builtin-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 "builtin.h"
  11 #include "tree-walk.h"
  12 #include "diff.h"
  13 #include "diffcore.h"
  14 #include "tag.h"
  15 #include "unpack-trees.h"
  16 #include "path-list.h"
  17 #include "xdiff-interface.h"
  18 #include "ll-merge.h"
  19 #include "interpolate.h"
  20 #include "attr.h"
  21 #include "merge-recursive.h"
  22
  23 static int subtree_merge;
  24
  25 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
  26 {
  27         unsigned char shifted[20];
  28
  29         /*
  30          * NEEDSWORK: this limits the recursion depth to hardcoded
  31          * value '2' to avoid excessive overhead.
  32          */
  33         shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
  34         if (!hashcmp(two->object.sha1, shifted))
  35                 return two;
  36         return lookup_tree(shifted);
  37 }
  38
  39 /*
  40  * A virtual commit has
  41  * - (const char *)commit->util set to the name, and
  42  * - *(int *)commit->object.sha1 set to the virtual id.
  43  */
  44
  45 static unsigned commit_list_count(const struct commit_list *l)
  46 {
  47         unsigned c = 0;
  48         for (; l; l = l->next )
  49                 c++;
  50         return c;
  51 }
  52
  53 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  54 {
  55         struct commit *commit = xcalloc(1, sizeof(struct commit));
  56         static unsigned virtual_id = 1;
  57         commit->tree = tree;
  58         commit->util = (void*)comment;
  59         *(int*)commit->object.sha1 = virtual_id++;
  60         /* avoid warnings */
  61         commit->object.parsed = 1;
  62         return commit;
  63 }
  64
  65 /*
  66  * Since we use get_tree_entry(), which does not put the read object into
  67  * the object pool, we cannot rely on a == b.
  68  */
  69 static int sha_eq(const unsigned char *a, const unsigned char *b)
  70 {
  71         if (!a && !b)
  72                 return 2;
  73         return a && b && hashcmp(a, b) == 0;
  74 }
  75
  76 /*
  77  * Since we want to write the index eventually, we cannot reuse the index
  78  * for these (temporary) data.
  79  */
  80 struct stage_data
  81 {
  82         struct
  83         {
  84                 unsigned mode;
  85                 unsigned char sha[20];
  86         } stages[4];
  87         unsigned processed:1;
  88 };
  89
  90 static struct path_list current_file_set = {NULL, 0, 0, 1};
  91 static struct path_list current_directory_set = {NULL, 0, 0, 1};
  92
  93 static int call_depth = 0;
  94 static int verbosity = 2;
  95 static int rename_limit = -1;
  96 static int buffer_output = 1;
  97 static struct strbuf obuf = STRBUF_INIT;
  98
  99 static int show(int v)
 100 {
 101         return (!call_depth && verbosity >= v) || verbosity >= 5;
 102 }
 103
 104 static void flush_output(void)
 105 {
 106         if (obuf.len) {
 107                 fputs(obuf.buf, stdout);
 108                 strbuf_reset(&obuf);
 109         }
 110 }
 111
 112 static void output(int v, const char *fmt, ...)
 113 {
 114         int len;
 115         va_list ap;
 116
 117         if (!show(v))
 118                 return;
 119
 120         strbuf_grow(&obuf, call_depth * 2 + 2);
 121         memset(obuf.buf + obuf.len, ' ', call_depth * 2);
 122         strbuf_setlen(&obuf, obuf.len + call_depth * 2);
 123
 124         va_start(ap, fmt);
 125         len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
 126         va_end(ap);
 127
 128         if (len < 0)
 129                 len = 0;
 130         if (len >= strbuf_avail(&obuf)) {
 131                 strbuf_grow(&obuf, len + 2);
 132                 va_start(ap, fmt);
 133                 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
 134                 va_end(ap);
 135                 if (len >= strbuf_avail(&obuf)) {
 136                         die("this should not happen, your snprintf is broken");
 137                 }
 138         }
 139         strbuf_setlen(&obuf, obuf.len + len);
 140         strbuf_add(&obuf, "\n", 1);
 141         if (!buffer_output)
 142                 flush_output();
 143 }
 144
 145 static void output_commit_title(struct commit *commit)
 146 {
 147         int i;
 148         flush_output();
 149         for (i = call_depth; i--;)
 150                 fputs("  ", stdout);
 151         if (commit->util)
 152                 printf("virtual %s\n", (char *)commit->util);
 153         else {
 154                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 155                 if (parse_commit(commit) != 0)
 156                         printf("(bad commit)\n");
 157                 else {
 158                         const char *s;
 159                         int len;
 160                         for (s = commit->buffer; *s; s++)
 161                                 if (*s == '\n' && s[1] == '\n') {
 162                                         s += 2;
 163                                         break;
 164                                 }
 165                         for (len = 0; s[len] && '\n' != s[len]; len++)
 166                                 ; /* do nothing */
 167                         printf("%.*s\n", len, s);
 168                 }
 169         }
 170 }
 171
 172 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 173                 const char *path, int stage, int refresh, int options)
 174 {
 175         struct cache_entry *ce;
 176         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 177         if (!ce)
 178                 return error("addinfo_cache failed for path '%s'", path);
 179         return add_cache_entry(ce, options);
 180 }
 181
 182 /*
 183  * This is a global variable which is used in a number of places but
 184  * only written to in the 'merge' function.
 185  *
 186  * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
 187  *                       don't update the working directory.
 188  *               0    => Leave unmerged entries in the cache and update
 189  *                       the working directory.
