builtin/log.c

   1 /*
   2  * Builtin "git log" and related commands (show, whatchanged)
   3  *
   4  * (C) Copyright 2006 Linus Torvalds
   5  *               2006 Junio Hamano
   6  */
   7 #include "cache.h"
   8 #include "color.h"
   9 #include "commit.h"
  10 #include "diff.h"
  11 #include "revision.h"
  12 #include "log-tree.h"
  13 #include "builtin.h"
  14 #include "tag.h"
  15 #include "reflog-walk.h"
  16 #include "patch-ids.h"
  17 #include "run-command.h"
  18 #include "shortlog.h"
  19 #include "remote.h"
  20 #include "string-list.h"
  21 #include "parse-options.h"
  22 #include "branch.h"
  23 #include "streaming.h"
  24
  25 /* Set a default date-time format for git log ("log.date" config variable) */
  26 static const char *default_date_mode = NULL;
  27
  28 static int default_abbrev_commit;
  29 static int default_show_root = 1;
  30 static int decoration_style;
  31 static int decoration_given;
  32 static const char *fmt_patch_subject_prefix = "PATCH";
  33 static const char *fmt_pretty;
  34
  35 static const char * const builtin_log_usage[] = {
  36         "git log [<options>] [<since>..<until>] [[--] <path>...]\n"
  37         "   or: git show [options] <object>...",
  38         NULL
  39 };
  40
  41 static int parse_decoration_style(const char *var, const char *value)
  42 {
  43         switch (git_config_maybe_bool(var, value)) {
  44         case 1:
  45                 return DECORATE_SHORT_REFS;
  46         case 0:
  47                 return 0;
  48         default:
  49                 break;
  50         }
  51         if (!strcmp(value, "full"))
  52                 return DECORATE_FULL_REFS;
  53         else if (!strcmp(value, "short"))
  54                 return DECORATE_SHORT_REFS;
  55         return -1;
  56 }
  57
  58 static int decorate_callback(const struct option *opt, const char *arg, int unset)
  59 {
  60         if (unset)
  61                 decoration_style = 0;
  62         else if (arg)
  63                 decoration_style = parse_decoration_style("command line", arg);
  64         else
  65                 decoration_style = DECORATE_SHORT_REFS;
  66
  67         if (decoration_style < 0)
  68                 die("invalid --decorate option: %s", arg);
  69
  70         decoration_given = 1;
  71
  72         return 0;
  73 }
  74
  75 static void cmd_log_init_defaults(struct rev_info *rev)
  76 {
  77         if (fmt_pretty)
  78                 get_commit_format(fmt_pretty, rev);
  79         rev->verbose_header = 1;
  80         DIFF_OPT_SET(&rev->diffopt, RECURSIVE);
  81         rev->abbrev_commit = default_abbrev_commit;
  82         rev->show_root_diff = default_show_root;
  83         rev->subject_prefix = fmt_patch_subject_prefix;
  84         DIFF_OPT_SET(&rev->diffopt, ALLOW_TEXTCONV);
  85
  86         if (default_date_mode)
  87                 rev->date_mode = parse_date_format(default_date_mode);
  88 }
  89
  90 static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
  91                          struct rev_info *rev, struct setup_revision_opt *opt)
  92 {
  93         struct userformat_want w;
  94         int quiet = 0, source = 0;
  95
  96         const struct option builtin_log_options[] = {
  97                 OPT_BOOLEAN(0, "quiet", &quiet, "suppress diff output"),
  98                 OPT_BOOLEAN(0, "source", &source, "show source"),
  99                 { OPTION_CALLBACK, 0, "decorate", NULL, NULL, "decorate options",
 100                   PARSE_OPT_OPTARG, decorate_callback},
 101                 OPT_END()
 102         };
 103
 104         argc = parse_options(argc, argv, prefix,
 105                              builtin_log_options, builtin_log_usage,
 106                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 107                              PARSE_OPT_KEEP_DASHDASH);
 108
 109         argc = setup_revisions(argc, argv, rev, opt);
 110         if (quiet)
 111                 rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
 112
 113         /* Any arguments at this point are not recognized */
 114         if (argc > 1)
 115                 die("unrecognized argument: %s", argv[1]);
 116
 117         memset(&w, 0, sizeof(w));
 118         userformat_find_requirements(NULL, &w);
 119
 120         if (!rev->show_notes_given && (!rev->pretty_given || w.notes))
 121                 rev->show_notes = 1;
 122         if (rev->show_notes)
 123                 init_display_notes(&rev->notes_opt);
 124
 125         if (rev->diffopt.pickaxe || rev->diffopt.filter)
 126                 rev->always_show_header = 0;
 127         if (DIFF_OPT_TST(&rev->diffopt, FOLLOW_RENAMES)) {
 128                 rev->always_show_header = 0;
 129                 if (rev->diffopt.pathspec.nr != 1)
 130                         usage("git logs can only follow renames on one pathname at a time");
 131         }
 132
 133         if (source)
 134                 rev->show_source = 1;
 135
 136         if (rev->pretty_given && rev->commit_format == CMIT_FMT_RAW) {
 137                 /*
 138                  * "log --pretty=raw" is special; ignore UI oriented
 139                  * configuration variables such as decoration.
 140                  */
 141                 if (!decoration_given)
 142                         decoration_style = 0;
 143                 if (!rev->abbrev_commit_given)
 144                         rev->abbrev_commit = 0;
 145         }
 146
 147         if (decoration_style) {
 148                 rev->show_decorations = 1;
 149                 load_ref_decorations(decoration_style);
 150         }
 151         setup_pager();
 152 }
 153
 154 static void cmd_log_init(int argc, const char **argv, const char *prefix,
 155                          struct rev_info *rev, struct setup_revision_opt *opt)
 156 {
 157         cmd_log_init_defaults(rev);
 158         cmd_log_init_finish(argc, argv, prefix, rev, opt);
 159 }
 160
 161 /*
 162  * This gives a rough estimate for how many commits we
 163  * will print out in the list.
 164  */
 165 static int estimate_commit_count(struct rev_info *rev, struct commit_list *list)
 166 {
 167         int n = 0;
 168
 169         while (list) {
 170                 struct commit *commit = list->item;
 171                 unsigned int flags = commit->object.flags;
 172                 list = list->next;
 173                 if (!(flags & (TREESAME | UNINTERESTING)))
 174                         n++;
 175         }
 176         return n;
 177 }
 178
 179 static void show_early_header(struct rev_info *rev, const char *stage, int nr)
 180 {
 181         if (rev->shown_one) {
 182                 rev->shown_one = 0;
 183                 if (rev->commit_format != CMIT_FMT_ONELINE)
 184                         putchar(rev->diffopt.line_termination);
 185         }
 186         printf(_("Final output: %d %s\n"), nr, stage);
 187 }
 188
 189 static struct itimerval early_output_timer;
 190
 191 static void log_show_early(struct rev_info *revs, struct commit_list *list)
 192 {
 193         int i = revs->early_output;
 194         int show_header = 1;
 195
 196         sort_in_topological_order(&list, revs->lifo);
 197         while (list && i) {
 198                 struct commit *commit = list->item;
 199                 switch (simplify_commit(revs, commit)) {
 200                 case commit_show:
 201                         if (show_header) {
 202                                 int n = estimate_commit_count(revs, list);
 203                                 show_early_header(revs, "incomplete", n);
 204                                 show_header = 0;
 205                         }
 206                         log_tree_commit(revs, commit);
 207                         i--;
 208                         break;
 209                 case commit_ignore:
 210                         break;
 211                 case commit_error:
 212                         return;
 213                 }
 214                 list = list->next;
 215         }
 216
 217         /* Did we already get enough commits for the early output? */
 218         if (!i)
 219                 return;
 220
 221         /*
 222          * ..if no, then repeat it twice a second until we
 223          * do.
