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 "object-store.h"
  11 #include "commit.h"
  12 #include "object.h"
  13 #include "tag.h"
  14 #include "diff.h"
  15 #include "diffcore.h"
  16 #include "log-tree.h"
  17 #include "revision.h"
  18 #include "decorate.h"
  19 #include "string-list.h"
  20 #include "utf8.h"
  21 #include "parse-options.h"
  22 #include "quote.h"
  23 #include "remote.h"
  24 #include "blob.h"
  25
  26 static const char *fast_export_usage[] = {
  27         N_("git fast-export [rev-list-opts]"),
  28         NULL
  29 };
  30
  31 static int progress;
  32 static enum { ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = ABORT;
  33 static enum { ERROR, DROP, REWRITE } tag_of_filtered_mode = ERROR;
  34 static int fake_missing_tagger;
  35 static int use_done_feature;
  36 static int no_data;
  37 static int full_tree;
  38 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
  39 static struct refspec *refspecs;
  40 static int refspecs_nr;
  41 static int anonymize;
  42
  43 static int parse_opt_signed_tag_mode(const struct option *opt,
  44                                      const char *arg, int unset)
  45 {
  46         if (unset || !strcmp(arg, "abort"))
  47                 signed_tag_mode = ABORT;
  48         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
  49                 signed_tag_mode = VERBATIM;
  50         else if (!strcmp(arg, "warn"))
  51                 signed_tag_mode = WARN;
  52         else if (!strcmp(arg, "warn-strip"))
  53                 signed_tag_mode = WARN_STRIP;
  54         else if (!strcmp(arg, "strip"))
  55                 signed_tag_mode = STRIP;
  56         else
  57                 return error("Unknown signed-tags mode: %s", arg);
  58         return 0;
  59 }
  60
  61 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
  62                                           const char *arg, int unset)
  63 {
  64         if (unset || !strcmp(arg, "abort"))
  65                 tag_of_filtered_mode = ERROR;
  66         else if (!strcmp(arg, "drop"))
  67                 tag_of_filtered_mode = DROP;
  68         else if (!strcmp(arg, "rewrite"))
  69                 tag_of_filtered_mode = REWRITE;
  70         else
  71                 return error("Unknown tag-of-filtered mode: %s", arg);
  72         return 0;
  73 }
  74
  75 static struct decoration idnums;
  76 static uint32_t last_idnum;
  77
  78 static int has_unshown_parent(struct commit *commit)
  79 {
  80         struct commit_list *parent;
  81
  82         for (parent = commit->parents; parent; parent = parent->next)
  83                 if (!(parent->item->object.flags & SHOWN) &&
  84                     !(parent->item->object.flags & UNINTERESTING))
  85                         return 1;
  86         return 0;
  87 }
  88
  89 struct anonymized_entry {
  90         struct hashmap_entry hash;
  91         const char *orig;
  92         size_t orig_len;
  93         const char *anon;
  94         size_t anon_len;
  95 };
  96
  97 static int anonymized_entry_cmp(const void *unused_cmp_data,
  98                                 const void *va, const void *vb,
  99                                 const void *unused_keydata)
 100 {
 101         const struct anonymized_entry *a = va, *b = vb;
 102         return a->orig_len != b->orig_len ||
 103                 memcmp(a->orig, b->orig, a->orig_len);
 104 }
 105
 106 /*
 107  * Basically keep a cache of X->Y so that we can repeatedly replace
 108  * the same anonymized string with another. The actual generation
 109  * is farmed out to the generate function.
 110  */
 111 static const void *anonymize_mem(struct hashmap *map,
 112                                  void *(*generate)(const void *, size_t *),
 113                                  const void *orig, size_t *len)
 114 {
 115         struct anonymized_entry key, *ret;
 116
 117         if (!map->cmpfn)
 118                 hashmap_init(map, anonymized_entry_cmp, NULL, 0);
 119
 120         hashmap_entry_init(&key, memhash(orig, *len));
 121         key.orig = orig;
 122         key.orig_len = *len;
 123         ret = hashmap_get(map, &key, NULL);
 124
 125         if (!ret) {
 126                 ret = xmalloc(sizeof(*ret));
 127                 hashmap_entry_init(&ret->hash, key.hash.hash);
 128                 ret->orig = xstrdup(orig);
 129                 ret->orig_len = *len;
 130                 ret->anon = generate(orig, len);
 131                 ret->anon_len = *len;
 132                 hashmap_put(map, ret);
 133         }
 134
 135         *len = ret->anon_len;
 136         return ret->anon;
 137 }
 138
 139 /*
 140  * We anonymize each component of a path individually,
 141  * so that paths a/b and a/c will share a common root.
