Merge branch 'sg/gpg-sig'
[git] / log-tree.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4 #include "tag.h"
5 #include "graph.h"
6 #include "log-tree.h"
7 #include "reflog-walk.h"
8 #include "refs.h"
9 #include "string-list.h"
10 #include "color.h"
11 #include "gpg-interface.h"
12 #include "sequencer.h"
13
14 struct decoration name_decoration = { "object names" };
15
16 enum decoration_type {
17         DECORATION_NONE = 0,
18         DECORATION_REF_LOCAL,
19         DECORATION_REF_REMOTE,
20         DECORATION_REF_TAG,
21         DECORATION_REF_STASH,
22         DECORATION_REF_HEAD,
23         DECORATION_GRAFTED,
24 };
25
26 static char decoration_colors[][COLOR_MAXLEN] = {
27         GIT_COLOR_RESET,
28         GIT_COLOR_BOLD_GREEN,   /* REF_LOCAL */
29         GIT_COLOR_BOLD_RED,     /* REF_REMOTE */
30         GIT_COLOR_BOLD_YELLOW,  /* REF_TAG */
31         GIT_COLOR_BOLD_MAGENTA, /* REF_STASH */
32         GIT_COLOR_BOLD_CYAN,    /* REF_HEAD */
33         GIT_COLOR_BOLD_BLUE,    /* GRAFTED */
34 };
35
36 static const char *decorate_get_color(int decorate_use_color, enum decoration_type ix)
37 {
38         if (want_color(decorate_use_color))
39                 return decoration_colors[ix];
40         return "";
41 }
42
43 static int parse_decorate_color_slot(const char *slot)
44 {
45         /*
46          * We're comparing with 'ignore-case' on
47          * (because config.c sets them all tolower),
48          * but let's match the letters in the literal
49          * string values here with how they are
50          * documented in Documentation/config.txt, for
51          * consistency.
52          *
53          * We love being consistent, don't we?
54          */
55         if (!strcasecmp(slot, "branch"))
56                 return DECORATION_REF_LOCAL;
57         if (!strcasecmp(slot, "remoteBranch"))
58                 return DECORATION_REF_REMOTE;
59         if (!strcasecmp(slot, "tag"))
60                 return DECORATION_REF_TAG;
61         if (!strcasecmp(slot, "stash"))
62                 return DECORATION_REF_STASH;
63         if (!strcasecmp(slot, "HEAD"))
64                 return DECORATION_REF_HEAD;
65         return -1;
66 }
67
68 int parse_decorate_color_config(const char *var, const int ofs, const char *value)
69 {
70         int slot = parse_decorate_color_slot(var + ofs);
71         if (slot < 0)
72                 return 0;
73         if (!value)
74                 return config_error_nonbool(var);
75         color_parse(value, var, decoration_colors[slot]);
76         return 0;
77 }
78
79 /*
80  * log-tree.c uses DIFF_OPT_TST for determining whether to use color
81  * for showing the commit sha1, use the same check for --decorate
82  */
83 #define decorate_get_color_opt(o, ix) \
84         decorate_get_color((o)->use_color, ix)
85
86 static void add_name_decoration(enum decoration_type type, const char *name, struct object *obj)
87 {
88         int nlen = strlen(name);
89         struct name_decoration *res = xmalloc(sizeof(struct name_decoration) + nlen);
90         memcpy(res->name, name, nlen + 1);
91         res->type = type;
92         res->next = add_decoration(&name_decoration, obj, res);
93 }
94
95 static int add_ref_decoration(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
96 {
97         struct object *obj;
98         enum decoration_type type = DECORATION_NONE;
99
100         if (!prefixcmp(refname, "refs/replace/")) {
101                 unsigned char original_sha1[20];
102                 if (!read_replace_refs)
103                         return 0;
104                 if (get_sha1_hex(refname + 13, original_sha1)) {
105                         warning("invalid replace ref %s", refname);
106                         return 0;
107                 }
108                 obj = parse_object(original_sha1);
109                 if (obj)
110                         add_name_decoration(DECORATION_GRAFTED, "replaced", obj);
111                 return 0;
112         }
113
114         obj = parse_object(sha1);
115         if (!obj)
116                 return 0;
117
118         if (!prefixcmp(refname, "refs/heads/"))
119                 type = DECORATION_REF_LOCAL;
120         else if (!prefixcmp(refname, "refs/remotes/"))
121                 type = DECORATION_REF_REMOTE;
122         else if (!prefixcmp(refname, "refs/tags/"))
123                 type = DECORATION_REF_TAG;
124         else if (!strcmp(refname, "refs/stash"))
125                 type = DECORATION_REF_STASH;
126         else if (!strcmp(refname, "HEAD"))
127                 type = DECORATION_REF_HEAD;
128
