIGNED_TAG_ABORT;
53         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
54                 signed_tag_mode = VERBATIM;
55         else if (!strcmp(arg, "warn"))
56                 signed_tag_mode = WARN;
57         else if (!strcmp(arg, "warn-strip"))
58                 signed_tag_mode = WARN_STRIP;
59         else if (!strcmp(arg, "strip"))
60                 signed_tag_mode = STRIP;
61         else
62                 return error("Unknown signed-tags mode: %s", arg);
63         return 0;
64 }
65
66 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
67                                           const char *arg, int unset)
68 {
69         if (unset || !strcmp(arg, "abort"))
70                 tag_of_filtered_mode = TAG_FILTERING_ABORT;
71         else if (!strcmp(arg, "drop"))
72                 tag_of_filtered_mode = DROP;
73         else if (!strcmp(arg, "rewrite"))
74                 tag_of_filtered_mode = REWRITE;
75         else
76                 return error("Unknown tag-of-filtered mode: %s", arg);
77         return 0;
78 }
79
80 static struct decoration idnums;
81 static uint32_t last_idnum;
82
83 static int has_unshown_parent(struct commit *commit)
84 {
85         struct commit_list *parent;
86
87         for (parent = commit->parents; parent; parent = parent->next)
88                 if (!(parent->item->object.flags & SHOWN) &&
89                     !(parent->item->object.flags & UNINTERESTING))
90                         return 1;
91         return 0;
92 }
93
94 struct anonymized_entry {
95         struct hashmap_entry hash;
96         const char *orig;
97         size_t orig_len;
98         const char *anon;
99         size_t anon_len;
100 };
101
102 static int anonymized_entry_cmp(const void *unused_cmp_data,
103                                 const void *va, const void *vb,
104                                 const void *unused_keydata)
105 {
106         const struct anonymized_entry *a = va, *b = vb;
107         return a->orig_len != b->orig_len ||
108                 memcmp(a->orig, b->orig, a->orig_len);
109 }
110
111 /*
112  * Basically keep a cache of X->Y so that we can repeatedly replace
113  * the same anonymized string with another. The actual generation
114  * is farmed out to the generate function.
115  */
116 static const void *anonymize_mem(struct hashmap *map,
117                                  void *(*generate)(const void *, size_t *),
118                                  const void *orig, size_t *len)
119 {
120         struct anonymized_entry key, *ret;
121
122         if (!map->cmpfn)
123                 hashmap_init(map, anonymized_entry_cmp, NULL, 0);
124
125         hashmap_entry_init(&key, memhash(orig, *len));
126         key.orig = orig;
127         key.orig_len = *len;
128         ret = hashmap_get(map, &key, NULL);
129
130         if (!ret) {
131                 ret = xmalloc(sizeof(*ret));
132                 hashmap_entry_init(&ret->hash, key.hash.hash);
133                 ret->orig = xstrdup(orig);
134                 ret->orig_len = *len;
135                 ret->anon = generate(orig, len);
136                 ret->anon_len = *len;
137                 hashmap_put(map, ret);
138         }
139
140         *len = ret->anon_len;
141         return ret->anon;
142 }
143
144 /*
145  * We anonymize each component of a path individually,
146  * so that paths a/b and a/c will share a common root.
147  * The paths are cached via anonymize_mem so that repeated
148  * lookups for "a" will yield the same value.
149  */
150 static void anonymize_path(struct strbuf *out, const char *path,
151                            struct hashmap *map,
152                            void *(*generate)(const void *, size_t *))
153 {
154         while (*path) {
155                 const char *end_of_component = strchrnul(path, '/');
156                 size_t len = end_of_component - path;
157                 const char *c = anonymize_mem(map, generate, path, &len);
158                 strbuf_add(out, c, len);
159                 path = end_of_component;
160                 if (*path)
161                         strbuf_addch(out, *path++);
162         }
163 }
164
165 static inline void *mark_to_ptr(uint32_t mark)
166 {
167         return (void *)(uintptr_t)mark;
168 }
169
170 static inline uint32_t ptr_to_mark(void * mark)
171 {
172         return (uint32_t)(uintptr_t)mark;
173 }
174
175 static inline void mark_object(struct object *object, uint32_t mark)
176 {
177         add_decoration(&idnums, object, mark_to_ptr(mark));
178 }
179
180 static inline void mark_next_object(struct object *object)
181 {
182         mark_object(object, ++last_idnum);
183 }
184
185 static int get_object_mark(struct object *object)
186 {
187         void *decoration = lookup_decoration(&idnums, object);
188         if (!decoration)
189                 return 0;
190         return ptr_to_mark(decoration);
191 }
192
193 static struct commit *rewrite_commit(struct commit *p)
194 {
195         for (;;) {
196                 if (p->parents && p->parents->next)
197                         break;
198                 if (p->object.flags & UNINTERESTING)
199                         break;
200                 if (!(p->object.flags & TREESAME))
201                         break;
202                 if (!p->parents)
203                         return NULL;
204                 p = p->parents->item;
205         }
206         return p;
207 }
208
209 static void show_progress(void)
210 {
211         static int counter = 0;
212         if (!progress)
213                 return;
214         if ((++counter % progress) == 0)
215                 printf("progress %d objects\n", counter);
216 }
217
218 /*
219  * Ideally we would want some transformation of the blob data here
220  * that is unreversible, but would still be the same size and have
221  * the same data relationship to other blobs (so that we get the same
222  * delta and packing behavior as the original). But the first and last
223  * requirements there are probably mutually exclusive, so let's take
224  * the easy way out for now, and just generate arbitrary content.
