git.oblomov.eu Git - git/blob - 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 "commit.h"
  11 #include "object.h"
  12 #include "tag.h"
  13 #include "diff.h"
  14 #include "diffcore.h"
  15 #include "log-tree.h"
  16 #include "revision.h"
  17 #include "decorate.h"
  18 #include "string-list.h"
  19 #include "utf8.h"
  20 #include "parse-options.h"
  21 #include "quote.h"
  22 #include "remote.h"
  23 #include "blob.h"
  24
  25 static const char *fast_export_usage[] = {
  26         N_("git fast-export [rev-list-opts]"),
  27         NULL
  28 };
  29
  30 static int progress;
  31 static enum { ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = ABORT;
  32 static enum { ERROR, DROP, REWRITE } tag_of_filtered_mode = ERROR;
  33 static int fake_missing_tagger;
  34 static int use_done_feature;
  35 static int no_data;
  36 static int full_tree;
  37 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
  38 static struct refspec *refspecs;
  39 static int refspecs_nr;
  40 static int anonymize;
  41
  42 static int parse_opt_signed_tag_mode(const struct option *opt,
  43                                      const char *arg, int unset)
  44 {
  45         if (unset || !strcmp(arg, "abort"))
  46                 signed_tag_mode = ABORT;
  47         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
  48                 signed_tag_mode = VERBATIM;
  49         else if (!strcmp(arg, "warn"))
  50                 signed_tag_mode = WARN;
  51         else if (!strcmp(arg, "warn-strip"))
  52                 signed_tag_mode = WARN_STRIP;
  53         else if (!strcmp(arg, "strip"))
  54                 signed_tag_mode = STRIP;
  55         else
  56                 return error("Unknown signed-tags mode: %s", arg);
  57         return 0;
  58 }
  59
  60 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
  61                                           const char *arg, int unset)
  62 {
  63         if (unset || !strcmp(arg, "abort"))
  64                 tag_of_filtered_mode = ERROR;
  65         else if (!strcmp(arg, "drop"))
  66                 tag_of_filtered_mode = DROP;
  67         else if (!strcmp(arg, "rewrite"))
  68                 tag_of_filtered_mode = REWRITE;
  69         else
  70                 return error("Unknown tag-of-filtered mode: %s", arg);
  71         return 0;
  72 }
  73
  74 static struct decoration idnums;
  75 static uint32_t last_idnum;
  76
  77 static int has_unshown_parent(struct commit *commit)
  78 {
  79         struct commit_list *parent;
  80
  81         for (parent = commit->parents; parent; parent = parent->next)
  82                 if (!(parent->item->object.flags & SHOWN) &&
  83                     !(parent->item->object.flags & UNINTERESTING))
  84                         return 1;
  85         return 0;
  86 }
  87
  88 struct anonymized_entry {
  89         struct hashmap_entry hash;
  90         const char *orig;
  91         size_t orig_len;
  92         const char *anon;
  93         size_t anon_len;
  94 };
  95
  96 static int anonymized_entry_cmp(const void *unused_cmp_data,
  97                                 const void *va, const void *vb,
  98                                 const void *unused_keydata)
  99 {
 100         const struct anonymized_entry *a = va, *b = vb;
 101         return a->orig_len != b->orig_len ||
 102                 memcmp(a->orig, b->orig, a->orig_len);
 103 }
 104
 105 /*
 106  * Basically keep a cache of X->Y so that we can repeatedly replace
 107  * the same anonymized string with another. The actual generation
 108  * is farmed out to the generate function.
 109  */
 110 static const void *anonymize_mem(struct hashmap *map,
 111                                  void *(*generate)(const void *, size_t *),
 112                                  const void *orig, size_t *len)
 113 {
 114         struct anonymized_entry key, *ret;
 115
 116         if (!map->cmpfn)
 117                 hashmap_init(map, anonymized_entry_cmp, NULL, 0);
 118
 119         hashmap_entry_init(&key, memhash(orig, *len));
 120         key.orig = orig;
 121         key.orig_len = *len;
 122         ret = hashmap_get(map, &key, NULL);
 123
 124         if (!ret) {
 125                 ret = xmalloc(sizeof(*ret));
 126                 hashmap_entry_init(&ret->hash, key.hash.hash);
 127                 ret->orig = xstrdup(orig);
 128                 ret->orig_len = *len;
 129                 ret->anon = generate(orig, len);
 130                 ret->anon_len = *len;
 131                 hashmap_put(map, ret);
 132         }
 133
 134         *len = ret->anon_len;
 135         return ret->anon;
 136 }
 137
 138 /*
 139  * We anonymize each component of a path individually,
 140  * so that paths a/b and a/c will share a common root.