 224          *
 225          * NOTE! We don't use "it_interval", because if the
 226          * reader isn't listening, we want our output to be
 227          * throttled by the writing, and not have the timer
 228          * trigger every second even if we're blocked on a
 229          * reader!
 230          */
 231         early_output_timer.it_value.tv_sec = 0;
 232         early_output_timer.it_value.tv_usec = 500000;
 233         setitimer(ITIMER_REAL, &early_output_timer, NULL);
 234 }
 235
 236 static void early_output(int signal)
 237 {
 238         show_early_output = log_show_early;
 239 }
 240
 241 static void setup_early_output(struct rev_info *rev)
 242 {
 243         struct sigaction sa;
 244
 245         /*
 246          * Set up the signal handler, minimally intrusively:
 247          * we only set a single volatile integer word (not
 248          * using sigatomic_t - trying to avoid unnecessary
 249          * system dependencies and headers), and using
 250          * SA_RESTART.
 251          */
 252         memset(&sa, 0, sizeof(sa));
 253         sa.sa_handler = early_output;
 254         sigemptyset(&sa.sa_mask);
 255         sa.sa_flags = SA_RESTART;
 256         sigaction(SIGALRM, &sa, NULL);
 257
 258         /*
 259          * If we can get the whole output in less than a
 260          * tenth of a second, don't even bother doing the
 261          * early-output thing..
 262          *
 263          * This is a one-time-only trigger.
 264          */
 265         early_output_timer.it_value.tv_sec = 0;
 266         early_output_timer.it_value.tv_usec = 100000;
 267         setitimer(ITIMER_REAL, &early_output_timer, NULL);
 268 }
 269
 270 static void finish_early_output(struct rev_info *rev)
 271 {
 272         int n = estimate_commit_count(rev, rev->commits);
 273         signal(SIGALRM, SIG_IGN);
 274         show_early_header(rev, "done", n);
 275 }
 276
 277 static int cmd_log_walk(struct rev_info *rev)
 278 {
 279         struct commit *commit;
 280         int saved_nrl = 0;
 281         int saved_dcctc = 0;
 282
 283         if (rev->early_output)
 284                 setup_early_output(rev);
 285
 286         if (prepare_revision_walk(rev))
 287                 die(_("revision walk setup failed"));
 288
 289         if (rev->early_output)
 290                 finish_early_output(rev);
 291
 292         /*
 293          * For --check and --exit-code, the exit code is based on CHECK_FAILED
 294          * and HAS_CHANGES being accumulated in rev->diffopt, so be careful to
 295          * retain that state information if replacing rev->diffopt in this loop
 296          */
 297         while ((commit = get_revision(rev)) != NULL) {
 298                 if (!log_tree_commit(rev, commit) &&
 299                     rev->max_count >= 0)
 300                         /*
 301                          * We decremented max_count in get_revision,
 302                          * but we didn't actually show the commit.
 303                          */
 304                         rev->max_count++;
 305                 if (!rev->reflog_info) {
 306                         /* we allow cycles in reflog ancestry */
 307                         free(commit->buffer);
 308                         commit->buffer = NULL;
 309                 }
 310                 free_commit_list(commit->parents);
 311                 commit->parents = NULL;
 312                 if (saved_nrl < rev->diffopt.needed_rename_limit)
 313                         saved_nrl = rev->diffopt.needed_rename_limit;
 314                 if (rev->diffopt.degraded_cc_to_c)
 315                         saved_dcctc = 1;
 316         }
 317         rev->diffopt.degraded_cc_to_c = saved_dcctc;
 318         rev->diffopt.needed_rename_limit = saved_nrl;
 319
 320         if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF &&
 321             DIFF_OPT_TST(&rev->diffopt, CHECK_FAILED)) {
 322                 return 02;
 323         }
 324         return diff_result_code(&rev->diffopt, 0);
 325 }
 326
 327 static int git_log_config(const char *var, const char *value, void *cb)
 328 {
 329         if (!strcmp(var, "format.pretty"))
 330                 return git_config_string(&fmt_pretty, var, value);
 331         if (!strcmp(var, "format.subjectprefix"))
 332                 return git_config_string(&fmt_patch_subject_prefix, var, value);
 333         if (!strcmp(var, "log.abbrevcommit")) {
 334                 default_abbrev_commit = git_config_bool(var, value);
 335                 return 0;
 336         }
 337         if (!strcmp(var, "log.date"))
 338                 return git_config_string(&default_date_mode, var, value);
 339         if (!strcmp(var, "log.decorate")) {
 340                 decoration_style = parse_decoration_style(var, value);
 341                 if (decoration_style < 0)
 342                         decoration_style = 0; /* maybe warn? */
 343                 return 0;
 344         }
 345         if (!strcmp(var, "log.showroot")) {
 346                 default_show_root = git_config_bool(var, value);
 347                 return 0;
 348         }
 349         if (!prefixcmp(var, "color.decorate."))
