builtin/fmt-merge-msg.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "commit.h"
   4 #include "diff.h"
   5 #include "revision.h"
   6 #include "tag.h"
   7 #include "string-list.h"
   8 #include "branch.h"
   9 #include "fmt-merge-msg.h"
  10 #include "gpg-interface.h"
  11
  12 static const char * const fmt_merge_msg_usage[] = {
  13         N_("git fmt-merge-msg [-m <message>] [--log[=<n>] | --no-log] [--file <file>]"),
  14         NULL
  15 };
  16
  17 static int use_branch_desc;
  18
  19 int fmt_merge_msg_config(const char *key, const char *value, void *cb)
  20 {
  21         if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
  22                 int is_bool;
  23                 merge_log_config = git_config_bool_or_int(key, value, &is_bool);
  24                 if (!is_bool && merge_log_config < 0)
  25                         return error("%s: negative length %s", key, value);
  26                 if (is_bool && merge_log_config)
  27                         merge_log_config = DEFAULT_MERGE_LOG_LEN;
  28         } else if (!strcmp(key, "merge.branchdesc")) {
  29                 use_branch_desc = git_config_bool(key, value);
  30         } else {
  31                 return git_default_config(key, value, cb);
  32         }
  33         return 0;
  34 }
  35
  36 /* merge data per repository where the merged tips came from */
  37 struct src_data {
  38         struct string_list branch, tag, r_branch, generic;
  39         int head_status;
  40 };
  41
  42 struct origin_data {
  43         unsigned char sha1[20];
  44         unsigned is_local_branch:1;
  45 };
  46
  47 static void init_src_data(struct src_data *data)
  48 {
  49         data->branch.strdup_strings = 1;
  50         data->tag.strdup_strings = 1;
  51         data->r_branch.strdup_strings = 1;
  52         data->generic.strdup_strings = 1;
  53 }
  54
  55 static struct string_list srcs = STRING_LIST_INIT_DUP;
  56 static struct string_list origins = STRING_LIST_INIT_DUP;
  57
  58 struct merge_parents {
  59         int alloc, nr;
  60         struct merge_parent {
  61                 unsigned char given[20];
  62                 unsigned char commit[20];
  63                 unsigned char used;
  64         } *item;
  65 };
  66
  67 /*
  68  * I know, I know, this is inefficient, but you won't be pulling and merging
  69  * hundreds of heads at a time anyway.
  70  */
  71 static struct merge_parent *find_merge_parent(struct merge_parents *table,
  72                                               unsigned char *given,
  73                                               unsigned char *commit)
  74 {
  75         int i;
  76         for (i = 0; i < table->nr; i++) {
  77                 if (given && hashcmp(table->item[i].given, given))
  78                         continue;
  79                 if (commit && hashcmp(table->item[i].commit, commit))
  80                         continue;
  81                 return &table->item[i];
  82         }
  83         return NULL;
  84 }
  85
  86 static void add_merge_parent(struct merge_parents *table,
  87                              unsigned char *given,
  88                              unsigned char *commit)
  89 {
  90         if (table->nr && find_merge_parent(table, given, commit))
  91                 return;
  92         ALLOC_GROW(table->item, table->nr + 1, table->alloc);
  93         hashcpy(table->item[table->nr].given, given);
  94         hashcpy(table->item[table->nr].commit, commit);
  95         table->item[table->nr].used = 0;
  96         table->nr++;
  97 }
  98
  99 static int handle_line(char *line, struct merge_parents *merge_parents)
 100 {
 101         int i, len = strlen(line);
 102         struct origin_data *origin_data;
 103         char *src;
 104         const char *origin;
 105         struct src_data *src_data;
 106         struct string_list_item *item;
 107         int pulling_head = 0;
 108         unsigned char sha1[20];
 109
 110         if (len < 43 || line[40] != '\t')
 111                 return 1;
 112
 113         if (starts_with(line + 41, "not-for-merge"))
 114                 return 0;
 115
 116         if (line[41] != '\t')
 117                 return 2;
 118
 119         i = get_sha1_hex(line, sha1);
 120         if (i)
 121                 return 3;
 122
 123         if (!find_merge_parent(merge_parents, sha1, NULL))
 124                 return 0; /* subsumed by other parents */
 125
 126         origin_data = xcalloc(1, sizeof(struct origin_data));
 127         hashcpy(origin_data->sha1, sha1);
 128
 129         if (line[len - 1] == '\n')
 130                 line[len - 1] = 0;
 131         line += 42;
 132
 133         /*
 134          * At this point, line points at the beginning of comment e.g.
