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 "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 "string-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 struct tree *shift_tree_object(struct tree *one, struct tree *two)
  24 {
  25         unsigned char shifted[20];
  26
  27         /*
  28          * NEEDSWORK: this limits the recursion depth to hardcoded
  29          * value '2' to avoid excessive overhead.
  30          */
  31         shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
  32         if (!hashcmp(two->object.sha1, shifted))
  33                 return two;
  34         return lookup_tree(shifted);
  35 }
  36
  37 /*
  38  * A virtual commit has (const char *)commit->util set to the name.
  39  */
  40
  41 struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  42 {
  43         struct commit *commit = xcalloc(1, sizeof(struct commit));
  44         commit->tree = tree;
  45         commit->util = (void*)comment;
  46         /* avoid warnings */
  47         commit->object.parsed = 1;
  48         return commit;
  49 }
  50
  51 /*
  52  * Since we use get_tree_entry(), which does not put the read object into
  53  * the object pool, we cannot rely on a == b.
  54  */
  55 static int sha_eq(const unsigned char *a, const unsigned char *b)
  56 {
  57         if (!a && !b)
  58                 return 2;
  59         return a && b && hashcmp(a, b) == 0;
  60 }
  61
  62 /*
  63  * Since we want to write the index eventually, we cannot reuse the index
  64  * for these (temporary) data.
  65  */
  66 struct stage_data
  67 {
  68         struct
  69         {
  70                 unsigned mode;
  71                 unsigned char sha[20];
  72         } stages[4];
  73         unsigned processed:1;
  74 };
  75
  76 static int show(struct merge_options *o, int v)
  77 {
  78         return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
  79 }
  80
  81 static void flush_output(struct merge_options *o)
  82 {
  83         if (o->obuf.len) {
  84                 fputs(o->obuf.buf, stdout);
  85                 strbuf_reset(&o->obuf);
  86         }
  87 }
  88
  89 static void output(struct merge_options *o, int v, const char *fmt, ...)
  90 {
  91         int len;
  92         va_list ap;
  93
  94         if (!show(o, v))
  95                 return;
  96
  97         strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
  98         memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
  99         strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 100
 101         va_start(ap, fmt);
 102         len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 103         va_end(ap);
 104
 105         if (len < 0)
 106                 len = 0;
 107         if (len >= strbuf_avail(&o->obuf)) {
 108                 strbuf_grow(&o->obuf, len + 2);
 109                 va_start(ap, fmt);
 110                 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 111                 va_end(ap);
 112                 if (len >= strbuf_avail(&o->obuf)) {
 113                         die("this should not happen, your snprintf is broken");
 114                 }
 115         }
 116         strbuf_setlen(&o->obuf, o->obuf.len + len);
 117         strbuf_add(&o->obuf, "\n", 1);
 118         if (!o->buffer_output)
 119                 flush_output(o);
 120 }
 121
 122 static void output_commit_title(struct merge_options *o, struct commit *commit)
 123 {
 124         int i;
 125         flush_output(o);
 126         for (i = o->call_depth; i--;)
 127                 fputs("  ", stdout);
 128         if (commit->util)
 129                 printf("virtual %s\n", (char *)commit->util);
 130         else {
 131                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 132                 if (parse_commit(commit) != 0)
 133                         printf("(bad commit)\n");
 134                 else {
 135                         const char *s;
 136                         int len;
 137                         for (s = commit->buffer; *s; s++)
 138                                 if (*s == '\n' && s[1] == '\n') {
 139                                         s += 2;
 140                                         break;
 141                                 }
 142                         for (len = 0; s[len] && '\n' != s[len]; len++)
 143                                 ; /* do nothing */
 144                         printf("%.*s\n", len, s);
 145                 }
 146         }
 147 }
 148
 149 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 150                 const char *path, int stage, int refresh, int options)
 151 {
 152         struct cache_entry *ce;
 153         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 154         if (!ce)
 155                 return error("addinfo_cache failed for path '%s'", path);
 156         return add_cache_entry(ce, options);
 157 }
 158
 159 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 160 {
 161         parse_tree(tree);
 162         init_tree_desc(desc, tree->buffer, tree->size);
 163 }
 164
 165 static int git_merge_trees(int index_only,
 166                            struct tree *common,
 167                            struct tree *head,
 168                            struct tree *merge)
 169 {
 170         int rc;
 171         struct tree_desc t[3];
 172         struct unpack_trees_options opts;