 350                 return parse_decorate_color_config(var, 15, value);
 351
 352         return git_diff_ui_config(var, value, cb);
 353 }
 354
 355 int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 356 {
 357         struct rev_info rev;
 358         struct setup_revision_opt opt;
 359
 360         git_config(git_log_config, NULL);
 361
 362         init_revisions(&rev, prefix);
 363         rev.diff = 1;
 364         rev.simplify_history = 0;
 365         memset(&opt, 0, sizeof(opt));
 366         opt.def = "HEAD";
 367         cmd_log_init(argc, argv, prefix, &rev, &opt);
 368         if (!rev.diffopt.output_format)
 369                 rev.diffopt.output_format = DIFF_FORMAT_RAW;
 370         return cmd_log_walk(&rev);
 371 }
 372
 373 static void show_tagger(char *buf, int len, struct rev_info *rev)
 374 {
 375         struct strbuf out = STRBUF_INIT;
 376         struct pretty_print_context pp = {0};
 377
 378         pp.fmt = rev->commit_format;
 379         pp.date_mode = rev->date_mode;
 380         pp_user_info(&pp, "Tagger", &out, buf, get_log_output_encoding());
 381         printf("%s", out.buf);
 382         strbuf_release(&out);
 383 }
 384
 385 static int show_blob_object(const unsigned char *sha1, struct rev_info *rev)
 386 {
 387         fflush(stdout);
 388         return stream_blob_to_fd(1, sha1, NULL, 0);
 389 }
 390
 391 static int show_tag_object(const unsigned char *sha1, struct rev_info *rev)
 392 {
 393         unsigned long size;
 394         enum object_type type;
 395         char *buf = read_sha1_file(sha1, &type, &size);
 396         int offset = 0;
 397
 398         if (!buf)
 399                 return error(_("Could not read object %s"), sha1_to_hex(sha1));
 400
 401         assert(type == OBJ_TAG);
 402         while (offset < size && buf[offset] != '\n') {
 403                 int new_offset = offset + 1;
 404                 while (new_offset < size && buf[new_offset++] != '\n')
 405                         ; /* do nothing */
 406                 if (!prefixcmp(buf + offset, "tagger "))
 407                         show_tagger(buf + offset + 7,
 408                                     new_offset - offset - 7, rev);
 409                 offset = new_offset;
 410         }
 411
 412         if (offset < size)
 413                 fwrite(buf + offset, size - offset, 1, stdout);
 414         free(buf);
 415         return 0;
 416 }
 417
 418 static int show_tree_object(const unsigned char *sha1,
 419                 const char *base, int baselen,
 420                 const char *pathname, unsigned mode, int stage, void *context)
 421 {
 422         printf("%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
 423         return 0;
 424 }
 425
 426 static void show_rev_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
 427 {
 428         if (rev->ignore_merges) {
 429                 /* There was no "-m" on the command line */
 430                 rev->ignore_merges = 0;
 431                 if (!rev->first_parent_only && !rev->combine_merges) {
 432                         /* No "--first-parent", "-c", nor "--cc" */
 433                         rev->combine_merges = 1;
 434                         rev->dense_combined_merges = 1;
 435                 }
 436         }
 437         if (!rev->diffopt.output_format)
 438                 rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 439 }
 440
 441 int cmd_show(int argc, const char **argv, const char *prefix)
 442 {
 443         struct rev_info rev;
 444         struct object_array_entry *objects;
 445         struct setup_revision_opt opt;
 446         struct pathspec match_all;
 447         int i, count, ret = 0;
 448
 449         git_config(git_log_config, NULL);
 450
 451         init_pathspec(&match_all, NULL);
 452         init_revisions(&rev, prefix);
 453         rev.diff = 1;
 454         rev.always_show_header = 1;
 455         rev.no_walk = 1;
 456         memset(&opt, 0, sizeof(opt));
 457         opt.def = "HEAD";
 458         opt.tweak = show_rev_tweak_rev;
 459         cmd_log_init(argc, argv, prefix, &rev, &opt);
 460
 461         count = rev.pending.nr;
 462         objects = rev.pending.objects;
 463         for (i = 0; i < count && !ret; i++) {
 464                 struct object *o = objects[i].item;
 465                 const char *name = objects[i].name;
 466                 switch (o->type) {
 467                 case OBJ_BLOB:
 468                         ret = show_blob_object(o->sha1, NULL);
 469                         break;
 470                 case OBJ_TAG: {
 471                         struct tag *t = (struct tag *)o;
 472
 473                         if (rev.shown_one)
 474                                 putchar('\n');
 475                         printf("%stag %s%s\n",
 476                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 477                                         t->tag,
 478                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 479                         ret = show_tag_object(o->sha1, &rev);
 480                         rev.shown_one = 1;
 481                         if (ret)
 482                                 break;
 483                         o = parse_object(t->tagged->sha1);
 484                         if (!o)
 485                                 ret = error(_("Could not read object %s"),
 486                                             sha1_to_hex(t->tagged->sha1));
 487                         objects[i].item = o;
 488                         i--;
 489                         break;
 490                 }
 491                 case OBJ_TREE:
 492                         if (rev.shown_one)
 493                                 putchar('\n');
 494                         printf("%stree %s%s\n\n",
 495                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 496                                         name,
 497                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 498                         read_tree_recursive((struct tree *)o, "", 0, 0, &match_all,
 499                                         show_tree_object, NULL);
 500                         rev.shown_one = 1;
 501                         break;
 502                 case OBJ_COMMIT:
 503                         rev.pending.nr = rev.pending.alloc = 0;
 504                         rev.pending.objects = NULL;
 505                         add_object_array(o, name, &rev.pending);
 506                         ret = cmd_log_walk(&rev);
 507                         break;
 508                 default:
 509                         ret = error(_("Unknown type: %d"), o->type);
 510                 }
 511         }
 512         free(objects);
 513         return ret;
 514 }
 515
 516 /*
 517  * This is equivalent to "git log -g --abbrev-commit --pretty=oneline"
 518  */
 519 int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 520 {
 521         struct rev_info rev;
 522         struct setup_revision_opt opt;
 523
 524         git_config(git_log_config, NULL);
 525
 526         init_revisions(&rev, prefix);
 527         init_reflog_walk(&rev.reflog_info);
 528         rev.verbose_header = 1;
 529         memset(&opt, 0, sizeof(opt));
 530         opt.def = "HEAD";
 531         cmd_log_init_defaults(&rev);
 532         rev.abbrev_commit = 1;
 533         rev.commit_format = CMIT_FMT_ONELINE;
 534         rev.use_terminator = 1;
 535         rev.always_show_header = 1;
 536         cmd_log_init_finish(argc, argv, prefix, &rev, &opt);
 537
 538         return cmd_log_walk(&rev);
 539 }
 540
 541 int cmd_log(int argc, const char **argv, const char *prefix)
 542 {
 543         struct rev_info rev;
 544         struct setup_revision_opt opt;
 545
 546         git_config(git_log_config, NULL);
 547
 548         init_revisions(&rev, prefix);
 549         rev.always_show_header = 1;
 550         memset(&opt, 0, sizeof(opt));
 551         opt.def = "HEAD";
 552         cmd_log_init(argc, argv, prefix, &rev, &opt);
 553         return cmd_log_walk(&rev);
 554 }
 555
 556 /* format-patch */
 557
 558 static const char *fmt_patch_suffix = ".patch";
 559 static int numbered = 0;
 560 static int auto_number = 1;
 561
 562 static char *default_attach = NULL;
 563
 564 static struct string_list extra_hdr;
 565 static struct string_list extra_to;
 566 static struct string_list extra_cc;
 567
 568 static void add_header(const char *value)
 569 {
 570         struct string_list_item *item;
 571         int len = strlen(value);
 572         while (len && value[len - 1] == '\n')
 573                 len--;
 574
 575         if (!strncasecmp(value, "to: ", 4)) {
 576                 item = string_list_append(&extra_to, value + 4);
