builtin/fmt-merge-msg.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "tag.h"
   8 #include "string-list.h"
   9 #include "branch.h"
  10 #include "fmt-merge-msg.h"
  11 #include "gpg-interface.h"
  12
  13 static const char * const fmt_merge_msg_usage[] = {
  14         N_("git fmt-merge-msg [-m <message>] [--log[=<n>] | --no-log] [--file <file>]"),
  15         NULL
  16 };
  17
  18 static int use_branch_desc;
  19
  20 int fmt_merge_msg_config(const char *key, const char *value, void *cb)
  21 {
  22         if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
  23                 int is_bool;
  24                 merge_log_config = git_config_bool_or_int(key, value, &is_bool);
  25                 if (!is_bool && merge_log_config < 0)
  26                         return error("%s: negative length %s", key, value);
  27                 if (is_bool && merge_log_config)
  28                         merge_log_config = DEFAULT_MERGE_LOG_LEN;
  29         } else if (!strcmp(key, "merge.branchdesc")) {
  30                 use_branch_desc = git_config_bool(key, value);
  31         } else {
  32                 return git_default_config(key, value, cb);
  33         }
  34         return 0;
  35 }
  36
  37 /* merge data per repository where the merged tips came from */
  38 struct src_data {
  39         struct string_list branch, tag, r_branch, generic;
  40         int head_status;
  41 };
  42
  43 struct origin_data {
  44         struct object_id oid;
  45         unsigned is_local_branch:1;
  46 };
  47
  48 static void init_src_data(struct src_data *data)
  49 {
  50         data->branch.strdup_strings = 1;
  51         data->tag.strdup_strings = 1;
  52         data->r_branch.strdup_strings = 1;
  53         data->generic.strdup_strings = 1;
  54 }
  55
  56 static struct string_list srcs = STRING_LIST_INIT_DUP;
  57 static struct string_list origins = STRING_LIST_INIT_DUP;
  58
  59 struct merge_parents {
  60         int alloc, nr;
  61         struct merge_parent {
  62                 struct object_id given;
  63                 struct object_id commit;
  64                 unsigned char used;
  65         } *item;
  66 };
  67
  68 /*
  69  * I know, I know, this is inefficient, but you won't be pulling and merging
  70  * hundreds of heads at a time anyway.
  71  */
  72 static struct merge_parent *find_merge_parent(struct merge_parents *table,
  73                                               struct object_id *given,
  74                                               struct object_id *commit)
  75 {
  76         int i;
  77         for (i = 0; i < table->nr; i++) {
  78                 if (given && oidcmp(&table->item[i].given, given))
  79                         continue;
  80                 if (commit && oidcmp(&table->item[i].commit, commit))
  81                         continue;
  82                 return &table->item[i];
  83         }
  84         return NULL;
  85 }
  86
  87 static void add_merge_parent(struct merge_parents *table,
  88                              struct object_id *given,
  89                              struct object_id *commit)
  90 {
  91         if (table->nr && find_merge_parent(table, given, commit))
  92                 return;
  93         ALLOC_GROW(table->item, table->nr + 1, table->alloc);
  94         oidcpy(&table->item[table->nr].given, given);
  95         oidcpy(&table->item[table->nr].commit, commit);
  96         table->item[table->nr].used = 0;
  97         table->nr++;
  98 }
  99
 100 static int handle_line(char *line, struct merge_parents *merge_parents)
 101 {
 102         int i, len = strlen(line);
 103         struct origin_data *origin_data;
 104         char *src;
 105         const char *origin;
 106         struct src_data *src_data;
 107         struct string_list_item *item;
 108         int pulling_head = 0;
 109         struct object_id oid;
 110
 111         if (len < GIT_SHA1_HEXSZ + 3 || line[GIT_SHA1_HEXSZ] != '\t')
 112                 return 1;
 113
 114         if (starts_with(line + GIT_SHA1_HEXSZ + 1, "not-for-merge"))
 115                 return 0;
 116
 117         if (line[GIT_SHA1_HEXSZ + 1] != '\t')
 118                 return 2;
 119
 120         i = get_oid_hex(line, &oid);
 121         if (i)
 122                 return 3;
 123
 124         if (!find_merge_parent(merge_parents, &oid, NULL))
 125                 return 0; /* subsumed by other parents */
 126
 127         origin_data = xcalloc(1, sizeof(struct origin_data));
 128         oidcpy(&origin_data->oid, &oid);
 129
 130         if (line[len - 1] == '\n')
 131                 line[len - 1] = 0;
 132         line += GIT_SHA1_HEXSZ + 2;
 133
 134         /*
 135          * At this point, line points at the beginning of comment e.g.