 142  * The paths are cached via anonymize_mem so that repeated
 143  * lookups for "a" will yield the same value.
 144  */
 145 static void anonymize_path(struct strbuf *out, const char *path,
 146                            struct hashmap *map,
 147                            void *(*generate)(const void *, size_t *))
 148 {
 149         while (*path) {
 150                 const char *end_of_component = strchrnul(path, '/');
 151                 size_t len = end_of_component - path;
 152                 const char *c = anonymize_mem(map, generate, path, &len);
 153                 strbuf_add(out, c, len);
 154                 path = end_of_component;
 155                 if (*path)
 156                         strbuf_addch(out, *path++);
 157         }
 158 }
 159
 160 /* Since intptr_t is C99, we do not use it here */
 161 static inline uint32_t *mark_to_ptr(uint32_t mark)
 162 {
 163         return ((uint32_t *)NULL) + mark;
 164 }
 165
 166 static inline uint32_t ptr_to_mark(void * mark)
 167 {
 168         return (uint32_t *)mark - (uint32_t *)NULL;
 169 }
 170
 171 static inline void mark_object(struct object *object, uint32_t mark)
 172 {
 173         add_decoration(&idnums, object, mark_to_ptr(mark));
 174 }
 175
 176 static inline void mark_next_object(struct object *object)
 177 {
 178         mark_object(object, ++last_idnum);
 179 }
 180
 181 static int get_object_mark(struct object *object)
 182 {
 183         void *decoration = lookup_decoration(&idnums, object);
 184         if (!decoration)
 185                 return 0;
 186         return ptr_to_mark(decoration);
 187 }
 188
 189 static void show_progress(void)
 190 {
 191         static int counter = 0;
 192         if (!progress)
 193                 return;
 194         if ((++counter % progress) == 0)
 195                 printf("progress %d objects\n", counter);
 196 }
 197
 198 /*
 199  * Ideally we would want some transformation of the blob data here
 200  * that is unreversible, but would still be the same size and have
 201  * the same data relationship to other blobs (so that we get the same
 202  * delta and packing behavior as the original). But the first and last
 203  * requirements there are probably mutually exclusive, so let's take
 204  * the easy way out for now, and just generate arbitrary content.
 205  *
 206  * There's no need to cache this result with anonymize_mem, since
 207  * we already handle blob content caching with marks.
 208  */
 209 static char *anonymize_blob(unsigned long *size)
 210 {
 211         static int counter;
 212         struct strbuf out = STRBUF_INIT;
 213         strbuf_addf(&out, "anonymous blob %d", counter++);
 214         *size = out.len;
 215         return strbuf_detach(&out, NULL);
 216 }
 217
 218 static void export_blob(const struct object_id *oid)
 219 {
 220         unsigned long size;
 221         enum object_type type;
 222         char *buf;
 223         struct object *object;
 224         int eaten;
 225
 226         if (no_data)
 227                 return;
 228
 229         if (is_null_oid(oid))
 230                 return;
 231
 232         object = lookup_object(oid->hash);
 233         if (object && object->flags & SHOWN)
 234                 return;
 235
 236         if (anonymize) {
 237                 buf = anonymize_blob(&size);
 238                 object = (struct object *)lookup_blob(oid);
 239                 eaten = 0;
 240         } else {
 241                 buf = read_object_file(oid, &type, &size);
 242                 if (!buf)
 243                         die ("Could not read blob %s", oid_to_hex(oid));
 244                 if (check_object_signature(oid, buf, size, type_name(type)) < 0)
 245                         die("sha1 mismatch in blob %s", oid_to_hex(oid));
 246                 object = parse_object_buffer(oid, type, size, buf, &eaten);
 247         }
 248
 249         if (!object)
 250                 die("Could not read blob %s", oid_to_hex(oid));
 251
 252         mark_next_object(object);
 253
 254         printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
 255         if (size && fwrite(buf, size, 1, stdout) != 1)
 256                 die_errno ("Could not write blob '%s'", oid_to_hex(oid));
 257         printf("\n");
 258
 259         show_progress();
 260
 261         object->flags |= SHOWN;
 262         if (!eaten)
 263                 free(buf);
 264 }
 265
 266 static int depth_first(const void *a_, const void *b_)
 267 {
 268         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
 269         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
 270         const char *name_a, *name_b;
 271         int len_a, len_b, len;
 272         int cmp;
 273
 274         name_a = a->one ? a->one->path : a->two->path;
 275         name_b = b->one ? b->one->path : b->two->path;
 276
 277         len_a = strlen(name_a);
 278         len_b = strlen(name_b);
 279         len = (len_a < len_b) ? len_a : len_b;
 280
 281         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
 282         cmp = memcmp(name_a, name_b, len);
 283         if (cmp)
 284                 return cmp;
 285         cmp = len_b - len_a;
 286         if (cmp)
 287                 return cmp;
 288         /*
 289          * Move 'R'ename entries last so that all references of the file
 290          * appear in the output before it is renamed (e.g., when a file
 291          * was copied and renamed in the same commit).
