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