 135          * "branch 'frotz' of git://that/repository.git".
 136          * Find the repository name and point it with src.
 137          */
 138         src = strstr(line, " of ");
 139         if (src) {
 140                 *src = 0;
 141                 src += 4;
 142                 pulling_head = 0;
 143         } else {
 144                 src = line;
 145                 pulling_head = 1;
 146         }
 147
 148         item = unsorted_string_list_lookup(&srcs, src);
 149         if (!item) {
 150                 item = string_list_append(&srcs, src);
 151                 item->util = xcalloc(1, sizeof(struct src_data));
 152                 init_src_data(item->util);
 153         }
 154         src_data = item->util;
 155
 156         if (pulling_head) {
 157                 origin = src;
 158                 src_data->head_status |= 1;
 159         } else if (starts_with(line, "branch ")) {
 160                 origin_data->is_local_branch = 1;
 161                 origin = line + 7;
 162                 string_list_append(&src_data->branch, origin);
 163                 src_data->head_status |= 2;
 164         } else if (starts_with(line, "tag ")) {
 165                 origin = line;
 166                 string_list_append(&src_data->tag, origin + 4);
 167                 src_data->head_status |= 2;
 168         } else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
 169                 string_list_append(&src_data->r_branch, origin);
 170                 src_data->head_status |= 2;
 171         } else {
 172                 origin = src;
 173                 string_list_append(&src_data->generic, line);
 174                 src_data->head_status |= 2;
 175         }
 176
 177         if (!strcmp(".", src) || !strcmp(src, origin)) {
 178                 int len = strlen(origin);
 179                 if (origin[0] == '\'' && origin[len - 1] == '\'')
 180                         origin = xmemdupz(origin + 1, len - 2);
 181         } else
 182                 origin = xstrfmt("%s of %s", origin, src);
 183         if (strcmp(".", src))
 184                 origin_data->is_local_branch = 0;
 185         string_list_append(&origins, origin)->util = origin_data;
 186         return 0;
 187 }
 188
 189 static void print_joined(const char *singular, const char *plural,
 190                 struct string_list *list, struct strbuf *out)
 191 {
 192         if (list->nr == 0)
 193                 return;
 194         if (list->nr == 1) {
 195                 strbuf_addf(out, "%s%s", singular, list->items[0].string);
 196         } else {
 197                 int i;
 198                 strbuf_addstr(out, plural);
 199                 for (i = 0; i < list->nr - 1; i++)
 200                         strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
 201                                     list->items[i].string);
 202                 strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
 203         }
 204 }
 205
 206 static void add_branch_desc(struct strbuf *out, const char *name)
 207 {
 208         struct strbuf desc = STRBUF_INIT;
 209
 210         if (!read_branch_desc(&desc, name)) {
 211                 const char *bp = desc.buf;
 212                 while (*bp) {
 213                         const char *ep = strchrnul(bp, '\n');
 214                         if (*ep)
 215                                 ep++;
 216                         strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
 217                         bp = ep;
 218                 }
 219                 strbuf_complete_line(out);
 220         }
 221         strbuf_release(&desc);
 222 }
 223
 224 #define util_as_integral(elem) ((intptr_t)((elem)->util))
 225
 226 static void record_person_from_buf(int which, struct string_list *people,
 227                                    const char *buffer)
 228 {
 229         char *name_buf, *name, *name_end;
 230         struct string_list_item *elem;
 231         const char *field;
 232
 233         field = (which == 'a') ? "\nauthor " : "\ncommitter ";
 234         name = strstr(buffer, field);
 235         if (!name)
 236                 return;
 237         name += strlen(field);
 238         name_end = strchrnul(name, '<');
 239         if (*name_end)
 240                 name_end--;
 241         while (isspace(*name_end) && name <= name_end)
 242                 name_end--;
 243         if (name_end < name)
 244                 return;
 245         name_buf = xmemdupz(name, name_end - name + 1);