129         if (!cb_data || *(int *)cb_data == DECORATE_SHORT_REFS)
130                 refname = prettify_refname(refname);
131         add_name_decoration(type, refname, obj);
132         while (obj->type == OBJ_TAG) {
133                 obj = ((struct tag *)obj)->tagged;
134                 if (!obj)
135                         break;
136                 add_name_decoration(DECORATION_REF_TAG, refname, obj);
137         }
138         return 0;
139 }
140
141 static int add_graft_decoration(const struct commit_graft *graft, void *cb_data)
142 {
143         struct commit *commit = lookup_commit(graft->sha1);
144         if (!commit)
145                 return 0;
146         add_name_decoration(DECORATION_GRAFTED, "grafted", &commit->object);
147         return 0;
148 }
149
150 void load_ref_decorations(int flags)
151 {
152         static int loaded;
153         if (!loaded) {
154                 loaded = 1;
155                 for_each_ref(add_ref_decoration, &flags);
156                 head_ref(add_ref_decoration, &flags);
157                 for_each_commit_graft(add_graft_decoration, NULL);
158         }
159 }
160
161 static void show_parents(struct commit *commit, int abbrev)
162 {
163         struct commit_list *p;
164         for (p = commit->parents; p ; p = p->next) {
165                 struct commit *parent = p->item;
166                 printf(" %s", find_unique_abbrev(parent->object.sha1, abbrev));
167         }
168 }
169
170 static void show_children(struct rev_info *opt, struct commit *commit, int abbrev)
171 {
172         struct commit_list *p = lookup_decoration(&opt->children, &commit->object);
173         for ( ; p; p = p->next) {
174                 printf(" %s", find_unique_abbrev(p->item->object.sha1, abbrev));
175         }
176 }
177
178 void show_decorations(struct rev_info *opt, struct commit *commit)
179 {
180         const char *prefix;
181         struct name_decoration *decoration;
182         const char *color_commit =
183                 diff_get_color_opt(&opt->diffopt, DIFF_COMMIT);
184         const char *color_reset =
185                 decorate_get_color_opt(&opt->diffopt, DECORATION_NONE);
186
187         if (opt->show_source && commit->util)
188                 printf("\t%s", (char *) commit->util);
189         if (!opt->show_decorations)
190                 return;
191         decoration = lookup_decoration(&name_decoration, &commit->object);
192         if (!decoration)
193                 return;
194         prefix = " (";
195         while (decoration) {
196                 printf("%s", prefix);
197                 fputs(decorate_get_color_opt(&opt->diffopt, decoration->type),
198                       stdout);
199                 if (decoration->type == DECORATION_REF_TAG)
200                         fputs("tag: ", stdout);
201                 printf("%s", decoration->name);
202                 fputs(color_reset, stdout);
203                 fputs(color_commit, stdout);
204                 prefix = ", ";
205                 decoration = decoration->next;
206         }
207         putchar(')');
208 }
209
210 static unsigned int digits_in_number(unsigned int number)
211 {
212         unsigned int i = 10, result = 1;
213         while (i <= number) {
214                 i *= 10;
215                 result++;
216         }
217         return result;
218 }
219
220 void fmt_output_subject(struct strbuf *filename,
221                         const char *subject,
222                         struct rev_info *info)
223 {
224         const char *suffix = info->patch_suffix;
225         int nr = info->nr;
226         int start_len = filename->len;
227         int max_len = start_len + FORMAT_PATCH_NAME_MAX - (strlen(suffix) + 1);
228
229         if (0 < info->reroll_count)
230                 strbuf_addf(filename, "v%d-", info->reroll_count);
231         strbuf_addf(filename, "%04d-%s", nr, subject);
232
233         if (max_len < filename->len)
234                 strbuf_setlen(filename, max_len);
235         strbuf_addstr(filename, suffix);
236 }
237
238 void fmt_output_commit(struct strbuf *filename,
239                        struct commit *commit,
240                        struct rev_info *info)
241 {
242         struct pretty_print_context ctx = {0};
243         struct strbuf subject = STRBUF_INIT;
244
245         format_commit_message(commit, "%f", &subject, &ctx);
246         fmt_output_subject(filename, subject.buf, info);
247         strbuf_release(&subject);
248 }
249
250 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
251                              const char **subject_p,
252                              const char **extra_headers_p,