 577                 len -= 4;
 578         } else if (!strncasecmp(value, "cc: ", 4)) {
 579                 item = string_list_append(&extra_cc, value + 4);
 580                 len -= 4;
 581         } else {
 582                 item = string_list_append(&extra_hdr, value);
 583         }
 584
 585         item->string[len] = '\0';
 586 }
 587
 588 #define THREAD_SHALLOW 1
 589 #define THREAD_DEEP 2
 590 static int thread;
 591 static int do_signoff;
 592 static const char *signature = git_version_string;
 593
 594 static int git_format_config(const char *var, const char *value, void *cb)
 595 {
 596         if (!strcmp(var, "format.headers")) {
 597                 if (!value)
 598                         die(_("format.headers without value"));
 599                 add_header(value);
 600                 return 0;
 601         }
 602         if (!strcmp(var, "format.suffix"))
 603                 return git_config_string(&fmt_patch_suffix, var, value);
 604         if (!strcmp(var, "format.to")) {
 605                 if (!value)
 606                         return config_error_nonbool(var);
 607                 string_list_append(&extra_to, value);
 608                 return 0;
 609         }
 610         if (!strcmp(var, "format.cc")) {
 611                 if (!value)
 612                         return config_error_nonbool(var);
 613                 string_list_append(&extra_cc, value);
 614                 return 0;
 615         }
 616         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff") ||
 617             !strcmp(var, "color.ui")) {
 618                 return 0;
 619         }
 620         if (!strcmp(var, "format.numbered")) {
 621                 if (value && !strcasecmp(value, "auto")) {
 622                         auto_number = 1;
 623                         return 0;
 624                 }
 625                 numbered = git_config_bool(var, value);
 626                 auto_number = auto_number && numbered;
 627                 return 0;
 628         }
 629         if (!strcmp(var, "format.attach")) {
 630                 if (value && *value)
 631                         default_attach = xstrdup(value);
 632                 else
 633                         default_attach = xstrdup(git_version_string);
 634                 return 0;
 635         }
 636         if (!strcmp(var, "format.thread")) {
 637                 if (value && !strcasecmp(value, "deep")) {
 638                         thread = THREAD_DEEP;
 639                         return 0;
 640                 }
 641                 if (value && !strcasecmp(value, "shallow")) {
 642                         thread = THREAD_SHALLOW;
 643                         return 0;
 644                 }
 645                 thread = git_config_bool(var, value) && THREAD_SHALLOW;
 646                 return 0;
 647         }
 648         if (!strcmp(var, "format.signoff")) {
 649                 do_signoff = git_config_bool(var, value);
 650                 return 0;
 651         }
 652         if (!strcmp(var, "format.signature"))
 653                 return git_config_string(&signature, var, value);
 654
 655         return git_log_config(var, value, cb);
 656 }
 657
 658 static FILE *realstdout = NULL;
 659 static const char *output_directory = NULL;
 660 static int outdir_offset;
 661
 662 static int reopen_stdout(struct commit *commit, struct rev_info *rev, int quiet)
 663 {
 664         struct strbuf filename = STRBUF_INIT;
 665         int suffix_len = strlen(fmt_patch_suffix) + 1;
 666
 667         if (output_directory) {
 668                 strbuf_addstr(&filename, output_directory);
 669                 if (filename.len >=
 670                     PATH_MAX - FORMAT_PATCH_NAME_MAX - suffix_len)
 671                         return error(_("name of output directory is too long"));
 672                 if (filename.buf[filename.len - 1] != '/')
 673                         strbuf_addch(&filename, '/');
 674         }
 675
 676         get_patch_filename(commit, rev->nr, fmt_patch_suffix, &filename);
 677
 678         if (!quiet)
 679                 fprintf(realstdout, "%s\n", filename.buf + outdir_offset);
 680
 681         if (freopen(filename.buf, "w", stdout) == NULL)
 682                 return error(_("Cannot open patch file %s"), filename.buf);
 683
 684         strbuf_release(&filename);
 685         return 0;
 686 }
 687
 688 static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
 689 {
 690         struct rev_info check_rev;
 691         struct commit *commit;
 692         struct object *o1, *o2;
 693         unsigned flags1, flags2;
 694
 695         if (rev->pending.nr != 2)
 696                 die(_("Need exactly one range."));
 697
 698         o1 = rev->pending.objects[0].item;
 699         flags1 = o1->flags;
 700         o2 = rev->pending.objects[1].item;
 701         flags2 = o2->flags;
 702
 703         if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
 704                 die(_("Not a range."));
 705
 706         init_patch_ids(ids);
 707
 708         /* given a range a..b get all patch ids for b..a */
 709         init_revisions(&check_rev, prefix);
 710         o1->flags ^= UNINTERESTING;
 711         o2->flags ^= UNINTERESTING;
 712         add_pending_object(&check_rev, o1, "o1");
 713         add_pending_object(&check_rev, o2, "o2");
 714         if (prepare_revision_walk(&check_rev))
 715                 die(_("revision walk setup failed"));
 716
 717         while ((commit = get_revision(&check_rev)) != NULL) {
 718                 /* ignore merges */
 719                 if (commit->parents && commit->parents->next)
 720                         continue;
 721
 722                 add_commit_patch_id(commit, ids);
 723         }
 724
 725         /* reset for next revision walk */
 726         clear_commit_marks((struct commit *)o1,
 727                         SEEN | UNINTERESTING | SHOWN | ADDED);
 728         clear_commit_marks((struct commit *)o2,
 729                         SEEN | UNINTERESTING | SHOWN | ADDED);
 730         o1->flags = flags1;
 731         o2->flags = flags2;
 732 }
 733
 734 static void gen_message_id(struct rev_info *info, char *base)
 735 {
 736         const char *committer = git_committer_info(IDENT_WARN_ON_NO_NAME);
 737         const char *email_start = strrchr(committer, '<');
 738         const char *email_end = strrchr(committer, '>');
 739         struct strbuf buf = STRBUF_INIT;
 740         if (!email_start || !email_end || email_start > email_end - 1)
 741                 die(_("Could not extract email from committer identity."));
 742         strbuf_addf(&buf, "%s.%lu.git.%.*s", base,
 743                     (unsigned long) time(NULL),
 744                     (int)(email_end - email_start - 1), email_start + 1);
 745         info->message_id = strbuf_detach(&buf, NULL);
 746 }
 747
 748 static void print_signature(void)
 749 {
 750         if (signature && *signature)
 751                 printf("-- \n%s\n\n", signature);
 752 }
 753
 754 static void add_branch_description(struct strbuf *buf, const char *branch_name)
 755 {
 756         struct strbuf desc = STRBUF_INIT;
 757         if (!branch_name || !*branch_name)
 758                 return;
 759         read_branch_desc(&desc, branch_name);
 760         if (desc.len) {
 761                 strbuf_addch(buf, '\n');
 762                 strbuf_add(buf, desc.buf, desc.len);
 763                 strbuf_addch(buf, '\n');
 764         }
 765 }
 766
 767 static void make_cover_letter(struct rev_info *rev, int use_stdout,
 768                               int numbered, int numbered_files,
 769                               struct commit *origin,
 770                               int nr, struct commit **list, struct commit *head,
 771                               const char *branch_name,
 772                               int quiet)
 773 {
 774         const char *committer;
 775         const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
 776         const char *msg;
 777         struct shortlog log;
 778         struct strbuf sb = STRBUF_INIT;
 779         int i;
 780         const char *encoding = "UTF-8";
 781         struct diff_options opts;
 782         int need_8bit_cte = 0;
 783         struct commit *commit = NULL;
 784         struct pretty_print_context pp = {0};
 785
 786         if (rev->commit_format != CMIT_FMT_EMAIL)
 787                 die(_("Cover letter needs email format"));
 788
 789         committer = git_committer_info(0);
 790
 791         if (!numbered_files) {
 792                 /*
 793                  * We fake a commit for the cover letter so we get the filename
 794                  * desired.
