git.oblomov.eu Git - git/blob - merge-recursive.c

   1 /*
   2  * Recursive Merge algorithm stolen from git-merge-recursive.py by
   3  * Fredrik Kuivinen.
   4  * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
   5  */
   6 #include "cache.h"
   7 #include "cache-tree.h"
   8 #include "commit.h"
   9 #include "blob.h"
  10 #include "tree-walk.h"
  11 #include "diff.h"
  12 #include "diffcore.h"
  13 #include "run-command.h"
  14 #include "tag.h"
  15 #include "unpack-trees.h"
  16 #include "path-list.h"
  17 #include "xdiff-interface.h"
  18
  19 /*
  20  * A virtual commit has
  21  * - (const char *)commit->util set to the name, and
  22  * - *(int *)commit->object.sha1 set to the virtual id.
  23  */
  24
  25 static unsigned commit_list_count(const struct commit_list *l)
  26 {
  27         unsigned c = 0;
  28         for (; l; l = l->next )
  29                 c++;
  30         return c;
  31 }
  32
  33 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  34 {
  35         struct commit *commit = xcalloc(1, sizeof(struct commit));
  36         static unsigned virtual_id = 1;
  37         commit->tree = tree;
  38         commit->util = (void*)comment;
  39         *(int*)commit->object.sha1 = virtual_id++;
  40         /* avoid warnings */
  41         commit->object.parsed = 1;
  42         return commit;
  43 }
  44
  45 /*
  46  * Since we use get_tree_entry(), which does not put the read object into
  47  * the object pool, we cannot rely on a == b.
  48  */
  49 static int sha_eq(const unsigned char *a, const unsigned char *b)
  50 {
  51         if (!a && !b)
  52                 return 2;
  53         return a && b && hashcmp(a, b) == 0;
  54 }
  55
  56 /*
  57  * Since we want to write the index eventually, we cannot reuse the index
  58  * for these (temporary) data.
  59  */
  60 struct stage_data
  61 {
  62         struct
  63         {
  64                 unsigned mode;
  65                 unsigned char sha[20];
  66         } stages[4];
  67         unsigned processed:1;
  68 };
  69
  70 struct output_buffer
  71 {
  72         struct output_buffer *next;
  73         char *str;
  74 };
  75
  76 static struct path_list current_file_set = {NULL, 0, 0, 1};
  77 static struct path_list current_directory_set = {NULL, 0, 0, 1};
  78
  79 static int call_depth = 0;
  80 static int verbosity = 2;
  81 static int buffer_output = 1;
  82 static int do_progress = 1;
  83 static unsigned last_percent;
  84 static unsigned merged_cnt;
  85 static unsigned total_cnt;
  86 static volatile sig_atomic_t progress_update;
  87 static struct output_buffer *output_list, *output_end;
  88
  89 static int show (int v)
  90 {
  91         return (!call_depth && verbosity >= v) || verbosity >= 5;
  92 }
  93
  94 static void output(int v, const char *fmt, ...)
  95 {
  96         va_list args;
  97         va_start(args, fmt);
  98         if (buffer_output && show(v)) {
  99                 struct output_buffer *b = xmalloc(sizeof(*b));
 100                 nfvasprintf(&b->str, fmt, args);
 101                 b->next = NULL;
 102                 if (output_end)
 103                         output_end->next = b;
 104                 else
 105                         output_list = b;
 106                 output_end = b;
 107         } else if (show(v)) {
 108                 int i;
 109                 for (i = call_depth; i--;)
 110                         fputs("  ", stdout);
 111                 vfprintf(stdout, fmt, args);
 112                 fputc('\n', stdout);
 113         }
 114         va_end(args);
 115 }
 116
 117 static void flush_output()
 118 {
 119         struct output_buffer *b, *n;
 120         for (b = output_list; b; b = n) {
 121                 int i;
 122                 for (i = call_depth; i--;)
 123                         fputs("  ", stdout);
 124                 fputs(b->str, stdout);
 125                 fputc('\n', stdout);
 126                 n = b->next;
 127                 free(b->str);
 128                 free(b);
 129         }
 130         output_list = NULL;
 131         output_end = NULL;
 132 }
 133
 134 static void output_commit_title(struct commit *commit)
 135 {
 136         int i;
 137         flush_output();
 138         for (i = call_depth; i--;)
 139                 fputs("  ", stdout);
 140         if (commit->util)
 141                 printf("virtual %s\n", (char *)commit->util);
 142         else {
 143                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 144                 if (parse_commit(commit) != 0)
 145                         printf("(bad commit)\n");
 146                 else {
 147                         const char *s;
 148                         int len;
 149                         for (s = commit->buffer; *s; s++)
 150                                 if (*s == '\n' && s[1] == '\n') {
 151                                         s += 2;
 152                                         break;
 153                                 }
 154                         for (len = 0; s[len] && '\n' != s[len]; len++)
 155                                 ; /* do nothing */
 156                         printf("%.*s\n", len, s);
 157                 }
 158         }
 159 }
 160
 161 static void progress_interval(int signum)
 162 {
 163         progress_update = 1;
 164 }
 165
 166 static void setup_progress_signal(void)
 167 {
 168         struct sigaction sa;
 169         struct itimerval v;
 170
 171         memset(&sa, 0, sizeof(sa));
 172         sa.sa_handler = progress_interval;
 173         sigemptyset(&sa.sa_mask);
 174         sa.sa_flags = SA_RESTART;
 175         sigaction(SIGALRM, &sa, NULL);
 176
 177         v.it_interval.tv_sec = 1;
 178         v.it_interval.tv_usec = 0;
 179         v.it_value = v.it_interval;
 180         setitimer(ITIMER_REAL, &v, NULL);
 181 }
 182
 183 static void display_progress()
 184 {
 185         unsigned percent = total_cnt ? merged_cnt * 100 / total_cnt : 0;
 186         if (progress_update || percent != last_percent) {
 187                 fprintf(stderr, "%4u%% (%u/%u) done\r",
 188                         percent, merged_cnt, total_cnt);
 189                 progress_update = 0;
 190                 last_percent = percent;
 191         }
 192 }
 193
 194 static struct cache_entry *make_cache_entry(unsigned int mode,
 195                 const unsigned char *sha1, const char *path, int stage, int refresh)
 196 {
 197         int size, len;
 198         struct cache_entry *ce;
 199
 200         if (!verify_path(path))
 201                 return NULL;
 202
 203         len = strlen(path);
 204         size = cache_entry_size(len);
 205         ce = xcalloc(1, size);
 206
 207         hashcpy(ce->sha1, sha1);
 208         memcpy(ce->name, path, len);
 209         ce->ce_flags = create_ce_flags(len, stage);
 210         ce->ce_mode = create_ce_mode(mode);
 211
 212         if (refresh)
 213                 return refresh_cache_entry(ce, 0);
 214
 215         return ce;
 216 }
 217
 218 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 219                 const char *path, int stage, int refresh, int options)
 220 {
 221         struct cache_entry *ce;
 222         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 223         if (!ce)
 224                 return error("cache_addinfo failed: %s", strerror(cache_errno));
 225         return add_cache_entry(ce, options);
 226 }
 227
 228 /*
 229  * This is a global variable which is used in a number of places but
 230  * only written to in the 'merge' function.