253                              int *need_8bit_cte_p)
254 {
255         const char *subject = NULL;
256         const char *extra_headers = opt->extra_headers;
257         const char *name = sha1_to_hex(commit->object.sha1);
258
259         *need_8bit_cte_p = 0; /* unknown */
260         if (opt->total > 0) {
261                 static char buffer[64];
262                 snprintf(buffer, sizeof(buffer),
263                          "Subject: [%s%s%0*d/%d] ",
264                          opt->subject_prefix,
265                          *opt->subject_prefix ? " " : "",
266                          digits_in_number(opt->total),
267                          opt->nr, opt->total);
268                 subject = buffer;
269         } else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
270                 static char buffer[256];
271                 snprintf(buffer, sizeof(buffer),
272                          "Subject: [%s] ",
273                          opt->subject_prefix);
274                 subject = buffer;
275         } else {
276                 subject = "Subject: ";
277         }
278
279         printf("From %s Mon Sep 17 00:00:00 2001\n", name);
280         graph_show_oneline(opt->graph);
281         if (opt->message_id) {
282                 printf("Message-Id: <%s>\n", opt->message_id);
283                 graph_show_oneline(opt->graph);
284         }
285         if (opt->ref_message_ids && opt->ref_message_ids->nr > 0) {
286                 int i, n;
287                 n = opt->ref_message_ids->nr;
288                 printf("In-Reply-To: <%s>\n", opt->ref_message_ids->items[n-1].string);
289                 for (i = 0; i < n; i++)
290                         printf("%s<%s>\n", (i > 0 ? "\t" : "References: "),
291                                opt->ref_message_ids->items[i].string);
292                 graph_show_oneline(opt->graph);
293         }
294         if (opt->mime_boundary) {
295                 static char subject_buffer[1024];
296                 static char buffer[1024];
297                 struct strbuf filename =  STRBUF_INIT;
298                 *need_8bit_cte_p = -1; /* NEVER */
299                 snprintf(subject_buffer, sizeof(subject_buffer) - 1,
300                          "%s"
301                          "MIME-Version: 1.0\n"
302                          "Content-Type: multipart/mixed;"
303                          " boundary=\"%s%s\"\n"
304                          "\n"
305                          "This is a multi-part message in MIME "
306                          "format.\n"
307                          "--%s%s\n"
308                          "Content-Type: text/plain; "
309                          "charset=UTF-8; format=fixed\n"
310                          "Content-Transfer-Encoding: 8bit\n\n",
311                          extra_headers ? extra_headers : "",
312                          mime_boundary_leader, opt->mime_boundary,
313                          mime_boundary_leader, opt->mime_boundary);
314                 extra_headers = subject_buffer;
315
316                 if (opt->numbered_files)
317                         strbuf_addf(&filename, "%d", opt->nr);
318                 else
319                         fmt_output_commit(&filename, commit, opt);
320                 snprintf(buffer, sizeof(buffer) - 1,
321                          "\n--%s%s\n"
322                          "Content-Type: text/x-patch;"
323                          " name=\"%s\"\n"
324                          "Content-Transfer-Encoding: 8bit\n"
325                          "Content-Disposition: %s;"
326                          " filename=\"%s\"\n\n",
327                          mime_boundary_leader, opt->mime_boundary,
328                          filename.buf,
329                          opt->no_inline ? "attachment" : "inline",
330                          filename.buf);
331                 opt->diffopt.stat_sep = buffer;
332                 strbuf_release(&filename);
333         }
334         *subject_p = subject;
335         *extra_headers_p = extra_headers;
336 }
337
338 static void show_sig_lines(struct rev_info *opt, int status, const char *bol)
339 {
340         const char *color, *reset, *eol;
341
342         color = diff_get_color_opt(&opt->diffopt,
343                                    status ? DIFF_WHITESPACE : DIFF_FRAGINFO);
344         reset = diff_get_color_opt(&opt->diffopt, DIFF_RESET);
345         while (*bol) {
346                 eol = strchrnul(bol, '\n');
347                 printf("%s%.*s%s%s", color, (int)(eol - bol), bol, reset,
348                        *eol ? "\n" : "");
