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
  23 /* Set a default date-time format for git log ("log.date" config variable) */
  24 static const char *default_date_mode = NULL;
  25
  26 static int default_abbrev_commit;
  27 static int default_show_root = 1;
  28 static int decoration_style;
  29 static int decoration_given;
  30 static const char *fmt_patch_subject_prefix = "PATCH";
  31 static const char *fmt_pretty;
  32
  33 static const char * const builtin_log_usage[] = {
  34         "git log [<options>] [<since>..<until>] [[--] <path>...]\n"
  35         "   or: git show [options] <object>...",
  36         NULL
  37 };
  38
  39 static int parse_decoration_style(const char *var, const char *value)
  40 {
  41         switch (git_config_maybe_bool(var, value)) {
  42         case 1:
  43                 return DECORATE_SHORT_REFS;
  44         case 0:
  45                 return 0;
  46         default:
  47                 break;
  48         }
  49         if (!strcmp(value, "full"))
  50                 return DECORATE_FULL_REFS;
  51         else if (!strcmp(value, "short"))
  52                 return DECORATE_SHORT_REFS;
  53         return -1;
  54 }
  55
  56 static int decorate_callback(const struct option *opt, const char *arg, int unset)
  57 {
  58         if (unset)
  59                 decoration_style = 0;
  60         else if (arg)
  61                 decoration_style = parse_decoration_style("command line", arg);
  62         else
  63                 decoration_style = DECORATE_SHORT_REFS;
  64
  65         if (decoration_style < 0)
  66                 die("invalid --decorate option: %s", arg);
  67
  68         decoration_given = 1;
  69
  70         return 0;
  71 }
  72
  73 static void cmd_log_init_defaults(struct rev_info *rev)
  74 {
  75         rev->abbrev = DEFAULT_ABBREV;
  76         rev->commit_format = CMIT_FMT_DEFAULT;
  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_object(const unsigned char *sha1, int show_tag_object,
 386         struct rev_info *rev)
 387 {
 388         unsigned long size;
 389         enum object_type type;
 390         char *buf = read_sha1_file(sha1, &type, &size);
 391         int offset = 0;
 392
 393         if (!buf)
 394                 return error(_("Could not read object %s"), sha1_to_hex(sha1));
 395
 396         if (show_tag_object)
 397                 while (offset < size && buf[offset] != '\n') {
 398                         int new_offset = offset + 1;
 399                         while (new_offset < size && buf[new_offset++] != '\n')
 400                                 ; /* do nothing */
 401                         if (!prefixcmp(buf + offset, "tagger "))
 402                                 show_tagger(buf + offset + 7,
 403                                             new_offset - offset - 7, rev);
 404                         offset = new_offset;
 405                 }
 406
 407         if (offset < size)
 408                 fwrite(buf + offset, size - offset, 1, stdout);
 409         free(buf);
 410         return 0;
 411 }
 412
 413 static int show_tree_object(const unsigned char *sha1,
 414                 const char *base, int baselen,
 415                 const char *pathname, unsigned mode, int stage, void *context)
 416 {
 417         printf("%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
 418         return 0;
 419 }
 420
 421 static void show_rev_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
 422 {
 423         if (rev->ignore_merges) {
 424                 /* There was no "-m" on the command line */
 425                 rev->ignore_merges = 0;
 426                 if (!rev->first_parent_only && !rev->combine_merges) {
 427                         /* No "--first-parent", "-c", nor "--cc" */
 428                         rev->combine_merges = 1;
 429                         rev->dense_combined_merges = 1;
 430                 }
 431         }
 432         if (!rev->diffopt.output_format)
 433                 rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 434 }
 435
 436 int cmd_show(int argc, const char **argv, const char *prefix)
 437 {
 438         struct rev_info rev;
 439         struct object_array_entry *objects;
 440         struct setup_revision_opt opt;
 441         struct pathspec match_all;
 442         int i, count, ret = 0;
 443
 444         git_config(git_log_config, NULL);
 445
 446         init_pathspec(&match_all, NULL);
 447         init_revisions(&rev, prefix);
 448         rev.diff = 1;
 449         rev.always_show_header = 1;
 450         rev.no_walk = 1;
 451         memset(&opt, 0, sizeof(opt));
 452         opt.def = "HEAD";
 453         opt.tweak = show_rev_tweak_rev;
 454         cmd_log_init(argc, argv, prefix, &rev, &opt);
 455
 456         count = rev.pending.nr;
 457         objects = rev.pending.objects;
 458         for (i = 0; i < count && !ret; i++) {
 459                 struct object *o = objects[i].item;
 460                 const char *name = objects[i].name;
 461                 switch (o->type) {
 462                 case OBJ_BLOB:
 463                         ret = show_object(o->sha1, 0, NULL);
 464                         break;
 465                 case OBJ_TAG: {
 466                         struct tag *t = (struct tag *)o;
 467
 468                         if (rev.shown_one)
 469                                 putchar('\n');
 470                         printf("%stag %s%s\n",
 471                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 472                                         t->tag,
 473                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 474                         ret = show_object(o->sha1, 1, &rev);
 475                         rev.shown_one = 1;
 476                         if (ret)
 477                                 break;