 231  *
 232  * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
 233  *                       don't update the working directory.
 234  *               0    => Leave unmerged entries in the cache and update
 235  *                       the working directory.
 236  */
 237 static int index_only = 0;
 238
 239 static int git_merge_trees(int index_only,
 240                            struct tree *common,
 241                            struct tree *head,
 242                            struct tree *merge)
 243 {
 244         int rc;
 245         struct object_list *trees = NULL;
 246         struct unpack_trees_options opts;
 247
 248         memset(&opts, 0, sizeof(opts));
 249         if (index_only)
 250                 opts.index_only = 1;
 251         else
 252                 opts.update = 1;
 253         opts.merge = 1;
 254         opts.head_idx = 2;
 255         opts.fn = threeway_merge;
 256
 257         object_list_append(&common->object, &trees);
 258         object_list_append(&head->object, &trees);
 259         object_list_append(&merge->object, &trees);
 260
 261         rc = unpack_trees(trees, &opts);
 262         cache_tree_free(&active_cache_tree);
 263         return rc;
 264 }
 265
 266 static int unmerged_index(void)
 267 {
 268         int i;
 269         for (i = 0; i < active_nr; i++) {
 270                 struct cache_entry *ce = active_cache[i];
 271                 if (ce_stage(ce))
 272                         return 1;
 273         }
 274         return 0;
 275 }
 276
 277 static struct tree *git_write_tree(void)
 278 {
 279         struct tree *result = NULL;
 280
 281         if (unmerged_index()) {
 282                 int i;
 283                 output(0, "There are unmerged index entries:");
 284                 for (i = 0; i < active_nr; i++) {
 285                         struct cache_entry *ce = active_cache[i];
 286                         if (ce_stage(ce))
 287                                 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
 288                 }
 289                 return NULL;
 290         }
 291
 292         if (!active_cache_tree)
 293                 active_cache_tree = cache_tree();
 294
 295         if (!cache_tree_fully_valid(active_cache_tree) &&
 296             cache_tree_update(active_cache_tree,
 297                               active_cache, active_nr, 0, 0) < 0)
 298                 die("error building trees");
 299
 300         result = lookup_tree(active_cache_tree->sha1);
 301
 302         return result;
 303 }
 304
 305 static int save_files_dirs(const unsigned char *sha1,
 306                 const char *base, int baselen, const char *path,
 307                 unsigned int mode, int stage)
 308 {
 309         int len = strlen(path);
 310         char *newpath = xmalloc(baselen + len + 1);
 311         memcpy(newpath, base, baselen);
 312         memcpy(newpath + baselen, path, len);
 313         newpath[baselen + len] = '\0';
 314
 315         if (S_ISDIR(mode))
 316                 path_list_insert(newpath, &current_directory_set);
 317         else
 318                 path_list_insert(newpath, &current_file_set);
 319         free(newpath);
 320
 321         return READ_TREE_RECURSIVE;
 322 }
 323
 324 static int get_files_dirs(struct tree *tree)
 325 {
 326         int n;
 327         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
 328                 return 0;
 329         n = current_file_set.nr + current_directory_set.nr;
 330         return n;
 331 }
 332
 333 /*
 334  * Returns a index_entry instance which doesn't have to correspond to
 335  * a real cache entry in Git's index.
 336  */
 337 static struct stage_data *insert_stage_data(const char *path,
 338                 struct tree *o, struct tree *a, struct tree *b,
 339                 struct path_list *entries)
 340 {
 341         struct path_list_item *item;
 342         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 343         get_tree_entry(o->object.sha1, path,
 344                         e->stages[1].sha, &e->stages[1].mode);
 345         get_tree_entry(a->object.sha1, path,
 346                         e->stages[2].sha, &e->stages[2].mode);
 347         get_tree_entry(b->object.sha1, path,
 348                         e->stages[3].sha, &e->stages[3].mode);
 349         item = path_list_insert(path, entries);
 350         item->util = e;
 351         return e;
 352 }
 353
 354 /*
 355  * Create a dictionary mapping file names to stage_data objects. The
 356  * dictionary contains one entry for every path with a non-zero stage entry.
