compat/bswap.h: detect endianness on more platforms that don't use BYTE_ORDER
[git] / builtin / log.c
1 /*
2  * Builtin "git log" and related commands (show, whatchanged)
3  *
4  * (C) Copyright 2006 Linus Torvalds
5  *               2006 Junio Hamano
6  */
7 #include "cache.h"
8 #include "color.h"
9 #include "commit.h"
10 #include "diff.h"
11 #include "revision.h"
12 #include "log-tree.h"
13 #include "builtin.h"
14 #include "tag.h"
15 #include "reflog-walk.h"
16 #include "patch-ids.h"
17 #include "run-command.h"
18 #include "shortlog.h"
19 #include "remote.h"
20 #include "string-list.h"
21 #include "parse-options.h"
22 #include "line-log.h"
23 #include "branch.h"
24 #include "streaming.h"
25 #include "version.h"
26 #include "mailmap.h"
27 #include "gpg-interface.h"
28
29 /* Set a default date-time format for git log ("log.date" config variable) */
30 static const char *default_date_mode = NULL;
31
32 static int default_abbrev_commit;
33 static int default_show_root = 1;
34 static int decoration_style;
35 static int decoration_given;
36 static int use_mailmap_config;
37 static const char *fmt_patch_subject_prefix = "PATCH";
38 static const char *fmt_pretty;
39
40 static const char * const builtin_log_usage[] = {
41         N_("git log [<options>] [<revision range>] [[--] <path>...]\n")
42         N_("   or: git show [options] <object>..."),
43         NULL
44 };
45
46 struct line_opt_callback_data {
47         struct rev_info *rev;
48         const char *prefix;
49         struct string_list args;
50 };
51
52 static int parse_decoration_style(const char *var, const char *value)
53 {
54         switch (git_config_maybe_bool(var, value)) {
55         case 1:
56                 return DECORATE_SHORT_REFS;
57         case 0:
58                 return 0;
59         default:
60                 break;
61         }
62         if (!strcmp(value, "full"))
63                 return DECORATE_FULL_REFS;
64         else if (!strcmp(value, "short"))
65                 return DECORATE_SHORT_REFS;
66         return -1;
67 }
68
69 static int decorate_callback(const struct option *opt, const char *arg, int unset)
70 {
71         if (unset)
72                 decoration_style = 0;
73         else if (arg)
74                 decoration_style = parse_decoration_style("command line", arg);
75         else
76                 decoration_style = DECORATE_SHORT_REFS;
77
78         if (decoration_style < 0)
79                 die("invalid --decorate option: %s", arg);
80
81         decoration_given = 1;
82
83         return 0;
84 }
85
86 static int log_line_range_callback(const struct option *option, const char *arg, int unset)
87 {
88         struct line_opt_callback_data *data = option->value;
89
90         if (!arg)
91                 return -1;
92
93         data->rev->line_level_traverse = 1;
94         string_list_append(&data->args, arg);
95
96         return 0;
97 }
98
99 static void cmd_log_init_defaults(struct rev_info *rev)
100 {
101         if (fmt_pretty)
102                 get_commit_format(fmt_pretty, rev);
103         rev->verbose_header = 1;
104         DIFF_OPT_SET(&rev->diffopt, RECURSIVE);
105         rev->diffopt.stat_width = -1; /* use full terminal width */
106         rev->diffopt.stat_graph_width = -1; /* respect statGraphWidth config */
107         rev->abbrev_commit = default_abbrev_commit;
108         rev->show_root_diff = default_show_root;
109         rev->subject_prefix = fmt_patch_subject_prefix;
110         DIFF_OPT_SET(&rev->diffopt, ALLOW_TEXTCONV);
111
112         if (default_date_mode)
113                 rev->date_mode = parse_date_format(default_date_mode);
114         rev->diffopt.touched_flags = 0;
115 }
116
117 static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
118                          struct rev_info *rev, struct setup_revision_opt *opt)
119 {
120         struct userformat_want w;
121         int quiet = 0, source = 0, mailmap = 0;
122         static struct line_opt_callback_data line_cb = {NULL, NULL, STRING_LIST_INIT_DUP};
123
124         const struct option builtin_log_options[] = {
125                 OPT__QUIET(&quiet, N_("suppress diff output")),
126                 OPT_BOOL(0, "source", &source, N_("show source")),
127                 OPT_BOOL(0, "use-mailmap", &mailmap, N_("Use mail map file")),
128                 { OPTION_CALLBACK, 0, "decorate", NULL, NULL, N_("decorate options"),
129                   PARSE_OPT_OPTARG, decorate_callback},
130                 OPT_CALLBACK('L', NULL, &line_cb, "n,m:file",
131                              "Process line range n,m in file, counting from 1",
132                              log_line_range_callback),
133                 OPT_END()
134         };
135
136         line_cb.rev = rev;
137         line_cb.prefix = prefix;
138
139         mailmap = use_mailmap_config;
140         argc = parse_options(argc, argv, prefix,
141                              builtin_log_options, builtin_log_usage,
142                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
143                              PARSE_OPT_KEEP_DASHDASH);
144
145         if (quiet)
146                 rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
147         argc = setup_revisions(argc, argv, rev, opt);
148
149         /* Any arguments at this point are not recognized */
150         if (argc > 1)
151                 die("unrecognized argument: %s", argv[1]);
152
153         memset(&w, 0, sizeof(w));
154         userformat_find_requirements(NULL, &w);
155
156         if (!rev->show_notes_given && (!rev->pretty_given || w.notes))
157                 rev->show_notes = 1;
158         if (rev->show_notes)
159                 init_display_notes(&rev->notes_opt);
160
161         if (rev->diffopt.pickaxe || rev->diffopt.filter)
162                 rev->always_show_header = 0;
163         if (DIFF_OPT_TST(&rev->diffopt, FOLLOW_RENAMES)) {
164                 rev->always_show_header = 0;
165                 if (rev->diffopt.pathspec.nr != 1)
166                         usage("git logs can only follow renames on one pathname at a time");
167         }
168
169         if (source)
170                 rev->show_source = 1;
171
172         if (mailmap) {
173                 rev->mailmap = xcalloc(1, sizeof(struct string_list));
174                 read_mailmap(rev->mailmap, NULL);
175         }
176
177         if (rev->pretty_given && rev->commit_format == CMIT_FMT_RAW) {
178                 /*
179                  * "log --pretty=raw" is special; ignore UI oriented
180                  * configuration variables such as decoration.
181                  */
182                 if (!decoration_given)
183                         decoration_style = 0;
184                 if (!rev->abbrev_commit_given)
185                         rev->abbrev_commit = 0;
186         }
187
188         if (decoration_style) {
189                 rev->show_decorations = 1;
190                 load_ref_decorations(decoration_style);
191         }
192
193         if (rev->line_level_traverse)
194                 line_log_init(rev, line_cb.prefix, &line_cb.args);
195
196         setup_pager();
197 }
198
199 static void cmd_log_init(int argc, const char **argv, const char *prefix,
200                          struct rev_info *rev, struct setup_revision_opt *opt)
201 {
202         cmd_log_init_defaults(rev);
203         cmd_log_init_finish(argc, argv, prefix, rev, opt);
204 }
205
206 /*
207  * This gives a rough estimate for how many commits we
208  * will print out in the list.