 246
 247         elem = string_list_lookup(people, name_buf);
 248         if (!elem) {
 249                 elem = string_list_insert(people, name_buf);
 250                 elem->util = (void *)0;
 251         }
 252         elem->util = (void*)(util_as_integral(elem) + 1);
 253         free(name_buf);
 254 }
 255
 256
 257 static void record_person(int which, struct string_list *people,
 258                           struct commit *commit)
 259 {
 260         const char *buffer = get_commit_buffer(commit, NULL);
 261         record_person_from_buf(which, people, buffer);
 262         unuse_commit_buffer(commit, buffer);
 263 }
 264
 265 static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
 266 {
 267         const struct string_list_item *a = a_, *b = b_;
 268         return util_as_integral(b) - util_as_integral(a);
 269 }
 270
 271 static void add_people_count(struct strbuf *out, struct string_list *people)
 272 {
 273         if (people->nr == 1)
 274                 strbuf_addf(out, "%s", people->items[0].string);
 275         else if (people->nr == 2)
 276                 strbuf_addf(out, "%s (%d) and %s (%d)",
 277                             people->items[0].string,
 278                             (int)util_as_integral(&people->items[0]),
 279                             people->items[1].string,
 280                             (int)util_as_integral(&people->items[1]));
 281         else if (people->nr)
 282                 strbuf_addf(out, "%s (%d) and others",
 283                             people->items[0].string,
 284                             (int)util_as_integral(&people->items[0]));
 285 }
 286
 287 static void credit_people(struct strbuf *out,
 288                           struct string_list *them,
 289                           int kind)
 290 {
 291         const char *label;
 292         const char *me;
 293
 294         if (kind == 'a') {
 295                 label = "By";
 296                 me = git_author_info(IDENT_NO_DATE);
 297         } else {
 298                 label = "Via";
 299                 me = git_committer_info(IDENT_NO_DATE);
 300         }
 301
 302         if (!them->nr ||
 303             (them->nr == 1 &&
 304              me &&
 305              skip_prefix(me, them->items->string, &me) &&
 306              starts_with(me, " <")))
 307                 return;
 308         strbuf_addf(out, "\n%c %s ", comment_line_char, label);
 309         add_people_count(out, them);
 310 }
 311
 312 static void add_people_info(struct strbuf *out,
 313                             struct string_list *authors,
 314                             struct string_list *committers)
 315 {
 316         if (authors->nr)
 317                 qsort(authors->items,
 318                       authors->nr, sizeof(authors->items[0]),
 319                       cmp_string_list_util_as_integral);
 320         if (committers->nr)
 321                 qsort(committers->items,
 322                       committers->nr, sizeof(committers->items[0]),
 323                       cmp_string_list_util_as_integral);
 324
 325         credit_people(out, authors, 'a');
 326         credit_people(out, committers, 'c');
 327 }
 328
 329 static void shortlog(const char *name,
 330                      struct origin_data *origin_data,
 331                      struct commit *head,
 332                      struct rev_info *rev,
 333                      struct fmt_merge_msg_opts *opts,
 334                      struct strbuf *out)
 335 {
 336         int i, count = 0;
 337         struct commit *commit;
 338         struct object *branch;
 339         struct string_list subjects = STRING_LIST_INIT_DUP;
 340         struct string_list authors = STRING_LIST_INIT_DUP;
 341         struct string_list committers = STRING_LIST_INIT_DUP;
 342         int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
 343         struct strbuf sb = STRBUF_INIT;
 344         const unsigned char *sha1 = origin_data->sha1;
 345         int limit = opts->shortlog_len;
 346
 347         branch = deref_tag(parse_object(sha1), sha1_to_hex(sha1), 40);
 348         if (!branch || branch->type != OBJ_COMMIT)
 349                 return;
 350
 351         setup_revisions(0, NULL, rev, NULL);
 352         add_pending_object(rev, branch, name);
 353         add_pending_object(rev, &head->object, "^HEAD");
 354         head->object.flags |= UNINTERESTING;
 355         if (prepare_revision_walk(rev))
 356                 die("revision walk setup failed");