 136          * "branch 'frotz' of git://that/repository.git".
 137          * Find the repository name and point it with src.
 138          */
 139         src = strstr(line, " of ");
 140         if (src) {
 141                 *src = 0;
 142                 src += 4;
 143                 pulling_head = 0;
 144         } else {
 145                 src = line;
 146                 pulling_head = 1;
 147         }
 148
 149         item = unsorted_string_list_lookup(&srcs, src);
 150         if (!item) {
 151                 item = string_list_append(&srcs, src);
 152                 item->util = xcalloc(1, sizeof(struct src_data));
 153                 init_src_data(item->util);
 154         }
 155         src_data = item->util;
 156
 157         if (pulling_head) {
 158                 origin = src;
 159                 src_data->head_status |= 1;
 160         } else if (starts_with(line, "branch ")) {
 161                 origin_data->is_local_branch = 1;
 162                 origin = line + 7;
 163                 string_list_append(&src_data->branch, origin);
 164                 src_data->head_status |= 2;
 165         } else if (starts_with(line, "tag ")) {
 166                 origin = line;
 167                 string_list_append(&src_data->tag, origin + 4);
 168                 src_data->head_status |= 2;
 169         } else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
 170                 string_list_append(&src_data->r_branch, origin);
 171                 src_data->head_status |= 2;
 172         } else {
 173                 origin = src;
 174                 string_list_append(&src_data->generic, line);
 175                 src_data->head_status |= 2;
 176         }
 177
 178         if (!strcmp(".", src) || !strcmp(src, origin)) {
 179                 int len = strlen(origin);
 180                 if (origin[0] == '\'' && origin[len - 1] == '\'')
 181                         origin = xmemdupz(origin + 1, len - 2);
 182         } else
 183                 origin = xstrfmt("%s of %s", origin, src);
 184         if (strcmp(".", src))
 185                 origin_data->is_local_branch = 0;
 186         string_list_append(&origins, origin)->util = origin_data;
 187         return 0;
 188 }
 189
 190 static void print_joined(const char *singular, const char *plural,
 191                 struct string_list *list, struct strbuf *out)
 192 {
 193         if (list->nr == 0)
 194                 return;
 195         if (list->nr == 1) {
 196                 strbuf_addf(out, "%s%s", singular, list->items[0].string);
 197         } else {
 198                 int i;
 199                 strbuf_addstr(out, plural);
 200                 for (i = 0; i < list->nr - 1; i++)
 201                         strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
 202                                     list->items[i].string);
 203                 strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
 204         }
 205 }
 206
 207 static void add_branch_desc(struct strbuf *out, const char *name)
 208 {
 209         struct strbuf desc = STRBUF_INIT;
 210
 211         if (!read_branch_desc(&desc, name)) {
 212                 const char *bp = desc.buf;
 213                 while (*bp) {
 214                         const char *ep = strchrnul(bp, '\n');
 215                         if (*ep)
 216                                 ep++;
 217                         strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
 218                         bp = ep;
 219                 }
 220                 strbuf_complete_line(out);
 221         }
 222         strbuf_release(&desc);
 223 }
 224
 225 #define util_as_integral(elem) ((intptr_t)((elem)->util))
 226
 227 static void record_person_from_buf(int which, struct string_list *people,
 228                                    const char *buffer)
 229 {
 230         char *name_buf, *name, *name_end;
 231         struct string_list_item *elem;
 232         const char *field;
 233
 234         field = (which == 'a') ? "\nauthor " : "\ncommitter ";
 235         name = strstr(buffer, field);
 236         if (!name)
 237                 return;
 238         name += strlen(field);
 239         name_end = strchrnul(name, '<');
 240         if (*name_end)
 241                 name_end--;
 242         while (isspace(*name_end) && name <= name_end)
 243                 name_end--;
 244         if (name_end < name)
 245                 return;