 173
 174         memset(&opts, 0, sizeof(opts));
 175         if (index_only)
 176                 opts.index_only = 1;
 177         else
 178                 opts.update = 1;
 179         opts.merge = 1;
 180         opts.head_idx = 2;
 181         opts.fn = threeway_merge;
 182         opts.src_index = &the_index;
 183         opts.dst_index = &the_index;
 184
 185         init_tree_desc_from_tree(t+0, common);
 186         init_tree_desc_from_tree(t+1, head);
 187         init_tree_desc_from_tree(t+2, merge);
 188
 189         rc = unpack_trees(3, t, &opts);
 190         cache_tree_free(&active_cache_tree);
 191         return rc;
 192 }
 193
 194 struct tree *write_tree_from_memory(struct merge_options *o)
 195 {
 196         struct tree *result = NULL;
 197
 198         if (unmerged_cache()) {
 199                 int i;
 200                 output(o, 0, "There are unmerged index entries:");
 201                 for (i = 0; i < active_nr; i++) {
 202                         struct cache_entry *ce = active_cache[i];
 203                         if (ce_stage(ce))
 204                                 output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
 205                 }
 206                 return NULL;
 207         }
 208
 209         if (!active_cache_tree)
 210                 active_cache_tree = cache_tree();
 211
 212         if (!cache_tree_fully_valid(active_cache_tree) &&
 213             cache_tree_update(active_cache_tree,
 214                               active_cache, active_nr, 0, 0) < 0)
 215                 die("error building trees");
 216
 217         result = lookup_tree(active_cache_tree->sha1);
 218
 219         return result;
 220 }
 221
 222 static int save_files_dirs(const unsigned char *sha1,
 223                 const char *base, int baselen, const char *path,
 224                 unsigned int mode, int stage, void *context)
 225 {
 226         int len = strlen(path);
 227         char *newpath = xmalloc(baselen + len + 1);
 228         struct merge_options *o = context;
 229
 230         memcpy(newpath, base, baselen);
 231         memcpy(newpath + baselen, path, len);
 232         newpath[baselen + len] = '\0';
 233
 234         if (S_ISDIR(mode))
 235                 string_list_insert(newpath, &o->current_directory_set);
 236         else
 237                 string_list_insert(newpath, &o->current_file_set);
 238         free(newpath);
 239
 240         return READ_TREE_RECURSIVE;
 241 }
 242
 243 static int get_files_dirs(struct merge_options *o, struct tree *tree)
 244 {
 245         int n;
 246         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 247                 return 0;
 248         n = o->current_file_set.nr + o->current_directory_set.nr;
 249         return n;
 250 }
 251
 252 /*
 253  * Returns an index_entry instance which doesn't have to correspond to
 254  * a real cache entry in Git's index.
 255  */
 256 static struct stage_data *insert_stage_data(const char *path,
 257                 struct tree *o, struct tree *a, struct tree *b,
 258                 struct string_list *entries)
 259 {
 260         struct string_list_item *item;
 261         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 262         get_tree_entry(o->object.sha1, path,
 263                         e->stages[1].sha, &e->stages[1].mode);
 264         get_tree_entry(a->object.sha1, path,
 265                         e->stages[2].sha, &e->stages[2].mode);
 266         get_tree_entry(b->object.sha1, path,
 267                         e->stages[3].sha, &e->stages[3].mode);
 268         item = string_list_insert(path, entries);
 269         item->util = e;
 270         return e;
 271 }
 272
 273 /*
 274  * Create a dictionary mapping file names to stage_data objects. The
 275  * dictionary contains one entry for every path with a non-zero stage entry.
 276  */
 277 static struct string_list *get_unmerged(void)
 278 {
 279         struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 280         int i;
 281
 282         unmerged->strdup_strings = 1;
 283
 284         for (i = 0; i < active_nr; i++) {
 285                 struct string_list_item *item;
 286                 struct stage_data *e;
 287                 struct cache_entry *ce = active_cache[i];
 288                 if (!ce_stage(ce))
 289                         continue;
 290
 291                 item = string_list_lookup(ce->name, unmerged);
 292                 if (!item) {
 293                         item = string_list_insert(ce->name, unmerged);
 294                         item->util = xcalloc(1, sizeof(struct stage_data));
 295                 }
 296                 e = item->util;
 297                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
 298                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 299         }
 300
 301         return unmerged;
 302 }
 303
 304 struct rename
 305 {
 306         struct diff_filepair *pair;
 307         struct stage_data *src_entry;
 308         struct stage_data *dst_entry;
 309         unsigned processed:1;
 310 };
 311
 312 /*
 313  * Get information of all renames which occurred between 'o_tree' and
 314  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 315  * 'b_tree') to be able to associate the correct cache entries with
 316  * the rename information. 'tree' is always equal to either a_tree or b_tree.