 141  * The paths are cached via anonymize_mem so that repeated
 142  * lookups for "a" will yield the same value.
 143  */
 144 static void anonymize_path(struct strbuf *out, const char *path,
 145                            struct hashmap *map,
 146                            void *(*generate)(const void *, size_t *))
 147 {
 148         while (*path) {
 149                 const char *end_of_component = strchrnul(path, '/');
 150                 size_t len = end_of_component - path;
 151                 const char *c = anonymize_mem(map, generate, path, &len);
 152                 strbuf_add(out, c, len);
 153                 path = end_of_component;
 154                 if (*path)
 155                         strbuf_addch(out, *path++);
 156         }
 157 }
 158
 159 static inline void *mark_to_ptr(uint32_t mark)
 160 {
 161         return (void *)(uintptr_t)mark;
 162 }
 163
 164 static inline uint32_t ptr_to_mark(void * mark)
 165 {
 166         return (uint32_t)(uintptr_t)mark;
 167 }
 168
 169 static inline void mark_object(struct object *object, uint32_t mark)
 170 {
 171         add_decoration(&idnums, object, mark_to_ptr(mark));
 172 }
 173
 174 static inline void mark_next_object(struct object *object)
 175 {
 176         mark_object(object, ++last_idnum);
 177 }
 178
 179 static int get_object_mark(struct object *object)
 180 {
 181         void *decoration = lookup_decoration(&idnums, object);
 182         if (!decoration)
 183                 return 0;
 184         return ptr_to_mark(decoration);
 185 }
 186
 187 static void show_progress(void)
 188 {
 189         static int counter = 0;
 190         if (!progress)
 191                 return;
 192         if ((++counter % progress) == 0)
 193                 printf("progress %d objects\n", counter);
 194 }
 195
 196 /*
 197  * Ideally we would want some transformation of the blob data here
 198  * that is unreversible, but would still be the same size and have
 199  * the same data relationship to other blobs (so that we get the same
 200  * delta and packing behavior as the original). But the first and last
 201  * requirements there are probably mutually exclusive, so let's take
 202  * the easy way out for now, and just generate arbitrary content.
 203  *
 204  * There's no need to cache this result with anonymize_mem, since
 205  * we already handle blob content caching with marks.
 206  */
 207 static char *anonymize_blob(unsigned long *size)
 208 {
 209         static int counter;
 210         struct strbuf out = STRBUF_INIT;
 211         strbuf_addf(&out, "anonymous blob %d", counter++);
 212         *size = out.len;
 213         return strbuf_detach(&out, NULL);
 214 }
 215
 216 static void export_blob(const struct object_id *oid)
 217 {
 218         unsigned long size;
 219         enum object_type type;
 220         char *buf;
 221         struct object *object;
 222         int eaten;
 223
 224         if (no_data)
 225                 return;
 226
 227         if (is_null_oid(oid))
 228                 return;
 229
 230         object = lookup_object(oid->hash);
 231         if (object && object->flags & SHOWN)
 232                 return;
 233
 234         if (anonymize) {
 235                 buf = anonymize_blob(&size);
 236                 object = (struct object *)lookup_blob(oid);
 237                 eaten = 0;
 238         } else {
 239                 buf = read_object_file(oid, &type, &size);
 240                 if (!buf)
 241                         die ("Could not read blob %s", oid_to_hex(oid));
 242                 if (check_object_signature(oid, buf, size, type_name(type)) < 0)
 243                         die("sha1 mismatch in blob %s", oid_to_hex(oid));
 244                 object = parse_object_buffer(oid, type, size, buf, &eaten);
 245         }
 246
 247         if (!object)
 248                 die("Could not read blob %s", oid_to_hex(oid));
 249
 250         mark_next_object(object);
 251
 252         printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
 253         if (size && fwrite(buf, size, 1, stdout) != 1)
 254                 die_errno ("Could not write blob '%s'", oid_to_hex(oid));
 255         printf("\n");
 256
 257         show_progress();
 258
 259         object->flags |= SHOWN;
 260         if (!eaten)
 261                 free(buf);
 262 }
 263
 264 static int depth_first(const void *a_, const void *b_)
 265 {
 266         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
 267         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
 268         const char *name_a, *name_b;
 269         int len_a, len_b, len;
 270         int cmp;
 271
 272         name_a = a->one ? a->one->path : a->two->path;
 273         name_b = b->one ? b->one->path : b->two->path;
 274
 275         len_a = strlen(name_a);
 276         len_b = strlen(name_b);
 277         len = (len_a < len_b) ? len_a : len_b;
 278
 279         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
 280         cmp = memcmp(name_a, name_b, len);
 281         if (cmp)
 282                 return cmp;
 283         cmp = len_b - len_a;
 284         if (cmp)
 285                 return cmp;
 286         /*
 287          * Move 'R'ename entries last so that all references of the file
 288          * appear in the output before it is renamed (e.g., when a file
 289          * was copied and renamed in the same commit).