 357  */
 358 static struct path_list *get_unmerged(void)
 359 {
 360         struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
 361         int i;
 362
 363         unmerged->strdup_paths = 1;
 364         total_cnt += active_nr;
 365
 366         for (i = 0; i < active_nr; i++, merged_cnt++) {
 367                 struct path_list_item *item;
 368                 struct stage_data *e;
 369                 struct cache_entry *ce = active_cache[i];
 370                 if (do_progress)
 371                         display_progress();
 372                 if (!ce_stage(ce))
 373                         continue;
 374
 375                 item = path_list_lookup(ce->name, unmerged);
 376                 if (!item) {
 377                         item = path_list_insert(ce->name, unmerged);
 378                         item->util = xcalloc(1, sizeof(struct stage_data));
 379                 }
 380                 e = item->util;
 381                 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
 382                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 383         }
 384
 385         return unmerged;
 386 }
 387
 388 struct rename
 389 {
 390         struct diff_filepair *pair;
 391         struct stage_data *src_entry;
 392         struct stage_data *dst_entry;
 393         unsigned processed:1;
 394 };
 395
 396 /*
 397  * Get information of all renames which occurred between 'o_tree' and
 398  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 399  * 'b_tree') to be able to associate the correct cache entries with
 400  * the rename information. 'tree' is always equal to either a_tree or b_tree.
 401  */
 402 static struct path_list *get_renames(struct tree *tree,
 403                                         struct tree *o_tree,
 404                                         struct tree *a_tree,
 405                                         struct tree *b_tree,
 406                                         struct path_list *entries)
 407 {
 408         int i;
 409         struct path_list *renames;
 410         struct diff_options opts;
 411
 412         renames = xcalloc(1, sizeof(struct path_list));
 413         diff_setup(&opts);
 414         opts.recursive = 1;
 415         opts.detect_rename = DIFF_DETECT_RENAME;
 416         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 417         if (diff_setup_done(&opts) < 0)
 418                 die("diff setup failed");
 419         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 420         diffcore_std(&opts);
 421         for (i = 0; i < diff_queued_diff.nr; ++i) {
 422                 struct path_list_item *item;
 423                 struct rename *re;
 424                 struct diff_filepair *pair = diff_queued_diff.queue[i];
 425                 if (pair->status != 'R') {
 426                         diff_free_filepair(pair);
 427                         continue;
 428                 }
 429                 re = xmalloc(sizeof(*re));
 430                 re->processed = 0;
 431                 re->pair = pair;
 432                 item = path_list_lookup(re->pair->one->path, entries);
 433                 if (!item)
 434                         re->src_entry = insert_stage_data(re->pair->one->path,
 435                                         o_tree, a_tree, b_tree, entries);
 436                 else
 437                         re->src_entry = item->util;
 438
 439                 item = path_list_lookup(re->pair->two->path, entries);
 440                 if (!item)
 441                         re->dst_entry = insert_stage_data(re->pair->two->path,
 442                                         o_tree, a_tree, b_tree, entries);
 443                 else
 444                         re->dst_entry = item->util;
 445                 item = path_list_insert(pair->one->path, renames);
 446                 item->util = re;
 447         }
 448         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 449         diff_queued_diff.nr = 0;
 450         diff_flush(&opts);
 451         return renames;
 452 }
 453
 454 static int update_stages(const char *path, struct diff_filespec *o,
 455                          struct diff_filespec *a, struct diff_filespec *b,
 456                          int clear)
 457 {
 458         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 459         if (clear)
 460                 if (remove_file_from_cache(path))
 461                         return -1;
 462         if (o)
 463                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 464                         return -1;
 465         if (a)
 466                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 467                         return -1;
 468         if (b)
 469                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 470                         return -1;
 471         return 0;
 472 }
 473
 474 static int remove_path(const char *name)
 475 {
 476         int ret, len;
 477         char *slash, *dirs;
 478
 479         ret = unlink(name);
 480         if (ret)
 481                 return ret;
 482         len = strlen(name);
 483         dirs = xmalloc(len+1);
 484         memcpy(dirs, name, len);
 485         dirs[len] = '\0';
 486         while ((slash = strrchr(name, '/'))) {
 487                 *slash = '\0';
 488                 len = slash - name;
 489                 if (rmdir(name) != 0)
 490                         break;
 491         }
 492         free(dirs);
 493         return ret;
 494 }
 495
 496 static int remove_file(int clean, const char *path, int no_wd)
 497 {
 498         int update_cache = index_only || clean;
 499         int update_working_directory = !index_only && !no_wd;
 500
 501         if (update_cache) {
 502                 if (remove_file_from_cache(path))
 503                         return -1;
 504         }
 505         if (update_working_directory) {
 506                 unlink(path);
 507                 if (errno != ENOENT || errno != EISDIR)
 508                         return -1;
 509                 remove_path(path);
 510         }
 511         return 0;
 512 }
 513
 514 static char *unique_path(const char *path, const char *branch)
 515 {
 516         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 517         int suffix = 0;
 518         struct stat st;
 519         char *p = newpath + strlen(path);
 520         strcpy(newpath, path);
 521         *(p++) = '~';
 522         strcpy(p, branch);
 523         for (; *p; ++p)
 524                 if ('/' == *p)
 525                         *p = '_';
 526         while (path_list_has_path(&current_file_set, newpath) ||
 527                path_list_has_path(&current_directory_set, newpath) ||
 528                lstat(newpath, &st) == 0)
 529                 sprintf(p, "_%d", suffix++);
 530
 531         path_list_insert(newpath, &current_file_set);
 532         return newpath;
 533 }
 534
 535 static int mkdir_p(const char *path, unsigned long mode)
 536 {
 537         /* path points to cache entries, so xstrdup before messing with it */
 538         char *buf = xstrdup(path);
 539         int result = safe_create_leading_directories(buf);
 540         free(buf);
 541         return result;
 542 }
 543
 544 static void flush_buffer(int fd, const char *buf, unsigned long size)
 545 {
 546         while (size > 0) {
 547                 long ret = write_in_full(fd, buf, size);
 548                 if (ret < 0) {
 549                         /* Ignore epipe */
 550                         if (errno == EPIPE)
 551                                 break;
 552                         die("merge-recursive: %s", strerror(errno));
 553                 } else if (!ret) {
 554                         die("merge-recursive: disk full?");