209  */
210 static int estimate_commit_count(struct rev_info *rev, struct commit_list *list)
211 {
212         int n = 0;
213
214         while (list) {
215                 struct commit *commit = list->item;
216                 unsigned int flags = commit->object.flags;
217                 list = list->next;
218                 if (!(flags & (TREESAME | UNINTERESTING)))
219                         n++;
220         }
221         return n;
222 }
223
224 static void show_early_header(struct rev_info *rev, const char *stage, int nr)
225 {
226         if (rev->shown_one) {
227                 rev->shown_one = 0;
228                 if (rev->commit_format != CMIT_FMT_ONELINE)
229                         putchar(rev->diffopt.line_termination);
230         }
231         printf(_("Final output: %d %s\n"), nr, stage);
232 }
233
234 static struct itimerval early_output_timer;
235
236 static void log_show_early(struct rev_info *revs, struct commit_list *list)
237 {
238         int i = revs->early_output;
239         int show_header = 1;
240
241         sort_in_topological_order(&list, revs->sort_order);
242         while (list && i) {
243                 struct commit *commit = list->item;
244                 switch (simplify_commit(revs, commit)) {
245                 case commit_show:
246                         if (show_header) {
247                                 int n = estimate_commit_count(revs, list);
248                                 show_early_header(revs, "incomplete", n);
249                                 show_header = 0;
250                         }
251                         log_tree_commit(revs, commit);
252                         i--;
253                         break;
254                 case commit_ignore:
255                         break;
256                 case commit_error:
257                         return;
258                 }
259                 list = list->next;
260         }
261
262         /* Did we already get enough commits for the early output? */
263         if (!i)
264                 return;
265
266         /*
267          * ..if no, then repeat it twice a second until we
268          * do.
269          *
270          * NOTE! We don't use "it_interval", because if the
271          * reader isn't listening, we want our output to be
272          * throttled by the writing, and not have the timer
273          * trigger every second even if we're blocked on a
274          * reader!
275          */
276         early_output_timer.it_value.tv_sec = 0;
277         early_output_timer.it_value.tv_usec = 500000;
278         setitimer(ITIMER_REAL, &early_output_timer, NULL);
279 }
280
281 static void early_output(int signal)
282 {
283         show_early_output = log_show_early;
284 }
285
286 static void setup_early_output(struct rev_info *rev)
287 {
288         struct sigaction sa;
289
290         /*
291          * Set up the signal handler, minimally intrusively:
292          * we only set a single volatile integer word (not
293          * using sigatomic_t - trying to avoid unnecessary
294          * system dependencies and headers), and using
295          * SA_RESTART.
296          */
297         memset(&sa, 0, sizeof(sa));
298         sa.sa_handler = early_output;
299         sigemptyset(&sa.sa_mask);
300         sa.sa_flags = SA_RESTART;
301         sigaction(SIGALRM, &sa, NULL);
302
303         /*
304          * If we can get the whole output in less than a
305          * tenth of a second, don't even bother doing the
306          * early-output thing..
307          *
308          * This is a one-time-only trigger.
309          */
310         early_output_timer.it_value.tv_sec = 0;
311         early_output_timer.it_value.tv_usec = 100000;
312         setitimer(ITIMER_REAL, &early_output_timer, NULL);
313 }
314
315 static void finish_early_output(struct rev_info *rev)
316 {
317         int n = estimate_commit_count(rev, rev->commits);
318         signal(SIGALRM, SIG_IGN);
319         show_early_header(rev, "done", n);
320 }
321
322 static int cmd_log_walk(struct rev_info *rev)
323 {
324         struct commit *commit;
325         int saved_nrl = 0;
326         int saved_dcctc = 0;
327
328         if (rev->early_output)
329                 setup_early_output(rev);
330
331         if (prepare_revision_walk(rev))
332                 die(_("revision walk setup failed"));
333
334         if (rev->early_output)
335                 finish_early_output(rev);
336
337         /*
338          * For --check and --exit-code, the exit code is based on CHECK_FAILED
339          * and HAS_CHANGES being accumulated in rev->diffopt, so be careful to
340          * retain that state information if replacing rev->diffopt in this loop
341          */
342         while ((commit = get_revision(rev)) != NULL) {
343                 if (!log_tree_commit(rev, commit) &&
344                     rev->max_count >= 0)
345                         /*
346                          * We decremented max_count in get_revision,
347                          * but we didn't actually show the commit.
348                          */
349                         rev->max_count++;
350                 if (!rev->reflog_info) {
351                         /* we allow cycles in reflog ancestry */
352                         free(commit->buffer);
353                         commit->buffer = NULL;
354                 }
355                 free_commit_list(commit->parents);
356                 commit->parents = NULL;
357                 if (saved_nrl < rev->diffopt.needed_rename_limit)
358                         saved_nrl = rev->diffopt.needed_rename_limit;
359                 if (rev->diffopt.degraded_cc_to_c)
360                         saved_dcctc = 1;
361         }
362         rev->diffopt.degraded_cc_to_c = saved_dcctc;
363         rev->diffopt.needed_rename_limit = saved_nrl;
364
365         if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF &&
366             DIFF_OPT_TST(&rev->diffopt, CHECK_FAILED)) {
367                 return 02;
368         }
369         return diff_result_code(&rev->diffopt, 0);
370 }
371
372 static int git_log_config(const char *var, const char *value, void *cb)
373 {
374         if (!strcmp(var, "format.pretty"))
375                 return git_config_string(&fmt_pretty, var, value);
376         if (!strcmp(var, "format.subjectprefix"))
377                 return git_config_string(&fmt_patch_subject_prefix, var, value);
378         if (!strcmp(var, "log.abbrevcommit")) {
379                 default_abbrev_commit = git_config_bool(var, value);
380                 return 0;
381         }
382         if (!strcmp(var, "log.date"))
383                 return git_config_string(&default_date_mode, var, value);
384         if (!strcmp(var, "log.decorate")) {
385                 decoration_style = parse_decoration_style(var, value);
386                 if (decoration_style < 0)
387                         decoration_style = 0; /* maybe warn? */
388                 return 0;
389         }
390         if (!strcmp(var, "log.showroot")) {
391                 default_show_root = git_config_bool(var, value);
392                 return 0;
393         }
394         if (starts_with(var, "color.decorate."))