 190  */
 191 static int index_only = 0;
 192
 193 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 194 {
 195         parse_tree(tree);
 196         init_tree_desc(desc, tree->buffer, tree->size);
 197 }
 198
 199 static int git_merge_trees(int index_only,
 200                            struct tree *common,
 201                            struct tree *head,
 202                            struct tree *merge)
 203 {
 204         int rc;
 205         struct tree_desc t[3];
 206         struct unpack_trees_options opts;
 207
 208         memset(&opts, 0, sizeof(opts));
 209         if (index_only)
 210                 opts.index_only = 1;
 211         else
 212                 opts.update = 1;
 213         opts.merge = 1;
 214         opts.head_idx = 2;
 215         opts.fn = threeway_merge;
 216
 217         init_tree_desc_from_tree(t+0, common);
 218         init_tree_desc_from_tree(t+1, head);
 219         init_tree_desc_from_tree(t+2, merge);
 220
 221         rc = unpack_trees(3, t, &opts);
 222         cache_tree_free(&active_cache_tree);
 223         return rc;
 224 }
 225
 226 struct tree *write_tree_from_memory(void)
 227 {
 228         struct tree *result = NULL;
 229
 230         if (unmerged_cache()) {
 231                 int i;
 232                 output(0, "There are unmerged index entries:");
 233                 for (i = 0; i < active_nr; i++) {
 234                         struct cache_entry *ce = active_cache[i];
 235                         if (ce_stage(ce))
 236                                 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
 237                 }
 238                 return NULL;
 239         }
 240
 241         if (!active_cache_tree)
 242                 active_cache_tree = cache_tree();
 243
 244         if (!cache_tree_fully_valid(active_cache_tree) &&
 245             cache_tree_update(active_cache_tree,
 246                               active_cache, active_nr, 0, 0) < 0)
 247                 die("error building trees");
 248
 249         result = lookup_tree(active_cache_tree->sha1);
 250
 251         return result;
 252 }
 253
 254 static int save_files_dirs(const unsigned char *sha1,
 255                 const char *base, int baselen, const char *path,
 256                 unsigned int mode, int stage)
 257 {
 258         int len = strlen(path);
 259         char *newpath = xmalloc(baselen + len + 1);
 260         memcpy(newpath, base, baselen);
 261         memcpy(newpath + baselen, path, len);
 262         newpath[baselen + len] = '\0';
 263
 264         if (S_ISDIR(mode))
 265                 path_list_insert(newpath, &current_directory_set);
 266         else
 267                 path_list_insert(newpath, &current_file_set);
 268         free(newpath);
 269
 270         return READ_TREE_RECURSIVE;
 271 }
 272
 273 static int get_files_dirs(struct tree *tree)
 274 {
 275         int n;
 276         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
 277                 return 0;
 278         n = current_file_set.nr + current_directory_set.nr;
 279         return n;
 280 }
 281
 282 /*
 283  * Returns an index_entry instance which doesn't have to correspond to
 284  * a real cache entry in Git's index.
 285  */
 286 static struct stage_data *insert_stage_data(const char *path,
 287                 struct tree *o, struct tree *a, struct tree *b,
 288                 struct path_list *entries)
 289 {
 290         struct path_list_item *item;
 291         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 292         get_tree_entry(o->object.sha1, path,
 293                         e->stages[1].sha, &e->stages[1].mode);
 294         get_tree_entry(a->object.sha1, path,
 295                         e->stages[2].sha, &e->stages[2].mode);
 296         get_tree_entry(b->object.sha1, path,
 297                         e->stages[3].sha, &e->stages[3].mode);
 298         item = path_list_insert(path, entries);
 299         item->util = e;
 300         return e;
 301 }
 302
 303 /*
 304  * Create a dictionary mapping file names to stage_data objects. The
 305  * dictionary contains one entry for every path with a non-zero stage entry.
 306  */
 307 static struct path_list *get_unmerged(void)
 308 {
 309         struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
 310         int i;
 311
 312         unmerged->strdup_paths = 1;
 313
 314         for (i = 0; i < active_nr; i++) {
 315                 struct path_list_item *item;
 316                 struct stage_data *e;
 317                 struct cache_entry *ce = active_cache[i];
 318                 if (!ce_stage(ce))
 319                         continue;
 320
 321                 item = path_list_lookup(ce->name, unmerged);
 322                 if (!item) {
 323                         item = path_list_insert(ce->name, unmerged);
 324                         item->util = xcalloc(1, sizeof(struct stage_data));
 325                 }
 326                 e = item->util;
 327                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
 328                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 329         }
 330
 331         return unmerged;
 332 }
 333
 334 struct rename
 335 {
 336         struct diff_filepair *pair;
 337         struct stage_data *src_entry;
 338         struct stage_data *dst_entry;
 339         unsigned processed:1;
 340 };
 341
 342 /*
 343  * Get information of all renames which occurred between 'o_tree' and
 344  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 345  * 'b_tree') to be able to associate the correct cache entries with
 346  * the rename information. 'tree' is always equal to either a_tree or b_tree.