 478                         o = parse_object(t->tagged->sha1);
 479                         if (!o)
 480                                 ret = error(_("Could not read object %s"),
 481                                             sha1_to_hex(t->tagged->sha1));
 482                         objects[i].item = o;
 483                         i--;
 484                         break;
 485                 }
 486                 case OBJ_TREE:
 487                         if (rev.shown_one)
 488                                 putchar('\n');
 489                         printf("%stree %s%s\n\n",
 490                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 491                                         name,
 492                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 493                         read_tree_recursive((struct tree *)o, "", 0, 0, &match_all,
 494                                         show_tree_object, NULL);
 495                         rev.shown_one = 1;
 496                         break;
 497                 case OBJ_COMMIT:
 498                         rev.pending.nr = rev.pending.alloc = 0;
 499                         rev.pending.objects = NULL;
 500                         add_object_array(o, name, &rev.pending);
 501                         ret = cmd_log_walk(&rev);
 502                         break;
 503                 default:
 504                         ret = error(_("Unknown type: %d"), o->type);
 505                 }
 506         }
 507         free(objects);
 508         return ret;
 509 }
 510
 511 /*
 512  * This is equivalent to "git log -g --abbrev-commit --pretty=oneline"
 513  */
 514 int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 515 {
 516         struct rev_info rev;
 517         struct setup_revision_opt opt;
 518
 519         git_config(git_log_config, NULL);
 520
 521         init_revisions(&rev, prefix);
 522         init_reflog_walk(&rev.reflog_info);
 523         rev.verbose_header = 1;
 524         memset(&opt, 0, sizeof(opt));
 525         opt.def = "HEAD";
 526         cmd_log_init_defaults(&rev);
 527         rev.abbrev_commit = 1;
 528         rev.commit_format = CMIT_FMT_ONELINE;
 529         rev.use_terminator = 1;
 530         rev.always_show_header = 1;
 531         cmd_log_init_finish(argc, argv, prefix, &rev, &opt);
 532
 533         return cmd_log_walk(&rev);
 534 }
 535
 536 int cmd_log(int argc, const char **argv, const char *prefix)
 537 {
 538         struct rev_info rev;
 539         struct setup_revision_opt opt;
 540
 541         git_config(git_log_config, NULL);
 542
 543         init_revisions(&rev, prefix);
 544         rev.always_show_header = 1;
 545         memset(&opt, 0, sizeof(opt));
 546         opt.def = "HEAD";
 547         cmd_log_init(argc, argv, prefix, &rev, &opt);
 548         return cmd_log_walk(&rev);
 549 }
 550
 551 /* format-patch */
 552
 553 static const char *fmt_patch_suffix = ".patch";
 554 static int numbered = 0;
 555 static int auto_number = 1;
 556
 557 static char *default_attach = NULL;
 558
 559 static struct string_list extra_hdr;
 560 static struct string_list extra_to;
 561 static struct string_list extra_cc;
 562
 563 static void add_header(const char *value)
 564 {
 565         struct string_list_item *item;
 566         int len = strlen(value);
 567         while (len && value[len - 1] == '\n')
 568                 len--;
 569
 570         if (!strncasecmp(value, "to: ", 4)) {
 571                 item = string_list_append(&extra_to, value + 4);
 572                 len -= 4;
 573         } else if (!strncasecmp(value, "cc: ", 4)) {
 574                 item = string_list_append(&extra_cc, value + 4);
 575                 len -= 4;
 576         } else {
 577                 item = string_list_append(&extra_hdr, value);
 578         }
 579
 580         item->string[len] = '\0';
 581 }
 582
 583 #define THREAD_SHALLOW 1
 584 #define THREAD_DEEP 2
 585 static int thread;
 586 static int do_signoff;
 587 static const char *signature = git_version_string;
 588
 589 static int git_format_config(const char *var, const char *value, void *cb)
 590 {
 591         if (!strcmp(var, "format.headers")) {
 592                 if (!value)
 593                         die(_("format.headers without value"));
 594                 add_header(value);
 595                 return 0;
 596         }
 597         if (!strcmp(var, "format.suffix"))
 598                 return git_config_string(&fmt_patch_suffix, var, value);
 599         if (!strcmp(var, "format.to")) {
 600                 if (!value)
 601                         return config_error_nonbool(var);
 602                 string_list_append(&extra_to, value);
 603                 return 0;
 604         }
 605         if (!strcmp(var, "format.cc")) {
 606                 if (!value)
 607                         return config_error_nonbool(var);
 608                 string_list_append(&extra_cc, value);
 609                 return 0;
 610         }
 611         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff") ||
 612             !strcmp(var, "color.ui")) {
 613                 return 0;
 614         }
 615         if (!strcmp(var, "format.numbered")) {
 616                 if (value && !strcasecmp(value, "auto")) {
 617                         auto_number = 1;
 618                         return 0;
 619                 }
 620                 numbered = git_config_bool(var, value);
 621                 auto_number = auto_number && numbered;
 622                 return 0;
 623         }
 624         if (!strcmp(var, "format.attach")) {
 625                 if (value && *value)
 626                         default_attach = xstrdup(value);
 627                 else
 628                         default_attach = xstrdup(git_version_string);
 629                 return 0;
 630         }