 555                 }
 556                 size -= ret;
 557                 buf += ret;
 558         }
 559 }
 560
 561 static void update_file_flags(const unsigned char *sha,
 562                               unsigned mode,
 563                               const char *path,
 564                               int update_cache,
 565                               int update_wd)
 566 {
 567         if (index_only)
 568                 update_wd = 0;
 569
 570         if (update_wd) {
 571                 enum object_type type;
 572                 void *buf;
 573                 unsigned long size;
 574
 575                 buf = read_sha1_file(sha, &type, &size);
 576                 if (!buf)
 577                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 578                 if (type != OBJ_BLOB)
 579                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 580
 581                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 582                         int fd;
 583                         if (mkdir_p(path, 0777))
 584                                 die("failed to create path %s: %s", path, strerror(errno));
 585                         unlink(path);
 586                         if (mode & 0100)
 587                                 mode = 0777;
 588                         else
 589                                 mode = 0666;
 590                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 591                         if (fd < 0)
 592                                 die("failed to open %s: %s", path, strerror(errno));
 593                         flush_buffer(fd, buf, size);
 594                         close(fd);
 595                 } else if (S_ISLNK(mode)) {
 596                         char *lnk = xmalloc(size + 1);
 597                         memcpy(lnk, buf, size);
 598                         lnk[size] = '\0';
 599                         mkdir_p(path, 0777);
 600                         unlink(path);
 601                         symlink(lnk, path);
 602                         free(lnk);
 603                 } else
 604                         die("do not know what to do with %06o %s '%s'",
 605                             mode, sha1_to_hex(sha), path);
 606         }
 607         if (update_cache)
 608                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 609 }
 610
 611 static void update_file(int clean,
 612                         const unsigned char *sha,
 613                         unsigned mode,
 614                         const char *path)
 615 {
 616         update_file_flags(sha, mode, path, index_only || clean, !index_only);
 617 }
 618
 619 /* Low level file merging, update and removal */
 620
 621 struct merge_file_info
 622 {
 623         unsigned char sha[20];
 624         unsigned mode;
 625         unsigned clean:1,
 626                  merge:1;
 627 };
 628
 629 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
 630 {
 631         unsigned long size;
 632         enum object_type type;
 633
 634         if (!hashcmp(sha1, null_sha1)) {
 635                 mm->ptr = xstrdup("");
 636                 mm->size = 0;
 637                 return;
 638         }
 639
 640         mm->ptr = read_sha1_file(sha1, &type, &size);
 641         if (!mm->ptr || type != OBJ_BLOB)
 642                 die("unable to read blob object %s", sha1_to_hex(sha1));
 643         mm->size = size;
 644 }
 645
 646 static struct merge_file_info merge_file(struct diff_filespec *o,
 647                 struct diff_filespec *a, struct diff_filespec *b,
 648                 const char *branch1, const char *branch2)
 649 {
 650         struct merge_file_info result;
 651         result.merge = 0;
 652         result.clean = 1;
 653
 654         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 655                 result.clean = 0;
 656                 if (S_ISREG(a->mode)) {
 657                         result.mode = a->mode;
 658                         hashcpy(result.sha, a->sha1);
 659                 } else {
 660                         result.mode = b->mode;
 661                         hashcpy(result.sha, b->sha1);
 662                 }
 663         } else {
 664                 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
 665                         result.merge = 1;
 666
 667                 result.mode = a->mode == o->mode ? b->mode: a->mode;
 668
 669                 if (sha_eq(a->sha1, o->sha1))
 670                         hashcpy(result.sha, b->sha1);
 671                 else if (sha_eq(b->sha1, o->sha1))
 672                         hashcpy(result.sha, a->sha1);
 673                 else if (S_ISREG(a->mode)) {
 674                         mmfile_t orig, src1, src2;
 675                         mmbuffer_t result_buf;
 676                         xpparam_t xpp;
 677                         char *name1, *name2;
 678                         int merge_status;
 679
 680                         name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 681                         name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 682
 683                         fill_mm(o->sha1, &orig);
 684                         fill_mm(a->sha1, &src1);
 685                         fill_mm(b->sha1, &src2);
 686
 687                         memset(&xpp, 0, sizeof(xpp));
 688                         merge_status = xdl_merge(&orig,
 689                                                  &src1, name1,
 690                                                  &src2, name2,
 691                                                  &xpp, XDL_MERGE_ZEALOUS,
 692                                                  &result_buf);
 693                         free(name1);
 694                         free(name2);
 695                         free(orig.ptr);
 696                         free(src1.ptr);
 697                         free(src2.ptr);
 698
 699                         if ((merge_status < 0) || !result_buf.ptr)
 700                                 die("Failed to execute internal merge");
 701
 702                         if (write_sha1_file(result_buf.ptr, result_buf.size,
 703                                             blob_type, result.sha))
 704                                 die("Unable to add %s to database",
 705                                     a->path);
 706
 707                         free(result_buf.ptr);
 708                         result.clean = (merge_status == 0);
 709                 } else {
 710                         if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
 711                                 die("cannot merge modes?");
 712
 713                         hashcpy(result.sha, a->sha1);
 714
 715                         if (!sha_eq(a->sha1, b->sha1))
 716                                 result.clean = 0;
 717                 }
 718         }
 719
 720         return result;
 721 }
 722
 723 static void conflict_rename_rename(struct rename *ren1,
 724                                    const char *branch1,
 725                                    struct rename *ren2,
 726                                    const char *branch2)
 727 {
 728         char *del[2];
 729         int delp = 0;
 730         const char *ren1_dst = ren1->pair->two->path;
 731         const char *ren2_dst = ren2->pair->two->path;
 732         const char *dst_name1 = ren1_dst;
 733         const char *dst_name2 = ren2_dst;
 734         if (path_list_has_path(&current_directory_set, ren1_dst)) {
 735                 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
 736                 output(1, "%s is a directory in %s added as %s instead",
 737                        ren1_dst, branch2, dst_name1);
 738                 remove_file(0, ren1_dst, 0);