 347  */
 348 static struct path_list *get_renames(struct tree *tree,
 349                                         struct tree *o_tree,
 350                                         struct tree *a_tree,
 351                                         struct tree *b_tree,
 352                                         struct path_list *entries)
 353 {
 354         int i;
 355         struct path_list *renames;
 356         struct diff_options opts;
 357
 358         renames = xcalloc(1, sizeof(struct path_list));
 359         diff_setup(&opts);
 360         DIFF_OPT_SET(&opts, RECURSIVE);
 361         opts.detect_rename = DIFF_DETECT_RENAME;
 362         opts.rename_limit = rename_limit;
 363         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 364         if (diff_setup_done(&opts) < 0)
 365                 die("diff setup failed");
 366         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 367         diffcore_std(&opts);
 368         for (i = 0; i < diff_queued_diff.nr; ++i) {
 369                 struct path_list_item *item;
 370                 struct rename *re;
 371                 struct diff_filepair *pair = diff_queued_diff.queue[i];
 372                 if (pair->status != 'R') {
 373                         diff_free_filepair(pair);
 374                         continue;
 375                 }
 376                 re = xmalloc(sizeof(*re));
 377                 re->processed = 0;
 378                 re->pair = pair;
 379                 item = path_list_lookup(re->pair->one->path, entries);
 380                 if (!item)
 381                         re->src_entry = insert_stage_data(re->pair->one->path,
 382                                         o_tree, a_tree, b_tree, entries);
 383                 else
 384                         re->src_entry = item->util;
 385
 386                 item = path_list_lookup(re->pair->two->path, entries);
 387                 if (!item)
 388                         re->dst_entry = insert_stage_data(re->pair->two->path,
 389                                         o_tree, a_tree, b_tree, entries);
 390                 else
 391                         re->dst_entry = item->util;
 392                 item = path_list_insert(pair->one->path, renames);
 393                 item->util = re;
 394         }
 395         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 396         diff_queued_diff.nr = 0;
 397         diff_flush(&opts);
 398         return renames;
 399 }
 400
 401 static int update_stages(const char *path, struct diff_filespec *o,
 402                          struct diff_filespec *a, struct diff_filespec *b,
 403                          int clear)
 404 {
 405         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 406         if (clear)
 407                 if (remove_file_from_cache(path))
 408                         return -1;
 409         if (o)
 410                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 411                         return -1;
 412         if (a)
 413                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 414                         return -1;
 415         if (b)
 416                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 417                         return -1;
 418         return 0;
 419 }
 420
 421 static int remove_path(const char *name)
 422 {
 423         int ret;
 424         char *slash, *dirs;
 425
 426         ret = unlink(name);
 427         if (ret)
 428                 return ret;
 429         dirs = xstrdup(name);
 430         while ((slash = strrchr(name, '/'))) {
 431                 *slash = '\0';
 432                 if (rmdir(name) != 0)
 433                         break;
 434         }
 435         free(dirs);
 436         return ret;
 437 }
 438
 439 static int remove_file(int clean, const char *path, int no_wd)
 440 {
 441         int update_cache = index_only || clean;
 442         int update_working_directory = !index_only && !no_wd;
 443
 444         if (update_cache) {
 445                 if (remove_file_from_cache(path))
 446                         return -1;
 447         }
 448         if (update_working_directory) {
 449                 unlink(path);
 450                 if (errno != ENOENT || errno != EISDIR)
 451                         return -1;
 452                 remove_path(path);
 453         }
 454         return 0;
 455 }
 456
 457 static char *unique_path(const char *path, const char *branch)
 458 {
 459         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 460         int suffix = 0;
 461         struct stat st;
 462         char *p = newpath + strlen(path);
 463         strcpy(newpath, path);
 464         *(p++) = '~';
 465         strcpy(p, branch);
 466         for (; *p; ++p)
 467                 if ('/' == *p)
 468                         *p = '_';
 469         while (path_list_has_path(&current_file_set, newpath) ||
 470                path_list_has_path(&current_directory_set, newpath) ||
 471                lstat(newpath, &st) == 0)
 472                 sprintf(p, "_%d", suffix++);
 473
 474         path_list_insert(newpath, &current_file_set);
 475         return newpath;
 476 }
 477
 478 static int mkdir_p(const char *path, unsigned long mode)
 479 {
 480         /* path points to cache entries, so xstrdup before messing with it */
 481         char *buf = xstrdup(path);
 482         int result = safe_create_leading_directories(buf);
 483         free(buf);
 484         return result;
 485 }
 486
 487 static void flush_buffer(int fd, const char *buf, unsigned long size)
 488 {
 489         while (size > 0) {
 490                 long ret = write_in_full(fd, buf, size);
 491                 if (ret < 0) {
 492                         /* Ignore epipe */
 493                         if (errno == EPIPE)
 494                                 break;
 495                         die("merge-recursive: %s", strerror(errno));
 496                 } else if (!ret) {
 497                         die("merge-recursive: disk full?");
 498                 }
 499                 size -= ret;
 500                 buf += ret;
 501         }
 502 }
 503
 504 static int make_room_for_path(const char *path)
 505 {
 506         int status;
 507         const char *msg = "failed to create path '%s'%s";
 508
 509         status = mkdir_p(path, 0777);
 510         if (status) {
 511                 if (status == -3) {
 512                         /* something else exists */
 513                         error(msg, path, ": perhaps a D/F conflict?");
 514                         return -1;
 515                 }
 516                 die(msg, path, "");
 517         }
 518
 519         /* Successful unlink is good.. */
 520         if (!unlink(path))
 521                 return 0;
 522         /* .. and so is no existing file */
 523         if (errno == ENOENT)
 524                 return 0;
 525         /* .. but not some other error (who really cares what?) */
 526         return error(msg, path, ": perhaps a D/F conflict?");
 527 }
 528
 529 static void update_file_flags(const unsigned char *sha,
 530                               unsigned mode,
 531                               const char *path,
 532                               int update_cache,
 533                               int update_wd)
 534 {
 535         if (index_only)
 536                 update_wd = 0;
 537
 538         if (update_wd) {
 539                 enum object_type type;
 540                 void *buf;
 541                 unsigned long size;
 542
 543                 if (S_ISGITLINK(mode))
 544                         die("cannot read object %s '%s': It is a submodule!",
 545                             sha1_to_hex(sha), path);
 546
 547                 buf = read_sha1_file(sha, &type, &size);
 548                 if (!buf)
 549                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 550                 if (type != OBJ_BLOB)