 631         if (!strcmp(var, "format.thread")) {
 632                 if (value && !strcasecmp(value, "deep")) {
 633                         thread = THREAD_DEEP;
 634                         return 0;
 635                 }
 636                 if (value && !strcasecmp(value, "shallow")) {
 637                         thread = THREAD_SHALLOW;
 638                         return 0;
 639                 }
 640                 thread = git_config_bool(var, value) && THREAD_SHALLOW;
 641                 return 0;
 642         }
 643         if (!strcmp(var, "format.signoff")) {
 644                 do_signoff = git_config_bool(var, value);
 645                 return 0;
 646         }
 647         if (!strcmp(var, "format.signature"))
 648                 return git_config_string(&signature, var, value);
 649
 650         return git_log_config(var, value, cb);
 651 }
 652
 653 static FILE *realstdout = NULL;
 654 static const char *output_directory = NULL;
 655 static int outdir_offset;
 656
 657 static int reopen_stdout(struct commit *commit, struct rev_info *rev, int quiet)
 658 {
 659         struct strbuf filename = STRBUF_INIT;
 660         int suffix_len = strlen(fmt_patch_suffix) + 1;
 661
 662         if (output_directory) {
 663                 strbuf_addstr(&filename, output_directory);
 664                 if (filename.len >=
 665                     PATH_MAX - FORMAT_PATCH_NAME_MAX - suffix_len)
 666                         return error(_("name of output directory is too long"));
 667                 if (filename.buf[filename.len - 1] != '/')
 668                         strbuf_addch(&filename, '/');
 669         }
 670
 671         get_patch_filename(commit, rev->nr, fmt_patch_suffix, &filename);
 672
 673         if (!quiet)
 674                 fprintf(realstdout, "%s\n", filename.buf + outdir_offset);
 675
 676         if (freopen(filename.buf, "w", stdout) == NULL)
 677                 return error(_("Cannot open patch file %s"), filename.buf);
 678
 679         strbuf_release(&filename);
 680         return 0;
 681 }
 682
 683 static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
 684 {
 685         struct rev_info check_rev;
 686         struct commit *commit;
 687         struct object *o1, *o2;
 688         unsigned flags1, flags2;
 689
 690         if (rev->pending.nr != 2)
 691                 die(_("Need exactly one range."));
 692
 693         o1 = rev->pending.objects[0].item;
 694         flags1 = o1->flags;
 695         o2 = rev->pending.objects[1].item;
 696         flags2 = o2->flags;
 697
 698         if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
 699                 die(_("Not a range."));
 700
 701         init_patch_ids(ids);
 702
 703         /* given a range a..b get all patch ids for b..a */
 704         init_revisions(&check_rev, prefix);
 705         o1->flags ^= UNINTERESTING;
 706         o2->flags ^= UNINTERESTING;
 707         add_pending_object(&check_rev, o1, "o1");
 708         add_pending_object(&check_rev, o2, "o2");
 709         if (prepare_revision_walk(&check_rev))
 710                 die(_("revision walk setup failed"));
 711
 712         while ((commit = get_revision(&check_rev)) != NULL) {
 713                 /* ignore merges */
 714                 if (commit->parents && commit->parents->next)
 715                         continue;
 716
 717                 add_commit_patch_id(commit, ids);
 718         }
 719
 720         /* reset for next revision walk */
 721         clear_commit_marks((struct commit *)o1,
 722                         SEEN | UNINTERESTING | SHOWN | ADDED);
 723         clear_commit_marks((struct commit *)o2,
 724                         SEEN | UNINTERESTING | SHOWN | ADDED);
 725         o1->flags = flags1;
 726         o2->flags = flags2;
 727 }
 728
 729 static void gen_message_id(struct rev_info *info, char *base)
 730 {
 731         const char *committer = git_committer_info(IDENT_WARN_ON_NO_NAME);
 732         const char *email_start = strrchr(committer, '<');
 733         const char *email_end = strrchr(committer, '>');
 734         struct strbuf buf = STRBUF_INIT;
 735         if (!email_start || !email_end || email_start > email_end - 1)
 736                 die(_("Could not extract email from committer identity."));
 737         strbuf_addf(&buf, "%s.%lu.git.%.*s", base,
 738                     (unsigned long) time(NULL),
 739                     (int)(email_end - email_start - 1), email_start + 1);
 740         info->message_id = strbuf_detach(&buf, NULL);
 741 }
 742
 743 static void print_signature(void)
 744 {
 745         if (signature && *signature)
 746                 printf("-- \n%s\n\n", signature);
 747 }
 748
 749 static void make_cover_letter(struct rev_info *rev, int use_stdout,
 750                               int numbered, int numbered_files,
 751                               struct commit *origin,
 752                               int nr, struct commit **list, struct commit *head,
 753                               int quiet)
 754 {
 755         const char *committer;
 756         const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
 757         const char *msg;
 758         struct shortlog log;
 759         struct strbuf sb = STRBUF_INIT;
 760         int i;
 761         const char *encoding = "UTF-8";
 762         struct diff_options opts;
 763         int need_8bit_cte = 0;
 764         struct commit *commit = NULL;
 765         struct pretty_print_context pp = {0};
 766
 767         if (rev->commit_format != CMIT_FMT_EMAIL)
 768                 die(_("Cover letter needs email format"));
 769
 770         committer = git_committer_info(0);
 771
 772         if (!numbered_files) {
 773                 /*
 774                  * We fake a commit for the cover letter so we get the filename
 775                  * desired.