 246         name_buf = xmemdupz(name, name_end - name + 1);
 247
 248         elem = string_list_lookup(people, name_buf);
 249         if (!elem) {
 250                 elem = string_list_insert(people, name_buf);
 251                 elem->util = (void *)0;
 252         }
 253         elem->util = (void*)(util_as_integral(elem) + 1);
 254         free(name_buf);
 255 }
 256
 257
 258 static void record_person(int which, struct string_list *people,
 259                           struct commit *commit)
 260 {
 261         const char *buffer = get_commit_buffer(commit, NULL);
 262         record_person_from_buf(which, people, buffer);
 263         unuse_commit_buffer(commit, buffer);
 264 }
 265
 266 static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
 267 {
 268         const struct string_list_item *a = a_, *b = b_;
 269         return util_as_integral(b) - util_as_integral(a);
 270 }
 271
 272 static void add_people_count(struct strbuf *out, struct string_list *people)
 273 {
 274         if (people->nr == 1)
 275                 strbuf_addstr(out, people->items[0].string);
 276         else if (people->nr == 2)
 277                 strbuf_addf(out, "%s (%d) and %s (%d)",
 278                             people->items[0].string,
 279                             (int)util_as_integral(&people->items[0]),
 280                             people->items[1].string,
 281                             (int)util_as_integral(&people->items[1]));
 282         else if (people->nr)
 283                 strbuf_addf(out, "%s (%d) and others",
 284                             people->items[0].string,
 285                             (int)util_as_integral(&people->items[0]));
 286 }
 287
 288 static void credit_people(struct strbuf *out,
 289                           struct string_list *them,
 290                           int kind)
 291 {
 292         const char *label;
 293         const char *me;
 294
 295         if (kind == 'a') {
 296                 label = "By";
 297                 me = git_author_info(IDENT_NO_DATE);
 298         } else {
 299                 label = "Via";
 300                 me = git_committer_info(IDENT_NO_DATE);
 301         }
 302
 303         if (!them->nr ||
 304             (them->nr == 1 &&
 305              me &&
 306              skip_prefix(me, them->items->string, &me) &&
 307              starts_with(me, " <")))
 308                 return;
 309         strbuf_addf(out, "\n%c %s ", comment_line_char, label);
 310         add_people_count(out, them);
 311 }
 312
 313 static void add_people_info(struct strbuf *out,
 314                             struct string_list *authors,
 315                             struct string_list *committers)
 316 {
 317         QSORT(authors->items, authors->nr,
 318               cmp_string_list_util_as_integral);
 319         QSORT(committers->items, committers->nr,
 320               cmp_string_list_util_as_integral);
 321
 322         credit_people(out, authors, 'a');
 323         credit_people(out, committers, 'c');
 324 }
 325
 326 static void shortlog(const char *name,
 327                      struct origin_data *origin_data,
 328                      struct commit *head,
 329                      struct rev_info *rev,
 330                      struct fmt_merge_msg_opts *opts,
 331                      struct strbuf *out)
 332 {
 333         int i, count = 0;
 334         struct commit *commit;
 335         struct object *branch;
 336         struct string_list subjects = STRING_LIST_INIT_DUP;
 337         struct string_list authors = STRING_LIST_INIT_DUP;
 338         struct string_list committers = STRING_LIST_INIT_DUP;
 339         int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
 340         struct strbuf sb = STRBUF_INIT;
 341         const struct object_id *oid = &origin_data->oid;
 342         int limit = opts->shortlog_len;
 343
 344         branch = deref_tag(parse_object(oid), oid_to_hex(oid), GIT_SHA1_HEXSZ);
 345         if (!branch || branch->type != OBJ_COMMIT)
 346                 return;
 347
 348         setup_revisions(0, NULL, rev, NULL);
 349         add_pending_object(rev, branch, name);
 350         add_pending_object(rev, &head->object, "^HEAD");
 351         head->object.flags |= UNINTERESTING;
 352         if (prepare_revision_walk(rev))
 353                 die("revision walk setup failed");
 354         while ((commit = get_revision(rev)) != NULL) {
 355                 struct pretty_print_context ctx = {0};