 292          */
 293         return (a->status == 'R') - (b->status == 'R');
 294 }
 295
 296 static void print_path_1(const char *path)
 297 {
 298         int need_quote = quote_c_style(path, NULL, NULL, 0);
 299         if (need_quote)
 300                 quote_c_style(path, NULL, stdout, 0);
 301         else if (strchr(path, ' '))
 302                 printf("\"%s\"", path);
 303         else
 304                 printf("%s", path);
 305 }
 306
 307 static void *anonymize_path_component(const void *path, size_t *len)
 308 {
 309         static int counter;
 310         struct strbuf out = STRBUF_INIT;
 311         strbuf_addf(&out, "path%d", counter++);
 312         return strbuf_detach(&out, len);
 313 }
 314
 315 static void print_path(const char *path)
 316 {
 317         if (!anonymize)
 318                 print_path_1(path);
 319         else {
 320                 static struct hashmap paths;
 321                 static struct strbuf anon = STRBUF_INIT;
 322
 323                 anonymize_path(&anon, path, &paths, anonymize_path_component);
 324                 print_path_1(anon.buf);
 325                 strbuf_reset(&anon);
 326         }
 327 }
 328
 329 static void *generate_fake_oid(const void *old, size_t *len)
 330 {
 331         static uint32_t counter = 1; /* avoid null sha1 */
 332         unsigned char *out = xcalloc(GIT_SHA1_RAWSZ, 1);
 333         put_be32(out + GIT_SHA1_RAWSZ - 4, counter++);
 334         return out;
 335 }
 336
 337 static const unsigned char *anonymize_sha1(const struct object_id *oid)
 338 {
 339         static struct hashmap sha1s;
 340         size_t len = GIT_SHA1_RAWSZ;
 341         return anonymize_mem(&sha1s, generate_fake_oid, oid, &len);
 342 }
 343
 344 static void show_filemodify(struct diff_queue_struct *q,
 345                             struct diff_options *options, void *data)
 346 {
 347         int i;
 348         struct string_list *changed = data;
 349
 350         /*
 351          * Handle files below a directory first, in case they are all deleted
 352          * and the directory changes to a file or symlink.
 353          */
 354         QSORT(q->queue, q->nr, depth_first);
 355
 356         for (i = 0; i < q->nr; i++) {
 357                 struct diff_filespec *ospec = q->queue[i]->one;
 358                 struct diff_filespec *spec = q->queue[i]->two;
 359
 360                 switch (q->queue[i]->status) {
 361                 case DIFF_STATUS_DELETED:
 362                         printf("D ");
 363                         print_path(spec->path);
 364                         string_list_insert(changed, spec->path);
 365                         putchar('\n');
 366                         break;
 367
 368                 case DIFF_STATUS_COPIED:
 369                 case DIFF_STATUS_RENAMED:
 370                         /*
 371                          * If a change in the file corresponding to ospec->path
 372                          * has been observed, we cannot trust its contents
 373                          * because the diff is calculated based on the prior
 374                          * contents, not the current contents.  So, declare a
 375                          * copy or rename only if there was no change observed.
 376                          */
 377                         if (!string_list_has_string(changed, ospec->path)) {
 378                                 printf("%c ", q->queue[i]->status);
 379                                 print_path(ospec->path);
 380                                 putchar(' ');
 381                                 print_path(spec->path);
 382                                 string_list_insert(changed, spec->path);
 383                                 putchar('\n');
 384
 385                                 if (!oidcmp(&ospec->oid, &spec->oid) &&
 386                                     ospec->mode == spec->mode)
 387                                         break;
 388                         }
 389                         /* fallthrough */
 390
 391                 case DIFF_STATUS_TYPE_CHANGED:
 392                 case DIFF_STATUS_MODIFIED:
 393                 case DIFF_STATUS_ADDED:
 394                         /*
 395                          * Links refer to objects in another repositories;
 396                          * output the SHA-1 verbatim.
 397                          */
 398                         if (no_data || S_ISGITLINK(spec->mode))
 399                                 printf("M %06o %s ", spec->mode,
 400                                        sha1_to_hex(anonymize ?