395                 return parse_decorate_color_config(var, 15, value);
396         if (!strcmp(var, "log.mailmap")) {
397                 use_mailmap_config = git_config_bool(var, value);
398                 return 0;
399         }
400
401         if (grep_config(var, value, cb) < 0)
402                 return -1;
403         if (git_gpg_config(var, value, cb) < 0)
404                 return -1;
405         return git_diff_ui_config(var, value, cb);
406 }
407
408 int cmd_whatchanged(int argc, const char **argv, const char *prefix)
409 {
410         struct rev_info rev;
411         struct setup_revision_opt opt;
412
413         init_grep_defaults();
414         git_config(git_log_config, NULL);
415
416         init_revisions(&rev, prefix);
417         rev.diff = 1;
418         rev.simplify_history = 0;
419         memset(&opt, 0, sizeof(opt));
420         opt.def = "HEAD";
421         opt.revarg_opt = REVARG_COMMITTISH;
422         cmd_log_init(argc, argv, prefix, &rev, &opt);
423         if (!rev.diffopt.output_format)
424                 rev.diffopt.output_format = DIFF_FORMAT_RAW;
425         return cmd_log_walk(&rev);
426 }
427
428 static void show_tagger(char *buf, int len, struct rev_info *rev)
429 {
430         struct strbuf out = STRBUF_INIT;
431         struct pretty_print_context pp = {0};
432
433         pp.fmt = rev->commit_format;
434         pp.date_mode = rev->date_mode;
435         pp_user_info(&pp, "Tagger", &out, buf, get_log_output_encoding());
436         printf("%s", out.buf);
437         strbuf_release(&out);
438 }
439
440 static int show_blob_object(const unsigned char *sha1, struct rev_info *rev, const char *obj_name)
441 {
442         unsigned char sha1c[20];
443         struct object_context obj_context;
444         char *buf;
445         unsigned long size;
446
447         fflush(stdout);
448         if (!DIFF_OPT_TOUCHED(&rev->diffopt, ALLOW_TEXTCONV) ||
449             !DIFF_OPT_TST(&rev->diffopt, ALLOW_TEXTCONV))
450                 return stream_blob_to_fd(1, sha1, NULL, 0);
451
452         if (get_sha1_with_context(obj_name, 0, sha1c, &obj_context))
453                 die("Not a valid object name %s", obj_name);
454         if (!obj_context.path[0] ||
455             !textconv_object(obj_context.path, obj_context.mode, sha1c, 1, &buf, &size))
456                 return stream_blob_to_fd(1, sha1, NULL, 0);
457
458         if (!buf)
459                 die("git show %s: bad file", obj_name);
460
461         write_or_die(1, buf, size);
462         return 0;
463 }
464
465 static int show_tag_object(const unsigned char *sha1, struct rev_info *rev)
466 {
467         unsigned long size;
468         enum object_type type;
469         char *buf = read_sha1_file(sha1, &type, &size);
470         int offset = 0;
471
472         if (!buf)
473                 return error(_("Could not read object %s"), sha1_to_hex(sha1));
474
475         assert(type == OBJ_TAG);
476         while (offset < size && buf[offset] != '\n') {
477                 int new_offset = offset + 1;
478                 while (new_offset < size && buf[new_offset++] != '\n')
479                         ; /* do nothing */
480                 if (starts_with(buf + offset, "tagger "))
481                         show_tagger(buf + offset + 7,
482                                     new_offset - offset - 7, rev);
483                 offset = new_offset;
484         }
485
486         if (offset < size)
487                 fwrite(buf + offset, size - offset, 1, stdout);
488         free(buf);
489         return 0;
490 }
491
492 static int show_tree_object(const unsigned char *sha1,
493                 const char *base, int baselen,
494                 const char *pathname, unsigned mode, int stage, void *context)
495 {
496         printf("%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
497         return 0;
498 }
499
500 static void show_rev_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
501 {
502         if (rev->ignore_merges) {
503                 /* There was no "-m" on the command line */
504                 rev->ignore_merges = 0;
505                 if (!rev->first_parent_only && !rev->combine_merges) {
506                         /* No "--first-parent", "-c", or "--cc" */
507                         rev->combine_merges = 1;
508                         rev->dense_combined_merges = 1;
509                 }
510         }
511         if (!rev->diffopt.output_format)
512                 rev->diffopt.output_format = DIFF_FORMAT_PATCH;
513 }
514
515 int cmd_show(int argc, const char **argv, const char *prefix)
516 {
517         struct rev_info rev;
518         struct object_array_entry *objects;
519         struct setup_revision_opt opt;
520         struct pathspec match_all;
521         int i, count, ret = 0;
522
523         init_grep_defaults();
524         git_config(git_log_config, NULL);
525
526         memset(&match_all, 0, sizeof(match_all));
527         init_revisions(&rev, prefix);
528         rev.diff = 1;
529         rev.always_show_header = 1;
530         rev.no_walk = REVISION_WALK_NO_WALK_SORTED;
531         rev.diffopt.stat_width = -1;    /* Scale to real terminal size */
532
533         memset(&opt, 0, sizeof(opt));
534         opt.def = "HEAD";
535         opt.tweak = show_rev_tweak_rev;
536         cmd_log_init(argc, argv, prefix, &rev, &opt);
537
538         if (!rev.no_walk)
539                 return cmd_log_walk(&rev);
540
541         count = rev.pending.nr;
542         objects = rev.pending.objects;
543         for (i = 0; i < count && !ret; i++) {
544                 struct object *o = objects[i].item;
545                 const char *name = objects[i].name;
546                 switch (o->type) {
547                 case OBJ_BLOB:
548                         ret = show_blob_object(o->sha1, &rev, name);
549                         break;
550                 case OBJ_TAG: {
551                         struct tag *t = (struct tag *)o;
552
553                         if (rev.shown_one)
554                                 putchar('\n');
555                         printf("%stag %s%s\n",
556                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
557                                         t->tag,
558                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
559                         ret = show_tag_object(o->sha1, &rev);
560                         rev.shown_one = 1;
561                         if (ret)
562                                 break;
563                         o = parse_object(t->tagged->sha1);
564                         if (!o)
565                                 ret = error(_("Could not read object %s"),
566                                             sha1_to_hex(t->tagged->sha1));
567                         objects[i].item = o;
568                         i--;
569                         break;
570                 }
571                 case OBJ_TREE:
572                         if (rev.shown_one)
573                                 putchar('\n');
574                         printf("%stree %s%s\n\n",
575                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
576                                         name,
577                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
578                         read_tree_recursive((struct tree *)o, "", 0, 0, &match_all,
579                                         show_tree_object, NULL);
580                         rev.shown_one = 1;
581                         break;
582                 case OBJ_COMMIT:
583                         rev.pending.nr = rev.pending.alloc = 0;
584                         rev.pending.objects = NULL;
585                         add_object_array(o, name, &rev.pending);
586                         ret = cmd_log_walk(&rev);
587                         break;
588                 default:
589                         ret = error(_("Unknown type: %d"), o->type);
590                 }
591         }
592         free(objects);
593         return ret;
594 }
595
596 /*
597  * This is equivalent to "git log -g --abbrev-commit --pretty=oneline"
598  */
599 int cmd_log_reflog(int argc, const char **argv, const char *prefix)
600 {
601         struct rev_info rev;
602         struct setup_revision_opt opt;
603
604         init_grep_defaults();
605         git_config(git_log_config, NULL);
606
607         init_revisions(&rev, prefix);