 317  */
 318 static struct string_list *get_renames(struct merge_options *o,
 319                                        struct tree *tree,
 320                                        struct tree *o_tree,
 321                                        struct tree *a_tree,
 322                                        struct tree *b_tree,
 323                                        struct string_list *entries)
 324 {
 325         int i;
 326         struct string_list *renames;
 327         struct diff_options opts;
 328
 329         renames = xcalloc(1, sizeof(struct string_list));
 330         diff_setup(&opts);
 331         DIFF_OPT_SET(&opts, RECURSIVE);
 332         opts.detect_rename = DIFF_DETECT_RENAME;
 333         opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 334                             o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 335                             500;
 336         opts.warn_on_too_large_rename = 1;
 337         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 338         if (diff_setup_done(&opts) < 0)
 339                 die("diff setup failed");
 340         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 341         diffcore_std(&opts);
 342         for (i = 0; i < diff_queued_diff.nr; ++i) {
 343                 struct string_list_item *item;
 344                 struct rename *re;
 345                 struct diff_filepair *pair = diff_queued_diff.queue[i];
 346                 if (pair->status != 'R') {
 347                         diff_free_filepair(pair);
 348                         continue;
 349                 }
 350                 re = xmalloc(sizeof(*re));
 351                 re->processed = 0;
 352                 re->pair = pair;
 353                 item = string_list_lookup(re->pair->one->path, entries);
 354                 if (!item)
 355                         re->src_entry = insert_stage_data(re->pair->one->path,
 356                                         o_tree, a_tree, b_tree, entries);
 357                 else
 358                         re->src_entry = item->util;
 359
 360                 item = string_list_lookup(re->pair->two->path, entries);
 361                 if (!item)
 362                         re->dst_entry = insert_stage_data(re->pair->two->path,
 363                                         o_tree, a_tree, b_tree, entries);
 364                 else
 365                         re->dst_entry = item->util;
 366                 item = string_list_insert(pair->one->path, renames);
 367                 item->util = re;
 368         }
 369         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 370         diff_queued_diff.nr = 0;
 371         diff_flush(&opts);
 372         return renames;
 373 }
 374
 375 static int update_stages(const char *path, struct diff_filespec *o,
 376                          struct diff_filespec *a, struct diff_filespec *b,
 377                          int clear)
 378 {
 379         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 380         if (clear)
 381                 if (remove_file_from_cache(path))
 382                         return -1;
 383         if (o)
 384                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 385                         return -1;
 386         if (a)
 387                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 388                         return -1;
 389         if (b)
 390                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 391                         return -1;
 392         return 0;
 393 }
 394
 395 static int remove_path(const char *name)
 396 {
 397         char *slash, *dirs;
 398
 399         if (unlink(name))
 400                 return -1;
 401         dirs = xstrdup(name);
 402         while ((slash = strrchr(name, '/'))) {
 403                 *slash = '\0';
 404                 if (rmdir(name) != 0)
 405                         break;
 406         }
 407         free(dirs);
 408         return 0;
 409 }
 410
 411 static int remove_file(struct merge_options *o, int clean,
 412                        const char *path, int no_wd)
 413 {
 414         int update_cache = o->call_depth || clean;
 415         int update_working_directory = !o->call_depth && !no_wd;
 416
 417         if (update_cache) {
 418                 if (remove_file_from_cache(path))
 419                         return -1;
 420         }
 421         if (update_working_directory) {
 422                 if (remove_path(path) && errno != ENOENT)
 423                         return -1;
 424         }
 425         return 0;
 426 }
 427
 428 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 429 {
 430         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 431         int suffix = 0;
 432         struct stat st;
 433         char *p = newpath + strlen(path);
 434         strcpy(newpath, path);
 435         *(p++) = '~';
 436         strcpy(p, branch);
 437         for (; *p; ++p)
 438                 if ('/' == *p)
 439                         *p = '_';
 440         while (string_list_has_string(&o->current_file_set, newpath) ||
 441                string_list_has_string(&o->current_directory_set, newpath) ||
 442                lstat(newpath, &st) == 0)
 443                 sprintf(p, "_%d", suffix++);
 444
 445         string_list_insert(newpath, &o->current_file_set);