225  *
226  * There's no need to cache this result with anonymize_mem, since
227  * we already handle blob content caching with marks.
228  */
229 static char *anonymize_blob(unsigned long *size)
230 {
231         static int counter;
232         struct strbuf out = STRBUF_INIT;
233         strbuf_addf(&out, "anonymous blob %d", counter++);
234         *size = out.len;
235         return strbuf_detach(&out, NULL);
236 }
237
238 static void export_blob(const struct object_id *oid)
239 {
240         unsigned long size;
241         enum object_type type;
242         char *buf;
243         struct object *object;
244         int eaten;
245
246         if (no_data)
247                 return;
248
249         if (is_null_oid(oid))
250                 return;
251
252         object = lookup_object(the_repository, oid->hash);
253         if (object && object->flags & SHOWN)
254                 return;
255
256         if (anonymize) {
257                 buf = anonymize_blob(&size);
258                 object = (struct object *)lookup_blob(the_repository, oid);
259                 eaten = 0;
260         } else {
261                 buf = read_object_file(oid, &type, &size);
262                 if (!buf)
263                         die("could not read blob %s", oid_to_hex(oid));
264                 if (check_object_signature(oid, buf, size, type_name(type)) < 0)
265                         die("oid mismatch in blob %s", oid_to_hex(oid));
266                 object = parse_object_buffer(the_repository, oid, type,
267                                              size, buf, &eaten);
268         }
269
270         if (!object)
271                 die("Could not read blob %s", oid_to_hex(oid));
272
273         mark_next_object(object);
274
275         printf("blob\nmark :%"PRIu32"\n", last_idnum);
276         if (show_original_ids)
277                 printf("original-oid %s\n", oid_to_hex(oid));
278         printf("data %"PRIuMAX"\n", (uintmax_t)size);
279         if (size && fwrite(buf, size, 1, stdout) != 1)
280                 die_errno("could not write blob '%s'", oid_to_hex(oid));
281         printf("\n");
282
283         show_progress();
284
285         object->flags |= SHOWN;
286         if (!eaten)
287                 free(buf);
288 }
289
290 static int depth_first(const void *a_, const void *b_)
291 {
292         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
293         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
294         const char *name_a, *name_b;
295         int len_a, len_b, len;
296         int cmp;
297
298         name_a = a->one ? a->one->path : a->two->path;
299         name_b = b->one ? b->one->path : b->two->path;
300
301         len_a = strlen(name_a);
302         len_b = strlen(name_b);
303         len = (len_a < len_b) ? len_a : len_b;
304
305         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
306         cmp = memcmp(name_a, name_b, len);
307         if (cmp)
308                 return cmp;
309         cmp = len_b - len_a;
310         if (cmp)
311                 return cmp;
312         /*
313          * Move 'R'ename entries last so that all references of the file
314          * appear in the output before it is renamed (e.g., when a file
315          * was copied and renamed in the same commit).