349                 bol = (*eol) ? (eol + 1) : eol;
350         }
351 }
352
353 static void show_signature(struct rev_info *opt, struct commit *commit)
354 {
355         struct strbuf payload = STRBUF_INIT;
356         struct strbuf signature = STRBUF_INIT;
357         struct strbuf gpg_output = STRBUF_INIT;
358         int status;
359
360         if (parse_signed_commit(commit->object.sha1, &payload, &signature) <= 0)
361                 goto out;
362
363         status = verify_signed_buffer(payload.buf, payload.len,
364                                       signature.buf, signature.len,
365                                       &gpg_output, NULL);
366         if (status && !gpg_output.len)
367                 strbuf_addstr(&gpg_output, "No signature\n");
368
369         show_sig_lines(opt, status, gpg_output.buf);
370
371  out:
372         strbuf_release(&gpg_output);
373         strbuf_release(&payload);
374         strbuf_release(&signature);
375 }
376
377 static int which_parent(const unsigned char *sha1, const struct commit *commit)
378 {
379         int nth;
380         const struct commit_list *parent;
381
382         for (nth = 0, parent = commit->parents; parent; parent = parent->next) {
383                 if (!hashcmp(parent->item->object.sha1, sha1))
384                         return nth;
385                 nth++;
386         }
387         return -1;
388 }
389
390 static int is_common_merge(const struct commit *commit)
391 {
392         return (commit->parents
393                 && commit->parents->next
394                 && !commit->parents->next->next);
395 }
396
397 static void show_one_mergetag(struct rev_info *opt,
398                               struct commit_extra_header *extra,
399                               struct commit *commit)
400 {
401         unsigned char sha1[20];
402         struct tag *tag;
403         struct strbuf verify_message;
404         int status, nth;
405         size_t payload_size, gpg_message_offset;
406
407         hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), sha1);
408         tag = lookup_tag(sha1);
409         if (!tag)
410                 return; /* error message already given */
411
412         strbuf_init(&verify_message, 256);
413         if (parse_tag_buffer(tag, extra->value, extra->len))
414                 strbuf_addstr(&verify_message, "malformed mergetag\n");
415         else if (is_common_merge(commit) &&
416                  !hashcmp(tag->tagged->sha1,
417                           commit->parents->next->item->object.sha1))
418                 strbuf_addf(&verify_message,
419                             "merged tag '%s'\n", tag->tag);
420         else if ((nth = which_parent(tag->tagged->sha1, commit)) < 0)
421                 strbuf_addf(&verify_message, "tag %s names a non-parent %s\n",
422                                     tag->tag, tag->tagged->sha1);
423         else
424                 strbuf_addf(&verify_message,
425                             "parent #%d, tagged '%s'\n", nth + 1, tag->tag);
426         gpg_message_offset = verify_message.len;
427
428         payload_size = parse_signature(extra->value, extra->len);
429         status = -1;
430         if (extra->len > payload_size)
431                 if (verify_signed_buffer(extra->value, payload_size,
432                                          extra->value + payload_size,
433                                          extra->len - payload_size,
434                                          &verify_message, NULL)) {
435                         if (verify_message.len <= gpg_message_offset)
436                                 strbuf_addstr(&verify_message, "No signature\n");
437                         else
438                                 status = 0;
439                 }
440
441         show_sig_lines(opt, status, verify_message.buf);
442         strbuf_release(&verify_message);
443 }
444
445 static void show_mergetag(struct rev_info *opt, struct commit *commit)
446 {
447         struct commit_extra_header *extra, *to_free;
448
449         to_free = read_commit_extra_headers(commit, NULL);
450         for (extra = to_free; extra; extra = extra->next) {
451                 if (strcmp(extra->key, "mergetag"))
452                         continue; /* not a merge tag */
453                 show_one_mergetag(opt, extra, commit);
454         }
455         free_commit_extra_headers(to_free);
456 }
457
458 void show_log(struct rev_info *opt)
459 {
460         struct strbuf msgbuf = STRBUF_INIT;
461         struct log_info *log = opt->loginfo;
462         struct commit *commit = log->commit, *parent = log->parent;