608         init_reflog_walk(&rev.reflog_info);
609         rev.verbose_header = 1;
610         memset(&opt, 0, sizeof(opt));
611         opt.def = "HEAD";
612         cmd_log_init_defaults(&rev);
613         rev.abbrev_commit = 1;
614         rev.commit_format = CMIT_FMT_ONELINE;
615         rev.use_terminator = 1;
616         rev.always_show_header = 1;
617         cmd_log_init_finish(argc, argv, prefix, &rev, &opt);
618
619         return cmd_log_walk(&rev);
620 }
621
622 int cmd_log(int argc, const char **argv, const char *prefix)
623 {
624         struct rev_info rev;
625         struct setup_revision_opt opt;
626
627         init_grep_defaults();
628         git_config(git_log_config, NULL);
629
630         init_revisions(&rev, prefix);
631         rev.always_show_header = 1;
632         memset(&opt, 0, sizeof(opt));
633         opt.def = "HEAD";
634         opt.revarg_opt = REVARG_COMMITTISH;
635         cmd_log_init(argc, argv, prefix, &rev, &opt);
636         return cmd_log_walk(&rev);
637 }
638
639 /* format-patch */
640
641 static const char *fmt_patch_suffix = ".patch";
642 static int numbered = 0;
643 static int auto_number = 1;
644
645 static char *default_attach = NULL;
646
647 static struct string_list extra_hdr;
648 static struct string_list extra_to;
649 static struct string_list extra_cc;
650
651 static void add_header(const char *value)
652 {
653         struct string_list_item *item;
654         int len = strlen(value);
655         while (len && value[len - 1] == '\n')
656                 len--;
657
658         if (!strncasecmp(value, "to: ", 4)) {
659                 item = string_list_append(&extra_to, value + 4);
660                 len -= 4;
661         } else if (!strncasecmp(value, "cc: ", 4)) {
662                 item = string_list_append(&extra_cc, value + 4);
663                 len -= 4;
664         } else {
665                 item = string_list_append(&extra_hdr, value);
666         }
667
668         item->string[len] = '\0';
669 }
670
671 #define THREAD_SHALLOW 1
672 #define THREAD_DEEP 2
673 static int thread;
674 static int do_signoff;
675 static const char *signature = git_version_string;
676 static int config_cover_letter;
677
678 enum {
679         COVER_UNSET,
680         COVER_OFF,
681         COVER_ON,
682         COVER_AUTO
683 };
684
685 static int git_format_config(const char *var, const char *value, void *cb)
686 {
687         if (!strcmp(var, "format.headers")) {
688                 if (!value)
689                         die(_("format.headers without value"));
690                 add_header(value);
691                 return 0;
692         }
693         if (!strcmp(var, "format.suffix"))
694                 return git_config_string(&fmt_patch_suffix, var, value);
695         if (!strcmp(var, "format.to")) {
696                 if (!value)
697                         return config_error_nonbool(var);
698                 string_list_append(&extra_to, value);
699                 return 0;
700         }
701         if (!strcmp(var, "format.cc")) {
702                 if (!value)
703                         return config_error_nonbool(var);
704                 string_list_append(&extra_cc, value);
705                 return 0;
706         }
707         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff") ||
708             !strcmp(var, "color.ui")) {
709                 return 0;
710         }
711         if (!strcmp(var, "format.numbered")) {
712                 if (value && !strcasecmp(value, "auto")) {
713                         auto_number = 1;
714                         return 0;
715                 }
716                 numbered = git_config_bool(var, value);
717                 auto_number = auto_number && numbered;
718                 return 0;
719         }
720         if (!strcmp(var, "format.attach")) {
721                 if (value && *value)
722                         default_attach = xstrdup(value);
723                 else
724                         default_attach = xstrdup(git_version_string);
725                 return 0;
726         }
727         if (!strcmp(var, "format.thread")) {
728                 if (value && !strcasecmp(value, "deep")) {
729                         thread = THREAD_DEEP;
730                         return 0;
731                 }
732                 if (value && !strcasecmp(value, "shallow")) {
733                         thread = THREAD_SHALLOW;
734                         return 0;
735                 }
736                 thread = git_config_bool(var, value) && THREAD_SHALLOW;
737                 return 0;
738         }
739         if (!strcmp(var, "format.signoff")) {
740                 do_signoff = git_config_bool(var, value);
741                 return 0;
742         }
743         if (!strcmp(var, "format.signature"))
744                 return git_config_string(&signature, var, value);
745         if (!strcmp(var, "format.coverletter")) {
746                 if (value && !strcasecmp(value, "auto")) {
747                         config_cover_letter = COVER_AUTO;
748                         return 0;
749                 }
750                 config_cover_letter = git_config_bool(var, value) ? COVER_ON : COVER_OFF;
751                 return 0;
752         }
753
754         return git_log_config(var, value, cb);
755 }
756
757 static FILE *realstdout = NULL;
758 static const char *output_directory = NULL;
759 static int outdir_offset;
760
761 static int reopen_stdout(struct commit *commit, const char *subject,
762                          struct rev_info *rev, int quiet)
763 {
764         struct strbuf filename = STRBUF_INIT;
765         int suffix_len = strlen(rev->patch_suffix) + 1;
766
767         if (output_directory) {
768                 strbuf_addstr(&filename, output_directory);
769                 if (filename.len >=
770                     PATH_MAX - FORMAT_PATCH_NAME_MAX - suffix_len)
771                         return error(_("name of output directory is too long"));
772                 if (filename.buf[filename.len - 1] != '/')
773                         strbuf_addch(&filename, '/');
774         }
775
776         if (rev->numbered_files)
777                 strbuf_addf(&filename, "%d", rev->nr);
778         else if (commit)
779                 fmt_output_commit(&filename, commit, rev);
780         else
781                 fmt_output_subject(&filename, subject, rev);
782
783         if (!quiet)
784                 fprintf(realstdout, "%s\n", filename.buf + outdir_offset);
785
786         if (freopen(filename.buf, "w", stdout) == NULL)
787                 return error(_("Cannot open patch file %s"), filename.buf);
788
789         strbuf_release(&filename);
790         return 0;
791 }
792
793 static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids)
794 {
795         struct rev_info check_rev;
796         struct commit *commit;
797         struct object *o1, *o2;
798         unsigned flags1, flags2;
799
800         if (rev->pending.nr != 2)
801                 die(_("Need exactly one range."));
802
803         o1 = rev->pending.objects[0].item;
804         flags1 = o1->flags;
805         o2 = rev->pending.objects[1].item;
806         flags2 = o2->flags;
807
808         if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
809                 die(_("Not a range."));
810
811         init_patch_ids(ids);
812
813         /* given a range a..b get all patch ids for b..a */
814         init_revisions(&check_rev, rev->prefix);
815         check_rev.max_parents = 1;
816         o1->flags ^= UNINTERESTING;
817         o2->flags ^= UNINTERESTING;
818         add_pending_object(&check_rev, o1, "o1");
819         add_pending_object(&check_rev, o2, "o2");
820         if (prepare_revision_walk(&check_rev))
821                 die(_("revision walk setup failed"));
822
823         while ((commit = get_revision(&check_rev)) != NULL) {
824                 add_commit_patch_id(commit, ids);
825         }
826
827         /* reset for next revision walk */
828         clear_commit_marks((struct commit *)o1,
829                         SEEN | UNINTERESTING | SHOWN | ADDED);
830         clear_commit_marks((struct commit *)o2,
831                         SEEN | UNINTERESTING | SHOWN | ADDED);
832         o1->flags = flags1;
833         o2->flags = flags2;
834 }
835
836 static void gen_message_id(struct rev_info *info, char *base)
837 {
838         struct strbuf buf = STRBUF_INIT;