316          */
317         return (a->status == 'R') - (b->status == 'R');
318 }
319
320 static void print_path_1(const char *path)
321 {
322         int need_quote = quote_c_style(path, NULL, NULL, 0);
323         if (need_quote)
324                 quote_c_style(path, NULL, stdout, 0);
325         else if (strchr(path, ' '))
326                 printf("\"%s\"", path);
327         else
328                 printf("%s", path);
329 }
330
331 static void *anonymize_path_component(const void *path, size_t *len)
332 {
333         static int counter;
334         struct strbuf out = STRBUF_INIT;
335         strbuf_addf(&out, "path%d", counter++);
336         return strbuf_detach(&out, len);
337 }
338
339 static void print_path(const char *path)
340 {
341         if (!anonymize)
342                 print_path_1(path);
343         else {
344                 static struct hashmap paths;
345                 static struct strbuf anon = STRBUF_INIT;
346
347                 anonymize_path(&anon, path, &paths, anonymize_path_component);
348                 print_path_1(anon.buf);
349                 strbuf_reset(&anon);
350         }
351 }
352
353 static void *generate_fake_oid(const void *old, size_t *len)
354 {
355         static uint32_t counter = 1; /* avoid null oid */
356         const unsigned hashsz = the_hash_algo->rawsz;
357         unsigned char *out = xcalloc(hashsz, 1);
358         put_be32(out + hashsz - 4, counter++);
359         return out;
360 }
361
362 static const struct object_id *anonymize_oid(const struct object_id *oid)
363 {
364         static struct hashmap objs;
365         size_t len = the_hash_algo->rawsz;
366         return anonymize_mem(&objs, generate_fake_oid, oid, &len);
367 }
368
369 static void show_filemodify(struct diff_queue_struct *q,
370                             struct diff_options *options, void *data)
371 {
372         int i;
373         struct string_list *changed = data;
374
375         /*
376          * Handle files below a directory first, in case they are all deleted
377          * and the directory changes to a file or symlink.
378          */
379         QSORT(q->queue, q->nr, depth_first);
380
381         for (i = 0; i < q->nr; i++) {
382                 struct diff_filespec *ospec = q->queue[i]->one;
383                 struct diff_filespec *spec = q->queue[i]->two;
384
385                 switch (q->queue[i]->status) {
386                 case DIFF_STATUS_DELETED:
387                         printf("D ");
388                         print_path(spec->path);
389                         string_list_insert(changed, spec->path);
390                         putchar('\n');
391                         break;
392
393                 case DIFF_STATUS_COPIED:
394                 case DIFF_STATUS_RENAMED:
395                         /*
396                          * If a change in the file corresponding to ospec->path
397                          * has been observed, we cannot trust its contents
398                          * because the diff is calculated based on the prior
399                          * contents, not the current contents.  So, declare a
400                          * copy or rename only if there was no change observed.
401                          */
402                         if (!string_list_has_string(changed, ospec->path)) {
403                                 printf("%c ", q->queue[i]->status);
404                                 print_path(ospec->path);
405                                 putchar(' ');
406                                 print_path(spec->path);
407                                 string_list_insert(changed, spec->path);
408                                 putchar('\n');
409
410                                 if (oideq(&ospec->oid, &spec->oid) &&
411                                     ospec->mode == spec->mode)
412                                         break;
413                         }
414                         /* fallthrough */
415
416                 case DIFF_STATUS_TYPE_CHANGED:
417                 case DIFF_STATUS_MODIFIED:
418                 case DIFF_STATUS_ADDED:
419                         /*
420                          * Links refer to objects in another repositories;
421                          * output the SHA-1 verbatim.
422                          */
423                         if (no_data || S_ISGITLINK(spec->mode))
424                                 printf("M %06o %s ", spec->mode,
425                                        oid_to_hex(anonymize ?
426                                                   anonymize_oid(&spec->oid) :
427                                                   &spec->oid));
428                         else {
429                                 struct object *object = lookup_object(the_repository,
430                                                                       spec->oid.hash);
431                                 printf("M %06o :%d ", spec->mode,
432                                        get_object_mark(object));
433                         }
434                         print_path(spec->path);
435                         string_list_insert(changed, spec->path);
436                         putchar('\n');
437                         break;
438
439                 default:
440                         die("Unexpected comparison status '%c' for %s, %s",
441                                 q->queue[i]->status,
442                                 ospec->path ? ospec->path : "none",
443                                 spec->path ? spec->path : "none");
444                 }
445         }
446 }
447
448 static const char *find_encoding(const char *begin, const char *end)
449 {
450         const char *needle = "\nencoding ";
451         char *bol, *eol;
452
453         bol = memmem(begin, end ? end - begin : strlen(begin),
454                      needle, strlen(needle));
455         if (!bol)
456                 return git_commit_encoding;
457         bol += strlen(needle);
458         eol = strchrnul(bol, '\n');
459         *eol = '\0';
460         return bol;
461 }
462
463 static void *anonymize_ref_component(const void *old, size_t *len)
464 {
465         static int counter;
466         struct strbuf out = STRBUF_INIT;
467         strbuf_addf(&out, "ref%d", counter++);
468         return strbuf_detach(&out, len);
469 }
470
471 static const char *anonymize_refname(const char *refname)
472 {
473         /*
474          * If any of these prefixes is found, we will leave it intact
475          * so that tags remain tags and so forth.