 776                  */
 777                 commit = xcalloc(1, sizeof(*commit));
 778                 commit->buffer = xmalloc(400);
 779                 snprintf(commit->buffer, 400,
 780                         "tree 0000000000000000000000000000000000000000\n"
 781                         "parent %s\n"
 782                         "author %s\n"
 783                         "committer %s\n\n"
 784                         "cover letter\n",
 785                         sha1_to_hex(head->object.sha1), committer, committer);
 786         }
 787
 788         if (!use_stdout && reopen_stdout(commit, rev, quiet))
 789                 return;
 790
 791         if (commit) {
 792
 793                 free(commit->buffer);
 794                 free(commit);
 795         }
 796
 797         log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
 798                                 &need_8bit_cte);
 799
 800         for (i = 0; !need_8bit_cte && i < nr; i++)
 801                 if (has_non_ascii(list[i]->buffer))
 802                         need_8bit_cte = 1;
 803
 804         msg = body;
 805         pp.fmt = CMIT_FMT_EMAIL;
 806         pp.date_mode = DATE_RFC2822;
 807         pp_user_info(&pp, NULL, &sb, committer, encoding);
 808         pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
 809         pp_remainder(&pp, &msg, &sb, 0);
 810         printf("%s\n", sb.buf);
 811
 812         strbuf_release(&sb);
 813
 814         shortlog_init(&log);
 815         log.wrap_lines = 1;
 816         log.wrap = 72;
 817         log.in1 = 2;
 818         log.in2 = 4;
 819         for (i = 0; i < nr; i++)
 820                 shortlog_add_commit(&log, list[i]);
 821
 822         shortlog_output(&log);
 823
 824         /*
 825          * We can only do diffstat with a unique reference point
 826          */
 827         if (!origin)
 828                 return;
 829
 830         memcpy(&opts, &rev->diffopt, sizeof(opts));
 831         opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 832
 833         diff_setup_done(&opts);
 834
 835         diff_tree_sha1(origin->tree->object.sha1,
 836                        head->tree->object.sha1,
 837                        "", &opts);
 838         diffcore_std(&opts);
 839         diff_flush(&opts);
 840
 841         printf("\n");
 842         print_signature();
 843 }
 844
 845 static const char *clean_message_id(const char *msg_id)
 846 {
 847         char ch;
 848         const char *a, *z, *m;
 849
 850         m = msg_id;
 851         while ((ch = *m) && (isspace(ch) || (ch == '<')))
 852                 m++;
 853         a = m;
 854         z = NULL;
 855         while ((ch = *m)) {
 856                 if (!isspace(ch) && (ch != '>'))
 857                         z = m;
 858                 m++;
 859         }
 860         if (!z)
 861                 die(_("insane in-reply-to: %s"), msg_id);
 862         if (++z == m)
 863                 return a;
 864         return xmemdupz(a, z - a);
 865 }
 866
 867 static const char *set_outdir(const char *prefix, const char *output_directory)
 868 {
 869         if (output_directory && is_absolute_path(output_directory))
 870                 return output_directory;
 871
 872         if (!prefix || !*prefix) {
 873                 if (output_directory)
 874                         return output_directory;
 875                 /* The user did not explicitly ask for "./" */
 876                 outdir_offset = 2;
 877                 return "./";
 878         }
 879
 880         outdir_offset = strlen(prefix);
 881         if (!output_directory)
 882                 return prefix;
 883
 884         return xstrdup(prefix_filename(prefix, outdir_offset,
 885                                        output_directory));
 886 }
 887
 888 static const char * const builtin_format_patch_usage[] = {
 889         "git format-patch [options] [<since> | <revision range>]",
 890         NULL
 891 };
 892
 893 static int keep_subject = 0;
 894
 895 static int keep_callback(const struct option *opt, const char *arg, int unset)
 896 {
 897         ((struct rev_info *)opt->value)->total = -1;
 898         keep_subject = 1;
 899         return 0;
 900 }
 901
 902 static int subject_prefix = 0;
 903
 904 static int subject_prefix_callback(const struct option *opt, const char *arg,
 905                             int unset)
 906 {
 907         subject_prefix = 1;
 908         ((struct rev_info *)opt->value)->subject_prefix = arg;
 909         return 0;
 910 }
 911
 912 static int numbered_cmdline_opt = 0;
 913
 914 static int numbered_callback(const struct option *opt, const char *arg,
 915                              int unset)
 916 {
 917         *(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
 918         if (unset)
 919                 auto_number =  0;
 920         return 0;
 921 }
 922
 923 static int no_numbered_callback(const struct option *opt, const char *arg,
 924                                 int unset)
 925 {
 926         return numbered_callback(opt, arg, 1);
 927 }
 928
 929 static int output_directory_callback(const struct option *opt, const char *arg,
 930                               int unset)
 931 {
 932         const char **dir = (const char **)opt->value;
 933         if (*dir)
 934                 die(_("Two output directories?"));
 935         *dir = arg;
 936         return 0;
 937 }
 938
 939 static int thread_callback(const struct option *opt, const char *arg, int unset)
 940 {
 941         int *thread = (int *)opt->value;
 942         if (unset)
 943                 *thread = 0;
 944         else if (!arg || !strcmp(arg, "shallow"))
 945                 *thread = THREAD_SHALLOW;
 946         else if (!strcmp(arg, "deep"))
 947                 *thread = THREAD_DEEP;
 948         else
 949                 return 1;
 950         return 0;
 951 }
 952
 953 static int attach_callback(const struct option *opt, const char *arg, int unset)
 954 {
 955         struct rev_info *rev = (struct rev_info *)opt->value;
 956         if (unset)
 957                 rev->mime_boundary = NULL;