839         strbuf_addf(&buf, "%s.%lu.git.%s", base,
840                     (unsigned long) time(NULL),
841                     git_committer_info(IDENT_NO_NAME|IDENT_NO_DATE|IDENT_STRICT));
842         info->message_id = strbuf_detach(&buf, NULL);
843 }
844
845 static void print_signature(void)
846 {
847         if (signature && *signature)
848                 printf("-- \n%s\n\n", signature);
849 }
850
851 static void add_branch_description(struct strbuf *buf, const char *branch_name)
852 {
853         struct strbuf desc = STRBUF_INIT;
854         if (!branch_name || !*branch_name)
855                 return;
856         read_branch_desc(&desc, branch_name);
857         if (desc.len) {
858                 strbuf_addch(buf, '\n');
859                 strbuf_add(buf, desc.buf, desc.len);
860                 strbuf_addch(buf, '\n');
861         }
862 }
863
864 static char *find_branch_name(struct rev_info *rev)
865 {
866         int i, positive = -1;
867         unsigned char branch_sha1[20];
868         const unsigned char *tip_sha1;
869         const char *ref;
870         char *full_ref, *branch = NULL;
871
872         for (i = 0; i < rev->cmdline.nr; i++) {
873                 if (rev->cmdline.rev[i].flags & UNINTERESTING)
874                         continue;
875                 if (positive < 0)
876                         positive = i;
877                 else
878                         return NULL;
879         }
880         if (positive < 0)
881                 return NULL;
882         ref = rev->cmdline.rev[positive].name;
883         tip_sha1 = rev->cmdline.rev[positive].item->sha1;
884         if (dwim_ref(ref, strlen(ref), branch_sha1, &full_ref) &&
885             starts_with(full_ref, "refs/heads/") &&
886             !hashcmp(tip_sha1, branch_sha1))
887                 branch = xstrdup(full_ref + strlen("refs/heads/"));
888         free(full_ref);
889         return branch;
890 }
891
892 static void make_cover_letter(struct rev_info *rev, int use_stdout,
893                               struct commit *origin,
894                               int nr, struct commit **list,
895                               const char *branch_name,
896                               int quiet)
897 {
898         const char *committer;
899         const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
900         const char *msg;
901         struct shortlog log;
902         struct strbuf sb = STRBUF_INIT;
903         int i;
904         const char *encoding = "UTF-8";
905         struct diff_options opts;
906         int need_8bit_cte = 0;
907         struct pretty_print_context pp = {0};
908         struct commit *head = list[0];
909
910         if (rev->commit_format != CMIT_FMT_EMAIL)
911                 die(_("Cover letter needs email format"));
912
913         committer = git_committer_info(0);
914
915         if (!use_stdout &&
916             reopen_stdout(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
917                 return;
918
919         log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
920                                 &need_8bit_cte);
921
922         for (i = 0; !need_8bit_cte && i < nr; i++)
923                 if (has_non_ascii(list[i]->buffer))
924                         need_8bit_cte = 1;
925
926         if (!branch_name)
927                 branch_name = find_branch_name(rev);
928
929         msg = body;
930         pp.fmt = CMIT_FMT_EMAIL;
931         pp.date_mode = DATE_RFC2822;
932         pp_user_info(&pp, NULL, &sb, committer, encoding);
933         pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
934         pp_remainder(&pp, &msg, &sb, 0);
935         add_branch_description(&sb, branch_name);
936         printf("%s\n", sb.buf);
937
938         strbuf_release(&sb);
939
940         shortlog_init(&log);
941         log.wrap_lines = 1;
942         log.wrap = 72;
943         log.in1 = 2;
944         log.in2 = 4;
945         for (i = 0; i < nr; i++)
946                 shortlog_add_commit(&log, list[i]);
947
948         shortlog_output(&log);
949
950         /*
951          * We can only do diffstat with a unique reference point
952          */
953         if (!origin)
954                 return;
955
956         memcpy(&opts, &rev->diffopt, sizeof(opts));
957         opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
958
959         diff_setup_done(&opts);
960
961         diff_tree_sha1(origin->tree->object.sha1,
962                        head->tree->object.sha1,
963                        "", &opts);
964         diffcore_std(&opts);
965         diff_flush(&opts);
966
967         printf("\n");
968         print_signature();
969 }
970
971 static const char *clean_message_id(const char *msg_id)
972 {
973         char ch;
974         const char *a, *z, *m;
975
976         m = msg_id;
977         while ((ch = *m) && (isspace(ch) || (ch == '<')))
978                 m++;
979         a = m;
980         z = NULL;
981         while ((ch = *m)) {
982                 if (!isspace(ch) && (ch != '>'))
983                         z = m;
984                 m++;
985         }
986         if (!z)
987                 die(_("insane in-reply-to: %s"), msg_id);
988         if (++z == m)
989                 return a;
990         return xmemdupz(a, z - a);
991 }
992
993 static const char *set_outdir(const char *prefix, const char *output_directory)
994 {
995         if (output_directory && is_absolute_path(output_directory))
996                 return output_directory;
997
998         if (!prefix || !*prefix) {
999                 if (output_directory)
1000                         return output_directory;
1001                 /* The user did not explicitly ask for "./" */
1002                 outdir_offset = 2;
1003                 return "./";
1004         }
1005
1006         outdir_offset = strlen(prefix);
1007         if (!output_directory)
1008                 return prefix;
1009
1010         return xstrdup(prefix_filename(prefix, outdir_offset,
1011                                        output_directory));
1012 }
1013
1014 static const char * const builtin_format_patch_usage[] = {
1015         N_("git format-patch [options] [<since> | <revision range>]"),
1016         NULL
1017 };
1018
1019 static int keep_subject = 0;
1020
1021 static int keep_callback(const struct option *opt, const char *arg, int unset)
1022 {
1023         ((struct rev_info *)opt->value)->total = -1;
1024         keep_subject = 1;
1025         return 0;
1026 }
1027
1028 static int subject_prefix = 0;
1029
1030 static int subject_prefix_callback(const struct option *opt, const char *arg,
1031                             int unset)
1032 {
1033         subject_prefix = 1;
1034         ((struct rev_info *)opt->value)->subject_prefix = arg;
1035         return 0;
1036 }
1037
1038 static int numbered_cmdline_opt = 0;
1039
1040 static int numbered_callback(const struct option *opt, const char *arg,
1041                              int unset)
1042 {
1043         *(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
1044         if (unset)
1045                 auto_number =  0;
1046         return 0;
1047 }
1048
1049 static int no_numbered_callback(const struct option *opt, const char *arg,
1050                                 int unset)
1051 {
1052         return numbered_callback(opt, arg, 1);
1053 }
1054
1055 static int output_directory_callback(const struct option *opt, const char *arg,
1056                               int unset)
1057 {
1058         const char **dir = (const char **)opt->value;
1059         if (*dir)
1060                 die(_("Two output directories?"));
1061         *dir = arg;
1062         return 0;
1063 }
1064
1065 static int thread_callback(const struct option *opt, const char *arg, int unset)
1066 {
1067         int *thread = (int *)opt->value;
1068         if (unset)
1069                 *thread = 0;
1070         else if (!arg || !strcmp(arg, "shallow"))
1071                 *thread = THREAD_SHALLOW;
1072         else if (!strcmp(arg, "deep"))
1073                 *thread = THREAD_DEEP;
1074         else
1075                 return 1;
1076         return 0;
1077 }
1078
1079 static int attach_callback(const struct option *opt, const char *arg, int unset)
1080 {
1081         struct rev_info *rev = (struct rev_info *)opt->value;
1082         if (unset)
1083                 rev->mime_boundary = NULL;
1084         else if (arg)
1085                 rev->mime_boundary = arg;