476          */
477         static const char *prefixes[] = {
478                 "refs/heads/",
479                 "refs/tags/",
480                 "refs/remotes/",
481                 "refs/"
482         };
483         static struct hashmap refs;
484         static struct strbuf anon = STRBUF_INIT;
485         int i;
486
487         /*
488          * We also leave "master" as a special case, since it does not reveal
489          * anything interesting.
490          */
491         if (!strcmp(refname, "refs/heads/master"))
492                 return refname;
493
494         strbuf_reset(&anon);
495         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
496                 if (skip_prefix(refname, prefixes[i], &refname)) {
497                         strbuf_addstr(&anon, prefixes[i]);
498                         break;
499                 }
500         }
501
502         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
503         return anon.buf;
504 }
505
506 /*
507  * We do not even bother to cache commit messages, as they are unlikely
508  * to be repeated verbatim, and it is not that interesting when they are.
509  */
510 static char *anonymize_commit_message(const char *old)
511 {
512         static int counter;
513         return xstrfmt("subject %d\n\nbody\n", counter++);
514 }
515
516 static struct hashmap idents;
517 static void *anonymize_ident(const void *old, size_t *len)
518 {
519         static int counter;
520         struct strbuf out = STRBUF_INIT;
521         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
522         counter++;
523         return strbuf_detach(&out, len);
524 }
525
526 /*
527  * Our strategy here is to anonymize the names and email addresses,
528  * but keep timestamps intact, as they influence things like traversal
529  * order (and by themselves should not be too revealing).
530  */
531 static void anonymize_ident_line(const char **beg, const char **end)
532 {
533         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
534         static unsigned which_buffer;
535
536         struct strbuf *out;
537         struct ident_split split;
538         const char *end_of_header;
539
540         out = &buffers[which_buffer++];
541         which_buffer %= ARRAY_SIZE(buffers);
542         strbuf_reset(out);
543
544         /* skip "committer", "author", "tagger", etc */
545         end_of_header = strchr(*beg, ' ');
546         if (!end_of_header)
547                 BUG("malformed line fed to anonymize_ident_line: %.*s",
548                     (int)(*end - *beg), *beg);
549         end_of_header++;
550         strbuf_add(out, *beg, end_of_header - *beg);
551
552         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
553             split.date_begin) {
554                 const char *ident;
555                 size_t len;
556
557                 len = split.mail_end - split.name_begin;
558                 ident = anonymize_mem(&idents, anonymize_ident,
559                                       split.name_begin, &len);
560                 strbuf_add(out, ident, len);
561                 strbuf_addch(out, ' ');
562                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
563         } else {
564                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
565         }
566
567         *beg = out->buf;
568         *end = out->buf + out->len;
569 }
570
571 static void handle_commit(struct commit *commit, struct rev_info *rev,
572                           struct string_list *paths_of_changed_objects)
573 {
574         int saved_output_format = rev->diffopt.output_format;
575         const char *commit_buffer;
576         const char *author, *author_end, *committer, *committer_end;
577         const char *encoding, *message;
578         char *reencoded = NULL;
579         struct commit_list *p;
580         const char *refname;
581         int i;
582
583         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
584
585         parse_commit_or_die(commit);
586         commit_buffer = get_commit_buffer(commit, NULL);
587         author = strstr(commit_buffer, "\nauthor ");
588         if (!author)
589                 die("could not find author in commit %s",
590                     oid_to_hex(&commit->object.oid));
591         author++;
592         author_end = strchrnul(author, '\n');
593         committer = strstr(author_end, "\ncommitter ");
594         if (!committer)
595                 die("could not find committer in commit %s",
596                     oid_to_hex(&commit->object.oid));
597         committer++;
598         committer_end = strchrnul(committer, '\n');
599         message = strstr(committer_end, "\n\n");
600         encoding = find_encoding(committer_end, message);
601         if (message)
602                 message += 2;
603
604         if (commit->parents &&
605             (get_object_mark(&commit->parents->item->object) != 0 ||
606              reference_excluded_commits) &&
607             !full_tree) {
608                 parse_commit_or_die(commit->parents->item);
609                 diff_tree_oid(get_commit_tree_oid(commit->parents->item),
610                               get_commit_tree_oid(commit), "", &rev->diffopt);
611         }
612         else
613                 diff_root_tree_oid(get_commit_tree_oid(commit),
614                                    "", &rev->diffopt);
615
616         /* Export the referenced blobs, and remember the marks. */
617         for (i = 0; i < diff_queued_diff.nr; i++)
618                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
619                         export_blob(&diff_queued_diff.queue[i]->two->oid);
620
621         refname = *revision_sources_at(&revision_sources, commit);
622         /*
623          * FIXME: string_list_remove() below for each ref is overall
624          * O(N^2).  Compared to a history walk and diffing trees, this is
625          * just lost in the noise in practice.  However, theoretically a
626          * repo may have enough refs for this to become slow.