 290          */
 291         return (a->status == 'R') - (b->status == 'R');
 292 }
 293
 294 static void print_path_1(const char *path)
 295 {
 296         int need_quote = quote_c_style(path, NULL, NULL, 0);
 297         if (need_quote)
 298                 quote_c_style(path, NULL, stdout, 0);
 299         else if (strchr(path, ' '))
 300                 printf("\"%s\"", path);
 301         else
 302                 printf("%s", path);
 303 }
 304
 305 static void *anonymize_path_component(const void *path, size_t *len)
 306 {
 307         static int counter;
 308         struct strbuf out = STRBUF_INIT;
 309         strbuf_addf(&out, "path%d", counter++);
 310         return strbuf_detach(&out, len);
 311 }
 312
 313 static void print_path(const char *path)
 314 {
 315         if (!anonymize)
 316                 print_path_1(path);
 317         else {
 318                 static struct hashmap paths;
 319                 static struct strbuf anon = STRBUF_INIT;
 320
 321                 anonymize_path(&anon, path, &paths, anonymize_path_component);
 322                 print_path_1(anon.buf);
 323                 strbuf_reset(&anon);
 324         }
 325 }
 326
 327 static void *generate_fake_oid(const void *old, size_t *len)
 328 {
 329         static uint32_t counter = 1; /* avoid null sha1 */
 330         unsigned char *out = xcalloc(GIT_SHA1_RAWSZ, 1);
 331         put_be32(out + GIT_SHA1_RAWSZ - 4, counter++);
 332         return out;
 333 }
 334
 335 static const unsigned char *anonymize_sha1(const struct object_id *oid)
 336 {
 337         static struct hashmap sha1s;
 338         size_t len = GIT_SHA1_RAWSZ;
 339         return anonymize_mem(&sha1s, generate_fake_oid, oid, &len);
 340 }
 341
 342 static void show_filemodify(struct diff_queue_struct *q,
 343                             struct diff_options *options, void *data)
 344 {
 345         int i;
 346         struct string_list *changed = data;
 347
 348         /*
 349          * Handle files below a directory first, in case they are all deleted
 350          * and the directory changes to a file or symlink.
 351          */
 352         QSORT(q->queue, q->nr, depth_first);
 353
 354         for (i = 0; i < q->nr; i++) {
 355                 struct diff_filespec *ospec = q->queue[i]->one;
 356                 struct diff_filespec *spec = q->queue[i]->two;
 357
 358                 switch (q->queue[i]->status) {
 359                 case DIFF_STATUS_DELETED:
 360                         printf("D ");
 361                         print_path(spec->path);
 362                         string_list_insert(changed, spec->path);
 363                         putchar('\n');
 364                         break;
 365
 366                 case DIFF_STATUS_COPIED:
 367                 case DIFF_STATUS_RENAMED:
 368                         /*
 369                          * If a change in the file corresponding to ospec->path
 370                          * has been observed, we cannot trust its contents
 371                          * because the diff is calculated based on the prior
 372                          * contents, not the current contents.  So, declare a
 373                          * copy or rename only if there was no change observed.
 374                          */
 375                         if (!string_list_has_string(changed, ospec->path)) {
 376                                 printf("%c ", q->queue[i]->status);
 377                                 print_path(ospec->path);
 378                                 putchar(' ');
 379                                 print_path(spec->path);
 380                                 string_list_insert(changed, spec->path);
 381                                 putchar('\n');
 382
 383                                 if (!oidcmp(&ospec->oid, &spec->oid) &&
 384                                     ospec->mode == spec->mode)
 385                                         break;
 386                         }
 387                         /* fallthrough */
 388
 389                 case DIFF_STATUS_TYPE_CHANGED:
 390                 case DIFF_STATUS_MODIFIED:
 391                 case DIFF_STATUS_ADDED:
 392                         /*
 393                          * Links refer to objects in another repositories;
 394                          * output the SHA-1 verbatim.
 395                          */
 396                         if (no_data || S_ISGITLINK(spec->mode))
 397                                 printf("M %06o %s ", spec->mode,
 398                                        sha1_to_hex(anonymize ?