463         int abbrev_commit = opt->abbrev_commit ? opt->abbrev : 40;
464         const char *extra_headers = opt->extra_headers;
465         struct pretty_print_context ctx = {0};
466
467         opt->loginfo = NULL;
468         if (!opt->verbose_header) {
469                 graph_show_commit(opt->graph);
470
471                 if (!opt->graph)
472                         put_revision_mark(opt, commit);
473                 fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
474                 if (opt->print_parents)
475                         show_parents(commit, abbrev_commit);
476                 if (opt->children.name)
477                         show_children(opt, commit, abbrev_commit);
478                 show_decorations(opt, commit);
479                 if (opt->graph && !graph_is_commit_finished(opt->graph)) {
480                         putchar('\n');
481                         graph_show_remainder(opt->graph);
482                 }
483                 putchar(opt->diffopt.line_termination);
484                 return;
485         }
486
487         /*
488          * If use_terminator is set, we already handled any record termination
489          * at the end of the last record.
490          * Otherwise, add a diffopt.line_termination character before all
491          * entries but the first.  (IOW, as a separator between entries)
492          */
493         if (opt->shown_one && !opt->use_terminator) {
494                 /*
495                  * If entries are separated by a newline, the output
496                  * should look human-readable.  If the last entry ended
497                  * with a newline, print the graph output before this
498                  * newline.  Otherwise it will end up as a completely blank
499                  * line and will look like a gap in the graph.
500                  *
501                  * If the entry separator is not a newline, the output is
502                  * primarily intended for programmatic consumption, and we
503                  * never want the extra graph output before the entry
504                  * separator.
505                  */
506                 if (opt->diffopt.line_termination == '\n' &&
507                     !opt->missing_newline)
508                         graph_show_padding(opt->graph);
509                 putchar(opt->diffopt.line_termination);
510         }
511         opt->shown_one = 1;
512
513         /*
514          * If the history graph was requested,
515          * print the graph, up to this commit's line
516          */
517         graph_show_commit(opt->graph);
518
519         /*
520          * Print header line of header..
521          */
522
523         if (opt->commit_format == CMIT_FMT_EMAIL) {
524                 log_write_email_headers(opt, commit, &ctx.subject, &extra_headers,
525                                         &ctx.need_8bit_cte);
526         } else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
527                 fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), stdout);
528                 if (opt->commit_format != CMIT_FMT_ONELINE)
529                         fputs("commit ", stdout);
530
531                 if (!opt->graph)
532                         put_revision_mark(opt, commit);
533                 fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit),
534                       stdout);
535                 if (opt->print_parents)
536                         show_parents(commit, abbrev_commit);
537                 if (opt->children.name)
538                         show_children(opt, commit, abbrev_commit);
539                 if (parent)
540                         printf(" (from %s)",
541                                find_unique_abbrev(parent->object.sha1,
542                                                   abbrev_commit));
543                 show_decorations(opt, commit);
544                 printf("%s", diff_get_color_opt(&opt->diffopt, DIFF_RESET));
545                 if (opt->commit_format == CMIT_FMT_ONELINE) {
546                         putchar(' ');
547                 } else {
548                         putchar('\n');
549                         graph_show_oneline(opt->graph);
550                 }
551                 if (opt->reflog_info) {
552                         /*
553                          * setup_revisions() ensures that opt->reflog_info
554                          * and opt->graph cannot both be set,
555                          * so we don't need to worry about printing the
556                          * graph info here.