 551                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 552
 553                 if (make_room_for_path(path) < 0) {
 554                         update_wd = 0;
 555                         goto update_index;
 556                 }
 557                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 558                         int fd;
 559                         if (mode & 0100)
 560                                 mode = 0777;
 561                         else
 562                                 mode = 0666;
 563                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 564                         if (fd < 0)
 565                                 die("failed to open %s: %s", path, strerror(errno));
 566                         flush_buffer(fd, buf, size);
 567                         close(fd);
 568                 } else if (S_ISLNK(mode)) {
 569                         char *lnk = xmemdupz(buf, size);
 570                         mkdir_p(path, 0777);
 571                         unlink(path);
 572                         symlink(lnk, path);
 573                         free(lnk);
 574                 } else
 575                         die("do not know what to do with %06o %s '%s'",
 576                             mode, sha1_to_hex(sha), path);
 577         }
 578  update_index:
 579         if (update_cache)
 580                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 581 }
 582
 583 static void update_file(int clean,
 584                         const unsigned char *sha,
 585                         unsigned mode,
 586                         const char *path)
 587 {
 588         update_file_flags(sha, mode, path, index_only || clean, !index_only);
 589 }
 590
 591 /* Low level file merging, update and removal */
 592
 593 struct merge_file_info
 594 {
 595         unsigned char sha[20];
 596         unsigned mode;
 597         unsigned clean:1,
 598                  merge:1;
 599 };
 600
 601 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
 602 {
 603         unsigned long size;
 604         enum object_type type;
 605
 606         if (!hashcmp(sha1, null_sha1)) {
 607                 mm->ptr = xstrdup("");
 608                 mm->size = 0;
 609                 return;
 610         }
 611
 612         mm->ptr = read_sha1_file(sha1, &type, &size);
 613         if (!mm->ptr || type != OBJ_BLOB)
 614                 die("unable to read blob object %s", sha1_to_hex(sha1));
 615         mm->size = size;
 616 }
 617
 618 static int merge_3way(mmbuffer_t *result_buf,
 619                       struct diff_filespec *o,
 620                       struct diff_filespec *a,
 621                       struct diff_filespec *b,
 622                       const char *branch1,
 623                       const char *branch2)
 624 {
 625         mmfile_t orig, src1, src2;
 626         char *name1, *name2;
 627         int merge_status;
 628
 629         name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 630         name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 631
 632         fill_mm(o->sha1, &orig);
 633         fill_mm(a->sha1, &src1);
 634         fill_mm(b->sha1, &src2);
 635
 636         merge_status = ll_merge(result_buf, a->path, &orig,
 637                                 &src1, name1, &src2, name2,
 638                                 index_only);
 639
 640         free(name1);
 641         free(name2);
 642         free(orig.ptr);
 643         free(src1.ptr);
 644         free(src2.ptr);
 645         return merge_status;
 646 }
 647
 648 static struct merge_file_info merge_file(struct diff_filespec *o,
 649                 struct diff_filespec *a, struct diff_filespec *b,
 650                 const char *branch1, const char *branch2)
 651 {
 652         struct merge_file_info result;
 653         result.merge = 0;
 654         result.clean = 1;
 655
 656         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 657                 result.clean = 0;
 658                 if (S_ISREG(a->mode)) {
 659                         result.mode = a->mode;
 660                         hashcpy(result.sha, a->sha1);
 661                 } else {
 662                         result.mode = b->mode;
 663                         hashcpy(result.sha, b->sha1);
 664                 }
 665         } else {
 666                 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
 667                         result.merge = 1;
 668
 669                 result.mode = a->mode == o->mode ? b->mode: a->mode;
 670
 671                 if (sha_eq(a->sha1, o->sha1))
 672                         hashcpy(result.sha, b->sha1);
 673                 else if (sha_eq(b->sha1, o->sha1))
 674                         hashcpy(result.sha, a->sha1);
 675                 else if (S_ISREG(a->mode)) {
 676                         mmbuffer_t result_buf;
 677                         int merge_status;
 678
 679                         merge_status = merge_3way(&result_buf, o, a, b,
 680                                                   branch1, branch2);
 681
 682                         if ((merge_status < 0) || !result_buf.ptr)
 683                                 die("Failed to execute internal merge");
 684
 685                         if (write_sha1_file(result_buf.ptr, result_buf.size,
 686                                             blob_type, result.sha))
 687                                 die("Unable to add %s to database",
 688                                     a->path);
 689
 690                         free(result_buf.ptr);
 691                         result.clean = (merge_status == 0);
 692                 } else if (S_ISGITLINK(a->mode)) {
 693                         result.clean = 0;
 694                         hashcpy(result.sha, a->sha1);
 695                 } else if (S_ISLNK(a->mode)) {
 696                         hashcpy(result.sha, a->sha1);
 697
 698                         if (!sha_eq(a->sha1, b->sha1))
 699                                 result.clean = 0;
 700                 } else {
 701                         die("unsupported object type in the tree");
 702                 }
 703         }
 704
 705         return result;
 706 }
 707
 708 static void conflict_rename_rename(struct rename *ren1,
 709                                    const char *branch1,
 710                                    struct rename *ren2,
 711                                    const char *branch2)
 712 {
 713         char *del[2];
 714         int delp = 0;
 715         const char *ren1_dst = ren1->pair->two->path;
 716         const char *ren2_dst = ren2->pair->two->path;
 717         const char *dst_name1 = ren1_dst;
 718         const char *dst_name2 = ren2_dst;
 719         if (path_list_has_path(&current_directory_set, ren1_dst)) {
 720                 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
 721                 output(1, "%s is a directory in %s added as %s instead",
 722                        ren1_dst, branch2, dst_name1);
 723                 remove_file(0, ren1_dst, 0);
 724         }
 725         if (path_list_has_path(&current_directory_set, ren2_dst)) {
 726                 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
 727                 output(1, "%s is a directory in %s added as %s instead",
 728                        ren2_dst, branch1, dst_name2);
 729                 remove_file(0, ren2_dst, 0);
 730         }
 731         if (index_only) {
 732                 remove_file_from_cache(dst_name1);
 733                 remove_file_from_cache(dst_name2);
 734                 /*
 735                  * Uncomment to leave the conflicting names in the resulting tree
 736                  *
 737                  * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
 738                  * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
 739                  */
 740         } else {