 401                                                    anonymize_sha1(&spec->oid) :
 402                                                    spec->oid.hash));
 403                         else {
 404                                 struct object *object = lookup_object(spec->oid.hash);
 405                                 printf("M %06o :%d ", spec->mode,
 406                                        get_object_mark(object));
 407                         }
 408                         print_path(spec->path);
 409                         string_list_insert(changed, spec->path);
 410                         putchar('\n');
 411                         break;
 412
 413                 default:
 414                         die("Unexpected comparison status '%c' for %s, %s",
 415                                 q->queue[i]->status,
 416                                 ospec->path ? ospec->path : "none",
 417                                 spec->path ? spec->path : "none");
 418                 }
 419         }
 420 }
 421
 422 static const char *find_encoding(const char *begin, const char *end)
 423 {
 424         const char *needle = "\nencoding ";
 425         char *bol, *eol;
 426
 427         bol = memmem(begin, end ? end - begin : strlen(begin),
 428                      needle, strlen(needle));
 429         if (!bol)
 430                 return git_commit_encoding;
 431         bol += strlen(needle);
 432         eol = strchrnul(bol, '\n');
 433         *eol = '\0';
 434         return bol;
 435 }
 436
 437 static void *anonymize_ref_component(const void *old, size_t *len)
 438 {
 439         static int counter;
 440         struct strbuf out = STRBUF_INIT;
 441         strbuf_addf(&out, "ref%d", counter++);
 442         return strbuf_detach(&out, len);
 443 }
 444
 445 static const char *anonymize_refname(const char *refname)
 446 {
 447         /*
 448          * If any of these prefixes is found, we will leave it intact
 449          * so that tags remain tags and so forth.
 450          */
 451         static const char *prefixes[] = {
 452                 "refs/heads/",
 453                 "refs/tags/",
 454                 "refs/remotes/",
 455                 "refs/"
 456         };
 457         static struct hashmap refs;
 458         static struct strbuf anon = STRBUF_INIT;
 459         int i;
 460
 461         /*
 462          * We also leave "master" as a special case, since it does not reveal
 463          * anything interesting.
 464          */
 465         if (!strcmp(refname, "refs/heads/master"))
 466                 return refname;
 467
 468         strbuf_reset(&anon);
 469         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 470                 if (skip_prefix(refname, prefixes[i], &refname)) {
 471                         strbuf_addstr(&anon, prefixes[i]);
 472                         break;
 473                 }
 474         }
 475
 476         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
 477         return anon.buf;
 478 }
 479
 480 /*
 481  * We do not even bother to cache commit messages, as they are unlikely
 482  * to be repeated verbatim, and it is not that interesting when they are.
 483  */
 484 static char *anonymize_commit_message(const char *old)
 485 {
 486         static int counter;
 487         return xstrfmt("subject %d\n\nbody\n", counter++);
 488 }
 489
 490 static struct hashmap idents;
 491 static void *anonymize_ident(const void *old, size_t *len)
 492 {
 493         static int counter;
 494         struct strbuf out = STRBUF_INIT;
 495         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
 496         counter++;
 497         return strbuf_detach(&out, len);
 498 }
 499
 500 /*
 501  * Our strategy here is to anonymize the names and email addresses,
 502  * but keep timestamps intact, as they influence things like traversal
 503  * order (and by themselves should not be too revealing).
 504  */
 505 static void anonymize_ident_line(const char **beg, const char **end)
 506 {
 507         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
 508         static unsigned which_buffer;
 509
 510         struct strbuf *out;
 511         struct ident_split split;
 512         const char *end_of_header;
 513
 514         out = &buffers[which_buffer++];
 515         which_buffer %= ARRAY_SIZE(buffers);
 516         strbuf_reset(out);
 517
 518         /* skip "committer", "author", "tagger", etc */
 519         end_of_header = strchr(*beg, ' ');
 520         if (!end_of_header)
 521                 die("BUG: malformed line fed to anonymize_ident_line: %.*s",
 522                     (int)(*end - *beg), *beg);
 523         end_of_header++;
 524         strbuf_add(out, *beg, end_of_header - *beg);
 525
 526         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
 527             split.date_begin) {
 528                 const char *ident;
 529                 size_t len;
 530
 531                 len = split.mail_end - split.name_begin;
 532                 ident = anonymize_mem(&idents, anonymize_ident,
 533                                       split.name_begin, &len);
 534                 strbuf_add(out, ident, len);
 535                 strbuf_addch(out, ' ');
 536                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
 537         } else {
 538                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
 539         }
 540
 541         *beg = out->buf;
 542         *end = out->buf + out->len;
 543 }
 544