1086         else
1087                 rev->mime_boundary = git_version_string;
1088         rev->no_inline = unset ? 0 : 1;
1089         return 0;
1090 }
1091
1092 static int inline_callback(const struct option *opt, const char *arg, int unset)
1093 {
1094         struct rev_info *rev = (struct rev_info *)opt->value;
1095         if (unset)
1096                 rev->mime_boundary = NULL;
1097         else if (arg)
1098                 rev->mime_boundary = arg;
1099         else
1100                 rev->mime_boundary = git_version_string;
1101         rev->no_inline = 0;
1102         return 0;
1103 }
1104
1105 static int header_callback(const struct option *opt, const char *arg, int unset)
1106 {
1107         if (unset) {
1108                 string_list_clear(&extra_hdr, 0);
1109                 string_list_clear(&extra_to, 0);
1110                 string_list_clear(&extra_cc, 0);
1111         } else {
1112             add_header(arg);
1113         }
1114         return 0;
1115 }
1116
1117 static int to_callback(const struct option *opt, const char *arg, int unset)
1118 {
1119         if (unset)
1120                 string_list_clear(&extra_to, 0);
1121         else
1122                 string_list_append(&extra_to, arg);
1123         return 0;
1124 }
1125
1126 static int cc_callback(const struct option *opt, const char *arg, int unset)
1127 {
1128         if (unset)
1129                 string_list_clear(&extra_cc, 0);
1130         else
1131                 string_list_append(&extra_cc, arg);
1132         return 0;
1133 }
1134
1135 static int from_callback(const struct option *opt, const char *arg, int unset)
1136 {
1137         char **from = opt->value;
1138
1139         free(*from);
1140
1141         if (unset)
1142                 *from = NULL;
1143         else if (arg)
1144                 *from = xstrdup(arg);
1145         else
1146                 *from = xstrdup(git_committer_info(IDENT_NO_DATE));
1147         return 0;
1148 }
1149
1150 int cmd_format_patch(int argc, const char **argv, const char *prefix)
1151 {
1152         struct commit *commit;
1153         struct commit **list = NULL;
1154         struct rev_info rev;
1155         struct setup_revision_opt s_r_opt;
1156         int nr = 0, total, i;
1157         int use_stdout = 0;
1158         int start_number = -1;
1159         int just_numbers = 0;
1160         int ignore_if_in_upstream = 0;
1161         int cover_letter = -1;
1162         int boundary_count = 0;
1163         int no_binary_diff = 0;
1164         struct commit *origin = NULL;
1165         const char *in_reply_to = NULL;
1166         struct patch_ids ids;
1167         struct strbuf buf = STRBUF_INIT;
1168         int use_patch_format = 0;
1169         int quiet = 0;
1170         int reroll_count = -1;
1171         char *branch_name = NULL;
1172         char *from = NULL;
1173         const struct option builtin_format_patch_options[] = {
1174                 { OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
1175                             N_("use [PATCH n/m] even with a single patch"),
1176                             PARSE_OPT_NOARG, numbered_callback },
1177                 { OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
1178                             N_("use [PATCH] even with multiple patches"),
1179                             PARSE_OPT_NOARG, no_numbered_callback },
1180                 OPT_BOOL('s', "signoff", &do_signoff, N_("add Signed-off-by:")),
1181                 OPT_BOOL(0, "stdout", &use_stdout,
1182                             N_("print patches to standard out")),
1183                 OPT_BOOL(0, "cover-letter", &cover_letter,
1184                             N_("generate a cover letter")),
1185                 OPT_BOOL(0, "numbered-files", &just_numbers,
1186                             N_("use simple number sequence for output file names")),
1187                 OPT_STRING(0, "suffix", &fmt_patch_suffix, N_("sfx"),
1188                             N_("use <sfx> instead of '.patch'")),
1189                 OPT_INTEGER(0, "start-number", &start_number,
1190                             N_("start numbering patches at <n> instead of 1")),
1191                 OPT_INTEGER('v', "reroll-count", &reroll_count,
1192                             N_("mark the series as Nth re-roll")),
1193                 { OPTION_CALLBACK, 0, "subject-prefix", &rev, N_("prefix"),
1194                             N_("Use [<prefix>] instead of [PATCH]"),
1195                             PARSE_OPT_NONEG, subject_prefix_callback },
1196                 { OPTION_CALLBACK, 'o', "output-directory", &output_directory,
1197                             N_("dir"), N_("store resulting files in <dir>"),
1198                             PARSE_OPT_NONEG, output_directory_callback },
1199                 { OPTION_CALLBACK, 'k', "keep-subject", &rev, NULL,
1200                             N_("don't strip/add [PATCH]"),
1201                             PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
1202                 OPT_BOOL(0, "no-binary", &no_binary_diff,
1203                          N_("don't output binary diffs")),
1204                 OPT_BOOL(0, "ignore-if-in-upstream", &ignore_if_in_upstream,
1205                          N_("don't include a patch matching a commit upstream")),
1206                 { OPTION_SET_INT, 'p', "no-stat", &use_patch_format, NULL,
1207                   N_("show patch format instead of default (patch + stat)"),
1208                   PARSE_OPT_NONEG | PARSE_OPT_NOARG, NULL, 1},
1209                 OPT_GROUP(N_("Messaging")),
1210                 { OPTION_CALLBACK, 0, "add-header", NULL, N_("header"),
1211                             N_("add email header"), 0, header_callback },
1212                 { OPTION_CALLBACK, 0, "to", NULL, N_("email"), N_("add To: header"),
1213                             0, to_callback },
1214                 { OPTION_CALLBACK, 0, "cc", NULL, N_("email"), N_("add Cc: header"),
1215                             0, cc_callback },
1216                 { OPTION_CALLBACK, 0, "from", &from, N_("ident"),
1217                             N_("set From address to <ident> (or committer ident if absent)"),
1218                             PARSE_OPT_OPTARG, from_callback },
1219                 OPT_STRING(0, "in-reply-to", &in_reply_to, N_("message-id"),
1220                             N_("make first mail a reply to <message-id>")),
1221                 { OPTION_CALLBACK, 0, "attach", &rev, N_("boundary"),
1222                             N_("attach the patch"), PARSE_OPT_OPTARG,
1223                             attach_callback },
1224                 { OPTION_CALLBACK, 0, "inline", &rev, N_("boundary"),
1225                             N_("inline the patch"),
1226                             PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
1227                             inline_callback },
1228                 { OPTION_CALLBACK, 0, "thread", &thread, N_("style"),
1229                             N_("enable message threading, styles: shallow, deep"),
1230                             PARSE_OPT_OPTARG, thread_callback },
1231                 OPT_STRING(0, "signature", &signature, N_("signature"),
1232                             N_("add a signature")),
1233                 OPT__QUIET(&quiet, N_("don't print the patch filenames")),
1234                 OPT_END()
1235         };
1236
1237         extra_hdr.strdup_strings = 1;
1238         extra_to.strdup_strings = 1;
1239         extra_cc.strdup_strings = 1;
1240         init_grep_defaults();
1241         git_config(git_format_config, NULL);
1242         init_revisions(&rev, prefix);
1243         rev.commit_format = CMIT_FMT_EMAIL;
1244         rev.verbose_header = 1;
1245         rev.diff = 1;
1246         rev.max_parents = 1;
1247         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
1248         rev.subject_prefix = fmt_patch_subject_prefix;
1249         memset(&s_r_opt, 0, sizeof(s_r_opt));
1250         s_r_opt.def = "HEAD";
1251         s_r_opt.revarg_opt = REVARG_COMMITTISH;
1252
1253         if (default_attach) {
1254                 rev.mime_boundary = default_attach;
1255                 rev.no_inline = 1;
1256         }
1257
1258         /*
1259          * Parse the arguments before setup_revisions(), or something
1260          * like "git format-patch -o a123 HEAD^.." may fail; a123 is
1261          * possibly a valid SHA1.