 741                 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
 742                 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
 743         }
 744         while (delp--)
 745                 free(del[delp]);
 746 }
 747
 748 static void conflict_rename_dir(struct rename *ren1,
 749                                 const char *branch1)
 750 {
 751         char *new_path = unique_path(ren1->pair->two->path, branch1);
 752         output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
 753         remove_file(0, ren1->pair->two->path, 0);
 754         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 755         free(new_path);
 756 }
 757
 758 static void conflict_rename_rename_2(struct rename *ren1,
 759                                      const char *branch1,
 760                                      struct rename *ren2,
 761                                      const char *branch2)
 762 {
 763         char *new_path1 = unique_path(ren1->pair->two->path, branch1);
 764         char *new_path2 = unique_path(ren2->pair->two->path, branch2);
 765         output(1, "Renamed %s to %s and %s to %s instead",
 766                ren1->pair->one->path, new_path1,
 767                ren2->pair->one->path, new_path2);
 768         remove_file(0, ren1->pair->two->path, 0);
 769         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 770         update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 771         free(new_path2);
 772         free(new_path1);
 773 }
 774
 775 static int process_renames(struct path_list *a_renames,
 776                            struct path_list *b_renames,
 777                            const char *a_branch,
 778                            const char *b_branch)
 779 {
 780         int clean_merge = 1, i, j;
 781         struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
 782         const struct rename *sre;
 783
 784         for (i = 0; i < a_renames->nr; i++) {
 785                 sre = a_renames->items[i].util;
 786                 path_list_insert(sre->pair->two->path, &a_by_dst)->util
 787                         = sre->dst_entry;
 788         }
 789         for (i = 0; i < b_renames->nr; i++) {
 790                 sre = b_renames->items[i].util;
 791                 path_list_insert(sre->pair->two->path, &b_by_dst)->util
 792                         = sre->dst_entry;
 793         }
 794
 795         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 796                 int compare;
 797                 char *src;
 798                 struct path_list *renames1, *renames2, *renames2Dst;
 799                 struct rename *ren1 = NULL, *ren2 = NULL;
 800                 const char *branch1, *branch2;
 801                 const char *ren1_src, *ren1_dst;
 802
 803                 if (i >= a_renames->nr) {
 804                         compare = 1;
 805                         ren2 = b_renames->items[j++].util;
 806                 } else if (j >= b_renames->nr) {
 807                         compare = -1;
 808                         ren1 = a_renames->items[i++].util;
 809                 } else {
 810                         compare = strcmp(a_renames->items[i].path,
 811                                         b_renames->items[j].path);
 812                         if (compare <= 0)
 813                                 ren1 = a_renames->items[i++].util;
 814                         if (compare >= 0)
 815                                 ren2 = b_renames->items[j++].util;
 816                 }
 817
 818                 /* TODO: refactor, so that 1/2 are not needed */
 819                 if (ren1) {
 820                         renames1 = a_renames;
 821                         renames2 = b_renames;
 822                         renames2Dst = &b_by_dst;
 823                         branch1 = a_branch;
 824                         branch2 = b_branch;
 825                 } else {
 826                         struct rename *tmp;
 827                         renames1 = b_renames;
 828                         renames2 = a_renames;
 829                         renames2Dst = &a_by_dst;
 830                         branch1 = b_branch;
 831                         branch2 = a_branch;
 832                         tmp = ren2;
 833                         ren2 = ren1;
 834                         ren1 = tmp;
 835                 }
 836                 src = ren1->pair->one->path;
 837
 838                 ren1->dst_entry->processed = 1;
 839                 ren1->src_entry->processed = 1;
 840
 841                 if (ren1->processed)
 842                         continue;
 843                 ren1->processed = 1;
 844
 845                 ren1_src = ren1->pair->one->path;
 846                 ren1_dst = ren1->pair->two->path;
 847
 848                 if (ren2) {
 849                         const char *ren2_src = ren2->pair->one->path;
 850                         const char *ren2_dst = ren2->pair->two->path;
 851                         /* Renamed in 1 and renamed in 2 */
 852                         if (strcmp(ren1_src, ren2_src) != 0)
 853                                 die("ren1.src != ren2.src");
 854                         ren2->dst_entry->processed = 1;
 855                         ren2->processed = 1;
 856                         if (strcmp(ren1_dst, ren2_dst) != 0) {
 857                                 clean_merge = 0;
 858                                 output(1, "CONFLICT (rename/rename): "
 859                                        "Rename \"%s\"->\"%s\" in branch \"%s\" "
 860                                        "rename \"%s\"->\"%s\" in \"%s\"%s",
 861                                        src, ren1_dst, branch1,
 862                                        src, ren2_dst, branch2,
 863                                        index_only ? " (left unresolved)": "");
 864                                 if (index_only) {
 865                                         remove_file_from_cache(src);
 866                                         update_file(0, ren1->pair->one->sha1,
 867                                                     ren1->pair->one->mode, src);
 868                                 }
 869                                 conflict_rename_rename(ren1, branch1, ren2, branch2);
 870                         } else {
 871                                 struct merge_file_info mfi;
 872                                 remove_file(1, ren1_src, 1);
 873                                 mfi = merge_file(ren1->pair->one,
 874                                                  ren1->pair->two,
 875                                                  ren2->pair->two,
 876                                                  branch1,
 877                                                  branch2);
 878                                 if (mfi.merge || !mfi.clean)
 879                                         output(1, "Renamed %s->%s", src, ren1_dst);
 880
 881                                 if (mfi.merge)
 882                                         output(2, "Auto-merged %s", ren1_dst);
 883
 884                                 if (!mfi.clean) {
 885                                         output(1, "CONFLICT (content): merge conflict in %s",
 886                                                ren1_dst);
 887                                         clean_merge = 0;
 888
 889                                         if (!index_only)
 890                                                 update_stages(ren1_dst,
 891                                                               ren1->pair->one,
 892                                                               ren1->pair->two,
 893                                                               ren2->pair->two,
 894                                                               1 /* clear */);
 895                                 }