627          */
628         string_list_remove(&extra_refs, refname, 0);
629         if (anonymize) {
630                 refname = anonymize_refname(refname);
631                 anonymize_ident_line(&committer, &committer_end);
632                 anonymize_ident_line(&author, &author_end);
633         }
634
635         mark_next_object(&commit->object);
636         if (anonymize)
637                 reencoded = anonymize_commit_message(message);
638         else if (!is_encoding_utf8(encoding))
639                 reencoded = reencode_string(message, "UTF-8", encoding);
640         if (!commit->parents)
641                 printf("reset %s\n", refname);
642         printf("commit %s\nmark :%"PRIu32"\n", refname, last_idnum);
643         if (show_original_ids)
644                 printf("original-oid %s\n", oid_to_hex(&commit->object.oid));
645         printf("%.*s\n%.*s\ndata %u\n%s",
646                (int)(author_end - author), author,
647                (int)(committer_end - committer), committer,
648                (unsigned)(reencoded
649                           ? strlen(reencoded) : message
650                           ? strlen(message) : 0),
651                reencoded ? reencoded : message ? message : "");
652         free(reencoded);
653         unuse_commit_buffer(commit, commit_buffer);
654
655         for (i = 0, p = commit->parents; p; p = p->next) {
656                 struct object *obj = &p->item->object;
657                 int mark = get_object_mark(obj);
658
659                 if (!mark && !reference_excluded_commits)
660                         continue;
661                 if (i == 0)
662                         printf("from ");
663                 else
664                         printf("merge ");
665                 if (mark)
666                         printf(":%d\n", mark);
667                 else
668                         printf("%s\n", oid_to_hex(anonymize ?
669                                                   anonymize_oid(&obj->oid) :
670                                                   &obj->oid));
671                 i++;
672         }
673
674         if (full_tree)
675                 printf("deleteall\n");
676         log_tree_diff_flush(rev);
677         string_list_clear(paths_of_changed_objects, 0);
678         rev->diffopt.output_format = saved_output_format;
679
680         printf("\n");
681
682         show_progress();
683 }
684
685 static void *anonymize_tag(const void *old, size_t *len)
686 {
687         static int counter;
688         struct strbuf out = STRBUF_INIT;
689         strbuf_addf(&out, "tag message %d", counter++);
690         return strbuf_detach(&out, len);
691 }
692
693 static void handle_tail(struct object_array *commits, struct rev_info *revs,
694                         struct string_list *paths_of_changed_objects)
695 {
696         struct commit *commit;
697         while (commits->nr) {
698                 commit = (struct commit *)object_array_pop(commits);
699                 if (has_unshown_parent(commit)) {
700                         /* Queue again, to be handled later */
701                         add_object_array(&commit->object, NULL, commits);
702                         return;
703                 }
704                 handle_commit(commit, revs, paths_of_changed_objects);
705         }
706 }
707
708 static void handle_tag(const char *name, struct tag *tag)
709 {
710         unsigned long size;
711         enum object_type type;
712         char *buf;
713         const char *tagger, *tagger_end, *message;
714         size_t message_size = 0;
715         struct object *tagged;
716         int tagged_mark;
717         struct commit *p;
718
719         /* Trees have no identifier in fast-export output, thus we have no way
720          * to output tags of trees, tags of tags of trees, etc.  Simply omit
721          * such tags.