557                          */
558                         show_reflog_message(opt->reflog_info,
559                                             opt->commit_format == CMIT_FMT_ONELINE,
560                                             opt->date_mode,
561                                             opt->date_mode_explicit);
562                         if (opt->commit_format == CMIT_FMT_ONELINE)
563                                 return;
564                 }
565         }
566
567         if (opt->show_signature) {
568                 show_signature(opt, commit);
569                 show_mergetag(opt, commit);
570         }
571
572         if (!commit->buffer)
573                 return;
574
575         if (opt->show_notes) {
576                 int raw;
577                 struct strbuf notebuf = STRBUF_INIT;
578
579                 raw = (opt->commit_format == CMIT_FMT_USERFORMAT);
580                 format_display_notes(commit->object.sha1, &notebuf,
581                                      get_log_output_encoding(), raw);
582                 ctx.notes_message = notebuf.len
583                         ? strbuf_detach(&notebuf, NULL)
584                         : xcalloc(1, 1);
585         }
586
587         /*
588          * And then the pretty-printed message itself
589          */
590         if (ctx.need_8bit_cte >= 0 && opt->add_signoff)
591                 ctx.need_8bit_cte =
592                         has_non_ascii(fmt_name(getenv("GIT_COMMITTER_NAME"),
593                                                getenv("GIT_COMMITTER_EMAIL")));
594         ctx.date_mode = opt->date_mode;
595         ctx.date_mode_explicit = opt->date_mode_explicit;
596         ctx.abbrev = opt->diffopt.abbrev;
597         ctx.after_subject = extra_headers;
598         ctx.preserve_subject = opt->preserve_subject;
599         ctx.reflog_info = opt->reflog_info;
600         ctx.fmt = opt->commit_format;
601         ctx.mailmap = opt->mailmap;
602         ctx.color = opt->diffopt.use_color;
603         pretty_print_commit(&ctx, commit, &msgbuf);
604
605         if (opt->add_signoff)
606                 append_signoff(&msgbuf, 0, APPEND_SIGNOFF_DEDUP);
607
608         if ((ctx.fmt != CMIT_FMT_USERFORMAT) &&
609             ctx.notes_message && *ctx.notes_message) {
610                 if (ctx.fmt == CMIT_FMT_EMAIL) {
611                         strbuf_addstr(&msgbuf, "---\n");
612                         opt->shown_dashes = 1;
613                 }
614                 strbuf_addstr(&msgbuf, ctx.notes_message);
615         }
616
617         if (opt->show_log_size) {
618                 printf("log size %i\n", (int)msgbuf.len);
619                 graph_show_oneline(opt->graph);
620         }
621
622         /*
623          * Set opt->missing_newline if msgbuf doesn't
624          * end in a newline (including if it is empty)
625          */
626         if (!msgbuf.len || msgbuf.buf[msgbuf.len - 1] != '\n')
627                 opt->missing_newline = 1;
628         else
629                 opt->missing_newline = 0;
630
631         if (opt->graph)
632                 graph_show_commit_msg(opt->graph, &msgbuf);
633         else
634                 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
635         if (opt->use_terminator) {
636                 if (!opt->missing_newline)
637                         graph_show_padding(opt->graph);
638                 putchar(opt->diffopt.line_termination);
639         }
640
641         strbuf_release(&msgbuf);
642         free(ctx.notes_message);
643 }
644
645 int log_tree_diff_flush(struct rev_info *opt)
646 {
647         opt->shown_dashes = 0;
648         diffcore_std(&opt->diffopt);
649
650         if (diff_queue_is_empty()) {
651                 int saved_fmt = opt->diffopt.output_format;
652                 opt->diffopt.output_format = DIFF_FORMAT_NO_OUTPUT;
653                 diff_flush(&opt->diffopt);
654                 opt->diffopt.output_format = saved_fmt;
655                 return 0;
656         }
657
658         if (opt->loginfo && !opt->no_commit_id) {
659                 show_log(opt);
660                 if ((opt->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT) &&
661                     opt->verbose_header &&
662                     opt->commit_format != CMIT_FMT_ONELINE) {
663                         /*
664                          * When showing a verbose header (i.e. log message),
665                          * and not in --pretty=oneline format, we would want
666                          * an extra newline between the end of log and the
667                          * diff/diffstat output for readability.