 739         }
 740         if (path_list_has_path(&current_directory_set, ren2_dst)) {
 741                 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
 742                 output(1, "%s is a directory in %s added as %s instead",
 743                        ren2_dst, branch1, dst_name2);
 744                 remove_file(0, ren2_dst, 0);
 745         }
 746         if (index_only) {
 747                 remove_file_from_cache(dst_name1);
 748                 remove_file_from_cache(dst_name2);
 749                 /*
 750                  * Uncomment to leave the conflicting names in the resulting tree
 751                  *
 752                  * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
 753                  * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
 754                  */
 755         } else {
 756                 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
 757                 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
 758         }
 759         while (delp--)
 760                 free(del[delp]);
 761 }
 762
 763 static void conflict_rename_dir(struct rename *ren1,
 764                                 const char *branch1)
 765 {
 766         char *new_path = unique_path(ren1->pair->two->path, branch1);
 767         output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
 768         remove_file(0, ren1->pair->two->path, 0);
 769         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 770         free(new_path);
 771 }
 772
 773 static void conflict_rename_rename_2(struct rename *ren1,
 774                                      const char *branch1,
 775                                      struct rename *ren2,
 776                                      const char *branch2)
 777 {
 778         char *new_path1 = unique_path(ren1->pair->two->path, branch1);
 779         char *new_path2 = unique_path(ren2->pair->two->path, branch2);
 780         output(1, "Renamed %s to %s and %s to %s instead",
 781                ren1->pair->one->path, new_path1,
 782                ren2->pair->one->path, new_path2);
 783         remove_file(0, ren1->pair->two->path, 0);
 784         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 785         update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 786         free(new_path2);
 787         free(new_path1);
 788 }
 789
 790 static int process_renames(struct path_list *a_renames,
 791                            struct path_list *b_renames,
 792                            const char *a_branch,
 793                            const char *b_branch)
 794 {
 795         int clean_merge = 1, i, j;
 796         struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
 797         const struct rename *sre;
 798
 799         for (i = 0; i < a_renames->nr; i++) {
 800                 sre = a_renames->items[i].util;
 801                 path_list_insert(sre->pair->two->path, &a_by_dst)->util
 802                         = sre->dst_entry;
 803         }
 804         for (i = 0; i < b_renames->nr; i++) {
 805                 sre = b_renames->items[i].util;
 806                 path_list_insert(sre->pair->two->path, &b_by_dst)->util
 807                         = sre->dst_entry;
 808         }
 809
 810         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 811                 int compare;
 812                 char *src;
 813                 struct path_list *renames1, *renames2, *renames2Dst;
 814                 struct rename *ren1 = NULL, *ren2 = NULL;
 815                 const char *branch1, *branch2;
 816                 const char *ren1_src, *ren1_dst;
 817
 818                 if (i >= a_renames->nr) {
 819                         compare = 1;
 820                         ren2 = b_renames->items[j++].util;
 821                 } else if (j >= b_renames->nr) {
 822                         compare = -1;
 823                         ren1 = a_renames->items[i++].util;
 824                 } else {
 825                         compare = strcmp(a_renames->items[i].path,
 826                                         b_renames->items[j].path);
 827                         if (compare <= 0)
 828                                 ren1 = a_renames->items[i++].util;
 829                         if (compare >= 0)
 830                                 ren2 = b_renames->items[j++].util;
 831                 }
 832
 833                 /* TODO: refactor, so that 1/2 are not needed */
 834                 if (ren1) {
 835                         renames1 = a_renames;
 836                         renames2 = b_renames;
 837                         renames2Dst = &b_by_dst;
 838                         branch1 = a_branch;
 839                         branch2 = b_branch;
 840                 } else {
 841                         struct rename *tmp;
 842                         renames1 = b_renames;
 843                         renames2 = a_renames;
 844                         renames2Dst = &a_by_dst;
 845                         branch1 = b_branch;
 846                         branch2 = a_branch;
 847                         tmp = ren2;
 848                         ren2 = ren1;
 849                         ren1 = tmp;
 850                 }
 851                 src = ren1->pair->one->path;
 852
 853                 ren1->dst_entry->processed = 1;
 854                 ren1->src_entry->processed = 1;
 855
 856                 if (ren1->processed)
 857                         continue;
 858                 ren1->processed = 1;
 859
 860                 ren1_src = ren1->pair->one->path;
 861                 ren1_dst = ren1->pair->two->path;
 862
 863                 if (ren2) {
 864                         const char *ren2_src = ren2->pair->one->path;
 865                         const char *ren2_dst = ren2->pair->two->path;
 866                         /* Renamed in 1 and renamed in 2 */
 867                         if (strcmp(ren1_src, ren2_src) != 0)
 868                                 die("ren1.src != ren2.src");
 869                         ren2->dst_entry->processed = 1;
 870                         ren2->processed = 1;
 871                         if (strcmp(ren1_dst, ren2_dst) != 0) {
 872                                 clean_merge = 0;
 873                                 output(1, "CONFLICT (rename/rename): "
 874                                        "Rename \"%s\"->\"%s\" in branch \"%s\" "
 875                                        "rename \"%s\"->\"%s\" in \"%s\"%s",
 876                                        src, ren1_dst, branch1,
 877                                        src, ren2_dst, branch2,
 878                                        index_only ? " (left unresolved)": "");
 879                                 if (index_only) {
 880                                         remove_file_from_cache(src);
 881                                         update_file(0, ren1->pair->one->sha1,
 882                                                     ren1->pair->one->mode, src);
 883                                 }
 884                                 conflict_rename_rename(ren1, branch1, ren2, branch2);
 885                         } else {
 886                                 struct merge_file_info mfi;
 887                                 remove_file(1, ren1_src, 1);
 888                                 mfi = merge_file(ren1->pair->one,
 889                                                  ren1->pair->two,
 890                                                  ren2->pair->two,
 891                                                  branch1,
 892                                                  branch2);
 893                                 if (mfi.merge || !mfi.clean)
 894                                         output(1, "Renamed %s->%s", src, ren1_dst);