 795                  */
 796                 commit = xcalloc(1, sizeof(*commit));
 797                 commit->buffer = xmalloc(400);
 798                 snprintf(commit->buffer, 400,
 799                         "tree 0000000000000000000000000000000000000000\n"
 800                         "parent %s\n"
 801                         "author %s\n"
 802                         "committer %s\n\n"
 803                         "cover letter\n",
 804                         sha1_to_hex(head->object.sha1), committer, committer);
 805         }
 806
 807         if (!use_stdout && reopen_stdout(commit, rev, quiet))
 808                 return;
 809
 810         if (commit) {
 811
 812                 free(commit->buffer);
 813                 free(commit);
 814         }
 815
 816         log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
 817                                 &need_8bit_cte);
 818
 819         for (i = 0; !need_8bit_cte && i < nr; i++)
 820                 if (has_non_ascii(list[i]->buffer))
 821                         need_8bit_cte = 1;
 822
 823         msg = body;
 824         pp.fmt = CMIT_FMT_EMAIL;
 825         pp.date_mode = DATE_RFC2822;
 826         pp_user_info(&pp, NULL, &sb, committer, encoding);
 827         pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
 828         pp_remainder(&pp, &msg, &sb, 0);
 829         add_branch_description(&sb, branch_name);
 830         printf("%s\n", sb.buf);
 831
 832         strbuf_release(&sb);
 833
 834         shortlog_init(&log);
 835         log.wrap_lines = 1;
 836         log.wrap = 72;
 837         log.in1 = 2;
 838         log.in2 = 4;
 839         for (i = 0; i < nr; i++)
 840                 shortlog_add_commit(&log, list[i]);
 841
 842         shortlog_output(&log);
 843
 844         /*
 845          * We can only do diffstat with a unique reference point
 846          */
 847         if (!origin)
 848                 return;
 849
 850         memcpy(&opts, &rev->diffopt, sizeof(opts));
 851         opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 852
 853         diff_setup_done(&opts);
 854
 855         diff_tree_sha1(origin->tree->object.sha1,
 856                        head->tree->object.sha1,
 857                        "", &opts);
 858         diffcore_std(&opts);
 859         diff_flush(&opts);
 860
 861         printf("\n");
 862         print_signature();
 863 }
 864
 865 static const char *clean_message_id(const char *msg_id)
 866 {
 867         char ch;
 868         const char *a, *z, *m;
 869
 870         m = msg_id;
 871         while ((ch = *m) && (isspace(ch) || (ch == '<')))
 872                 m++;
 873         a = m;
 874         z = NULL;
 875         while ((ch = *m)) {
 876                 if (!isspace(ch) && (ch != '>'))
 877                         z = m;
 878                 m++;
 879         }
 880         if (!z)
 881                 die(_("insane in-reply-to: %s"), msg_id);
 882         if (++z == m)
 883                 return a;
 884         return xmemdupz(a, z - a);
 885 }
 886
 887 static const char *set_outdir(const char *prefix, const char *output_directory)
 888 {
 889         if (output_directory && is_absolute_path(output_directory))
 890                 return output_directory;
 891
 892         if (!prefix || !*prefix) {
 893                 if (output_directory)
 894                         return output_directory;
 895                 /* The user did not explicitly ask for "./" */
 896                 outdir_offset = 2;
 897                 return "./";
 898         }
 899
 900         outdir_offset = strlen(prefix);
 901         if (!output_directory)
 902                 return prefix;
 903
 904         return xstrdup(prefix_filename(prefix, outdir_offset,
 905                                        output_directory));
 906 }
 907
 908 static const char * const builtin_format_patch_usage[] = {
 909         "git format-patch [options] [<since> | <revision range>]",
 910         NULL
 911 };
 912
 913 static int keep_subject = 0;
 914
 915 static int keep_callback(const struct option *opt, const char *arg, int unset)
 916 {
 917         ((struct rev_info *)opt->value)->total = -1;
 918         keep_subject = 1;
 919         return 0;
 920 }
 921
 922 static int subject_prefix = 0;
 923
 924 static int subject_prefix_callback(const struct option *opt, const char *arg,
 925                             int unset)
 926 {
 927         subject_prefix = 1;
 928         ((struct rev_info *)opt->value)->subject_prefix = arg;
 929         return 0;
 930 }
 931
 932 static int numbered_cmdline_opt = 0;
 933
 934 static int numbered_callback(const struct option *opt, const char *arg,
 935                              int unset)
 936 {
 937         *(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
 938         if (unset)
 939                 auto_number =  0;
 940         return 0;
 941 }
 942
 943 static int no_numbered_callback(const struct option *opt, const char *arg,
 944                                 int unset)
 945 {
 946         return numbered_callback(opt, arg, 1);
 947 }
 948
 949 static int output_directory_callback(const struct option *opt, const char *arg,
 950                               int unset)
 951 {
 952         const char **dir = (const char **)opt->value;
 953         if (*dir)
 954                 die(_("Two output directories?"));
 955         *dir = arg;
 956         return 0;
 957 }
 958
 959 static int thread_callback(const struct option *opt, const char *arg, int unset)
 960 {
 961         int *thread = (int *)opt->value;
 962         if (unset)
 963                 *thread = 0;
 964         else if (!arg || !strcmp(arg, "shallow"))
 965                 *thread = THREAD_SHALLOW;
 966         else if (!strcmp(arg, "deep"))
 967                 *thread = THREAD_DEEP;
 968         else
 969                 return 1;
 970         return 0;
 971 }
 972
 973 static int attach_callback(const struct option *opt, const char *arg, int unset)
 974 {
 975         struct rev_info *rev = (struct rev_info *)opt->value;
 976         if (unset)
 977                 rev->mime_boundary = NULL;
 978         else if (arg)
 979                 rev->mime_boundary = arg;
 980         else
 981                 rev->mime_boundary = git_version_string;
 982         rev->no_inline = unset ? 0 : 1;
 983         return 0;
 984 }
 985
 986 static int inline_callback(const struct option *opt, const char *arg, int unset)
 987 {
 988         struct rev_info *rev = (struct rev_info *)opt->value;
 989         if (unset)
 990                 rev->mime_boundary = NULL;
 991         else if (arg)
 992                 rev->mime_boundary = arg;
 993         else
 994                 rev->mime_boundary = git_version_string;
 995         rev->no_inline = 0;
 996         return 0;
 997 }
 998
 999 static int header_callback(const struct option *opt, const char *arg, int unset)
1000 {
1001         if (unset) {
1002                 string_list_clear(&extra_hdr, 0);
1003                 string_list_clear(&extra_to, 0);
1004                 string_list_clear(&extra_cc, 0);
1005         } else {
1006             add_header(arg);
1007         }
1008         return 0;
1009 }
1010
1011 static int to_callback(const struct option *opt, const char *arg, int unset)
1012 {
1013         if (unset)
1014                 string_list_clear(&extra_to, 0);
1015         else