 399                                                    anonymize_sha1(&spec->oid) :
 400                                                    spec->oid.hash));
 401                         else {
 402                                 struct object *object = lookup_object(spec->oid.hash);
 403                                 printf("M %06o :%d ", spec->mode,
 404                                        get_object_mark(object));
 405                         }
 406                         print_path(spec->path);
 407                         string_list_insert(changed, spec->path);
 408                         putchar('\n');
 409                         break;
 410
 411                 default:
 412                         die("Unexpected comparison status '%c' for %s, %s",
 413                                 q->queue[i]->status,
 414                                 ospec->path ? ospec->path : "none",
 415                                 spec->path ? spec->path : "none");
 416                 }
 417         }
 418 }
 419
 420 static const char *find_encoding(const char *begin, const char *end)
 421 {
 422         const char *needle = "\nencoding ";
 423         char *bol, *eol;
 424
 425         bol = memmem(begin, end ? end - begin : strlen(begin),
 426                      needle, strlen(needle));
 427         if (!bol)
 428                 return git_commit_encoding;
 429         bol += strlen(needle);
 430         eol = strchrnul(bol, '\n');
 431         *eol = '\0';
 432         return bol;
 433 }
 434
 435 static void *anonymize_ref_component(const void *old, size_t *len)
 436 {
 437         static int counter;
 438         struct strbuf out = STRBUF_INIT;
 439         strbuf_addf(&out, "ref%d", counter++);
 440         return strbuf_detach(&out, len);
 441 }
 442
 443 static const char *anonymize_refname(const char *refname)
 444 {
 445         /*
 446          * If any of these prefixes is found, we will leave it intact
 447          * so that tags remain tags and so forth.
 448          */
 449         static const char *prefixes[] = {
 450                 "refs/heads/",
 451                 "refs/tags/",
 452                 "refs/remotes/",
 453                 "refs/"
 454         };
 455         static struct hashmap refs;
 456         static struct strbuf anon = STRBUF_INIT;
 457         int i;
 458
 459         /*
 460          * We also leave "master" as a special case, since it does not reveal
 461          * anything interesting.
 462          */
 463         if (!strcmp(refname, "refs/heads/master"))
 464                 return refname;
 465
 466         strbuf_reset(&anon);
 467         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 468                 if (skip_prefix(refname, prefixes[i], &refname)) {
 469                         strbuf_addstr(&anon, prefixes[i]);
 470                         break;
 471                 }
 472         }
 473
 474         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
 475         return anon.buf;
 476 }
 477
 478 /*
 479  * We do not even bother to cache commit messages, as they are unlikely
 480  * to be repeated verbatim, and it is not that interesting when they are.
 481  */
 482 static char *anonymize_commit_message(const char *old)
 483 {
 484         static int counter;
 485         return xstrfmt("subject %d\n\nbody\n", counter++);
 486 }
 487
 488 static struct hashmap idents;
 489 static void *anonymize_ident(const void *old, size_t *len)
 490 {
 491         static int counter;
 492         struct strbuf out = STRBUF_INIT;
 493         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
 494         counter++;
 495         return strbuf_detach(&out, len);
 496 }
 497
 498 /*
 499  * Our strategy here is to anonymize the names and email addresses,
 500  * but keep timestamps intact, as they influence things like traversal
 501  * order (and by themselves should not be too revealing).
 502  */
 503 static void anonymize_ident_line(const char **beg, const char **end)
 504 {
 505         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
 506         static unsigned which_buffer;
 507
 508         struct strbuf *out;
 509         struct ident_split split;
 510         const char *end_of_header;
 511
 512         out = &buffers[which_buffer++];
 513         which_buffer %= ARRAY_SIZE(buffers);
 514         strbuf_reset(out);
 515
 516         /* skip "committer", "author", "tagger", etc */
 517         end_of_header = strchr(*beg, ' ');
 518         if (!end_of_header)
 519                 BUG("malformed line fed to anonymize_ident_line: %.*s",
 520                     (int)(*end - *beg), *beg);
 521         end_of_header++;
 522         strbuf_add(out, *beg, end_of_header - *beg);
 523
 524         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
 525             split.date_begin) {
 526                 const char *ident;
 527                 size_t len;
 528
 529                 len = split.mail_end - split.name_begin;
 530                 ident = anonymize_mem(&idents, anonymize_ident,
 531                                       split.name_begin, &len);
 532                 strbuf_add(out, ident, len);
 533                 strbuf_addch(out, ' ');
 534                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
 535         } else {
 536                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
 537         }
 538
 539         *beg = out->buf;
 540         *end = out->buf + out->len;
 541 }
 542
 543 static void handle_commit(struct commit *commit, struct rev_info *rev,