 895
 896                                 if (mfi.merge)
 897                                         output(2, "Auto-merged %s", ren1_dst);
 898
 899                                 if (!mfi.clean) {
 900                                         output(1, "CONFLICT (content): merge conflict in %s",
 901                                                ren1_dst);
 902                                         clean_merge = 0;
 903
 904                                         if (!index_only)
 905                                                 update_stages(ren1_dst,
 906                                                               ren1->pair->one,
 907                                                               ren1->pair->two,
 908                                                               ren2->pair->two,
 909                                                               1 /* clear */);
 910                                 }
 911                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 912                         }
 913                 } else {
 914                         /* Renamed in 1, maybe changed in 2 */
 915                         struct path_list_item *item;
 916                         /* we only use sha1 and mode of these */
 917                         struct diff_filespec src_other, dst_other;
 918                         int try_merge, stage = a_renames == renames1 ? 3: 2;
 919
 920                         remove_file(1, ren1_src, index_only || stage == 3);
 921
 922                         hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
 923                         src_other.mode = ren1->src_entry->stages[stage].mode;
 924                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
 925                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
 926
 927                         try_merge = 0;
 928
 929                         if (path_list_has_path(&current_directory_set, ren1_dst)) {
 930                                 clean_merge = 0;
 931                                 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
 932                                        " directory %s added in %s",
 933                                        ren1_src, ren1_dst, branch1,
 934                                        ren1_dst, branch2);
 935                                 conflict_rename_dir(ren1, branch1);
 936                         } else if (sha_eq(src_other.sha1, null_sha1)) {
 937                                 clean_merge = 0;
 938                                 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
 939                                        "and deleted in %s",
 940                                        ren1_src, ren1_dst, branch1,
 941                                        branch2);
 942                                 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 943                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
 944                                 const char *new_path;
 945                                 clean_merge = 0;
 946                                 try_merge = 1;
 947                                 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
 948                                        "%s added in %s",
 949                                        ren1_src, ren1_dst, branch1,
 950                                        ren1_dst, branch2);
 951                                 new_path = unique_path(ren1_dst, branch2);
 952                                 output(1, "Added as %s instead", new_path);
 953                                 update_file(0, dst_other.sha1, dst_other.mode, new_path);
 954                         } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
 955                                 ren2 = item->util;
 956                                 clean_merge = 0;
 957                                 ren2->processed = 1;
 958                                 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
 959                                        "Renamed %s->%s in %s",
 960                                        ren1_src, ren1_dst, branch1,
 961                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
 962                                 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
 963                         } else
 964                                 try_merge = 1;
 965
 966                         if (try_merge) {
 967                                 struct diff_filespec *o, *a, *b;
 968                                 struct merge_file_info mfi;
 969                                 src_other.path = (char *)ren1_src;
 970
 971                                 o = ren1->pair->one;
 972                                 if (a_renames == renames1) {
 973                                         a = ren1->pair->two;
 974                                         b = &src_other;
 975                                 } else {
 976                                         b = ren1->pair->two;
 977                                         a = &src_other;
 978                                 }
 979                                 mfi = merge_file(o, a, b,
 980                                                 a_branch, b_branch);
 981
 982                                 if (mfi.merge || !mfi.clean)
 983                                         output(1, "Renamed %s => %s", ren1_src, ren1_dst);
 984                                 if (mfi.merge)
 985                                         output(2, "Auto-merged %s", ren1_dst);
 986                                 if (!mfi.clean) {
 987                                         output(1, "CONFLICT (rename/modify): Merge conflict in %s",
 988                                                ren1_dst);
 989                                         clean_merge = 0;
 990
 991                                         if (!index_only)
 992                                                 update_stages(ren1_dst,
 993                                                                 o, a, b, 1);
 994                                 }
 995                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 996                         }
 997                 }
 998         }
 999         path_list_clear(&a_by_dst, 0);
1000         path_list_clear(&b_by_dst, 0);
1001
1002         return clean_merge;
1003 }
1004
1005 static unsigned char *has_sha(const unsigned char *sha)
1006 {
1007         return is_null_sha1(sha) ? NULL: (unsigned char *)sha;
1008 }
1009
1010 /* Per entry merge function */
1011 static int process_entry(const char *path, struct stage_data *entry,
1012                          const char *branch1,
1013                          const char *branch2)
1014 {
1015         /*
1016         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1017         print_index_entry("\tpath: ", entry);
1018         */
1019         int clean_merge = 1;
1020         unsigned char *o_sha = has_sha(entry->stages[1].sha);
1021         unsigned char *a_sha = has_sha(entry->stages[2].sha);
1022         unsigned char *b_sha = has_sha(entry->stages[3].sha);
1023         unsigned o_mode = entry->stages[1].mode;
1024         unsigned a_mode = entry->stages[2].mode;
1025         unsigned b_mode = entry->stages[3].mode;
1026
1027         if (o_sha && (!a_sha || !b_sha)) {
1028                 /* Case A: Deleted in one */
1029                 if ((!a_sha && !b_sha) ||
1030                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1031                     (!a_sha && sha_eq(b_sha, o_sha))) {
1032                         /* Deleted in both or deleted in one and
1033                          * unchanged in the other */