1016                 string_list_append(&extra_to, arg);
1017         return 0;
1018 }
1019
1020 static int cc_callback(const struct option *opt, const char *arg, int unset)
1021 {
1022         if (unset)
1023                 string_list_clear(&extra_cc, 0);
1024         else
1025                 string_list_append(&extra_cc, arg);
1026         return 0;
1027 }
1028
1029 static char *find_branch_name(struct rev_info *rev)
1030 {
1031         int i, positive = -1;
1032         unsigned char branch_sha1[20];
1033         struct strbuf buf = STRBUF_INIT;
1034         const char *branch;
1035
1036         for (i = 0; i < rev->cmdline.nr; i++) {
1037                 if (rev->cmdline.rev[i].flags & UNINTERESTING)
1038                         continue;
1039                 if (positive < 0)
1040                         positive = i;
1041                 else
1042                         return NULL;
1043         }
1044         if (positive < 0)
1045                 return NULL;
1046         strbuf_addf(&buf, "refs/heads/%s", rev->cmdline.rev[positive].name);
1047         branch = resolve_ref_unsafe(buf.buf, branch_sha1, 1, NULL);
1048         if (!branch ||
1049             prefixcmp(branch, "refs/heads/") ||
1050             hashcmp(rev->cmdline.rev[positive].item->sha1, branch_sha1))
1051                 branch = NULL;
1052         strbuf_release(&buf);
1053         if (branch)
1054                 return xstrdup(rev->cmdline.rev[positive].name);
1055         return NULL;
1056 }
1057
1058 int cmd_format_patch(int argc, const char **argv, const char *prefix)
1059 {
1060         struct commit *commit;
1061         struct commit **list = NULL;
1062         struct rev_info rev;
1063         struct setup_revision_opt s_r_opt;
1064         int nr = 0, total, i;
1065         int use_stdout = 0;
1066         int start_number = -1;
1067         int numbered_files = 0;         /* _just_ numbers */
1068         int ignore_if_in_upstream = 0;
1069         int cover_letter = 0;
1070         int boundary_count = 0;
1071         int no_binary_diff = 0;
1072         struct commit *origin = NULL, *head = NULL;
1073         const char *in_reply_to = NULL;
1074         struct patch_ids ids;
1075         char *add_signoff = NULL;
1076         struct strbuf buf = STRBUF_INIT;
1077         int use_patch_format = 0;
1078         int quiet = 0;
1079         char *branch_name = NULL;
1080         const struct option builtin_format_patch_options[] = {
1081                 { OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
1082                             "use [PATCH n/m] even with a single patch",
1083                             PARSE_OPT_NOARG, numbered_callback },
1084                 { OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
1085                             "use [PATCH] even with multiple patches",
1086                             PARSE_OPT_NOARG, no_numbered_callback },
1087                 OPT_BOOLEAN('s', "signoff", &do_signoff, "add Signed-off-by:"),
1088                 OPT_BOOLEAN(0, "stdout", &use_stdout,
1089                             "print patches to standard out"),
1090                 OPT_BOOLEAN(0, "cover-letter", &cover_letter,
1091                             "generate a cover letter"),
1092                 OPT_BOOLEAN(0, "numbered-files", &numbered_files,
1093                             "use simple number sequence for output file names"),
1094                 OPT_STRING(0, "suffix", &fmt_patch_suffix, "sfx",
1095                             "use <sfx> instead of '.patch'"),
1096                 OPT_INTEGER(0, "start-number", &start_number,
1097                             "start numbering patches at <n> instead of 1"),
1098                 { OPTION_CALLBACK, 0, "subject-prefix", &rev, "prefix",
1099                             "Use [<prefix>] instead of [PATCH]",
1100                             PARSE_OPT_NONEG, subject_prefix_callback },
1101                 { OPTION_CALLBACK, 'o', "output-directory", &output_directory,
1102                             "dir", "store resulting files in <dir>",
1103                             PARSE_OPT_NONEG, output_directory_callback },
1104                 { OPTION_CALLBACK, 'k', "keep-subject", &rev, NULL,
1105                             "don't strip/add [PATCH]",
1106                             PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
1107                 OPT_BOOLEAN(0, "no-binary", &no_binary_diff,
1108                             "don't output binary diffs"),
1109                 OPT_BOOLEAN(0, "ignore-if-in-upstream", &ignore_if_in_upstream,
1110                             "don't include a patch matching a commit upstream"),
1111                 { OPTION_BOOLEAN, 'p', "no-stat", &use_patch_format, NULL,
1112                   "show patch format instead of default (patch + stat)",
1113                   PARSE_OPT_NONEG | PARSE_OPT_NOARG },
1114                 OPT_GROUP("Messaging"),
1115                 { OPTION_CALLBACK, 0, "add-header", NULL, "header",
1116                             "add email header", 0, header_callback },
1117                 { OPTION_CALLBACK, 0, "to", NULL, "email", "add To: header",
1118                             0, to_callback },
1119                 { OPTION_CALLBACK, 0, "cc", NULL, "email", "add Cc: header",
1120                             0, cc_callback },
1121                 OPT_STRING(0, "in-reply-to", &in_reply_to, "message-id",
1122                             "make first mail a reply to <message-id>"),
1123                 { OPTION_CALLBACK, 0, "attach", &rev, "boundary",
1124                             "attach the patch", PARSE_OPT_OPTARG,
1125                             attach_callback },
1126                 { OPTION_CALLBACK, 0, "inline", &rev, "boundary",
1127                             "inline the patch",
1128                             PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
1129                             inline_callback },
1130                 { OPTION_CALLBACK, 0, "thread", &thread, "style",
1131                             "enable message threading, styles: shallow, deep",
1132                             PARSE_OPT_OPTARG, thread_callback },
1133                 OPT_STRING(0, "signature", &signature, "signature",
1134                             "add a signature"),
1135                 OPT_BOOLEAN(0, "quiet", &quiet,
1136                             "don't print the patch filenames"),
1137                 OPT_END()
1138         };
1139
1140         extra_hdr.strdup_strings = 1;
1141         extra_to.strdup_strings = 1;
1142         extra_cc.strdup_strings = 1;
1143         git_config(git_format_config, NULL);
1144         init_revisions(&rev, prefix);
1145         rev.commit_format = CMIT_FMT_EMAIL;
1146         rev.verbose_header = 1;
1147         rev.diff = 1;
1148         rev.max_parents = 1;
1149         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
1150         rev.subject_prefix = fmt_patch_subject_prefix;
1151         memset(&s_r_opt, 0, sizeof(s_r_opt));
1152         s_r_opt.def = "HEAD";
1153
1154         if (default_attach) {
1155                 rev.mime_boundary = default_attach;
1156                 rev.no_inline = 1;
1157         }
1158
1159         /*
1160          * Parse the arguments before setup_revisions(), or something
1161          * like "git format-patch -o a123 HEAD^.." may fail; a123 is
1162          * possibly a valid SHA1.