1262          */
1263         argc = parse_options(argc, argv, prefix, builtin_format_patch_options,
1264                              builtin_format_patch_usage,
1265                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
1266                              PARSE_OPT_KEEP_DASHDASH);
1267
1268         if (0 < reroll_count) {
1269                 struct strbuf sprefix = STRBUF_INIT;
1270                 strbuf_addf(&sprefix, "%s v%d",
1271                             rev.subject_prefix, reroll_count);
1272                 rev.reroll_count = reroll_count;
1273                 rev.subject_prefix = strbuf_detach(&sprefix, NULL);
1274         }
1275
1276         for (i = 0; i < extra_hdr.nr; i++) {
1277                 strbuf_addstr(&buf, extra_hdr.items[i].string);
1278                 strbuf_addch(&buf, '\n');
1279         }
1280
1281         if (extra_to.nr)
1282                 strbuf_addstr(&buf, "To: ");
1283         for (i = 0; i < extra_to.nr; i++) {
1284                 if (i)
1285                         strbuf_addstr(&buf, "    ");
1286                 strbuf_addstr(&buf, extra_to.items[i].string);
1287                 if (i + 1 < extra_to.nr)
1288                         strbuf_addch(&buf, ',');
1289                 strbuf_addch(&buf, '\n');
1290         }
1291
1292         if (extra_cc.nr)
1293                 strbuf_addstr(&buf, "Cc: ");
1294         for (i = 0; i < extra_cc.nr; i++) {
1295                 if (i)
1296                         strbuf_addstr(&buf, "    ");
1297                 strbuf_addstr(&buf, extra_cc.items[i].string);
1298                 if (i + 1 < extra_cc.nr)
1299                         strbuf_addch(&buf, ',');
1300                 strbuf_addch(&buf, '\n');
1301         }
1302
1303         rev.extra_headers = strbuf_detach(&buf, NULL);
1304
1305         if (from) {
1306                 if (split_ident_line(&rev.from_ident, from, strlen(from)))
1307                         die(_("invalid ident line: %s"), from);
1308         }
1309
1310         if (start_number < 0)
1311                 start_number = 1;
1312
1313         /*
1314          * If numbered is set solely due to format.numbered in config,
1315          * and it would conflict with --keep-subject (-k) from the
1316          * command line, reset "numbered".
1317          */
1318         if (numbered && keep_subject && !numbered_cmdline_opt)
1319                 numbered = 0;
1320
1321         if (numbered && keep_subject)
1322                 die (_("-n and -k are mutually exclusive."));
1323         if (keep_subject && subject_prefix)
1324                 die (_("--subject-prefix and -k are mutually exclusive."));
1325         rev.preserve_subject = keep_subject;
1326
1327         argc = setup_revisions(argc, argv, &rev, &s_r_opt);
1328         if (argc > 1)
1329                 die (_("unrecognized argument: %s"), argv[1]);
1330
1331         if (rev.diffopt.output_format & DIFF_FORMAT_NAME)
1332                 die(_("--name-only does not make sense"));
1333         if (rev.diffopt.output_format & DIFF_FORMAT_NAME_STATUS)
1334                 die(_("--name-status does not make sense"));
1335         if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF)
1336                 die(_("--check does not make sense"));
1337
1338         if (!use_patch_format &&
1339                 (!rev.diffopt.output_format ||
1340                  rev.diffopt.output_format == DIFF_FORMAT_PATCH))
1341                 rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY;
1342
1343         /* Always generate a patch */
1344         rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
1345
1346         if (!DIFF_OPT_TST(&rev.diffopt, TEXT) && !no_binary_diff)
1347                 DIFF_OPT_SET(&rev.diffopt, BINARY);
1348
1349         if (rev.show_notes)
1350                 init_display_notes(&rev.notes_opt);
1351
1352         if (!use_stdout)
1353                 output_directory = set_outdir(prefix, output_directory);
1354         else
1355                 setup_pager();
1356
1357         if (output_directory) {
1358                 if (use_stdout)
1359                         die(_("standard output, or directory, which one?"));
1360                 if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
1361                         die_errno(_("Could not create directory '%s'"),
1362                                   output_directory);
1363         }
1364
1365         if (rev.pending.nr == 1) {
1366                 int check_head = 0;
1367
1368                 if (rev.max_count < 0 && !rev.show_root_diff) {
1369                         /*
1370                          * This is traditional behaviour of "git format-patch
1371                          * origin" that prepares what the origin side still
1372                          * does not have.
1373                          */
1374                         rev.pending.objects[0].item->flags |= UNINTERESTING;
1375                         add_head_to_pending(&rev);
1376                         check_head = 1;
1377                 }
1378                 /*
1379                  * Otherwise, it is "format-patch -22 HEAD", and/or
1380                  * "format-patch --root HEAD".  The user wants
1381                  * get_revision() to do the usual traversal.
1382                  */
1383
1384                 if (!strcmp(rev.pending.objects[0].name, "HEAD"))
1385                         check_head = 1;
1386
1387                 if (check_head) {
1388                         unsigned char sha1[20];
1389                         const char *ref;
1390                         ref = resolve_ref_unsafe("HEAD", sha1, 1, NULL);
1391                         if (ref && starts_with(ref, "refs/heads/"))
1392                                 branch_name = xstrdup(ref + strlen("refs/heads/"));
1393                         else
1394                                 branch_name = xstrdup(""); /* no branch */
1395                 }
1396         }
1397
1398         /*
1399          * We cannot move this anywhere earlier because we do want to
1400          * know if --root was given explicitly from the command line.
1401          */
1402         rev.show_root_diff = 1;
1403
1404         if (ignore_if_in_upstream) {
1405                 /* Don't say anything if head and upstream are the same. */
1406                 if (rev.pending.nr == 2) {
1407                         struct object_array_entry *o = rev.pending.objects;
1408                         if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1409                                 return 0;
1410                 }
1411                 get_patch_ids(&rev, &ids);
1412         }
1413
1414         if (!use_stdout)
1415                 realstdout = xfdopen(xdup(1), "w");
1416
1417         if (prepare_revision_walk(&rev))
1418                 die(_("revision walk setup failed"));
1419         rev.boundary = 1;
1420         while ((commit = get_revision(&rev)) != NULL) {
1421                 if (commit->object.flags & BOUNDARY) {
1422                         boundary_count++;
1423                         origin = (boundary_count == 1) ? commit : NULL;
1424                         continue;
1425                 }
1426
1427                 if (ignore_if_in_upstream &&
1428                                 has_commit_patch_id(commit, &ids))
1429                         continue;
1430
1431                 nr++;
1432                 list = xrealloc(list, nr * sizeof(list[0]));
1433                 list[nr - 1] = commit;
1434         }
1435         if (nr == 0)
1436                 /* nothing to do */
1437                 return 0;
1438         total = nr;
1439         if (!keep_subject && auto_number && total > 1)
1440                 numbered = 1;
1441         if (numbered)
1442                 rev.total = total + start_number - 1;
1443         if (cover_letter == -1) {
1444                 if (config_cover_letter == COVER_AUTO)
1445                         cover_letter = (total > 1);
1446                 else
1447                         cover_letter = (config_cover_letter == COVER_ON);
1448         }
1449
1450         if (in_reply_to || thread || cover_letter)
1451                 rev.ref_message_ids = xcalloc(1, sizeof(struct string_list));
1452         if (in_reply_to) {
1453                 const char *msgid = clean_message_id(in_reply_to);
1454                 string_list_append(rev.ref_message_ids, msgid);
1455         }
1456         rev.numbered_files = just_numbers;
1457         rev.patch_suffix = fmt_patch_suffix;
1458         if (cover_letter) {
1459                 if (thread)
1460                         gen_message_id(&rev, "cover");
1461                 make_cover_letter(&rev, use_stdout,
1462                                   origin, nr, list, branch_name, quiet);
1463                 total++;
1464                 start_number--;
1465         }
1466         rev.add_signoff = do_signoff;
1467         while (0 <= --nr) {
1468                 int shown;
1469                 commit = list[nr];
1470                 rev.nr = total - nr + (start_number - 1);
1471                 /* Make the second and subsequent mails replies to the first */
1472                 if (thread) {
1473                         /* Have we already had a message ID? */
1474                         if (rev.message_id) {
1475                                 /*
1476                                  * For deep threading: make every mail
1477                                  * a reply to the previous one, no
1478                                  * matter what other options are set.
