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