1163          */
1164         argc = parse_options(argc, argv, prefix, builtin_format_patch_options,
1165                              builtin_format_patch_usage,
1166                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
1167                              PARSE_OPT_KEEP_DASHDASH);
1168
1169         if (do_signoff) {
1170                 const char *committer;
1171                 const char *endpos;
1172                 committer = git_committer_info(IDENT_ERROR_ON_NO_NAME);
1173                 endpos = strchr(committer, '>');
1174                 if (!endpos)
1175                         die(_("bogus committer info %s"), committer);
1176                 add_signoff = xmemdupz(committer, endpos - committer + 1);
1177         }
1178
1179         for (i = 0; i < extra_hdr.nr; i++) {
1180                 strbuf_addstr(&buf, extra_hdr.items[i].string);
1181                 strbuf_addch(&buf, '\n');
1182         }
1183
1184         if (extra_to.nr)
1185                 strbuf_addstr(&buf, "To: ");
1186         for (i = 0; i < extra_to.nr; i++) {
1187                 if (i)
1188                         strbuf_addstr(&buf, "    ");
1189                 strbuf_addstr(&buf, extra_to.items[i].string);
1190                 if (i + 1 < extra_to.nr)
1191                         strbuf_addch(&buf, ',');
1192                 strbuf_addch(&buf, '\n');
1193         }
1194
1195         if (extra_cc.nr)
1196                 strbuf_addstr(&buf, "Cc: ");
1197         for (i = 0; i < extra_cc.nr; i++) {
1198                 if (i)
1199                         strbuf_addstr(&buf, "    ");
1200                 strbuf_addstr(&buf, extra_cc.items[i].string);
1201                 if (i + 1 < extra_cc.nr)
1202                         strbuf_addch(&buf, ',');
1203                 strbuf_addch(&buf, '\n');
1204         }
1205
1206         rev.extra_headers = strbuf_detach(&buf, NULL);
1207
1208         if (start_number < 0)
1209                 start_number = 1;
1210
1211         /*
1212          * If numbered is set solely due to format.numbered in config,
1213          * and it would conflict with --keep-subject (-k) from the
1214          * command line, reset "numbered".
1215          */
1216         if (numbered && keep_subject && !numbered_cmdline_opt)
1217                 numbered = 0;
1218
1219         if (numbered && keep_subject)
1220                 die (_("-n and -k are mutually exclusive."));
1221         if (keep_subject && subject_prefix)
1222                 die (_("--subject-prefix and -k are mutually exclusive."));
1223         rev.preserve_subject = keep_subject;
1224
1225         argc = setup_revisions(argc, argv, &rev, &s_r_opt);
1226         if (argc > 1)
1227                 die (_("unrecognized argument: %s"), argv[1]);
1228
1229         if (rev.diffopt.output_format & DIFF_FORMAT_NAME)
1230                 die(_("--name-only does not make sense"));
1231         if (rev.diffopt.output_format & DIFF_FORMAT_NAME_STATUS)
1232                 die(_("--name-status does not make sense"));
1233         if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF)
1234                 die(_("--check does not make sense"));
1235
1236         if (!use_patch_format &&
1237                 (!rev.diffopt.output_format ||
1238                  rev.diffopt.output_format == DIFF_FORMAT_PATCH))
1239                 rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY;
1240
1241         /* Always generate a patch */
1242         rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
1243
1244         if (!DIFF_OPT_TST(&rev.diffopt, TEXT) && !no_binary_diff)
1245                 DIFF_OPT_SET(&rev.diffopt, BINARY);
1246
1247         if (rev.show_notes)
1248                 init_display_notes(&rev.notes_opt);
1249
1250         if (!use_stdout)
1251                 output_directory = set_outdir(prefix, output_directory);
1252         else
1253                 setup_pager();
1254
1255         if (output_directory) {
1256                 if (use_stdout)
1257                         die(_("standard output, or directory, which one?"));
1258                 if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
1259                         die_errno(_("Could not create directory '%s'"),
1260                                   output_directory);
1261         }
1262
1263         if (rev.pending.nr == 1) {
1264                 if (rev.max_count < 0 && !rev.show_root_diff) {
1265                         /*
1266                          * This is traditional behaviour of "git format-patch
1267                          * origin" that prepares what the origin side still
1268                          * does not have.
1269                          */
1270                         unsigned char sha1[20];
1271                         const char *ref;
1272
1273                         rev.pending.objects[0].item->flags |= UNINTERESTING;
1274                         add_head_to_pending(&rev);
1275                         ref = resolve_ref_unsafe("HEAD", sha1, 1, NULL);
1276                         if (ref && !prefixcmp(ref, "refs/heads/"))
1277                                 branch_name = xstrdup(ref + strlen("refs/heads/"));
1278                         else
1279                                 branch_name = xstrdup(""); /* no branch */
1280                 }
1281                 /*
1282                  * Otherwise, it is "format-patch -22 HEAD", and/or
1283                  * "format-patch --root HEAD".  The user wants
1284                  * get_revision() to do the usual traversal.
1285                  */
1286         }
1287
1288         /*
1289          * We cannot move this anywhere earlier because we do want to
1290          * know if --root was given explicitly from the command line.
1291          */
1292         rev.show_root_diff = 1;
1293
1294         if (cover_letter) {
1295                 /*
1296                  * NEEDSWORK:randomly pick one positive commit to show
1297                  * diffstat; this is often the tip and the command
1298                  * happens to do the right thing in most cases, but a
1299                  * complex command like "--cover-letter a b c ^bottom"
1300                  * picks "c" and shows diffstat between bottom..c
1301                  * which may not match what the series represents at
1302                  * all and totally broken.
1303                  */
1304                 int i;
1305                 for (i = 0; i < rev.pending.nr; i++) {
1306                         struct object *o = rev.pending.objects[i].item;
1307                         if (!(o->flags & UNINTERESTING))
1308                                 head = (struct commit *)o;
1309                 }
1310                 /* There is nothing to show; it is not an error, though. */
1311                 if (!head)
1312                         return 0;
1313                 if (!branch_name)
1314                         branch_name = find_branch_name(&rev);
1315         }
1316
1317         if (ignore_if_in_upstream) {
1318                 /* Don't say anything if head and upstream are the same. */
1319                 if (rev.pending.nr == 2) {
1320                         struct object_array_entry *o = rev.pending.objects;
1321                         if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1322                                 return 0;
1323                 }
1324                 get_patch_ids(&rev, &ids, prefix);
1325         }
1326
1327         if (!use_stdout)
1328                 realstdout = xfdopen(xdup(1), "w");
1329
1330         if (prepare_revision_walk(&rev))
1331                 die(_("revision walk setup failed"));
1332         rev.boundary = 1;
1333         while ((commit = get_revision(&rev)) != NULL) {
1334                 if (commit->object.flags & BOUNDARY) {
1335                         boundary_count++;
1336                         origin = (boundary_count == 1) ? commit : NULL;
1337                         continue;
1338                 }
1339
1340                 if (ignore_if_in_upstream &&
1341                                 has_commit_patch_id(commit, &ids))
1342                         continue;
1343
1344                 nr++;
1345                 list = xrealloc(list, nr * sizeof(list[0]));
1346                 list[nr - 1] = commit;
1347         }
1348         total = nr;
1349         if (!keep_subject && auto_number && total > 1)
1350                 numbered = 1;
1351         if (numbered)
1352                 rev.total = total + start_number - 1;
1353         if (in_reply_to || thread || cover_letter)
1354                 rev.ref_message_ids = xcalloc(1, sizeof(struct string_list));
1355         if (in_reply_to) {
1356                 const char *msgid = clean_message_id(in_reply_to);
1357                 string_list_append(rev.ref_message_ids, msgid);
1358         }
1359         rev.numbered_files = numbered_files;
1360         rev.patch_suffix = fmt_patch_suffix;
1361         if (cover_letter) {
1362                 if (thread)
1363                         gen_message_id(&rev, "cover");
1364                 make_cover_letter(&rev, use_stdout, numbered, numbered_files,
1365                                   origin, nr, list, head, branch_name, quiet);
1366                 total++;
1367                 start_number--;
1368         }
1369         rev.add_signoff = add_signoff;
1370         while (0 <= --nr) {
1371                 int shown;
1372                 commit = list[nr];
1373                 rev.nr = total - nr + (start_number - 1);
1374                 /* Make the second and subsequent mails replies to the first */
1375                 if (thread) {
1376                         /* Have we already had a message ID? */
1377                         if (rev.message_id) {
1378                                 /*
1379                                  * For deep threading: make every mail
1380                                  * a reply to the previous one, no
1381                                  * matter what other options are set.