1479                                  *
1480                                  * For shallow threading:
1481                                  *
1482                                  * Without --cover-letter and
1483                                  * --in-reply-to, make every mail a
1484                                  * reply to the one before.
1485                                  *
1486                                  * With --in-reply-to but no
1487                                  * --cover-letter, make every mail a
1488                                  * reply to the <reply-to>.
1489                                  *
1490                                  * With --cover-letter, make every
1491                                  * mail but the cover letter a reply
1492                                  * to the cover letter.  The cover
1493                                  * letter is a reply to the
1494                                  * --in-reply-to, if specified.
1495                                  */
1496                                 if (thread == THREAD_SHALLOW
1497                                     && rev.ref_message_ids->nr > 0
1498                                     && (!cover_letter || rev.nr > 1))
1499                                         free(rev.message_id);
1500                                 else
1501                                         string_list_append(rev.ref_message_ids,
1502                                                            rev.message_id);
1503                         }
1504                         gen_message_id(&rev, sha1_to_hex(commit->object.sha1));
1505                 }
1506
1507                 if (!use_stdout &&
1508                     reopen_stdout(rev.numbered_files ? NULL : commit, NULL, &rev, quiet))
1509                         die(_("Failed to create output files"));
1510                 shown = log_tree_commit(&rev, commit);
1511                 free(commit->buffer);
1512                 commit->buffer = NULL;
1513
1514                 /* We put one extra blank line between formatted
1515                  * patches and this flag is used by log-tree code
1516                  * to see if it needs to emit a LF before showing
1517                  * the log; when using one file per patch, we do
1518                  * not want the extra blank line.
1519                  */
1520                 if (!use_stdout)
1521                         rev.shown_one = 0;
1522                 if (shown) {
1523                         if (rev.mime_boundary)
1524                                 printf("\n--%s%s--\n\n\n",
1525                                        mime_boundary_leader,
1526                                        rev.mime_boundary);
1527                         else
1528                                 print_signature();
1529                 }
1530                 if (!use_stdout)
1531                         fclose(stdout);
1532         }
1533         free(list);
1534         free(branch_name);
1535         string_list_clear(&extra_to, 0);
1536         string_list_clear(&extra_cc, 0);
1537         string_list_clear(&extra_hdr, 0);
1538         if (ignore_if_in_upstream)
1539                 free_patch_ids(&ids);
1540         return 0;
1541 }
1542
1543 static int add_pending_commit(const char *arg, struct rev_info *revs, int flags)
1544 {
1545         unsigned char sha1[20];
1546         if (get_sha1(arg, sha1) == 0) {
1547                 struct commit *commit = lookup_commit_reference(sha1);
1548                 if (commit) {
1549                         commit->object.flags |= flags;
1550                         add_pending_object(revs, &commit->object, arg);
1551                         return 0;
1552                 }
1553         }
1554         return -1;
1555 }
1556
1557 static const char * const cherry_usage[] = {
1558         N_("git cherry [-v] [<upstream> [<head> [<limit>]]]"),
1559         NULL
1560 };
1561
1562 static void print_commit(char sign, struct commit *commit, int verbose,
1563                          int abbrev)
1564 {
1565         if (!verbose) {
1566                 printf("%c %s\n", sign,
1567                        find_unique_abbrev(commit->object.sha1, abbrev));
1568         } else {
1569                 struct strbuf buf = STRBUF_INIT;
1570                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
1571                 printf("%c %s %s\n", sign,
1572                        find_unique_abbrev(commit->object.sha1, abbrev),
1573                        buf.buf);
1574                 strbuf_release(&buf);
1575         }
1576 }
1577
1578 int cmd_cherry(int argc, const char **argv, const char *prefix)
1579 {
1580         struct rev_info revs;
1581         struct patch_ids ids;
1582         struct commit *commit;
1583         struct commit_list *list = NULL;
1584         struct branch *current_branch;
1585         const char *upstream;
1586         const char *head = "HEAD";
1587         const char *limit = NULL;
1588         int verbose = 0, abbrev = 0;
1589
1590         struct option options[] = {
1591                 OPT__ABBREV(&abbrev),
1592                 OPT__VERBOSE(&verbose, N_("be verbose")),
1593                 OPT_END()
1594         };
1595
1596         argc = parse_options(argc, argv, prefix, options, cherry_usage, 0);
1597
1598         switch (argc) {
1599         case 3:
1600                 limit = argv[2];
1601                 /* FALLTHROUGH */
1602         case 2:
1603                 head = argv[1];
1604                 /* FALLTHROUGH */
1605         case 1:
1606                 upstream = argv[0];
1607                 break;
1608         default:
1609                 current_branch = branch_get(NULL);
1610                 if (!current_branch || !current_branch->merge
1611                                         || !current_branch->merge[0]
1612                                         || !current_branch->merge[0]->dst) {
1613                         fprintf(stderr, _("Could not find a tracked"
1614                                         " remote branch, please"
1615                                         " specify <upstream> manually.\n"));
1616                         usage_with_options(cherry_usage, options);
1617                 }
1618
1619                 upstream = current_branch->merge[0]->dst;
1620         }
1621
1622         init_revisions(&revs, prefix);
1623         revs.max_parents = 1;
1624
1625         if (add_pending_commit(head, &revs, 0))
1626                 die(_("Unknown commit %s"), head);
1627         if (add_pending_commit(upstream, &revs, UNINTERESTING))
1628                 die(_("Unknown commit %s"), upstream);
1629
1630         /* Don't say anything if head and upstream are the same. */
1631         if (revs.pending.nr == 2) {
1632                 struct object_array_entry *o = revs.pending.objects;
1633                 if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1634                         return 0;
1635         }
1636
1637         get_patch_ids(&revs, &ids);
1638
1639         if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
1640                 die(_("Unknown commit %s"), limit);
1641
1642         /* reverse the list of commits */
1643         if (prepare_revision_walk(&revs))
1644                 die(_("revision walk setup failed"));
1645         while ((commit = get_revision(&revs)) != NULL) {
1646                 commit_list_insert(commit, &list);
1647         }
1648
1649         while (list) {
1650                 char sign = '+';
1651
1652                 commit = list->item;
1653                 if (has_commit_patch_id(commit, &ids))
1654                         sign = '-';
1655                 print_commit(sign, commit, verbose, abbrev);
1656                 list = list->next;
1657         }
1658
1659         free_patch_ids(&ids);
1660         return 0;
1661 }