 356
 357                 if (commit->parents && commit->parents->next) {
 358                         /* do not list a merge but count committer */
 359                         if (opts->credit_people)
 360                                 record_person('c', &committers, commit);
 361                         continue;
 362                 }
 363                 if (!count && opts->credit_people)
 364                         /* the 'tip' committer */
 365                         record_person('c', &committers, commit);
 366                 if (opts->credit_people)
 367                         record_person('a', &authors, commit);
 368                 count++;
 369                 if (subjects.nr > limit)
 370                         continue;
 371
 372                 format_commit_message(commit, "%s", &sb, &ctx);
 373                 strbuf_ltrim(&sb);
 374
 375                 if (!sb.len)
 376                         string_list_append(&subjects,
 377                                            oid_to_hex(&commit->object.oid));
 378                 else
 379                         string_list_append(&subjects, strbuf_detach(&sb, NULL));
 380         }
 381
 382         if (opts->credit_people)
 383                 add_people_info(out, &authors, &committers);
 384         if (count > limit)
 385                 strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
 386         else
 387                 strbuf_addf(out, "\n* %s:\n", name);
 388
 389         if (origin_data->is_local_branch && use_branch_desc)
 390                 add_branch_desc(out, name);
 391
 392         for (i = 0; i < subjects.nr; i++)
 393                 if (i >= limit)
 394                         strbuf_addstr(out, "  ...\n");
 395                 else
 396                         strbuf_addf(out, "  %s\n", subjects.items[i].string);
 397
 398         clear_commit_marks((struct commit *)branch, flags);
 399         clear_commit_marks(head, flags);
 400         free_commit_list(rev->commits);
 401         rev->commits = NULL;
 402         rev->pending.nr = 0;
 403
 404         string_list_clear(&authors, 0);
 405         string_list_clear(&committers, 0);
 406         string_list_clear(&subjects, 0);
 407 }
 408
 409 static void fmt_merge_msg_title(struct strbuf *out,
 410         const char *current_branch) {
 411         int i = 0;
 412         char *sep = "";
 413
 414         strbuf_addstr(out, "Merge ");
 415         for (i = 0; i < srcs.nr; i++) {
 416                 struct src_data *src_data = srcs.items[i].util;
 417                 const char *subsep = "";
 418
 419                 strbuf_addstr(out, sep);
 420                 sep = "; ";
 421
 422                 if (src_data->head_status == 1) {
 423                         strbuf_addstr(out, srcs.items[i].string);
 424                         continue;
 425                 }
 426                 if (src_data->head_status == 3) {
 427                         subsep = ", ";
 428                         strbuf_addstr(out, "HEAD");
 429                 }
 430                 if (src_data->branch.nr) {
 431                         strbuf_addstr(out, subsep);
 432                         subsep = ", ";
 433                         print_joined("branch ", "branches ", &src_data->branch,
 434                                         out);
 435                 }
 436                 if (src_data->r_branch.nr) {
 437                         strbuf_addstr(out, subsep);
 438                         subsep = ", ";
 439                         print_joined("remote-tracking branch ", "remote-tracking branches ",
 440                                         &src_data->r_branch, out);
 441                 }
 442                 if (src_data->tag.nr) {
 443                         strbuf_addstr(out, subsep);
 444                         subsep = ", ";
 445                         print_joined("tag ", "tags ", &src_data->tag, out);
 446                 }
 447                 if (src_data->generic.nr) {
 448                         strbuf_addstr(out, subsep);
 449                         print_joined("commit ", "commits ", &src_data->generic,
 450                                         out);
 451                 }
 452                 if (strcmp(".", srcs.items[i].string))
 453                         strbuf_addf(out, " of %s", srcs.items[i].string);
 454         }
 455
 456         if (!strcmp("master", current_branch))
 457                 strbuf_addch(out, '\n');