1382                                  *
1383                                  * For shallow threading:
1384                                  *
1385                                  * Without --cover-letter and
1386                                  * --in-reply-to, make every mail a
1387                                  * reply to the one before.
1388                                  *
1389                                  * With --in-reply-to but no
1390                                  * --cover-letter, make every mail a
1391                                  * reply to the <reply-to>.
1392                                  *
1393                                  * With --cover-letter, make every
1394                                  * mail but the cover letter a reply
1395                                  * to the cover letter.  The cover
1396                                  * letter is a reply to the
1397                                  * --in-reply-to, if specified.
1398                                  */
1399                                 if (thread == THREAD_SHALLOW
1400                                     && rev.ref_message_ids->nr > 0
1401                                     && (!cover_letter || rev.nr > 1))
1402                                         free(rev.message_id);
1403                                 else
1404                                         string_list_append(rev.ref_message_ids,
1405                                                            rev.message_id);
1406                         }
1407                         gen_message_id(&rev, sha1_to_hex(commit->object.sha1));
1408                 }
1409
1410                 if (!use_stdout && reopen_stdout(numbered_files ? NULL : commit,
1411                                                  &rev, quiet))
1412                         die(_("Failed to create output files"));
1413                 shown = log_tree_commit(&rev, commit);
1414                 free(commit->buffer);
1415                 commit->buffer = NULL;
1416
1417                 /* We put one extra blank line between formatted
1418                  * patches and this flag is used by log-tree code
1419                  * to see if it needs to emit a LF before showing
1420                  * the log; when using one file per patch, we do
1421                  * not want the extra blank line.
1422                  */
1423                 if (!use_stdout)
1424                         rev.shown_one = 0;
1425                 if (shown) {
1426                         if (rev.mime_boundary)
1427                                 printf("\n--%s%s--\n\n\n",
1428                                        mime_boundary_leader,
1429                                        rev.mime_boundary);
1430                         else
1431                                 print_signature();
1432                 }
1433                 if (!use_stdout)
1434                         fclose(stdout);
1435         }
1436         free(list);
1437         free(branch_name);
1438         string_list_clear(&extra_to, 0);
1439         string_list_clear(&extra_cc, 0);
1440         string_list_clear(&extra_hdr, 0);
1441         if (ignore_if_in_upstream)
1442                 free_patch_ids(&ids);
1443         return 0;
1444 }
1445
1446 static int add_pending_commit(const char *arg, struct rev_info *revs, int flags)
1447 {
1448         unsigned char sha1[20];
1449         if (get_sha1(arg, sha1) == 0) {
1450                 struct commit *commit = lookup_commit_reference(sha1);
1451                 if (commit) {
1452                         commit->object.flags |= flags;
1453                         add_pending_object(revs, &commit->object, arg);
1454                         return 0;
1455                 }
1456         }
1457         return -1;
1458 }
1459
1460 static const char * const cherry_usage[] = {
1461         "git cherry [-v] [<upstream> [<head> [<limit>]]]",
1462         NULL
1463 };
1464
1465 static void print_commit(char sign, struct commit *commit, int verbose,
1466                          int abbrev)
1467 {
1468         if (!verbose) {
1469                 printf("%c %s\n", sign,
1470                        find_unique_abbrev(commit->object.sha1, abbrev));
1471         } else {
1472                 struct strbuf buf = STRBUF_INIT;
1473                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
1474                 printf("%c %s %s\n", sign,
1475                        find_unique_abbrev(commit->object.sha1, abbrev),
1476                        buf.buf);
1477                 strbuf_release(&buf);
1478         }
1479 }
1480
1481 int cmd_cherry(int argc, const char **argv, const char *prefix)
1482 {
1483         struct rev_info revs;
1484         struct patch_ids ids;
1485         struct commit *commit;
1486         struct commit_list *list = NULL;
1487         struct branch *current_branch;
1488         const char *upstream;
1489         const char *head = "HEAD";
1490         const char *limit = NULL;
1491         int verbose = 0, abbrev = 0;
1492
1493         struct option options[] = {
1494                 OPT__ABBREV(&abbrev),
1495                 OPT__VERBOSE(&verbose, "be verbose"),
1496                 OPT_END()
1497         };
1498
1499         argc = parse_options(argc, argv, prefix, options, cherry_usage, 0);
1500
1501         switch (argc) {
1502         case 3:
1503                 limit = argv[2];
1504                 /* FALLTHROUGH */
1505         case 2:
1506                 head = argv[1];
1507                 /* FALLTHROUGH */
1508         case 1:
1509                 upstream = argv[0];
1510                 break;
1511         default:
1512                 current_branch = branch_get(NULL);
1513                 if (!current_branch || !current_branch->merge
1514                                         || !current_branch->merge[0]
1515                                         || !current_branch->merge[0]->dst) {
1516                         fprintf(stderr, _("Could not find a tracked"
1517                                         " remote branch, please"
1518                                         " specify <upstream> manually.\n"));
1519                         usage_with_options(cherry_usage, options);
1520                 }
1521
1522                 upstream = current_branch->merge[0]->dst;
1523         }
1524
1525         init_revisions(&revs, prefix);
1526         revs.diff = 1;
1527         revs.combine_merges = 0;
1528         revs.ignore_merges = 1;
1529         DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
1530
1531         if (add_pending_commit(head, &revs, 0))
1532                 die(_("Unknown commit %s"), head);
1533         if (add_pending_commit(upstream, &revs, UNINTERESTING))
1534                 die(_("Unknown commit %s"), upstream);
1535
1536         /* Don't say anything if head and upstream are the same. */
1537         if (revs.pending.nr == 2) {
1538                 struct object_array_entry *o = revs.pending.objects;
1539                 if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1540                         return 0;
1541         }
1542
1543         get_patch_ids(&revs, &ids, prefix);
1544
1545         if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
1546                 die(_("Unknown commit %s"), limit);
1547
1548         /* reverse the list of commits */
1549         if (prepare_revision_walk(&revs))
1550                 die(_("revision walk setup failed"));
1551         while ((commit = get_revision(&revs)) != NULL) {
1552                 /* ignore merges */
1553                 if (commit->parents && commit->parents->next)
1554                         continue;
1555
1556                 commit_list_insert(commit, &list);
1557         }
1558
1559         while (list) {
1560                 char sign = '+';
1561
1562                 commit = list->item;
1563                 if (has_commit_patch_id(commit, &ids))
1564                         sign = '-';
1565                 print_commit(sign, commit, verbose, abbrev);
1566                 list = list->next;
1567         }
1568
1569         free_patch_ids(&ids);
1570         return 0;
1571 }