 958         else if (arg)
 959                 rev->mime_boundary = arg;
 960         else
 961                 rev->mime_boundary = git_version_string;
 962         rev->no_inline = unset ? 0 : 1;
 963         return 0;
 964 }
 965
 966 static int inline_callback(const struct option *opt, const char *arg, int unset)
 967 {
 968         struct rev_info *rev = (struct rev_info *)opt->value;
 969         if (unset)
 970                 rev->mime_boundary = NULL;
 971         else if (arg)
 972                 rev->mime_boundary = arg;
 973         else
 974                 rev->mime_boundary = git_version_string;
 975         rev->no_inline = 0;
 976         return 0;
 977 }
 978
 979 static int header_callback(const struct option *opt, const char *arg, int unset)
 980 {
 981         if (unset) {
 982                 string_list_clear(&extra_hdr, 0);
 983                 string_list_clear(&extra_to, 0);
 984                 string_list_clear(&extra_cc, 0);
 985         } else {
 986             add_header(arg);
 987         }
 988         return 0;
 989 }
 990
 991 static int to_callback(const struct option *opt, const char *arg, int unset)
 992 {
 993         if (unset)
 994                 string_list_clear(&extra_to, 0);
 995         else
 996                 string_list_append(&extra_to, arg);
 997         return 0;
 998 }
 999
1000 static int cc_callback(const struct option *opt, const char *arg, int unset)
1001 {
1002         if (unset)
1003                 string_list_clear(&extra_cc, 0);
1004         else
1005                 string_list_append(&extra_cc, arg);
1006         return 0;
1007 }
1008
1009 int cmd_format_patch(int argc, const char **argv, const char *prefix)
1010 {
1011         struct commit *commit;
1012         struct commit **list = NULL;
1013         struct rev_info rev;
1014         struct setup_revision_opt s_r_opt;
1015         int nr = 0, total, i;
1016         int use_stdout = 0;
1017         int start_number = -1;
1018         int numbered_files = 0;         /* _just_ numbers */
1019         int ignore_if_in_upstream = 0;
1020         int cover_letter = 0;
1021         int boundary_count = 0;
1022         int no_binary_diff = 0;
1023         struct commit *origin = NULL, *head = NULL;
1024         const char *in_reply_to = NULL;
1025         struct patch_ids ids;
1026         char *add_signoff = NULL;
1027         struct strbuf buf = STRBUF_INIT;
1028         int use_patch_format = 0;
1029         int quiet = 0;
1030         const struct option builtin_format_patch_options[] = {
1031                 { OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
1032                             "use [PATCH n/m] even with a single patch",
1033                             PARSE_OPT_NOARG, numbered_callback },
1034                 { OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
1035                             "use [PATCH] even with multiple patches",
1036                             PARSE_OPT_NOARG, no_numbered_callback },
1037                 OPT_BOOLEAN('s', "signoff", &do_signoff, "add Signed-off-by:"),
1038                 OPT_BOOLEAN(0, "stdout", &use_stdout,
1039                             "print patches to standard out"),
1040                 OPT_BOOLEAN(0, "cover-letter", &cover_letter,
1041                             "generate a cover letter"),
1042                 OPT_BOOLEAN(0, "numbered-files", &numbered_files,
1043                             "use simple number sequence for output file names"),
1044                 OPT_STRING(0, "suffix", &fmt_patch_suffix, "sfx",
1045                             "use <sfx> instead of '.patch'"),
1046                 OPT_INTEGER(0, "start-number", &start_number,
1047                             "start numbering patches at <n> instead of 1"),
1048                 { OPTION_CALLBACK, 0, "subject-prefix", &rev, "prefix",
1049                             "Use [<prefix>] instead of [PATCH]",
1050                             PARSE_OPT_NONEG, subject_prefix_callback },
1051                 { OPTION_CALLBACK, 'o', "output-directory", &output_directory,
1052                             "dir", "store resulting files in <dir>",
1053                             PARSE_OPT_NONEG, output_directory_callback },
1054                 { OPTION_CALLBACK, 'k', "keep-subject", &rev, NULL,
1055                             "don't strip/add [PATCH]",
1056                             PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
1057                 OPT_BOOLEAN(0, "no-binary", &no_binary_diff,
1058                             "don't output binary diffs"),
1059                 OPT_BOOLEAN(0, "ignore-if-in-upstream", &ignore_if_in_upstream,
1060                             "don't include a patch matching a commit upstream"),
1061                 { OPTION_BOOLEAN, 'p', "no-stat", &use_patch_format, NULL,
1062                   "show patch format instead of default (patch + stat)",
1063                   PARSE_OPT_NONEG | PARSE_OPT_NOARG },
1064                 OPT_GROUP("Messaging"),
1065                 { OPTION_CALLBACK, 0, "add-header", NULL, "header",
1066                             "add email header", 0, header_callback },
1067                 { OPTION_CALLBACK, 0, "to", NULL, "email", "add To: header",
1068                             0, to_callback },
1069                 { OPTION_CALLBACK, 0, "cc", NULL, "email", "add Cc: header",
1070                             0, cc_callback },
1071                 OPT_STRING(0, "in-reply-to", &in_reply_to, "message-id",
1072                             "make first mail a reply to <message-id>"),
1073                 { OPTION_CALLBACK, 0, "attach", &rev, "boundary",
1074                             "attach the patch", PARSE_OPT_OPTARG,
1075                             attach_callback },
1076                 { OPTION_CALLBACK, 0, "inline", &rev, "boundary",
1077                             "inline the patch",
1078                             PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
1079                             inline_callback },
1080                 { OPTION_CALLBACK, 0, "thread", &thread, "style",