 544                           struct string_list *paths_of_changed_objects)
 545 {
 546         int saved_output_format = rev->diffopt.output_format;
 547         const char *commit_buffer;
 548         const char *author, *author_end, *committer, *committer_end;
 549         const char *encoding, *message;
 550         char *reencoded = NULL;
 551         struct commit_list *p;
 552         const char *refname;
 553         int i;
 554
 555         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
 556
 557         parse_commit_or_die(commit);
 558         commit_buffer = get_commit_buffer(commit, NULL);
 559         author = strstr(commit_buffer, "\nauthor ");
 560         if (!author)
 561                 die ("Could not find author in commit %s",
 562                      oid_to_hex(&commit->object.oid));
 563         author++;
 564         author_end = strchrnul(author, '\n');
 565         committer = strstr(author_end, "\ncommitter ");
 566         if (!committer)
 567                 die ("Could not find committer in commit %s",
 568                      oid_to_hex(&commit->object.oid));
 569         committer++;
 570         committer_end = strchrnul(committer, '\n');
 571         message = strstr(committer_end, "\n\n");
 572         encoding = find_encoding(committer_end, message);
 573         if (message)
 574                 message += 2;
 575
 576         if (commit->parents &&
 577             get_object_mark(&commit->parents->item->object) != 0 &&
 578             !full_tree) {
 579                 parse_commit_or_die(commit->parents->item);
 580                 diff_tree_oid(get_commit_tree_oid(commit->parents->item),
 581                               get_commit_tree_oid(commit), "", &rev->diffopt);
 582         }
 583         else
 584                 diff_root_tree_oid(get_commit_tree_oid(commit),
 585                                    "", &rev->diffopt);
 586
 587         /* Export the referenced blobs, and remember the marks. */
 588         for (i = 0; i < diff_queued_diff.nr; i++)
 589                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
 590                         export_blob(&diff_queued_diff.queue[i]->two->oid);
 591
 592         refname = commit->util;
 593         if (anonymize) {
 594                 refname = anonymize_refname(refname);
 595                 anonymize_ident_line(&committer, &committer_end);
 596                 anonymize_ident_line(&author, &author_end);
 597         }
 598
 599         mark_next_object(&commit->object);
 600         if (anonymize)
 601                 reencoded = anonymize_commit_message(message);
 602         else if (!is_encoding_utf8(encoding))
 603                 reencoded = reencode_string(message, "UTF-8", encoding);
 604         if (!commit->parents)
 605                 printf("reset %s\n", refname);
 606         printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
 607                refname, last_idnum,
 608                (int)(author_end - author), author,
 609                (int)(committer_end - committer), committer,
 610                (unsigned)(reencoded
 611                           ? strlen(reencoded) : message
 612                           ? strlen(message) : 0),
 613                reencoded ? reencoded : message ? message : "");
 614         free(reencoded);
 615         unuse_commit_buffer(commit, commit_buffer);
 616
 617         for (i = 0, p = commit->parents; p; p = p->next) {
 618                 int mark = get_object_mark(&p->item->object);
 619                 if (!mark)
 620                         continue;
 621                 if (i == 0)
 622                         printf("from :%d\n", mark);
 623                 else
 624                         printf("merge :%d\n", mark);
 625                 i++;
 626         }
 627
 628         if (full_tree)
 629                 printf("deleteall\n");
 630         log_tree_diff_flush(rev);
 631         string_list_clear(paths_of_changed_objects, 0);
 632         rev->diffopt.output_format = saved_output_format;
 633
 634         printf("\n");
 635
 636         show_progress();
 637 }
 638
 639 static void *anonymize_tag(const void *old, size_t *len)
 640 {
 641         static int counter;
 642         struct strbuf out = STRBUF_INIT;
 643         strbuf_addf(&out, "tag message %d", counter++);
 644         return strbuf_detach(&out, len);
 645 }
 646
 647 static void handle_tail(struct object_array *commits, struct rev_info *revs,
 648                         struct string_list *paths_of_changed_objects)
 649 {
 650         struct commit *commit;
 651         while (commits->nr) {
 652                 commit = (struct commit *)object_array_pop(commits);
 653                 if (has_unshown_parent(commit)) {
 654                         /* Queue again, to be handled later */
 655                         add_object_array(&commit->object, NULL, commits);
 656                         return;
 657                 }
 658                 handle_commit(commit, revs, paths_of_changed_objects);
 659         }
 660 }
 661
 662 static void handle_tag(const char *name, struct tag *tag)
 663 {
 664         unsigned long size;
 665         enum object_type type;
 666         char *buf;
 667         const char *tagger, *tagger_end, *message;
 668         size_t message_size = 0;
 669         struct object *tagged;
 670         int tagged_mark;
 671         struct commit *p;
 672
 673         /* Trees have no identifier in fast-export output, thus we have no way
 674          * to output tags of trees, tags of tags of trees, etc.  Simply omit
 675          * such tags.