 545 static void handle_commit(struct commit *commit, struct rev_info *rev,
 546                           struct string_list *paths_of_changed_objects)
 547 {
 548         int saved_output_format = rev->diffopt.output_format;
 549         const char *commit_buffer;
 550         const char *author, *author_end, *committer, *committer_end;
 551         const char *encoding, *message;
 552         char *reencoded = NULL;
 553         struct commit_list *p;
 554         const char *refname;
 555         int i;
 556
 557         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
 558
 559         parse_commit_or_die(commit);
 560         commit_buffer = get_commit_buffer(commit, NULL);
 561         author = strstr(commit_buffer, "\nauthor ");
 562         if (!author)
 563                 die ("Could not find author in commit %s",
 564                      oid_to_hex(&commit->object.oid));
 565         author++;
 566         author_end = strchrnul(author, '\n');
 567         committer = strstr(author_end, "\ncommitter ");
 568         if (!committer)
 569                 die ("Could not find committer in commit %s",
 570                      oid_to_hex(&commit->object.oid));
 571         committer++;
 572         committer_end = strchrnul(committer, '\n');
 573         message = strstr(committer_end, "\n\n");
 574         encoding = find_encoding(committer_end, message);
 575         if (message)
 576                 message += 2;
 577
 578         if (commit->parents &&
 579             get_object_mark(&commit->parents->item->object) != 0 &&
 580             !full_tree) {
 581                 parse_commit_or_die(commit->parents->item);
 582                 diff_tree_oid(&commit->parents->item->tree->object.oid,
 583                               &commit->tree->object.oid, "", &rev->diffopt);
 584         }
 585         else
 586                 diff_root_tree_oid(&commit->tree->object.oid,
 587                                    "", &rev->diffopt);
 588
 589         /* Export the referenced blobs, and remember the marks. */
 590         for (i = 0; i < diff_queued_diff.nr; i++)
 591                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
 592                         export_blob(&diff_queued_diff.queue[i]->two->oid);
 593
 594         refname = commit->util;
 595         if (anonymize) {
 596                 refname = anonymize_refname(refname);
 597                 anonymize_ident_line(&committer, &committer_end);
 598                 anonymize_ident_line(&author, &author_end);
 599         }
 600
 601         mark_next_object(&commit->object);
 602         if (anonymize)
 603                 reencoded = anonymize_commit_message(message);
 604         else if (!is_encoding_utf8(encoding))
 605                 reencoded = reencode_string(message, "UTF-8", encoding);
 606         if (!commit->parents)
 607                 printf("reset %s\n", refname);
 608         printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
 609                refname, last_idnum,
 610                (int)(author_end - author), author,
 611                (int)(committer_end - committer), committer,
 612                (unsigned)(reencoded
 613                           ? strlen(reencoded) : message
 614                           ? strlen(message) : 0),
 615                reencoded ? reencoded : message ? message : "");
 616         free(reencoded);
 617         unuse_commit_buffer(commit, commit_buffer);
 618
 619         for (i = 0, p = commit->parents; p; p = p->next) {
 620                 int mark = get_object_mark(&p->item->object);
 621                 if (!mark)
 622                         continue;
 623                 if (i == 0)
 624                         printf("from :%d\n", mark);
 625                 else
 626                         printf("merge :%d\n", mark);
 627                 i++;
 628         }
 629
 630         if (full_tree)
 631                 printf("deleteall\n");
 632         log_tree_diff_flush(rev);
 633         string_list_clear(paths_of_changed_objects, 0);
 634         rev->diffopt.output_format = saved_output_format;
 635
 636         printf("\n");
 637
 638         show_progress();
 639 }
 640
 641 static void *anonymize_tag(const void *old, size_t *len)
 642 {
 643         static int counter;
 644         struct strbuf out = STRBUF_INIT;
 645         strbuf_addf(&out, "tag message %d", counter++);
 646         return strbuf_detach(&out, len);
 647 }
 648
 649 static void handle_tail(struct object_array *commits, struct rev_info *revs,
 650                         struct string_list *paths_of_changed_objects)
 651 {
 652         struct commit *commit;
 653         while (commits->nr) {
 654                 commit = (struct commit *)object_array_pop(commits);
 655                 if (has_unshown_parent(commit))
 656                         return;
 657                 handle_commit(commit, revs, paths_of_changed_objects);
 658         }
 659 }
 660
 661 static void handle_tag(const char *name, struct tag *tag)
 662 {
 663         unsigned long size;
 664         enum object_type type;
 665         char *buf;
 666         const char *tagger, *tagger_end, *message;
 667         size_t message_size = 0;
 668         struct object *tagged;
 669         int tagged_mark;
 670         struct commit *p;
 671
 672         /* Trees have no identifier in fast-export output, thus we have no way
 673          * to output tags of trees, tags of tags of trees, etc.  Simply omit
 674          * such tags.
