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