722          */
723         tagged = tag->tagged;
724         while (tagged->type == OBJ_TAG) {
725                 tagged = ((struct tag *)tagged)->tagged;
726         }
727         if (tagged->type == OBJ_TREE) {
728                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
729                         oid_to_hex(&tag->object.oid));
730                 return;
731         }
732
733         buf = read_object_file(&tag->object.oid, &type, &size);
734         if (!buf)
735                 die("could not read tag %s", oid_to_hex(&tag->object.oid));
736         message = memmem(buf, size, "\n\n", 2);
737         if (message) {
738                 message += 2;
739                 message_size = strlen(message);
740         }
741         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
742         if (!tagger) {
743                 if (fake_missing_tagger)
744                         tagger = "tagger Unspecified Tagger "
745                                 "<unspecified-tagger> 0 +0000";
746                 else
747                         tagger = "";
748                 tagger_end = tagger + strlen(tagger);
749         } else {
750                 tagger++;
751                 tagger_end = strchrnul(tagger, '\n');
752                 if (anonymize)
753                         anonymize_ident_line(&tagger, &tagger_end);
754         }
755
756         if (anonymize) {
757                 name = anonymize_refname(name);
758                 if (message) {
759                         static struct hashmap tags;
760                         message = anonymize_mem(&tags, anonymize_tag,
761                                                 message, &message_size);
762                 }
763         }
764
765         /* handle signed tags */
766         if (message) {
767                 const char *signature = strstr(message,
768                                                "\n-----BEGIN PGP SIGNATURE-----\n");
769                 if (signature)
770                         switch(signed_tag_mode) {
771                         case SIGNED_TAG_ABORT:
772                                 die("encountered signed tag %s; use "
773                                     "--signed-tags=<mode> to handle it",
774                                     oid_to_hex(&tag->object.oid));
775                         case WARN:
776                                 warning("exporting signed tag %s",
777                                         oid_to_hex(&tag->object.oid));
778                                 /* fallthru */
779                         case VERBATIM:
780                                 break;
781                         case WARN_STRIP:
782                                 warning("stripping signature from tag %s",
783                                         oid_to_hex(&tag->object.oid));
784                                 /* fallthru */
785                         case STRIP:
786                                 message_size = signature + 1 - message;
787                                 break;
788                         }
789         }
790
791         /* handle tag->tagged having been filtered out due to paths specified */
792         tagged = tag->tagged;
793         tagged_mark = get_object_mark(tagged);
794         if (!tagged_mark) {
795                 switch(tag_of_filtered_mode) {
796                 case TAG_FILTERING_ABORT:
797                         die("tag %s tags unexported object; use "
798                             "--tag-of-filtered-object=<mode> to handle it",
799                             oid_to_hex(&tag->object.oid));
800                 case DROP:
801                         /* Ignore this tag altogether */
802                         free(buf);
803                         return;
804                 case REWRITE:
805                         if (tagged->type != OBJ_COMMIT) {
806                                 die("tag %s tags unexported %s!",
807                                     oid_to_hex(&tag->object.oid),
808                                     type_name(tagged->type));
809                         }
810                         p = rewrite_commit((struct commit *)tagged);
811                         if (!p) {
812                                 printf("reset %s\nfrom %s\n\n",
813                                        name, oid_to_hex(&null_oid));
814                                 free(buf);
815                                 return;
816                         }
817                         tagged_mark = get_object_mark(&p->object);
818                 }
819         }
820
821         if (starts_with(name, "refs/tags/"))
822                 name += 10;
823         printf("tag %s\nfrom :%d\n", name, tagged_mark);
824         if (show_original_ids)
825                 printf("original-oid %s\n", oid_to_hex(&tag->object.oid));
826         printf("%.*s%sdata %d\n%.*s\n",
827                (int)(tagger_end - tagger), tagger,
828                tagger == tagger_end ? "" : "\n",
829                (int)message_size, (int)message_size, message ? message : "");
830         free(buf);
831 }
832
833 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
834 {
835         switch (e->item->type) {
836         case OBJ_COMMIT:
837                 return (struct commit *)e->item;
838         case OBJ_TAG: {
839                 struct tag *tag = (struct tag *)e->item;
840
841                 /* handle nested tags */
842                 while (tag && tag->object.type == OBJ_TAG) {
843                         parse_object(the_repository, &tag->object.oid);
844                         string_list_append(&tag_refs, full_name)->util = tag;
845                         tag = (struct tag *)tag->tagged;
846                 }
847                 if (!tag)
848                         die("Tag %s points nowhere?", e->name);
849                 return (struct commit *)tag;
850                 break;
851         }
852         default:
853                 return NULL;
854         }
855 }
856
857 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
858 {
859         int i;
860
861         for (i = 0; i < info->nr; i++) {
862                 struct rev_cmdline_entry *e = info->rev + i;
863                 struct object_id oid;
864                 struct commit *commit;
865                 char *full_name;
866
867                 if (e->flags & UNINTERESTING)
868                         continue;
869
870                 if (dwim_ref(e->name, strlen(e->name), &oid, &full_name) != 1)
871                         continue;
872
873                 if (refspecs.nr) {
874                         char *private;
875                         private = apply_refspecs(&refspecs, full_name);
876                         if (private) {
877                                 free(full_name);
878                                 full_name = private;
879                         }
880                 }
881
882                 commit = get_commit(e, full_name);
883                 if (!commit) {
884                         warning("%s: Unexpected object of type %s, skipping.",
885                                 e->name,
886                                 type_name(e->item->type));
887                         continue;
888                 }
889
890                 switch(commit->object.type) {
891                 case OBJ_COMMIT:
892                         break;
893                 case OBJ_BLOB:
894                         export_blob(&commit->object.oid);
895                         continue;
896                 default: /* OBJ_TAG (nested tags) is already handled */
897                         warning("Tag points to object of unexpected type %s, skipping.",
898                                 type_name(commit->object.type));
899                         continue;
900                 }
901
902                 /*
903                  * Make sure this ref gets properly updated eventually, whether
904                  * through a commit or manually at the end.