 357         while ((commit = get_revision(rev)) != NULL) {
 358                 struct pretty_print_context ctx = {0};
 359
 360                 if (commit->parents && commit->parents->next) {
 361                         /* do not list a merge but count committer */
 362                         if (opts->credit_people)
 363                                 record_person('c', &committers, commit);
 364                         continue;
 365                 }
 366                 if (!count && opts->credit_people)
 367                         /* the 'tip' committer */
 368                         record_person('c', &committers, commit);
 369                 if (opts->credit_people)
 370                         record_person('a', &authors, commit);
 371                 count++;
 372                 if (subjects.nr > limit)
 373                         continue;
 374
 375                 format_commit_message(commit, "%s", &sb, &ctx);
 376                 strbuf_ltrim(&sb);
 377
 378                 if (!sb.len)
 379                         string_list_append(&subjects,
 380                                            sha1_to_hex(commit->object.sha1));
 381                 else
 382                         string_list_append(&subjects, strbuf_detach(&sb, NULL));
 383         }
 384
 385         if (opts->credit_people)
 386                 add_people_info(out, &authors, &committers);
 387         if (count > limit)
 388                 strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
 389         else
 390                 strbuf_addf(out, "\n* %s:\n", name);
 391
 392         if (origin_data->is_local_branch && use_branch_desc)
 393                 add_branch_desc(out, name);
 394
 395         for (i = 0; i < subjects.nr; i++)
 396                 if (i >= limit)
 397                         strbuf_addf(out, "  ...\n");
 398                 else
 399                         strbuf_addf(out, "  %s\n", subjects.items[i].string);
 400
 401         clear_commit_marks((struct commit *)branch, flags);
 402         clear_commit_marks(head, flags);
 403         free_commit_list(rev->commits);
 404         rev->commits = NULL;
 405         rev->pending.nr = 0;
 406
 407         string_list_clear(&authors, 0);
 408         string_list_clear(&committers, 0);
 409         string_list_clear(&subjects, 0);
 410 }
 411
 412 static void fmt_merge_msg_title(struct strbuf *out,
 413         const char *current_branch) {
 414         int i = 0;
 415         char *sep = "";
 416
 417         strbuf_addstr(out, "Merge ");
 418         for (i = 0; i < srcs.nr; i++) {
 419                 struct src_data *src_data = srcs.items[i].util;
 420                 const char *subsep = "";
 421
 422                 strbuf_addstr(out, sep);
 423                 sep = "; ";
 424
 425                 if (src_data->head_status == 1) {
 426                         strbuf_addstr(out, srcs.items[i].string);
 427                         continue;
 428                 }
 429                 if (src_data->head_status == 3) {
 430                         subsep = ", ";
 431                         strbuf_addstr(out, "HEAD");
 432                 }
 433                 if (src_data->branch.nr) {
 434                         strbuf_addstr(out, subsep);
 435                         subsep = ", ";
 436                         print_joined("branch ", "branches ", &src_data->branch,
 437                                         out);
 438                 }
 439                 if (src_data->r_branch.nr) {
 440                         strbuf_addstr(out, subsep);
 441                         subsep = ", ";
 442                         print_joined("remote-tracking branch ", "remote-tracking branches ",
 443                                         &src_data->r_branch, out);
 444                 }
 445                 if (src_data->tag.nr) {
 446                         strbuf_addstr(out, subsep);
 447                         subsep = ", ";
 448                         print_joined("tag ", "tags ", &src_data->tag, out);
 449                 }
 450                 if (src_data->generic.nr) {
 451                         strbuf_addstr(out, subsep);
 452                         print_joined("commit ", "commits ", &src_data->generic,
 453                                         out);
 454                 }
 455                 if (strcmp(".", srcs.items[i].string))
 456                         strbuf_addf(out, " of %s", srcs.items[i].string);
 457         }
 458
 459         if (!strcmp("master", current_branch))