1034                         if (a_sha)
1035                                 output(2, "Removed %s", path);
1036                         /* do not touch working file if it did not exist */
1037                         remove_file(1, path, !a_sha);
1038                 } else {
1039                         /* Deleted in one and changed in the other */
1040                         clean_merge = 0;
1041                         if (!a_sha) {
1042                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1043                                        "and modified in %s. Version %s of %s left in tree.",
1044                                        path, branch1,
1045                                        branch2, branch2, path);
1046                                 update_file(0, b_sha, b_mode, path);
1047                         } else {
1048                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1049                                        "and modified in %s. Version %s of %s left in tree.",
1050                                        path, branch2,
1051                                        branch1, branch1, path);
1052                                 update_file(0, a_sha, a_mode, path);
1053                         }
1054                 }
1055
1056         } else if ((!o_sha && a_sha && !b_sha) ||
1057                    (!o_sha && !a_sha && b_sha)) {
1058                 /* Case B: Added in one. */
1059                 const char *add_branch;
1060                 const char *other_branch;
1061                 unsigned mode;
1062                 const unsigned char *sha;
1063                 const char *conf;
1064
1065                 if (a_sha) {
1066                         add_branch = branch1;
1067                         other_branch = branch2;
1068                         mode = a_mode;
1069                         sha = a_sha;
1070                         conf = "file/directory";
1071                 } else {
1072                         add_branch = branch2;
1073                         other_branch = branch1;
1074                         mode = b_mode;
1075                         sha = b_sha;
1076                         conf = "directory/file";
1077                 }
1078                 if (path_list_has_path(&current_directory_set, path)) {
1079                         const char *new_path = unique_path(path, add_branch);
1080                         clean_merge = 0;
1081                         output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1082                                "Added %s as %s",
1083                                conf, path, other_branch, path, new_path);
1084                         remove_file(0, path, 0);
1085                         update_file(0, sha, mode, new_path);
1086                 } else {
1087                         output(2, "Added %s", path);
1088                         update_file(1, sha, mode, path);
1089                 }
1090         } else if (a_sha && b_sha) {
1091                 /* Case C: Added in both (check for same permissions) and */
1092                 /* case D: Modified in both, but differently. */
1093                 const char *reason = "content";
1094                 struct merge_file_info mfi;
1095                 struct diff_filespec o, a, b;
1096
1097                 if (!o_sha) {
1098                         reason = "add/add";
1099                         o_sha = (unsigned char *)null_sha1;
1100                 }
1101                 output(2, "Auto-merged %s", path);
1102                 o.path = a.path = b.path = (char *)path;
1103                 hashcpy(o.sha1, o_sha);
1104                 o.mode = o_mode;
1105                 hashcpy(a.sha1, a_sha);
1106                 a.mode = a_mode;
1107                 hashcpy(b.sha1, b_sha);
1108                 b.mode = b_mode;
1109
1110                 mfi = merge_file(&o, &a, &b,
1111                                  branch1, branch2);
1112
1113                 if (mfi.clean)
1114                         update_file(1, mfi.sha, mfi.mode, path);
1115                 else {
1116                         clean_merge = 0;
1117                         output(1, "CONFLICT (%s): Merge conflict in %s",
1118                                         reason, path);
1119
1120                         if (index_only)
1121                                 update_file(0, mfi.sha, mfi.mode, path);
1122                         else
1123                                 update_file_flags(mfi.sha, mfi.mode, path,
1124                                               0 /* update_cache */, 1 /* update_working_directory */);
1125                 }
1126         } else
1127                 die("Fatal merge failure, shouldn't happen.");
1128
1129         return clean_merge;
1130 }
1131
1132 static int merge_trees(struct tree *head,
1133                        struct tree *merge,
1134                        struct tree *common,
1135                        const char *branch1,
1136                        const char *branch2,
1137                        struct tree **result)
1138 {
1139         int code, clean;
1140         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1141                 output(0, "Already uptodate!");
1142                 *result = head;
1143                 return 1;
1144         }
1145
1146         code = git_merge_trees(index_only, common, head, merge);
1147
1148         if (code != 0)
1149                 die("merging of trees %s and %s failed",
1150                     sha1_to_hex(head->object.sha1),
1151                     sha1_to_hex(merge->object.sha1));
1152
1153         if (unmerged_index()) {
1154                 struct path_list *entries, *re_head, *re_merge;
1155                 int i;
1156                 path_list_clear(&current_file_set, 1);
1157                 path_list_clear(&current_directory_set, 1);
1158                 get_files_dirs(head);
1159                 get_files_dirs(merge);
1160
1161                 entries = get_unmerged();
1162                 re_head  = get_renames(head, common, head, merge, entries);
1163                 re_merge = get_renames(merge, common, head, merge, entries);
1164                 clean = process_renames(re_head, re_merge,
1165                                 branch1, branch2);
1166                 total_cnt += entries->nr;
1167                 for (i = 0; i < entries->nr; i++, merged_cnt++) {
1168                         const char *path = entries->items[i].path;
1169                         struct stage_data *e = entries->items[i].util;
1170                         if (!e->processed
1171                                 && !process_entry(path, e, branch1, branch2))
1172                                 clean = 0;
1173                         if (do_progress)
1174                                 display_progress();
1175                 }
1176
1177                 path_list_clear(re_merge, 0);
1178                 path_list_clear(re_head, 0);
1179                 path_list_clear(entries, 1);
1180
1181         }
1182         else
1183                 clean = 1;
1184
1185         if (index_only)
1186                 *result = git_write_tree();
1187
1188         return clean;
1189 }
1190
1191 static struct commit_list *reverse_commit_list(struct commit_list *list)
1192 {
1193         struct commit_list *next = NULL, *current, *backup;
1194         for (current = list; current; current = backup) {
1195                 backup = current->next;
1196                 current->next = next;
1197                 next = current;
1198         }
1199         return next;
1200 }
1201
1202 /*
1203  * Merge the commits h1 and h2, return the resulting virtual
1204  * commit object and a flag indicating the cleanness of the merge.