 676          */
 677         tagged = tag->tagged;
 678         while (tagged->type == OBJ_TAG) {
 679                 tagged = ((struct tag *)tagged)->tagged;
 680         }
 681         if (tagged->type == OBJ_TREE) {
 682                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
 683                         oid_to_hex(&tag->object.oid));
 684                 return;
 685         }
 686
 687         buf = read_object_file(&tag->object.oid, &type, &size);
 688         if (!buf)
 689                 die ("Could not read tag %s", oid_to_hex(&tag->object.oid));
 690         message = memmem(buf, size, "\n\n", 2);
 691         if (message) {
 692                 message += 2;
 693                 message_size = strlen(message);
 694         }
 695         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 696         if (!tagger) {
 697                 if (fake_missing_tagger)
 698                         tagger = "tagger Unspecified Tagger "
 699                                 "<unspecified-tagger> 0 +0000";
 700                 else
 701                         tagger = "";
 702                 tagger_end = tagger + strlen(tagger);
 703         } else {
 704                 tagger++;
 705                 tagger_end = strchrnul(tagger, '\n');
 706                 if (anonymize)
 707                         anonymize_ident_line(&tagger, &tagger_end);
 708         }
 709
 710         if (anonymize) {
 711                 name = anonymize_refname(name);
 712                 if (message) {
 713                         static struct hashmap tags;
 714                         message = anonymize_mem(&tags, anonymize_tag,
 715                                                 message, &message_size);
 716                 }
 717         }
 718
 719         /* handle signed tags */
 720         if (message) {
 721                 const char *signature = strstr(message,
 722                                                "\n-----BEGIN PGP SIGNATURE-----\n");
 723                 if (signature)
 724                         switch(signed_tag_mode) {
 725                         case ABORT:
 726                                 die ("Encountered signed tag %s; use "
 727                                      "--signed-tags=<mode> to handle it.",
 728                                      oid_to_hex(&tag->object.oid));
 729                         case WARN:
 730                                 warning ("Exporting signed tag %s",
 731                                          oid_to_hex(&tag->object.oid));
 732                                 /* fallthru */
 733                         case VERBATIM:
 734                                 break;
 735                         case WARN_STRIP:
 736                                 warning ("Stripping signature from tag %s",
 737                                          oid_to_hex(&tag->object.oid));
 738                                 /* fallthru */
 739                         case STRIP:
 740                                 message_size = signature + 1 - message;
 741                                 break;
 742                         }
 743         }
 744
 745         /* handle tag->tagged having been filtered out due to paths specified */
 746         tagged = tag->tagged;
 747         tagged_mark = get_object_mark(tagged);
 748         if (!tagged_mark) {
 749                 switch(tag_of_filtered_mode) {
 750                 case ABORT:
 751                         die ("Tag %s tags unexported object; use "
 752                              "--tag-of-filtered-object=<mode> to handle it.",
 753                              oid_to_hex(&tag->object.oid));
 754                 case DROP:
 755                         /* Ignore this tag altogether */
 756                         free(buf);
 757                         return;
 758                 case REWRITE:
 759                         if (tagged->type != OBJ_COMMIT) {
 760                                 die ("Tag %s tags unexported %s!",
 761                                      oid_to_hex(&tag->object.oid),
 762                                      type_name(tagged->type));
 763                         }
 764                         p = (struct commit *)tagged;
 765                         for (;;) {
 766                                 if (p->parents && p->parents->next)
 767                                         break;
 768                                 if (p->object.flags & UNINTERESTING)
 769                                         break;
 770                                 if (!(p->object.flags & TREESAME))
 771                                         break;
 772                                 if (!p->parents)
 773                                         die ("Can't find replacement commit for tag %s\n",
 774                                              oid_to_hex(&tag->object.oid));
 775                                 p = p->parents->item;
 776                         }
 777                         tagged_mark = get_object_mark(&p->object);
 778                 }
 779         }
 780
 781         if (starts_with(name, "refs/tags/"))
 782                 name += 10;
 783         printf("tag %s\nfrom :%d\n%.*s%sdata %d\n%.*s\n",
 784                name, tagged_mark,
 785                (int)(tagger_end - tagger), tagger,
 786                tagger == tagger_end ? "" : "\n",
 787                (int)message_size, (int)message_size, message ? message : "");
 788         free(buf);
 789 }
 790
 791 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 792 {
 793         switch (e->item->type) {
 794         case OBJ_COMMIT:
 795                 return (struct commit *)e->item;
 796         case OBJ_TAG: {
 797                 struct tag *tag = (struct tag *)e->item;
 798
 799                 /* handle nested tags */
 800                 while (tag && tag->object.type == OBJ_TAG) {
 801                         parse_object(&tag->object.oid);