 460                 strbuf_addch(out, '\n');
 461         else
 462                 strbuf_addf(out, " into %s\n", current_branch);
 463 }
 464
 465 static void fmt_tag_signature(struct strbuf *tagbuf,
 466                               struct strbuf *sig,
 467                               const char *buf,
 468                               unsigned long len)
 469 {
 470         const char *tag_body = strstr(buf, "\n\n");
 471         if (tag_body) {
 472                 tag_body += 2;
 473                 strbuf_add(tagbuf, tag_body, buf + len - tag_body);
 474         }
 475         strbuf_complete_line(tagbuf);
 476         if (sig->len) {
 477                 strbuf_addch(tagbuf, '\n');
 478                 strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
 479         }
 480 }
 481
 482 static void fmt_merge_msg_sigs(struct strbuf *out)
 483 {
 484         int i, tag_number = 0, first_tag = 0;
 485         struct strbuf tagbuf = STRBUF_INIT;
 486
 487         for (i = 0; i < origins.nr; i++) {
 488                 unsigned char *sha1 = origins.items[i].util;
 489                 enum object_type type;
 490                 unsigned long size, len;
 491                 char *buf = read_sha1_file(sha1, &type, &size);
 492                 struct strbuf sig = STRBUF_INIT;
 493
 494                 if (!buf || type != OBJ_TAG)
 495                         goto next;
 496                 len = parse_signature(buf, size);
 497
 498                 if (size == len)
 499                         ; /* merely annotated */
 500                 else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
 501                         if (!sig.len)
 502                                 strbuf_addstr(&sig, "gpg verification failed.\n");
 503                 }
 504
 505                 if (!tag_number++) {
 506                         fmt_tag_signature(&tagbuf, &sig, buf, len);
 507                         first_tag = i;
 508                 } else {
 509                         if (tag_number == 2) {
 510                                 struct strbuf tagline = STRBUF_INIT;
 511                                 strbuf_addch(&tagline, '\n');
 512                                 strbuf_add_commented_lines(&tagline,
 513                                                 origins.items[first_tag].string,
 514                                                 strlen(origins.items[first_tag].string));
 515                                 strbuf_insert(&tagbuf, 0, tagline.buf,
 516                                               tagline.len);
 517                                 strbuf_release(&tagline);
 518                         }
 519                         strbuf_addch(&tagbuf, '\n');
 520                         strbuf_add_commented_lines(&tagbuf,
 521                                         origins.items[i].string,
 522                                         strlen(origins.items[i].string));
 523                         fmt_tag_signature(&tagbuf, &sig, buf, len);
 524                 }
 525                 strbuf_release(&sig);
 526         next:
 527                 free(buf);
 528         }
 529         if (tagbuf.len) {
 530                 strbuf_addch(out, '\n');
 531                 strbuf_addbuf(out, &tagbuf);
 532         }
 533         strbuf_release(&tagbuf);
 534 }
 535
 536 static void find_merge_parents(struct merge_parents *result,
 537                                struct strbuf *in, unsigned char *head)
 538 {
 539         struct commit_list *parents, *next;
 540         struct commit *head_commit;
 541         int pos = 0, i, j;
 542
 543         parents = NULL;
 544         while (pos < in->len) {
 545                 int len;
 546                 char *p = in->buf + pos;
 547                 char *newline = strchr(p, '\n');
 548                 unsigned char sha1[20];
 549                 struct commit *parent;
 550                 struct object *obj;
 551
 552                 len = newline ? newline - p : strlen(p);
 553                 pos += len + !!newline;
 554
 555                 if (len < 43 ||
 556                     get_sha1_hex(p, sha1) ||
 557                     p[40] != '\t' ||
 558                     p[41] != '\t')
 559                         continue; /* skip not-for-merge */
 560                 /*
 561                  * Do not use get_merge_parent() here; we do not have
 562                  * "name" here and we do not want to contaminate its
 563                  * util field yet.