1205  */
1206 static int merge(struct commit *h1,
1207                  struct commit *h2,
1208                  const char *branch1,
1209                  const char *branch2,
1210                  struct commit_list *ca,
1211                  struct commit **result)
1212 {
1213         struct commit_list *iter;
1214         struct commit *merged_common_ancestors;
1215         struct tree *mrtree;
1216         int clean;
1217
1218         if (show(4)) {
1219                 output(4, "Merging:");
1220                 output_commit_title(h1);
1221                 output_commit_title(h2);
1222         }
1223
1224         if (!ca) {
1225                 ca = get_merge_bases(h1, h2, 1);
1226                 ca = reverse_commit_list(ca);
1227         }
1228
1229         if (show(5)) {
1230                 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1231                 for (iter = ca; iter; iter = iter->next)
1232                         output_commit_title(iter->item);
1233         }
1234
1235         merged_common_ancestors = pop_commit(&ca);
1236         if (merged_common_ancestors == NULL) {
1237                 /* if there is no common ancestor, make an empty tree */
1238                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1239
1240                 tree->object.parsed = 1;
1241                 tree->object.type = OBJ_TREE;
1242                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1243                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1244         }
1245
1246         for (iter = ca; iter; iter = iter->next) {
1247                 call_depth++;
1248                 /*
1249                  * When the merge fails, the result contains files
1250                  * with conflict markers. The cleanness flag is
1251                  * ignored, it was never actually used, as result of
1252                  * merge_trees has always overwritten it: the committed
1253                  * "conflicts" were already resolved.
1254                  */
1255                 discard_cache();
1256                 merge(merged_common_ancestors, iter->item,
1257                       "Temporary merge branch 1",
1258                       "Temporary merge branch 2",
1259                       NULL,
1260                       &merged_common_ancestors);
1261                 call_depth--;
1262
1263                 if (!merged_common_ancestors)
1264                         die("merge returned no commit");
1265         }
1266
1267         discard_cache();
1268         if (!call_depth) {
1269                 read_cache();
1270                 index_only = 0;
1271         } else
1272                 index_only = 1;
1273
1274         clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1275                             branch1, branch2, &mrtree);
1276
1277         if (index_only) {
1278                 *result = make_virtual_commit(mrtree, "merged tree");
1279                 commit_list_insert(h1, &(*result)->parents);
1280                 commit_list_insert(h2, &(*result)->parents->next);
1281         }
1282         if (!call_depth && do_progress) {
1283                 /* Make sure we end at 100% */
1284                 if (!total_cnt)
1285                         total_cnt = 1;
1286                 merged_cnt = total_cnt;
1287                 progress_update = 1;
1288                 display_progress();
1289                 fputc('\n', stderr);
1290         }
1291         flush_output();
1292         return clean;
1293 }
1294
1295 static const char *better_branch_name(const char *branch)
1296 {
1297         static char githead_env[8 + 40 + 1];
1298         char *name;
1299
1300         if (strlen(branch) != 40)
1301                 return branch;
1302         sprintf(githead_env, "GITHEAD_%s", branch);
1303         name = getenv(githead_env);
1304         return name ? name : branch;
1305 }
1306
1307 static struct commit *get_ref(const char *ref)
1308 {
1309         unsigned char sha1[20];
1310         struct object *object;
1311
1312         if (get_sha1(ref, sha1))
1313                 die("Could not resolve ref '%s'", ref);
1314         object = deref_tag(parse_object(sha1), ref, strlen(ref));
1315         if (object->type == OBJ_TREE)
1316                 return make_virtual_commit((struct tree*)object,
1317                         better_branch_name(ref));
1318         if (object->type != OBJ_COMMIT)
1319                 return NULL;
1320         if (parse_commit((struct commit *)object))
1321                 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1322         return (struct commit *)object;
1323 }
1324
1325 static int merge_config(const char *var, const char *value)
1326 {
1327         if (!strcasecmp(var, "merge.verbosity")) {
1328                 verbosity = git_config_int(var, value);
1329                 return 0;
1330         }
1331         return git_default_config(var, value);
1332 }
1333
1334 int main(int argc, char *argv[])
1335 {
1336         static const char *bases[20];
1337         static unsigned bases_count = 0;
1338         int i, clean;
1339         const char *branch1, *branch2;
1340         struct commit *result, *h1, *h2;
1341         struct commit_list *ca = NULL;
1342         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1343         int index_fd;
1344
1345         git_config(merge_config);
1346         if (getenv("GIT_MERGE_VERBOSITY"))
1347                 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1348
1349         if (argc < 4)
1350                 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1351
1352         for (i = 1; i < argc; ++i) {
1353                 if (!strcmp(argv[i], "--"))
1354                         break;
1355                 if (bases_count < sizeof(bases)/sizeof(*bases))
1356                         bases[bases_count++] = argv[i];
1357         }
1358         if (argc - i != 3) /* "--" "<head>" "<remote>" */
1359                 die("Not handling anything other than two heads merge.");
1360         if (verbosity >= 5) {
1361                 buffer_output = 0;
1362                 do_progress = 0;
1363         }
1364         else
1365                 do_progress = isatty(1);
1366
1367         branch1 = argv[++i];
1368         branch2 = argv[++i];
1369
1370         h1 = get_ref(branch1);
1371         h2 = get_ref(branch2);
1372
1373         branch1 = better_branch_name(branch1);
1374         branch2 = better_branch_name(branch2);
1375
1376         if (do_progress)
1377                 setup_progress_signal();
1378         if (show(3))
1379                 printf("Merging %s with %s\n", branch1, branch2);
1380
1381         index_fd = hold_lock_file_for_update(lock, get_index_file(), 1);
1382
1383         for (i = 0; i < bases_count; i++) {
1384                 struct commit *ancestor = get_ref(bases[i]);
1385                 ca = commit_list_insert(ancestor, &ca);
1386         }
1387         clean = merge(h1, h2, branch1, branch2, ca, &result);
1388
1389         if (active_cache_changed &&
1390             (write_cache(index_fd, active_cache, active_nr) ||
1391              close(index_fd) || commit_lock_file(lock)))
1392                         die ("unable to write %s", get_index_file());
1393
1394         return clean ? 0: 1;
1395 }