 675          */
 676         tagged = tag->tagged;
 677         while (tagged->type == OBJ_TAG) {
 678                 tagged = ((struct tag *)tagged)->tagged;
 679         }
 680         if (tagged->type == OBJ_TREE) {
 681                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
 682                         oid_to_hex(&tag->object.oid));
 683                 return;
 684         }
 685
 686         buf = read_object_file(&tag->object.oid, &type, &size);
 687         if (!buf)
 688                 die ("Could not read tag %s", oid_to_hex(&tag->object.oid));
 689         message = memmem(buf, size, "\n\n", 2);
 690         if (message) {
 691                 message += 2;
 692                 message_size = strlen(message);
 693         }
 694         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 695         if (!tagger) {
 696                 if (fake_missing_tagger)
 697                         tagger = "tagger Unspecified Tagger "
 698                                 "<unspecified-tagger> 0 +0000";
 699                 else
 700                         tagger = "";
 701                 tagger_end = tagger + strlen(tagger);
 702         } else {
 703                 tagger++;
 704                 tagger_end = strchrnul(tagger, '\n');
 705                 if (anonymize)
 706                         anonymize_ident_line(&tagger, &tagger_end);
 707         }
 708
 709         if (anonymize) {
 710                 name = anonymize_refname(name);
 711                 if (message) {
 712                         static struct hashmap tags;
 713                         message = anonymize_mem(&tags, anonymize_tag,
 714                                                 message, &message_size);
 715                 }
 716         }
 717
 718         /* handle signed tags */
 719         if (message) {
 720                 const char *signature = strstr(message,
 721                                                "\n-----BEGIN PGP SIGNATURE-----\n");
 722                 if (signature)
 723                         switch(signed_tag_mode) {
 724                         case ABORT:
 725                                 die ("Encountered signed tag %s; use "
 726                                      "--signed-tags=<mode> to handle it.",
 727                                      oid_to_hex(&tag->object.oid));
 728                         case WARN:
 729                                 warning ("Exporting signed tag %s",
 730                                          oid_to_hex(&tag->object.oid));
 731                                 /* fallthru */
 732                         case VERBATIM:
 733                                 break;
 734                         case WARN_STRIP:
 735                                 warning ("Stripping signature from tag %s",
 736                                          oid_to_hex(&tag->object.oid));
 737                                 /* fallthru */
 738                         case STRIP:
 739                                 message_size = signature + 1 - message;
 740                                 break;
 741                         }
 742         }
 743
 744         /* handle tag->tagged having been filtered out due to paths specified */
 745         tagged = tag->tagged;
 746         tagged_mark = get_object_mark(tagged);
 747         if (!tagged_mark) {
 748                 switch(tag_of_filtered_mode) {
 749                 case ABORT:
 750                         die ("Tag %s tags unexported object; use "
 751                              "--tag-of-filtered-object=<mode> to handle it.",
 752                              oid_to_hex(&tag->object.oid));
 753                 case DROP:
 754                         /* Ignore this tag altogether */
 755                         free(buf);
 756                         return;
 757                 case REWRITE:
 758                         if (tagged->type != OBJ_COMMIT) {
 759                                 die ("Tag %s tags unexported %s!",
 760                                      oid_to_hex(&tag->object.oid),
 761                                      type_name(tagged->type));
 762                         }
 763                         p = (struct commit *)tagged;
 764                         for (;;) {
 765                                 if (p->parents && p->parents->next)
 766                                         break;
 767                                 if (p->object.flags & UNINTERESTING)
 768                                         break;
 769                                 if (!(p->object.flags & TREESAME))
 770                                         break;
 771                                 if (!p->parents)
 772                                         die ("Can't find replacement commit for tag %s\n",
 773                                              oid_to_hex(&tag->object.oid));
 774                                 p = p->parents->item;
 775                         }
 776                         tagged_mark = get_object_mark(&p->object);
 777                 }
 778         }
 779
 780         if (starts_with(name, "refs/tags/"))
 781                 name += 10;
 782         printf("tag %s\nfrom :%d\n%.*s%sdata %d\n%.*s\n",
 783                name, tagged_mark,
 784                (int)(tagger_end - tagger), tagger,
 785                tagger == tagger_end ? "" : "\n",
 786                (int)message_size, (int)message_size, message ? message : "");
 787         free(buf);
 788 }
 789
 790 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 791 {
 792         switch (e->item->type) {
 793         case OBJ_COMMIT:
 794                 return (struct commit *)e->item;
 795         case OBJ_TAG: {
 796                 struct tag *tag = (struct tag *)e->item;
 797
 798                 /* handle nested tags */
 799                 while (tag && tag->object.type == OBJ_TAG) {
 800                         parse_object(&tag->object.oid);