 564                  */
 565                 obj = parse_object(sha1);
 566                 parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
 567                 if (!parent)
 568                         continue;
 569                 commit_list_insert(parent, &parents);
 570                 add_merge_parent(result, obj->sha1, parent->object.sha1);
 571         }
 572         head_commit = lookup_commit(head);
 573         if (head_commit)
 574                 commit_list_insert(head_commit, &parents);
 575         parents = reduce_heads(parents);
 576
 577         while (parents) {
 578                 for (i = 0; i < result->nr; i++)
 579                         if (!hashcmp(result->item[i].commit,
 580                                      parents->item->object.sha1))
 581                                 result->item[i].used = 1;
 582                 next = parents->next;
 583                 free(parents);
 584                 parents = next;
 585         }
 586
 587         for (i = j = 0; i < result->nr; i++) {
 588                 if (result->item[i].used) {
 589                         if (i != j)
 590                                 result->item[j] = result->item[i];
 591                         j++;
 592                 }
 593         }
 594         result->nr = j;
 595 }
 596
 597 int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 598                   struct fmt_merge_msg_opts *opts)
 599 {
 600         int i = 0, pos = 0;
 601         unsigned char head_sha1[20];
 602         const char *current_branch;
 603         void *current_branch_to_free;
 604         struct merge_parents merge_parents;
 605
 606         memset(&merge_parents, 0, sizeof(merge_parents));
 607
 608         /* get current branch */
 609         current_branch = current_branch_to_free =
 610                 resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
 611         if (!current_branch)
 612                 die("No current branch");
 613         if (starts_with(current_branch, "refs/heads/"))
 614                 current_branch += 11;
 615
 616         find_merge_parents(&merge_parents, in, head_sha1);
 617
 618         /* get a line */
 619         while (pos < in->len) {
 620                 int len;
 621                 char *newline, *p = in->buf + pos;
 622
 623                 newline = strchr(p, '\n');
 624                 len = newline ? newline - p : strlen(p);
 625                 pos += len + !!newline;
 626                 i++;
 627                 p[len] = 0;
 628                 if (handle_line(p, &merge_parents))
 629                         die ("Error in line %d: %.*s", i, len, p);
 630         }
 631
 632         if (opts->add_title && srcs.nr)
 633                 fmt_merge_msg_title(out, current_branch);
 634
 635         if (origins.nr)
 636                 fmt_merge_msg_sigs(out);
 637
 638         if (opts->shortlog_len) {
 639                 struct commit *head;
 640                 struct rev_info rev;
 641
 642                 head = lookup_commit_or_die(head_sha1, "HEAD");
 643                 init_revisions(&rev, NULL);
 644                 rev.commit_format = CMIT_FMT_ONELINE;
 645                 rev.ignore_merges = 1;
 646                 rev.limited = 1;
 647
 648                 strbuf_complete_line(out);
 649
 650                 for (i = 0; i < origins.nr; i++)
 651                         shortlog(origins.items[i].string,
 652                                  origins.items[i].util,
 653                                  head, &rev, opts, out);
 654         }
 655
 656         strbuf_complete_line(out);
 657         free(current_branch_to_free);
 658         free(merge_parents.item);
 659         return 0;
 660 }
 661
 662 int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 663 {
 664         const char *inpath = NULL;
 665         const char *message = NULL;
 666         int shortlog_len = -1;
 667         struct option options[] = {
 668                 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
 669                   N_("populate log with at most <n> entries from shortlog"),
 670                   PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
 671                 { OPTION_INTEGER, 0, "summary", &shortlog_len, N_("n"),
 672                   N_("alias for --log (deprecated)"),
 673                   PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, NULL,
 674                   DEFAULT_MERGE_LOG_LEN },
 675                 OPT_STRING('m', "message", &message, N_("text"),
 676                         N_("use <text> as start of message")),
 677                 OPT_FILENAME('F', "file", &inpath, N_("file to read from")),
 678                 OPT_END()
 679         };
 680
 681         FILE *in = stdin;
 682         struct strbuf input = STRBUF_INIT, output = STRBUF_INIT;
 683         int ret;
 684         struct fmt_merge_msg_opts opts;
 685
 686         git_config(fmt_merge_msg_config, NULL);
 687         argc = parse_options(argc, argv, prefix, options, fmt_merge_msg_usage,
 688                              0);
 689         if (argc > 0)
 690                 usage_with_options(fmt_merge_msg_usage, options);
 691         if (shortlog_len < 0)
 692                 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
 693
 694         if (inpath && strcmp(inpath, "-")) {
 695                 in = fopen(inpath, "r");
 696                 if (!in)
 697                         die_errno("cannot open '%s'", inpath);
 698         }
 699
 700         if (strbuf_read(&input, fileno(in), 0) < 0)
 701                 die_errno("could not read input file");
 702
 703         if (message)
 704                 strbuf_addstr(&output, message);
 705
 706         memset(&opts, 0, sizeof(opts));
 707         opts.add_title = !message;
 708         opts.credit_people = 1;
 709         opts.shortlog_len = shortlog_len;
 710
 711         ret = fmt_merge_msg(&input, &output, &opts);
 712         if (ret)
 713                 return ret;
 714         write_in_full(STDOUT_FILENO, output.buf, output.len);
 715         return 0;
 716 }