 896                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 897                         }
 898                 } else {
 899                         /* Renamed in 1, maybe changed in 2 */
 900                         struct path_list_item *item;
 901                         /* we only use sha1 and mode of these */
 902                         struct diff_filespec src_other, dst_other;
 903                         int try_merge, stage = a_renames == renames1 ? 3: 2;
 904
 905                         remove_file(1, ren1_src, index_only || stage == 3);
 906
 907                         hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
 908                         src_other.mode = ren1->src_entry->stages[stage].mode;
 909                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
 910                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
 911
 912                         try_merge = 0;
 913
 914                         if (path_list_has_path(&current_directory_set, ren1_dst)) {
 915                                 clean_merge = 0;
 916                                 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
 917                                        " directory %s added in %s",
 918                                        ren1_src, ren1_dst, branch1,
 919                                        ren1_dst, branch2);
 920                                 conflict_rename_dir(ren1, branch1);
 921                         } else if (sha_eq(src_other.sha1, null_sha1)) {
 922                                 clean_merge = 0;
 923                                 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
 924                                        "and deleted in %s",
 925                                        ren1_src, ren1_dst, branch1,
 926                                        branch2);
 927                                 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 928                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
 929                                 const char *new_path;
 930                                 clean_merge = 0;
 931                                 try_merge = 1;
 932                                 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
 933                                        "%s added in %s",
 934                                        ren1_src, ren1_dst, branch1,
 935                                        ren1_dst, branch2);
 936                                 new_path = unique_path(ren1_dst, branch2);
 937                                 output(1, "Added as %s instead", new_path);
 938                                 update_file(0, dst_other.sha1, dst_other.mode, new_path);
 939                         } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
 940                                 ren2 = item->util;
 941                                 clean_merge = 0;
 942                                 ren2->processed = 1;
 943                                 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
 944                                        "Renamed %s->%s in %s",
 945                                        ren1_src, ren1_dst, branch1,
 946                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
 947                                 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
 948                         } else
 949                                 try_merge = 1;
 950
 951                         if (try_merge) {
 952                                 struct diff_filespec *o, *a, *b;
 953                                 struct merge_file_info mfi;
 954                                 src_other.path = (char *)ren1_src;
 955
 956                                 o = ren1->pair->one;
 957                                 if (a_renames == renames1) {
 958                                         a = ren1->pair->two;
 959                                         b = &src_other;
 960                                 } else {
 961                                         b = ren1->pair->two;
 962                                         a = &src_other;
 963                                 }
 964                                 mfi = merge_file(o, a, b,
 965                                                 a_branch, b_branch);
 966
 967                                 if (mfi.clean &&
 968                                     sha_eq(mfi.sha, ren1->pair->two->sha1) &&
 969                                     mfi.mode == ren1->pair->two->mode)
 970                                         /*
 971                                          * This messaged is part of
 972                                          * t6022 test. If you change
 973                                          * it update the test too.
 974                                          */
 975                                         output(3, "Skipped %s (merged same as existing)", ren1_dst);
 976                                 else {
 977                                         if (mfi.merge || !mfi.clean)
 978                                                 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
 979                                         if (mfi.merge)
 980                                                 output(2, "Auto-merged %s", ren1_dst);
 981                                         if (!mfi.clean) {
 982                                                 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
 983                                                        ren1_dst);
 984                                                 clean_merge = 0;
 985
 986                                                 if (!index_only)
 987                                                         update_stages(ren1_dst,
 988                                                                       o, a, b, 1);
 989                                         }
 990                                         update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 991                                 }
 992                         }
 993                 }
 994         }
 995         path_list_clear(&a_by_dst, 0);
 996         path_list_clear(&b_by_dst, 0);
 997
 998         return clean_merge;
 999 }
1000
1001 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1002 {
1003         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1004 }
1005
1006 /* Per entry merge function */
1007 static int process_entry(const char *path, struct stage_data *entry,
1008                          const char *branch1,
1009                          const char *branch2)
1010 {
1011         /*
1012         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1013         print_index_entry("\tpath: ", entry);
1014         */
1015         int clean_merge = 1;
1016         unsigned o_mode = entry->stages[1].mode;
1017         unsigned a_mode = entry->stages[2].mode;
1018         unsigned b_mode = entry->stages[3].mode;
1019         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1020         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1021         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1022
1023         if (o_sha && (!a_sha || !b_sha)) {
1024                 /* Case A: Deleted in one */
1025                 if ((!a_sha && !b_sha) ||
1026                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1027                     (!a_sha && sha_eq(b_sha, o_sha))) {
1028                         /* Deleted in both or deleted in one and
1029                          * unchanged in the other */
1030                         if (a_sha)
1031                                 output(2, "Removed %s", path);
1032                         /* do not touch working file if it did not exist */
1033                         remove_file(1, path, !a_sha);
1034                 } else {
1035                         /* Deleted in one and changed in the other */