905                  */
906                 if (e->item->type != OBJ_TAG)
907                         string_list_append(&extra_refs, full_name)->util = commit;
908
909                 if (!*revision_sources_at(&revision_sources, commit))
910                         *revision_sources_at(&revision_sources, commit) = full_name;
911         }
912
913         string_list_sort(&extra_refs);
914         string_list_remove_duplicates(&extra_refs, 0);
915 }
916
917 static void handle_tags_and_duplicates(struct string_list *extras)
918 {
919         struct commit *commit;
920         int i;
921
922         for (i = extras->nr - 1; i >= 0; i--) {
923                 const char *name = extras->items[i].string;
924                 struct object *object = extras->items[i].util;
925                 int mark;
926
927                 switch (object->type) {
928                 case OBJ_TAG:
929                         handle_tag(name, (struct tag *)object);
930                         break;
931                 case OBJ_COMMIT:
932                         if (anonymize)
933                                 name = anonymize_refname(name);
934                         /* create refs pointing to already seen commits */
935                         commit = rewrite_commit((struct commit *)object);
936                         if (!commit) {
937                                 /*
938                                  * Neither this object nor any of its
939                                  * ancestors touch any relevant paths, so
940                                  * it has been filtered to nothing.  Delete
941                                  * it.
942                                  */
943                                 printf("reset %s\nfrom %s\n\n",
944                                        name, oid_to_hex(&null_oid));
945                                 continue;
946                         }
947
948                         mark = get_object_mark(&commit->object);
949                         if (!mark) {
950                                 /*
951                                  * Getting here means we have a commit which
952                                  * was excluded by a negative refspec (e.g.
953                                  * fast-export ^master master).  If we are
954                                  * referencing excluded commits, set the ref
955                                  * to the exact commit.  Otherwise, the user
956                                  * wants the branch exported but every commit
957                                  * in its history to be deleted, which basically
958                                  * just means deletion of the ref.
959                                  */
960                                 if (!reference_excluded_commits) {
961                                         /* delete the ref */
962                                         printf("reset %s\nfrom %s\n\n",
963                                                name, oid_to_hex(&null_oid));
964                                         continue;
965                                 }
966                                 /* set ref to commit using oid, not mark */
967                                 printf("reset %s\nfrom %s\n\n", name,
968                                        oid_to_hex(&commit->object.oid));
969                                 continue;
970                         }
971
972                         printf("reset %s\nfrom :%d\n\n", name, mark
973                                );
974                         show_progress();
975                         break;
976                 }
977         }
978 }
979
980 static void export_marks(char *file)
981 {
982         unsigned int i;
983         uint32_t mark;
984         struct decoration_entry *deco = idnums.entries;
985         FILE *f;
986         int e = 0;
987
988         f = fopen_for_writing(file);
989         if (!f)
990                 die_errno("Unable to open marks file %s for writing.", file);
991
992         for (i = 0; i < idnums.size; i++) {
993                 if (deco->base && deco->base->type == 1) {
994                         mark = ptr_to_mark(deco->decoration);
995                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
996                                 oid_to_hex(&deco->base->oid)) < 0) {
997                             e = 1;
998                             break;
999                         }
1000                 }
1001                 deco++;
1002         }
1003
1004         e |= ferror(f);
1005         e |= fclose(f);
1006         if (e)
1007                 error("Unable to write marks file %s.", file);
1008 }
1009
1010 static void import_marks(char *input_file)
1011 {
1012         char line[512];
1013         FILE *f = xfopen(input_file, "r");
1014
1015         while (fgets(line, sizeof(line), f)) {
1016                 uint32_t mark;
1017                 char *line_end, *mark_end;
1018                 struct object_id oid;
1019                 struct object *object;
1020                 struct commit *commit;
1021                 enum object_type type;
1022
1023                 line_end = strchr(line, '\n');
1024                 if (line[0] != ':' || !line_end)
1025                         die("corrupt mark line: %s", line);
1026                 *line_end = '\0';
1027
1028                 mark = strtoumax(line + 1, &mark_end, 10);
1029                 if (!mark || mark_end == line + 1
1030                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
1031                         die("corrupt mark line: %s", line);
1032
1033                 if (last_idnum < mark)
1034                         last_idnum = mark;
1035
1036                 type = oid_object_info(the_repository, &oid, NULL);
1037                 if (type < 0)
1038                         die("object not found: %s", oid_to_hex(&oid));
1039
1040                 if (type != OBJ_COMMIT)
1041                         /* only commits */
1042                         continue;