1081                             "enable message threading, styles: shallow, deep",
1082                             PARSE_OPT_OPTARG, thread_callback },
1083                 OPT_STRING(0, "signature", &signature, "signature",
1084                             "add a signature"),
1085                 OPT_BOOLEAN(0, "quiet", &quiet,
1086                             "don't print the patch filenames"),
1087                 OPT_END()
1088         };
1089
1090         extra_hdr.strdup_strings = 1;
1091         extra_to.strdup_strings = 1;
1092         extra_cc.strdup_strings = 1;
1093         git_config(git_format_config, NULL);
1094         init_revisions(&rev, prefix);
1095         rev.commit_format = CMIT_FMT_EMAIL;
1096         rev.verbose_header = 1;
1097         rev.diff = 1;
1098         rev.max_parents = 1;
1099         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
1100         rev.subject_prefix = fmt_patch_subject_prefix;
1101         memset(&s_r_opt, 0, sizeof(s_r_opt));
1102         s_r_opt.def = "HEAD";
1103
1104         if (default_attach) {
1105                 rev.mime_boundary = default_attach;
1106                 rev.no_inline = 1;
1107         }
1108
1109         /*
1110          * Parse the arguments before setup_revisions(), or something
1111          * like "git format-patch -o a123 HEAD^.." may fail; a123 is
1112          * possibly a valid SHA1.
1113          */
1114         argc = parse_options(argc, argv, prefix, builtin_format_patch_options,
1115                              builtin_format_patch_usage,
1116                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
1117                              PARSE_OPT_KEEP_DASHDASH);
1118
1119         if (do_signoff) {
1120                 const char *committer;
1121                 const char *endpos;
1122                 committer = git_committer_info(IDENT_ERROR_ON_NO_NAME);
1123                 endpos = strchr(committer, '>');
1124                 if (!endpos)
1125                         die(_("bogus committer info %s"), committer);
1126                 add_signoff = xmemdupz(committer, endpos - committer + 1);
1127         }
1128
1129         for (i = 0; i < extra_hdr.nr; i++) {
1130                 strbuf_addstr(&buf, extra_hdr.items[i].string);
1131                 strbuf_addch(&buf, '\n');
1132         }
1133
1134         if (extra_to.nr)
1135                 strbuf_addstr(&buf, "To: ");
1136         for (i = 0; i < extra_to.nr; i++) {
1137                 if (i)
1138                         strbuf_addstr(&buf, "    ");
1139                 strbuf_addstr(&buf, extra_to.items[i].string);
1140                 if (i + 1 < extra_to.nr)
1141                         strbuf_addch(&buf, ',');
1142                 strbuf_addch(&buf, '\n');
1143         }
1144
1145         if (extra_cc.nr)
1146                 strbuf_addstr(&buf, "Cc: ");
1147         for (i = 0; i < extra_cc.nr; i++) {
1148                 if (i)
1149                         strbuf_addstr(&buf, "    ");
1150                 strbuf_addstr(&buf, extra_cc.items[i].string);
1151                 if (i + 1 < extra_cc.nr)
1152                         strbuf_addch(&buf, ',');
1153                 strbuf_addch(&buf, '\n');
1154         }
1155
1156         rev.extra_headers = strbuf_detach(&buf, NULL);
1157
1158         if (start_number < 0)
1159                 start_number = 1;
1160
1161         /*
1162          * If numbered is set solely due to format.numbered in config,
1163          * and it would conflict with --keep-subject (-k) from the
1164          * command line, reset "numbered".
1165          */
1166         if (numbered && keep_subject && !numbered_cmdline_opt)
1167                 numbered = 0;
1168
1169         if (numbered && keep_subject)
1170                 die (_("-n and -k are mutually exclusive."));
1171         if (keep_subject && subject_prefix)
1172                 die (_("--subject-prefix and -k are mutually exclusive."));
1173         rev.preserve_subject = keep_subject;
1174
1175         argc = setup_revisions(argc, argv, &rev, &s_r_opt);
1176         if (argc > 1)
1177                 die (_("unrecognized argument: %s"), argv[1]);
1178
1179         if (rev.diffopt.output_format & DIFF_FORMAT_NAME)
1180                 die(_("--name-only does not make sense"));
1181         if (rev.diffopt.output_format & DIFF_FORMAT_NAME_STATUS)
1182                 die(_("--name-status does not make sense"));
1183         if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF)
1184                 die(_("--check does not make sense"));
1185
1186         if (!use_patch_format &&
1187                 (!rev.diffopt.output_format ||
1188                  rev.diffopt.output_format == DIFF_FORMAT_PATCH))
1189                 rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY;
1190
1191         /* Always generate a patch */
1192         rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
1193
1194         if (!DIFF_OPT_TST(&rev.diffopt, TEXT) && !no_binary_diff)
1195                 DIFF_OPT_SET(&rev.diffopt, BINARY);
1196
1197         if (rev.show_notes)
1198                 init_display_notes(&rev.notes_opt);
1199
1200         if (!use_stdout)
1201                 output_directory = set_outdir(prefix, output_directory);
1202         else
1203                 setup_pager();
1204
1205         if (output_directory) {
1206                 if (use_stdout)
1207                         die(_("standard output, or directory, which one?"));
1208                 if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
1209                         die_errno(_("Could not create directory '%s'"),
1210                                   output_directory);
1211         }
1212
1213         if (rev.pending.nr == 1) {
1214                 if (rev.max_count < 0 && !rev.show_root_diff) {
1215                         /*
1216                          * This is traditional behaviour of "git format-patch
1217                          * origin" that prepares what the origin side still
1218                          * does not have.