 802                         string_list_append(&extra_refs, full_name)->util = tag;
 803                         tag = (struct tag *)tag->tagged;
 804                 }
 805                 if (!tag)
 806                         die("Tag %s points nowhere?", e->name);
 807                 return (struct commit *)tag;
 808                 break;
 809         }
 810         default:
 811                 return NULL;
 812         }
 813 }
 814
 815 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 816 {
 817         int i;
 818
 819         for (i = 0; i < info->nr; i++) {
 820                 struct rev_cmdline_entry *e = info->rev + i;
 821                 struct object_id oid;
 822                 struct commit *commit;
 823                 char *full_name;
 824
 825                 if (e->flags & UNINTERESTING)
 826                         continue;
 827
 828                 if (dwim_ref(e->name, strlen(e->name), &oid, &full_name) != 1)
 829                         continue;
 830
 831                 if (refspecs) {
 832                         char *private;
 833                         private = apply_refspecs(refspecs, refspecs_nr, full_name);
 834                         if (private) {
 835                                 free(full_name);
 836                                 full_name = private;
 837                         }
 838                 }
 839
 840                 commit = get_commit(e, full_name);
 841                 if (!commit) {
 842                         warning("%s: Unexpected object of type %s, skipping.",
 843                                 e->name,
 844                                 type_name(e->item->type));
 845                         continue;
 846                 }
 847
 848                 switch(commit->object.type) {
 849                 case OBJ_COMMIT:
 850                         break;
 851                 case OBJ_BLOB:
 852                         export_blob(&commit->object.oid);
 853                         continue;
 854                 default: /* OBJ_TAG (nested tags) is already handled */
 855                         warning("Tag points to object of unexpected type %s, skipping.",
 856                                 type_name(commit->object.type));
 857                         continue;
 858                 }
 859
 860                 /*
 861                  * This ref will not be updated through a commit, lets make
 862                  * sure it gets properly updated eventually.
 863                  */
 864                 if (commit->util || commit->object.flags & SHOWN)
 865                         string_list_append(&extra_refs, full_name)->util = commit;
 866                 if (!commit->util)
 867                         commit->util = full_name;
 868         }
 869 }
 870
 871 static void handle_tags_and_duplicates(void)
 872 {
 873         struct commit *commit;
 874         int i;
 875
 876         for (i = extra_refs.nr - 1; i >= 0; i--) {
 877                 const char *name = extra_refs.items[i].string;
 878                 struct object *object = extra_refs.items[i].util;
 879                 switch (object->type) {
 880                 case OBJ_TAG:
 881                         handle_tag(name, (struct tag *)object);
 882                         break;
 883                 case OBJ_COMMIT:
 884                         if (anonymize)
 885                                 name = anonymize_refname(name);
 886                         /* create refs pointing to already seen commits */
 887                         commit = (struct commit *)object;
 888                         printf("reset %s\nfrom :%d\n\n", name,
 889                                get_object_mark(&commit->object));
 890                         show_progress();
 891                         break;
 892                 }
 893         }
 894 }
 895
 896 static void export_marks(char *file)
 897 {
 898         unsigned int i;
 899         uint32_t mark;
 900         struct decoration_entry *deco = idnums.entries;
 901         FILE *f;
 902         int e = 0;
 903
 904         f = fopen_for_writing(file);
 905         if (!f)
 906                 die_errno("Unable to open marks file %s for writing.", file);
 907
 908         for (i = 0; i < idnums.size; i++) {
 909                 if (deco->base && deco->base->type == 1) {
 910                         mark = ptr_to_mark(deco->decoration);
 911                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
 912                                 oid_to_hex(&deco->base->oid)) < 0) {
 913                             e = 1;
 914                             break;
 915                         }
 916                 }
 917                 deco++;
 918         }
 919
 920         e |= ferror(f);
 921         e |= fclose(f);
 922         if (e)
 923                 error("Unable to write marks file %s.", file);
 924 }
 925
 926 static void import_marks(char *input_file)
 927 {
 928         char line[512];
 929         FILE *f = xfopen(input_file, "r");
 930
 931         while (fgets(line, sizeof(line), f)) {
 932                 uint32_t mark;
 933                 char *line_end, *mark_end;
 934                 struct object_id oid;
 935                 struct object *object;
 936                 struct commit *commit;
 937                 enum object_type type;
 938
 939                 line_end = strchr(line, '\n');
 940                 if (line[0] != ':' || !line_end)
 941                         die("corrupt mark line: %s", line);
 942                 *line_end = '\0';
 943
 944                 mark = strtoumax(line + 1, &mark_end, 10);
 945                 if (!mark || mark_end == line + 1
 946                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
 947                         die("corrupt mark line: %s", line);
 948
 949                 if (last_idnum < mark)
 950                         last_idnum = mark;
 951
 952                 type = oid_object_info(the_repository, &oid, NULL);
 953                 if (type < 0)