 801                         string_list_append(&extra_refs, full_name)->util = tag;
 802                         tag = (struct tag *)tag->tagged;
 803                 }
 804                 if (!tag)
 805                         die("Tag %s points nowhere?", e->name);
 806                 return (struct commit *)tag;
 807                 break;
 808         }
 809         default:
 810                 return NULL;
 811         }
 812 }
 813
 814 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 815 {
 816         int i;
 817
 818         for (i = 0; i < info->nr; i++) {
 819                 struct rev_cmdline_entry *e = info->rev + i;
 820                 struct object_id oid;
 821                 struct commit *commit;
 822                 char *full_name;
 823
 824                 if (e->flags & UNINTERESTING)
 825                         continue;
 826
 827                 if (dwim_ref(e->name, strlen(e->name), &oid, &full_name) != 1)
 828                         continue;
 829
 830                 if (refspecs) {
 831                         char *private;
 832                         private = apply_refspecs(refspecs, refspecs_nr, full_name);
 833                         if (private) {
 834                                 free(full_name);
 835                                 full_name = private;
 836                         }
 837                 }
 838
 839                 commit = get_commit(e, full_name);
 840                 if (!commit) {
 841                         warning("%s: Unexpected object of type %s, skipping.",
 842                                 e->name,
 843                                 type_name(e->item->type));
 844                         continue;
 845                 }
 846
 847                 switch(commit->object.type) {
 848                 case OBJ_COMMIT:
 849                         break;
 850                 case OBJ_BLOB:
 851                         export_blob(&commit->object.oid);
 852                         continue;
 853                 default: /* OBJ_TAG (nested tags) is already handled */
 854                         warning("Tag points to object of unexpected type %s, skipping.",
 855                                 type_name(commit->object.type));
 856                         continue;
 857                 }
 858
 859                 /*
 860                  * This ref will not be updated through a commit, lets make
 861                  * sure it gets properly updated eventually.
 862                  */
 863                 if (commit->util || commit->object.flags & SHOWN)
 864                         string_list_append(&extra_refs, full_name)->util = commit;
 865                 if (!commit->util)
 866                         commit->util = full_name;
 867         }
 868 }
 869
 870 static void handle_tags_and_duplicates(void)
 871 {
 872         struct commit *commit;
 873         int i;
 874
 875         for (i = extra_refs.nr - 1; i >= 0; i--) {
 876                 const char *name = extra_refs.items[i].string;
 877                 struct object *object = extra_refs.items[i].util;
 878                 switch (object->type) {
 879                 case OBJ_TAG:
 880                         handle_tag(name, (struct tag *)object);
 881                         break;
 882                 case OBJ_COMMIT:
 883                         if (anonymize)
 884                                 name = anonymize_refname(name);
 885                         /* create refs pointing to already seen commits */
 886                         commit = (struct commit *)object;
 887                         printf("reset %s\nfrom :%d\n\n", name,
 888                                get_object_mark(&commit->object));
 889                         show_progress();
 890                         break;
 891                 }
 892         }
 893 }
 894
 895 static void export_marks(char *file)
 896 {
 897         unsigned int i;
 898         uint32_t mark;
 899         struct decoration_entry *deco = idnums.entries;
 900         FILE *f;
 901         int e = 0;
 902
 903         f = fopen_for_writing(file);
 904         if (!f)
 905                 die_errno("Unable to open marks file %s for writing.", file);
 906
 907         for (i = 0; i < idnums.size; i++) {
 908                 if (deco->base && deco->base->type == 1) {
 909                         mark = ptr_to_mark(deco->decoration);
 910                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
 911                                 oid_to_hex(&deco->base->oid)) < 0) {
 912                             e = 1;
 913                             break;
 914                         }
 915                 }
 916                 deco++;
 917         }
 918
 919         e |= ferror(f);
 920         e |= fclose(f);
 921         if (e)
 922                 error("Unable to write marks file %s.", file);
 923 }
 924
 925 static void import_marks(char *input_file)
 926 {
 927         char line[512];
 928         FILE *f = xfopen(input_file, "r");
 929
 930         while (fgets(line, sizeof(line), f)) {
 931                 uint32_t mark;
 932                 char *line_end, *mark_end;
 933                 struct object_id oid;
 934                 struct object *object;
 935                 struct commit *commit;
 936                 enum object_type type;
 937
 938                 line_end = strchr(line, '\n');
 939                 if (line[0] != ':' || !line_end)
 940                         die("corrupt mark line: %s", line);
 941                 *line_end = '\0';
 942
 943                 mark = strtoumax(line + 1, &mark_end, 10);
 944                 if (!mark || mark_end == line + 1
 945                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
 946                         die("corrupt mark line: %s", line);
 947
 948                 if (last_idnum < mark)
 949                         last_idnum = mark;
 950
 951                 type = oid_object_info(the_repository, &oid, NULL);
 952                 if (type < 0)