1219                          */
1220                         rev.pending.objects[0].item->flags |= UNINTERESTING;
1221                         add_head_to_pending(&rev);
1222                 }
1223                 /*
1224                  * Otherwise, it is "format-patch -22 HEAD", and/or
1225                  * "format-patch --root HEAD".  The user wants
1226                  * get_revision() to do the usual traversal.
1227                  */
1228         }
1229
1230         /*
1231          * We cannot move this anywhere earlier because we do want to
1232          * know if --root was given explicitly from the command line.
1233          */
1234         rev.show_root_diff = 1;
1235
1236         if (cover_letter) {
1237                 /* remember the range */
1238                 int i;
1239                 for (i = 0; i < rev.pending.nr; i++) {
1240                         struct object *o = rev.pending.objects[i].item;
1241                         if (!(o->flags & UNINTERESTING))
1242                                 head = (struct commit *)o;
1243                 }
1244                 /* We can't generate a cover letter without any patches */
1245                 if (!head)
1246                         return 0;
1247         }
1248
1249         if (ignore_if_in_upstream) {
1250                 /* Don't say anything if head and upstream are the same. */
1251                 if (rev.pending.nr == 2) {
1252                         struct object_array_entry *o = rev.pending.objects;
1253                         if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1254                                 return 0;
1255                 }
1256                 get_patch_ids(&rev, &ids, prefix);
1257         }
1258
1259         if (!use_stdout)
1260                 realstdout = xfdopen(xdup(1), "w");
1261
1262         if (prepare_revision_walk(&rev))
1263                 die(_("revision walk setup failed"));
1264         rev.boundary = 1;
1265         while ((commit = get_revision(&rev)) != NULL) {
1266                 if (commit->object.flags & BOUNDARY) {
1267                         boundary_count++;
1268                         origin = (boundary_count == 1) ? commit : NULL;
1269                         continue;
1270                 }
1271
1272                 if (ignore_if_in_upstream &&
1273                                 has_commit_patch_id(commit, &ids))
1274                         continue;
1275
1276                 nr++;
1277                 list = xrealloc(list, nr * sizeof(list[0]));
1278                 list[nr - 1] = commit;
1279         }
1280         total = nr;
1281         if (!keep_subject && auto_number && total > 1)
1282                 numbered = 1;
1283         if (numbered)
1284                 rev.total = total + start_number - 1;
1285         if (in_reply_to || thread || cover_letter)
1286                 rev.ref_message_ids = xcalloc(1, sizeof(struct string_list));
1287         if (in_reply_to) {
1288                 const char *msgid = clean_message_id(in_reply_to);
1289                 string_list_append(rev.ref_message_ids, msgid);
1290         }
1291         rev.numbered_files = numbered_files;
1292         rev.patch_suffix = fmt_patch_suffix;
1293         if (cover_letter) {
1294                 if (thread)
1295                         gen_message_id(&rev, "cover");
1296                 make_cover_letter(&rev, use_stdout, numbered, numbered_files,
1297                                   origin, nr, list, head, quiet);
1298                 total++;
1299                 start_number--;
1300         }
1301         rev.add_signoff = add_signoff;
1302         while (0 <= --nr) {
1303                 int shown;
1304                 commit = list[nr];
1305                 rev.nr = total - nr + (start_number - 1);
1306                 /* Make the second and subsequent mails replies to the first */
1307                 if (thread) {
1308                         /* Have we already had a message ID? */
1309                         if (rev.message_id) {
1310                                 /*
1311                                  * For deep threading: make every mail
1312                                  * a reply to the previous one, no
1313                                  * matter what other options are set.
1314                                  *
1315                                  * For shallow threading:
1316                                  *
1317                                  * Without --cover-letter and
1318                                  * --in-reply-to, make every mail a
1319                                  * reply to the one before.
1320                                  *
1321                                  * With --in-reply-to but no
1322                                  * --cover-letter, make every mail a
1323                                  * reply to the <reply-to>.
1324                                  *
1325                                  * With --cover-letter, make every
1326                                  * mail but the cover letter a reply
1327                                  * to the cover letter.  The cover
1328                                  * letter is a reply to the
1329                                  * --in-reply-to, if specified.
1330                                  */
1331                                 if (thread == THREAD_SHALLOW
1332                                     && rev.ref_message_ids->nr > 0
1333                                     && (!cover_letter || rev.nr > 1))
1334                                         free(rev.message_id);
1335                                 else
1336                                         string_list_append(rev.ref_message_ids,
1337                                                            rev.message_id);
1338                         }
1339                         gen_message_id(&rev, sha1_to_hex(commit->object.sha1));
1340                 }
1341
1342                 if (!use_stdout && reopen_stdout(numbered_files ? NULL : commit,
1343                                                  &rev, quiet))
1344                         die(_("Failed to create output files"));
1345                 shown = log_tree_commit(&rev, commit);
1346                 free(commit->buffer);
1347                 commit->buffer = NULL;
1348
1349                 /* We put one extra blank line between formatted
1350                  * patches and this flag is used by log-tree code
1351                  * to see if it needs to emit a LF before showing
1352                  * the log; when using one file per patch, we do
1353                  * not want the extra blank line.