 954                         die("object not found: %s", oid_to_hex(&oid));
 955
 956                 if (type != OBJ_COMMIT)
 957                         /* only commits */
 958                         continue;
 959
 960                 commit = lookup_commit(&oid);
 961                 if (!commit)
 962                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
 963
 964                 object = &commit->object;
 965
 966                 if (object->flags & SHOWN)
 967                         error("Object %s already has a mark", oid_to_hex(&oid));
 968
 969                 mark_object(object, mark);
 970
 971                 object->flags |= SHOWN;
 972         }
 973         fclose(f);
 974 }
 975
 976 static void handle_deletes(void)
 977 {
 978         int i;
 979         for (i = 0; i < refspecs_nr; i++) {
 980                 struct refspec *refspec = &refspecs[i];
 981                 if (*refspec->src)
 982                         continue;
 983
 984                 printf("reset %s\nfrom %s\n\n",
 985                                 refspec->dst, sha1_to_hex(null_sha1));
 986         }
 987 }
 988
 989 int cmd_fast_export(int argc, const char **argv, const char *prefix)
 990 {
 991         struct rev_info revs;
 992         struct object_array commits = OBJECT_ARRAY_INIT;
 993         struct commit *commit;
 994         char *export_filename = NULL, *import_filename = NULL;
 995         uint32_t lastimportid;
 996         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
 997         struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
 998         struct option options[] = {
 999                 OPT_INTEGER(0, "progress", &progress,
1000                             N_("show progress after <n> objects")),
1001                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
1002                              N_("select handling of signed tags"),
1003                              parse_opt_signed_tag_mode),
1004                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
1005                              N_("select handling of tags that tag filtered objects"),
1006                              parse_opt_tag_of_filtered_mode),
1007                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
1008                              N_("Dump marks to this file")),
1009                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
1010                              N_("Import marks from this file")),
1011                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
1012                          N_("Fake a tagger when tags lack one")),
1013                 OPT_BOOL(0, "full-tree", &full_tree,
1014                          N_("Output full tree for each commit")),
1015                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
1016                              N_("Use the done feature to terminate the stream")),
1017                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
1018                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1019                              N_("Apply refspec to exported refs")),
1020                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1021                 OPT_END()
1022         };
1023
1024         if (argc == 1)
1025                 usage_with_options (fast_export_usage, options);
1026
1027         /* we handle encodings */
1028         git_config(git_default_config, NULL);
1029
1030         init_revisions(&revs, prefix);
1031         revs.topo_order = 1;
1032         revs.show_source = 1;
1033         revs.rewrite_parents = 1;
1034         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1035                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
1036         argc = setup_revisions(argc, argv, &revs, NULL);
1037         if (argc > 1)
1038                 usage_with_options (fast_export_usage, options);
1039
1040         if (refspecs_list.nr) {
1041                 const char **refspecs_str;
1042                 int i;
1043
1044                 ALLOC_ARRAY(refspecs_str, refspecs_list.nr);
1045                 for (i = 0; i < refspecs_list.nr; i++)
1046                         refspecs_str[i] = refspecs_list.items[i].string;
1047
1048                 refspecs_nr = refspecs_list.nr;
1049                 refspecs = parse_fetch_refspec(refspecs_nr, refspecs_str);
1050
1051                 string_list_clear(&refspecs_list, 1);
1052                 free(refspecs_str);
1053         }
1054
1055         if (use_done_feature)
1056                 printf("feature done\n");
1057
1058         if (import_filename)
1059                 import_marks(import_filename);
1060         lastimportid = last_idnum;
1061
1062         if (import_filename && revs.prune_data.nr)
1063                 full_tree = 1;
1064
1065         get_tags_and_duplicates(&revs.cmdline);
1066
1067         if (prepare_revision_walk(&revs))
1068                 die("revision walk setup failed");
1069         revs.diffopt.format_callback = show_filemodify;
1070         revs.diffopt.format_callback_data = &paths_of_changed_objects;
1071         revs.diffopt.flags.recursive = 1;
1072         while ((commit = get_revision(&revs))) {
1073                 if (has_unshown_parent(commit)) {
1074                         add_object_array(&commit->object, NULL, &commits);
1075                 }
1076                 else {
1077                         handle_commit(commit, &revs, &paths_of_changed_objects);
1078                         handle_tail(&commits, &revs, &paths_of_changed_objects);
1079                 }
1080         }
1081
1082         handle_tags_and_duplicates();
1083         handle_deletes();
1084
1085         if (export_filename && lastimportid != last_idnum)
1086                 export_marks(export_filename);
1087
1088         if (use_done_feature)
1089                 printf("done\n");
1090
1091         free_refspec(refspecs_nr, refspecs);
1092
1093         return 0;
1094 }