1043
1044                 commit = lookup_commit(the_repository, &oid);
1045                 if (!commit)
1046                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
1047
1048                 object = &commit->object;
1049
1050                 if (object->flags & SHOWN)
1051                         error("Object %s already has a mark", oid_to_hex(&oid));
1052
1053                 mark_object(object, mark);
1054
1055                 object->flags |= SHOWN;
1056         }
1057         fclose(f);
1058 }
1059
1060 static void handle_deletes(void)
1061 {
1062         int i;
1063         for (i = 0; i < refspecs.nr; i++) {
1064                 struct refspec_item *refspec = &refspecs.items[i];
1065                 if (*refspec->src)
1066                         continue;
1067
1068                 printf("reset %s\nfrom %s\n\n",
1069                                 refspec->dst, oid_to_hex(&null_oid));
1070         }
1071 }
1072
1073 int cmd_fast_export(int argc, const char **argv, const char *prefix)
1074 {
1075         struct rev_info revs;
1076         struct object_array commits = OBJECT_ARRAY_INIT;
1077         struct commit *commit;
1078         char *export_filename = NULL, *import_filename = NULL;
1079         uint32_t lastimportid;
1080         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
1081         struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
1082         struct option options[] = {
1083                 OPT_INTEGER(0, "progress", &progress,
1084                             N_("show progress after <n> objects")),
1085                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
1086                              N_("select handling of signed tags"),
1087                              parse_opt_signed_tag_mode),
1088                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
1089                              N_("select handling of tags that tag filtered objects"),
1090                              parse_opt_tag_of_filtered_mode),
1091                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
1092                              N_("Dump marks to this file")),
1093                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
1094                              N_("Import marks from this file")),
1095                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
1096                          N_("Fake a tagger when tags lack one")),
1097                 OPT_BOOL(0, "full-tree", &full_tree,
1098                          N_("Output full tree for each commit")),
1099                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
1100                              N_("Use the done feature to terminate the stream")),
1101                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
1102                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1103                              N_("Apply refspec to exported refs")),
1104                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1105                 OPT_BOOL(0, "reference-excluded-parents",
1106                          &reference_excluded_commits, N_("Reference parents which are not in fast-export stream by object id")),
1107                 OPT_BOOL(0, "show-original-ids", &show_original_ids,
1108                             N_("Show original object ids of blobs/commits")),
1109
1110                 OPT_END()
1111         };
1112
1113         if (argc == 1)
1114                 usage_with_options (fast_export_usage, options);
1115
1116         /* we handle encodings */
1117         git_config(git_default_config, NULL);
1118
1119         repo_init_revisions(the_repository, &revs, prefix);
1120         init_revision_sources(&revision_sources);
1121         revs.topo_order = 1;
1122         revs.sources = &revision_sources;
1123         revs.rewrite_parents = 1;
1124         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1125                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
1126         argc = setup_revisions(argc, argv, &revs, NULL);
1127         if (argc > 1)
1128                 usage_with_options (fast_export_usage, options);
1129
1130         if (refspecs_list.nr) {
1131                 int i;
1132
1133                 for (i = 0; i < refspecs_list.nr; i++)
1134                         refspec_append(&refspecs, refspecs_list.items[i].string);
1135
1136                 string_list_clear(&refspecs_list, 1);
1137         }
1138
1139         if (use_done_feature)
1140                 printf("feature done\n");
1141
1142         if (import_filename)
1143                 import_marks(import_filename);
1144         lastimportid = last_idnum;
1145
1146         if (import_filename && revs.prune_data.nr)
1147                 full_tree = 1;
1148
1149         get_tags_and_duplicates(&revs.cmdline);
1150
1151         if (prepare_revision_walk(&revs))
1152                 die("revision walk setup failed");
1153         revs.diffopt.format_callback = show_filemodify;
1154         revs.diffopt.format_callback_data = &paths_of_changed_objects;
1155         revs.diffopt.flags.recursive = 1;
1156         while ((commit = get_revision(&revs))) {
1157                 if (has_unshown_parent(commit)) {
1158                         add_object_array(&commit->object, NULL, &commits);
1159                 }
1160                 else {
1161                         handle_commit(commit, &revs, &paths_of_changed_objects);
1162                         handle_tail(&commits, &revs, &paths_of_changed_objects);
1163                 }
1164         }
1165
1166         handle_tags_and_duplicates(&extra_refs);
1167         handle_tags_and_duplicates(&tag_refs);
1168         handle_deletes();
1169
1170         if (export_filename && lastimportid != last_idnum)
1171                 export_marks(export_filename);
1172
1173         if (use_done_feature)
1174                 printf("done\n");
1175
1176         refspec_clear(&refspecs);
1177
1178         return 0;
1179 }