1354                  */
1355                 if (!use_stdout)
1356                         rev.shown_one = 0;
1357                 if (shown) {
1358                         if (rev.mime_boundary)
1359                                 printf("\n--%s%s--\n\n\n",
1360                                        mime_boundary_leader,
1361                                        rev.mime_boundary);
1362                         else
1363                                 print_signature();
1364                 }
1365                 if (!use_stdout)
1366                         fclose(stdout);
1367         }
1368         free(list);
1369         string_list_clear(&extra_to, 0);
1370         string_list_clear(&extra_cc, 0);
1371         string_list_clear(&extra_hdr, 0);
1372         if (ignore_if_in_upstream)
1373                 free_patch_ids(&ids);
1374         return 0;
1375 }
1376
1377 static int add_pending_commit(const char *arg, struct rev_info *revs, int flags)
1378 {
1379         unsigned char sha1[20];
1380         if (get_sha1(arg, sha1) == 0) {
1381                 struct commit *commit = lookup_commit_reference(sha1);
1382                 if (commit) {
1383                         commit->object.flags |= flags;
1384                         add_pending_object(revs, &commit->object, arg);
1385                         return 0;
1386                 }
1387         }
1388         return -1;
1389 }
1390
1391 static const char * const cherry_usage[] = {
1392         "git cherry [-v] [<upstream> [<head> [<limit>]]]",
1393         NULL
1394 };
1395
1396 static void print_commit(char sign, struct commit *commit, int verbose,
1397                          int abbrev)
1398 {
1399         if (!verbose) {
1400                 printf("%c %s\n", sign,
1401                        find_unique_abbrev(commit->object.sha1, abbrev));
1402         } else {
1403                 struct strbuf buf = STRBUF_INIT;
1404                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
1405                 printf("%c %s %s\n", sign,
1406                        find_unique_abbrev(commit->object.sha1, abbrev),
1407                        buf.buf);
1408                 strbuf_release(&buf);
1409         }
1410 }
1411
1412 int cmd_cherry(int argc, const char **argv, const char *prefix)
1413 {
1414         struct rev_info revs;
1415         struct patch_ids ids;
1416         struct commit *commit;
1417         struct commit_list *list = NULL;
1418         struct branch *current_branch;
1419         const char *upstream;
1420         const char *head = "HEAD";
1421         const char *limit = NULL;
1422         int verbose = 0, abbrev = 0;
1423
1424         struct option options[] = {
1425                 OPT__ABBREV(&abbrev),
1426                 OPT__VERBOSE(&verbose, "be verbose"),
1427                 OPT_END()
1428         };
1429
1430         argc = parse_options(argc, argv, prefix, options, cherry_usage, 0);
1431
1432         switch (argc) {
1433         case 3:
1434                 limit = argv[2];
1435                 /* FALLTHROUGH */
1436         case 2:
1437                 head = argv[1];
1438                 /* FALLTHROUGH */
1439         case 1:
1440                 upstream = argv[0];
1441                 break;
1442         default:
1443                 current_branch = branch_get(NULL);
1444                 if (!current_branch || !current_branch->merge
1445                                         || !current_branch->merge[0]
1446                                         || !current_branch->merge[0]->dst) {
1447                         fprintf(stderr, _("Could not find a tracked"
1448                                         " remote branch, please"
1449                                         " specify <upstream> manually.\n"));
1450                         usage_with_options(cherry_usage, options);
1451                 }
1452
1453                 upstream = current_branch->merge[0]->dst;
1454         }
1455
1456         init_revisions(&revs, prefix);
1457         revs.diff = 1;
1458         revs.combine_merges = 0;
1459         revs.ignore_merges = 1;
1460         DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
1461
1462         if (add_pending_commit(head, &revs, 0))
1463                 die(_("Unknown commit %s"), head);
1464         if (add_pending_commit(upstream, &revs, UNINTERESTING))
1465                 die(_("Unknown commit %s"), upstream);
1466
1467         /* Don't say anything if head and upstream are the same. */
1468         if (revs.pending.nr == 2) {
1469                 struct object_array_entry *o = revs.pending.objects;
1470                 if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1471                         return 0;
1472         }
1473
1474         get_patch_ids(&revs, &ids, prefix);
1475
1476         if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
1477                 die(_("Unknown commit %s"), limit);
1478
1479         /* reverse the list of commits */
1480         if (prepare_revision_walk(&revs))
1481                 die(_("revision walk setup failed"));
1482         while ((commit = get_revision(&revs)) != NULL) {
1483                 /* ignore merges */
1484                 if (commit->parents && commit->parents->next)
1485                         continue;
1486
1487                 commit_list_insert(commit, &list);
1488         }
1489
1490         while (list) {
1491                 char sign = '+';
1492
1493                 commit = list->item;
1494                 if (has_commit_patch_id(commit, &ids))
1495                         sign = '-';
1496                 print_commit(sign, commit, verbose, abbrev);
1497                 list = list->next;
1498         }
1499
1500         free_patch_ids(&ids);
1501         return 0;
1502 }