 458         else
 459                 strbuf_addf(out, " into %s\n", current_branch);
 460 }
 461
 462 static void fmt_tag_signature(struct strbuf *tagbuf,
 463                               struct strbuf *sig,
 464                               const char *buf,
 465                               unsigned long len)
 466 {
 467         const char *tag_body = strstr(buf, "\n\n");
 468         if (tag_body) {
 469                 tag_body += 2;
 470                 strbuf_add(tagbuf, tag_body, buf + len - tag_body);
 471         }
 472         strbuf_complete_line(tagbuf);
 473         if (sig->len) {
 474                 strbuf_addch(tagbuf, '\n');
 475                 strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
 476         }
 477 }
 478
 479 static void fmt_merge_msg_sigs(struct strbuf *out)
 480 {
 481         int i, tag_number = 0, first_tag = 0;
 482         struct strbuf tagbuf = STRBUF_INIT;
 483
 484         for (i = 0; i < origins.nr; i++) {
 485                 unsigned char *sha1 = origins.items[i].util;
 486                 enum object_type type;
 487                 unsigned long size, len;
 488                 char *buf = read_sha1_file(sha1, &type, &size);
 489                 struct strbuf sig = STRBUF_INIT;
 490
 491                 if (!buf || type != OBJ_TAG)
 492                         goto next;
 493                 len = parse_signature(buf, size);
 494
 495                 if (size == len)
 496                         ; /* merely annotated */
 497                 else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
 498                         if (!sig.len)
 499                                 strbuf_addstr(&sig, "gpg verification failed.\n");
 500                 }
 501
 502                 if (!tag_number++) {
 503                         fmt_tag_signature(&tagbuf, &sig, buf, len);
 504                         first_tag = i;
 505                 } else {
 506                         if (tag_number == 2) {
 507                                 struct strbuf tagline = STRBUF_INIT;
 508                                 strbuf_addch(&tagline, '\n');
 509                                 strbuf_add_commented_lines(&tagline,
 510                                                 origins.items[first_tag].string,
 511                                                 strlen(origins.items[first_tag].string));
 512                                 strbuf_insert(&tagbuf, 0, tagline.buf,
 513                                               tagline.len);
 514                                 strbuf_release(&tagline);
 515                         }
 516                         strbuf_addch(&tagbuf, '\n');
 517                         strbuf_add_commented_lines(&tagbuf,
 518                                         origins.items[i].string,
 519                                         strlen(origins.items[i].string));
 520                         fmt_tag_signature(&tagbuf, &sig, buf, len);
 521                 }
 522                 strbuf_release(&sig);
 523         next:
 524                 free(buf);
 525         }
 526         if (tagbuf.len) {
 527                 strbuf_addch(out, '\n');
 528                 strbuf_addbuf(out, &tagbuf);
 529         }
 530         strbuf_release(&tagbuf);
 531 }
 532
 533 static void find_merge_parents(struct merge_parents *result,
 534                                struct strbuf *in, struct object_id *head)
 535 {
 536         struct commit_list *parents;
 537         struct commit *head_commit;
 538         int pos = 0, i, j;
 539
 540         parents = NULL;
 541         while (pos < in->len) {
 542                 int len;
 543                 char *p = in->buf + pos;
 544                 char *newline = strchr(p, '\n');
 545                 struct object_id oid;
 546                 struct commit *parent;
 547                 struct object *obj;
 548
 549                 len = newline ? newline - p : strlen(p);
 550                 pos += len + !!newline;
 551
 552                 if (len < GIT_SHA1_HEXSZ + 3 ||
 553                     get_oid_hex(p, &oid) ||
 554                     p[GIT_SHA1_HEXSZ] != '\t' ||
 555                     p[GIT_SHA1_HEXSZ + 1] != '\t')
 556                         continue; /* skip not-for-merge */
 557                 /*
 558                  * Do not use get_merge_parent() here; we do not have
 559                  * "name" here and we do not want to contaminate its
 560                  * util field yet.