1036                         clean_merge = 0;
1037                         if (!a_sha) {
1038                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1039                                        "and modified in %s. Version %s of %s left in tree.",
1040                                        path, branch1,
1041                                        branch2, branch2, path);
1042                                 update_file(0, b_sha, b_mode, path);
1043                         } else {
1044                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1045                                        "and modified in %s. Version %s of %s left in tree.",
1046                                        path, branch2,
1047                                        branch1, branch1, path);
1048                                 update_file(0, a_sha, a_mode, path);
1049                         }
1050                 }
1051
1052         } else if ((!o_sha && a_sha && !b_sha) ||
1053                    (!o_sha && !a_sha && b_sha)) {
1054                 /* Case B: Added in one. */
1055                 const char *add_branch;
1056                 const char *other_branch;
1057                 unsigned mode;
1058                 const unsigned char *sha;
1059                 const char *conf;
1060
1061                 if (a_sha) {
1062                         add_branch = branch1;
1063                         other_branch = branch2;
1064                         mode = a_mode;
1065                         sha = a_sha;
1066                         conf = "file/directory";
1067                 } else {
1068                         add_branch = branch2;
1069                         other_branch = branch1;
1070                         mode = b_mode;
1071                         sha = b_sha;
1072                         conf = "directory/file";
1073                 }
1074                 if (path_list_has_path(&current_directory_set, path)) {
1075                         const char *new_path = unique_path(path, add_branch);
1076                         clean_merge = 0;
1077                         output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1078                                "Added %s as %s",
1079                                conf, path, other_branch, path, new_path);
1080                         remove_file(0, path, 0);
1081                         update_file(0, sha, mode, new_path);
1082                 } else {
1083                         output(2, "Added %s", path);
1084                         update_file(1, sha, mode, path);
1085                 }
1086         } else if (a_sha && b_sha) {
1087                 /* Case C: Added in both (check for same permissions) and */
1088                 /* case D: Modified in both, but differently. */
1089                 const char *reason = "content";
1090                 struct merge_file_info mfi;
1091                 struct diff_filespec o, a, b;
1092
1093                 if (!o_sha) {
1094                         reason = "add/add";
1095                         o_sha = (unsigned char *)null_sha1;
1096                 }
1097                 output(2, "Auto-merged %s", path);
1098                 o.path = a.path = b.path = (char *)path;
1099                 hashcpy(o.sha1, o_sha);
1100                 o.mode = o_mode;
1101                 hashcpy(a.sha1, a_sha);
1102                 a.mode = a_mode;
1103                 hashcpy(b.sha1, b_sha);
1104                 b.mode = b_mode;
1105
1106                 mfi = merge_file(&o, &a, &b,
1107                                  branch1, branch2);
1108
1109                 clean_merge = mfi.clean;
1110                 if (mfi.clean)
1111                         update_file(1, mfi.sha, mfi.mode, path);
1112                 else if (S_ISGITLINK(mfi.mode))
1113                         output(1, "CONFLICT (submodule): Merge conflict in %s "
1114                                "- needs %s", path, sha1_to_hex(b.sha1));
1115                 else {
1116                         output(1, "CONFLICT (%s): Merge conflict in %s",
1117                                         reason, path);
1118
1119                         if (index_only)
1120                                 update_file(0, mfi.sha, mfi.mode, path);
1121                         else
1122                                 update_file_flags(mfi.sha, mfi.mode, path,
1123                                               0 /* update_cache */, 1 /* update_working_directory */);
1124                 }
1125         } else if (!o_sha && !a_sha && !b_sha) {
1126                 /*
1127                  * this entry was deleted altogether. a_mode == 0 means
1128                  * we had that path and want to actively remove it.
1129                  */
1130                 remove_file(1, path, !a_mode);
1131         } else
1132                 die("Fatal merge failure, shouldn't happen.");
1133
1134         return clean_merge;
1135 }
1136
1137 int merge_trees(struct tree *head,
1138                 struct tree *merge,
1139                 struct tree *common,
1140                 const char *branch1,
1141                 const char *branch2,
1142                 struct tree **result)
1143 {
1144         int code, clean;
1145
1146         if (subtree_merge) {
1147                 merge = shift_tree_object(head, merge);
1148                 common = shift_tree_object(head, common);
1149         }
1150
1151         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1152                 output(0, "Already uptodate!");
1153                 *result = head;
1154                 return 1;
1155         }
1156
1157         code = git_merge_trees(index_only, common, head, merge);
1158
1159         if (code != 0)
1160                 die("merging of trees %s and %s failed",
1161                     sha1_to_hex(head->object.sha1),
1162                     sha1_to_hex(merge->object.sha1));
1163
1164         if (unmerged_cache()) {
1165                 struct path_list *entries, *re_head, *re_merge;
1166                 int i;
1167                 path_list_clear(&current_file_set, 1);
1168                 path_list_clear(&current_directory_set, 1);
1169                 get_files_dirs(head);
1170                 get_files_dirs(merge);
1171
1172                 entries = get_unmerged();
1173                 re_head  = get_renames(head, common, head, merge, entries);
1174                 re_merge = get_renames(merge, common, head, merge, entries);
1175                 clean = process_renames(re_head, re_merge,
1176                                 branch1, branch2);
1177                 for (i = 0; i < entries->nr; i++) {
1178                         const char *path = entries->items[i].path;
1179                         struct stage_data *e = entries->items[i].util;
1180                         if (!e->processed
1181                                 && !process_entry(path, e, branch1, branch2))
1182                                 clean = 0;
1183                 }
1184
1185                 path_list_clear(re_merge, 0);
1186                 path_list_clear(re_head, 0);
1187                 path_list_clear(entries, 1);
1188
1189         }
1190         else
1191                 clean = 1;
1192
1193         if (index_only)
1194                 *result = write_tree_from_memory();
1195
1196         return clean;
1197 }
1198
1199 static struct commit_list *reverse_commit_list(struct commit_list *list)
1200 {
1201         struct commit_list *next = NULL, *current, *backup;
1202         for (current = list; current; current = backup) {
1203                 backup = current->next;
1204                 current->next = next;
1205                 next = current;
1206         }
1207         return next;
1208 }
1209
1210 /*
1211  * Merge the commits h1 and h2, return the resulting virtual
1212  * commit object and a flag indicating the cleanness of the merge.