 953                         die("object not found: %s", oid_to_hex(&oid));
 954
 955                 if (type != OBJ_COMMIT)
 956                         /* only commits */
 957                         continue;
 958
 959                 commit = lookup_commit(&oid);
 960                 if (!commit)
 961                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
 962
 963                 object = &commit->object;
 964
 965                 if (object->flags & SHOWN)
 966                         error("Object %s already has a mark", oid_to_hex(&oid));
 967
 968                 mark_object(object, mark);
 969
 970                 object->flags |= SHOWN;
 971         }
 972         fclose(f);
 973 }
 974
 975 static void handle_deletes(void)
 976 {
 977         int i;
 978         for (i = 0; i < refspecs_nr; i++) {
 979                 struct refspec *refspec = &refspecs[i];
 980                 if (*refspec->src)
 981                         continue;
 982
 983                 printf("reset %s\nfrom %s\n\n",
 984                                 refspec->dst, sha1_to_hex(null_sha1));
 985         }
 986 }
 987
 988 int cmd_fast_export(int argc, const char **argv, const char *prefix)
 989 {
 990         struct rev_info revs;
 991         struct object_array commits = OBJECT_ARRAY_INIT;
 992         struct commit *commit;
 993         char *export_filename = NULL, *import_filename = NULL;
 994         uint32_t lastimportid;
 995         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
 996         struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
 997         struct option options[] = {
 998                 OPT_INTEGER(0, "progress", &progress,
 999                             N_("show progress after <n> objects")),
1000                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
1001                              N_("select handling of signed tags"),
1002                              parse_opt_signed_tag_mode),
1003                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
1004                              N_("select handling of tags that tag filtered objects"),
1005                              parse_opt_tag_of_filtered_mode),
1006                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
1007                              N_("Dump marks to this file")),
1008                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
1009                              N_("Import marks from this file")),
1010                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
1011                          N_("Fake a tagger when tags lack one")),
1012                 OPT_BOOL(0, "full-tree", &full_tree,
1013                          N_("Output full tree for each commit")),
1014                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
1015                              N_("Use the done feature to terminate the stream")),
1016                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
1017                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1018                              N_("Apply refspec to exported refs")),
1019                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1020                 OPT_END()
1021         };
1022
1023         if (argc == 1)
1024                 usage_with_options (fast_export_usage, options);
1025
1026         /* we handle encodings */
1027         git_config(git_default_config, NULL);
1028
1029         init_revisions(&revs, prefix);
1030         revs.topo_order = 1;
1031         revs.show_source = 1;
1032         revs.rewrite_parents = 1;
1033         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1034                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
1035         argc = setup_revisions(argc, argv, &revs, NULL);
1036         if (argc > 1)
1037                 usage_with_options (fast_export_usage, options);
1038
1039         if (refspecs_list.nr) {
1040                 const char **refspecs_str;
1041                 int i;
1042
1043                 ALLOC_ARRAY(refspecs_str, refspecs_list.nr);
1044                 for (i = 0; i < refspecs_list.nr; i++)
1045                         refspecs_str[i] = refspecs_list.items[i].string;
1046
1047                 refspecs_nr = refspecs_list.nr;
1048                 refspecs = parse_fetch_refspec(refspecs_nr, refspecs_str);
1049
1050                 string_list_clear(&refspecs_list, 1);
1051                 free(refspecs_str);
1052         }
1053
1054         if (use_done_feature)
1055                 printf("feature done\n");
1056
1057         if (import_filename)
1058                 import_marks(import_filename);
1059         lastimportid = last_idnum;
1060
1061         if (import_filename && revs.prune_data.nr)
1062                 full_tree = 1;
1063
1064         get_tags_and_duplicates(&revs.cmdline);
1065
1066         if (prepare_revision_walk(&revs))
1067                 die("revision walk setup failed");
1068         revs.diffopt.format_callback = show_filemodify;
1069         revs.diffopt.format_callback_data = &paths_of_changed_objects;
1070         revs.diffopt.flags.recursive = 1;
1071         while ((commit = get_revision(&revs))) {
1072                 if (has_unshown_parent(commit)) {
1073                         add_object_array(&commit->object, NULL, &commits);
1074                 }
1075                 else {
1076                         handle_commit(commit, &revs, &paths_of_changed_objects);
1077                         handle_tail(&commits, &revs, &paths_of_changed_objects);
1078                 }
1079         }
1080
1081         handle_tags_and_duplicates();
1082         handle_deletes();
1083
1084         if (export_filename && lastimportid != last_idnum)
1085                 export_marks(export_filename);
1086
1087         if (use_done_feature)
1088                 printf("done\n");
1089
1090         free_refspec(refspecs_nr, refspecs);
1091
1092         return 0;
1093 }