668                          */
669                         int pch = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_PATCH;
670                         if (opt->diffopt.output_prefix) {
671                                 struct strbuf *msg = NULL;
672                                 msg = opt->diffopt.output_prefix(&opt->diffopt,
673                                         opt->diffopt.output_prefix_data);
674                                 fwrite(msg->buf, msg->len, 1, stdout);
675                         }
676
677                         /*
678                          * We may have shown three-dashes line early
679                          * between notes and the log message, in which
680                          * case we only want a blank line after the
681                          * notes without (an extra) three-dashes line.
682                          * Otherwise, we show the three-dashes line if
683                          * we are showing the patch with diffstat, but
684                          * in that case, there is no extra blank line
685                          * after the three-dashes line.
686                          */
687                         if (!opt->shown_dashes &&
688                             (pch & opt->diffopt.output_format) == pch)
689                                 printf("---");
690                         putchar('\n');
691                 }
692         }
693         diff_flush(&opt->diffopt);
694         return 1;
695 }
696
697 static int do_diff_combined(struct rev_info *opt, struct commit *commit)
698 {
699         diff_tree_combined_merge(commit, opt->dense_combined_merges, opt);
700         return !opt->loginfo;
701 }
702
703 /*
704  * Show the diff of a commit.
705  *
706  * Return true if we printed any log info messages
707  */
708 static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log_info *log)
709 {
710         int showed_log;
711         struct commit_list *parents;
712         unsigned const char *sha1;
713
714         if (!opt->diff && !DIFF_OPT_TST(&opt->diffopt, EXIT_WITH_STATUS))
715                 return 0;
716
717         parse_commit(commit);
718         sha1 = commit->tree->object.sha1;
719
720         /* Root commit? */
721         parents = commit->parents;
722         if (!parents) {
723                 if (opt->show_root_diff) {
724                         diff_root_tree_sha1(sha1, "", &opt->diffopt);
725                         log_tree_diff_flush(opt);
726                 }
727                 return !opt->loginfo;
728         }
729
730         /* More than one parent? */
731         if (parents && parents->next) {
732                 if (opt->ignore_merges)
733                         return 0;
734                 else if (opt->combine_merges)
735                         return do_diff_combined(opt, commit);
736                 else if (opt->first_parent_only) {
737                         /*
738                          * Generate merge log entry only for the first
739                          * parent, showing summary diff of the others
740                          * we merged _in_.
741                          */
742                         parse_commit(parents->item);
743                         diff_tree_sha1(parents->item->tree->object.sha1,
744                                        sha1, "", &opt->diffopt);
745                         log_tree_diff_flush(opt);
746                         return !opt->loginfo;
747                 }
748
749                 /* If we show individual diffs, show the parent info */
750                 log->parent = parents->item;
751         }
752
753         showed_log = 0;
754         for (;;) {
755                 struct commit *parent = parents->item;
756
757                 parse_commit(parent);
758                 diff_tree_sha1(parent->tree->object.sha1,
759                                sha1, "", &opt->diffopt);
760                 log_tree_diff_flush(opt);
761
762                 showed_log |= !opt->loginfo;
763
764                 /* Set up the log info for the next parent, if any.. */
765                 parents = parents->next;
766                 if (!parents)
767                         break;
768                 log->parent = parents->item;
769                 opt->loginfo = log;
770         }
771         return showed_log;
772 }
773
774 int log_tree_commit(struct rev_info *opt, struct commit *commit)
775 {
776         struct log_info log;
777         int shown;
778
779         log.commit = commit;
780         log.parent = NULL;
781         opt->loginfo = &log;
782
783         shown = log_tree_diff(opt, commit, &log);
784         if (!shown && opt->loginfo && opt->always_show_header) {
785                 log.parent = NULL;
786                 show_log(opt);
787                 shown = 1;
788         }
789         opt->loginfo = NULL;
790         maybe_flush_or_die(stdout, "stdout");
791         return shown;
792 }