1213  */
1214 int merge_recursive(struct commit *h1,
1215                     struct commit *h2,
1216                     const char *branch1,
1217                     const char *branch2,
1218                     struct commit_list *ca,
1219                     struct commit **result)
1220 {
1221         struct commit_list *iter;
1222         struct commit *merged_common_ancestors;
1223         struct tree *mrtree = mrtree;
1224         int clean;
1225
1226         if (show(4)) {
1227                 output(4, "Merging:");
1228                 output_commit_title(h1);
1229                 output_commit_title(h2);
1230         }
1231
1232         if (!ca) {
1233                 ca = get_merge_bases(h1, h2, 1);
1234                 ca = reverse_commit_list(ca);
1235         }
1236
1237         if (show(5)) {
1238                 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1239                 for (iter = ca; iter; iter = iter->next)
1240                         output_commit_title(iter->item);
1241         }
1242
1243         merged_common_ancestors = pop_commit(&ca);
1244         if (merged_common_ancestors == NULL) {
1245                 /* if there is no common ancestor, make an empty tree */
1246                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1247
1248                 tree->object.parsed = 1;
1249                 tree->object.type = OBJ_TREE;
1250                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1251                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1252         }
1253
1254         for (iter = ca; iter; iter = iter->next) {
1255                 call_depth++;
1256                 /*
1257                  * When the merge fails, the result contains files
1258                  * with conflict markers. The cleanness flag is
1259                  * ignored, it was never actually used, as result of
1260                  * merge_trees has always overwritten it: the committed
1261                  * "conflicts" were already resolved.
1262                  */
1263                 discard_cache();
1264                 merge_recursive(merged_common_ancestors, iter->item,
1265                                 "Temporary merge branch 1",
1266                                 "Temporary merge branch 2",
1267                                 NULL,
1268                                 &merged_common_ancestors);
1269                 call_depth--;
1270
1271                 if (!merged_common_ancestors)
1272                         die("merge returned no commit");
1273         }
1274
1275         discard_cache();
1276         if (!call_depth) {
1277                 read_cache();
1278                 index_only = 0;
1279         } else
1280                 index_only = 1;
1281
1282         clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1283                             branch1, branch2, &mrtree);
1284
1285         if (index_only) {
1286                 *result = make_virtual_commit(mrtree, "merged tree");
1287                 commit_list_insert(h1, &(*result)->parents);
1288                 commit_list_insert(h2, &(*result)->parents->next);
1289         }
1290         flush_output();
1291         return clean;
1292 }
1293
1294 static const char *better_branch_name(const char *branch)
1295 {
1296         static char githead_env[8 + 40 + 1];
1297         char *name;
1298
1299         if (strlen(branch) != 40)
1300                 return branch;
1301         sprintf(githead_env, "GITHEAD_%s", branch);
1302         name = getenv(githead_env);
1303         return name ? name : branch;
1304 }
1305
1306 static struct commit *get_ref(const char *ref)
1307 {
1308         unsigned char sha1[20];
1309         struct object *object;
1310
1311         if (get_sha1(ref, sha1))
1312                 die("Could not resolve ref '%s'", ref);
1313         object = deref_tag(parse_object(sha1), ref, strlen(ref));
1314         if (!object)
1315                 return NULL;
1316         if (object->type == OBJ_TREE)
1317                 return make_virtual_commit((struct tree*)object,
1318                         better_branch_name(ref));
1319         if (object->type != OBJ_COMMIT)
1320                 return NULL;
1321         if (parse_commit((struct commit *)object))
1322                 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1323         return (struct commit *)object;
1324 }
1325
1326 static int merge_config(const char *var, const char *value)
1327 {
1328         if (!strcasecmp(var, "merge.verbosity")) {
1329                 verbosity = git_config_int(var, value);
1330                 return 0;
1331         }
1332         if (!strcasecmp(var, "diff.renamelimit")) {
1333                 rename_limit = git_config_int(var, value);
1334                 return 0;
1335         }
1336         return git_default_config(var, value);
1337 }
1338
1339 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1340 {
1341         static const char *bases[20];
1342         static unsigned bases_count = 0;
1343         int i, clean;
1344         const char *branch1, *branch2;
1345         struct commit *result, *h1, *h2;
1346         struct commit_list *ca = NULL;
1347         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1348         int index_fd;
1349
1350         if (argv[0]) {
1351                 int namelen = strlen(argv[0]);
1352                 if (8 < namelen &&
1353                     !strcmp(argv[0] + namelen - 8, "-subtree"))
1354                         subtree_merge = 1;
1355         }
1356
1357         git_config(merge_config);
1358         if (getenv("GIT_MERGE_VERBOSITY"))
1359                 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1360
1361         if (argc < 4)
1362                 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1363
1364         for (i = 1; i < argc; ++i) {
1365                 if (!strcmp(argv[i], "--"))
1366                         break;
1367                 if (bases_count < sizeof(bases)/sizeof(*bases))
1368                         bases[bases_count++] = argv[i];
1369         }
1370         if (argc - i != 3) /* "--" "<head>" "<remote>" */
1371                 die("Not handling anything other than two heads merge.");
1372         if (verbosity >= 5)
1373                 buffer_output = 0;
1374
1375         branch1 = argv[++i];
1376         branch2 = argv[++i];
1377
1378         h1 = get_ref(branch1);
1379         h2 = get_ref(branch2);
1380
1381         branch1 = better_branch_name(branch1);
1382         branch2 = better_branch_name(branch2);
1383
1384         if (show(3))
1385                 printf("Merging %s with %s\n", branch1, branch2);
1386
1387         index_fd = hold_locked_index(lock, 1);
1388
1389         for (i = 0; i < bases_count; i++) {
1390                 struct commit *ancestor = get_ref(bases[i]);
1391                 ca = commit_list_insert(ancestor, &ca);
1392         }
1393         clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1394
1395         if (active_cache_changed &&
1396             (write_cache(index_fd, active_cache, active_nr) ||
1397              commit_locked_index(lock)))
1398                         die ("unable to write %s", get_index_file());
1399
1400         return clean ? 0: 1;
1401 }