 561                  */
 562                 obj = parse_object(&oid);
 563                 parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
 564                 if (!parent)
 565                         continue;
 566                 commit_list_insert(parent, &parents);
 567                 add_merge_parent(result, &obj->oid, &parent->object.oid);
 568         }
 569         head_commit = lookup_commit(head);
 570         if (head_commit)
 571                 commit_list_insert(head_commit, &parents);
 572         parents = reduce_heads(parents);
 573
 574         while (parents) {
 575                 struct commit *cmit = pop_commit(&parents);
 576                 for (i = 0; i < result->nr; i++)
 577                         if (!oidcmp(&result->item[i].commit, &cmit->object.oid))
 578                                 result->item[i].used = 1;
 579         }
 580
 581         for (i = j = 0; i < result->nr; i++) {
 582                 if (result->item[i].used) {
 583                         if (i != j)
 584                                 result->item[j] = result->item[i];
 585                         j++;
 586                 }
 587         }
 588         result->nr = j;
 589 }
 590
 591 int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 592                   struct fmt_merge_msg_opts *opts)
 593 {
 594         int i = 0, pos = 0;
 595         struct object_id head_oid;
 596         const char *current_branch;
 597         void *current_branch_to_free;
 598         struct merge_parents merge_parents;
 599
 600         memset(&merge_parents, 0, sizeof(merge_parents));
 601
 602         /* get current branch */
 603         current_branch = current_branch_to_free =
 604                 resolve_refdup("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL);
 605         if (!current_branch)
 606                 die("No current branch");
 607         if (starts_with(current_branch, "refs/heads/"))
 608                 current_branch += 11;
 609
 610         find_merge_parents(&merge_parents, in, &head_oid);
 611
 612         /* get a line */
 613         while (pos < in->len) {
 614                 int len;
 615                 char *newline, *p = in->buf + pos;
 616
 617                 newline = strchr(p, '\n');
 618                 len = newline ? newline - p : strlen(p);
 619                 pos += len + !!newline;
 620                 i++;
 621                 p[len] = 0;
 622                 if (handle_line(p, &merge_parents))
 623                         die ("Error in line %d: %.*s", i, len, p);
 624         }
 625
 626         if (opts->add_title && srcs.nr)
 627                 fmt_merge_msg_title(out, current_branch);
 628
 629         if (origins.nr)
 630                 fmt_merge_msg_sigs(out);
 631
 632         if (opts->shortlog_len) {
 633                 struct commit *head;
 634                 struct rev_info rev;
 635
 636                 head = lookup_commit_or_die(&head_oid, "HEAD");
 637                 init_revisions(&rev, NULL);
 638                 rev.commit_format = CMIT_FMT_ONELINE;
 639                 rev.ignore_merges = 1;
 640                 rev.limited = 1;
 641
 642                 strbuf_complete_line(out);
 643
 644                 for (i = 0; i < origins.nr; i++)
 645                         shortlog(origins.items[i].string,
 646                                  origins.items[i].util,
 647                                  head, &rev, opts, out);
 648         }
 649
 650         strbuf_complete_line(out);
 651         free(current_branch_to_free);
 652         free(merge_parents.item);
 653         return 0;
 654 }
 655
 656 int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 657 {
 658         const char *inpath = NULL;
 659         const char *message = NULL;
 660         int shortlog_len = -1;
 661         struct option options[] = {
 662                 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
 663                   N_("populate log with at most <n> entries from shortlog"),
 664                   PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
 665                 { OPTION_INTEGER, 0, "summary", &shortlog_len, N_("n"),
 666                   N_("alias for --log (deprecated)"),
 667                   PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, NULL,
 668                   DEFAULT_MERGE_LOG_LEN },
 669                 OPT_STRING('m', "message", &message, N_("text"),
 670                         N_("use <text> as start of message")),
 671                 OPT_FILENAME('F', "file", &inpath, N_("file to read from")),
 672                 OPT_END()
 673         };
 674
 675         FILE *in = stdin;
 676         struct strbuf input = STRBUF_INIT, output = STRBUF_INIT;
 677         int ret;
 678         struct fmt_merge_msg_opts opts;
 679
 680         git_config(fmt_merge_msg_config, NULL);
 681         argc = parse_options(argc, argv, prefix, options, fmt_merge_msg_usage,
 682                              0);
 683         if (argc > 0)
 684                 usage_with_options(fmt_merge_msg_usage, options);
 685         if (shortlog_len < 0)
 686                 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
 687
 688         if (inpath && strcmp(inpath, "-")) {
 689                 in = fopen(inpath, "r");
 690                 if (!in)
 691                         die_errno("cannot open '%s'", inpath);
 692         }
 693
 694         if (strbuf_read(&input, fileno(in), 0) < 0)
 695                 die_errno("could not read input file");
 696
 697         if (message)
 698                 strbuf_addstr(&output, message);
 699
 700         memset(&opts, 0, sizeof(opts));
 701         opts.add_title = !message;
 702         opts.credit_people = 1;
 703         opts.shortlog_len = shortlog_len;
 704
 705         ret = fmt_merge_msg(&input, &output, &opts);
 706         if (ret)
 707                 return ret;
 708         write_in_full(STDOUT_FILENO, output.buf, output.len);
 709         return 0;
 710 }