 446         return newpath;
 447 }
 448
 449 static void flush_buffer(int fd, const char *buf, unsigned long size)
 450 {
 451         while (size > 0) {
 452                 long ret = write_in_full(fd, buf, size);
 453                 if (ret < 0) {
 454                         /* Ignore epipe */
 455                         if (errno == EPIPE)
 456                                 break;
 457                         die("merge-recursive: %s", strerror(errno));
 458                 } else if (!ret) {
 459                         die("merge-recursive: disk full?");
 460                 }
 461                 size -= ret;
 462                 buf += ret;
 463         }
 464 }
 465
 466 static int make_room_for_path(const char *path)
 467 {
 468         int status;
 469         const char *msg = "failed to create path '%s'%s";
 470
 471         status = safe_create_leading_directories_const(path);
 472         if (status) {
 473                 if (status == -3) {
 474                         /* something else exists */
 475                         error(msg, path, ": perhaps a D/F conflict?");
 476                         return -1;
 477                 }
 478                 die(msg, path, "");
 479         }
 480
 481         /* Successful unlink is good.. */
 482         if (!unlink(path))
 483                 return 0;
 484         /* .. and so is no existing file */
 485         if (errno == ENOENT)
 486                 return 0;
 487         /* .. but not some other error (who really cares what?) */
 488         return error(msg, path, ": perhaps a D/F conflict?");
 489 }
 490
 491 static void update_file_flags(struct merge_options *o,
 492                               const unsigned char *sha,
 493                               unsigned mode,
 494                               const char *path,
 495                               int update_cache,
 496                               int update_wd)
 497 {
 498         if (o->call_depth)
 499                 update_wd = 0;
 500
 501         if (update_wd) {
 502                 enum object_type type;
 503                 void *buf;
 504                 unsigned long size;
 505
 506                 if (S_ISGITLINK(mode))
 507                         die("cannot read object %s '%s': It is a submodule!",
 508                             sha1_to_hex(sha), path);
 509
 510                 buf = read_sha1_file(sha, &type, &size);
 511                 if (!buf)
 512                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 513                 if (type != OBJ_BLOB)
 514                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 515                 if (S_ISREG(mode)) {
 516                         struct strbuf strbuf;
 517                         strbuf_init(&strbuf, 0);
 518                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
 519                                 free(buf);
 520                                 size = strbuf.len;
 521                                 buf = strbuf_detach(&strbuf, NULL);
 522                         }
 523                 }
 524
 525                 if (make_room_for_path(path) < 0) {
 526                         update_wd = 0;
 527                         free(buf);
 528                         goto update_index;
 529                 }
 530                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 531                         int fd;
 532                         if (mode & 0100)
 533                                 mode = 0777;
 534                         else
 535                                 mode = 0666;
 536                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 537                         if (fd < 0)
 538                                 die("failed to open %s: %s", path, strerror(errno));
 539                         flush_buffer(fd, buf, size);
 540                         close(fd);
 541                 } else if (S_ISLNK(mode)) {
 542                         char *lnk = xmemdupz(buf, size);
 543                         safe_create_leading_directories_const(path);
 544                         unlink(path);
 545                         symlink(lnk, path);
 546                         free(lnk);
 547                 } else
 548                         die("do not know what to do with %06o %s '%s'",
 549                             mode, sha1_to_hex(sha), path);
 550                 free(buf);
 551         }
 552  update_index:
 553         if (update_cache)
 554                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 555 }
 556
 557 static void update_file(struct merge_options *o,
 558                         int clean,
 559                         const unsigned char *sha,
 560                         unsigned mode,
 561                         const char *path)
 562 {
 563         update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 564 }
 565
 566 /* Low level file merging, update and removal */
 567
 568 struct merge_file_info
 569 {
 570         unsigned char sha[20];
 571         unsigned mode;
 572         unsigned clean:1,
 573                  merge:1;
 574 };
 575
 576 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
 577 {
 578         unsigned long size;
 579         enum object_type type;
 580
 581         if (!hashcmp(sha1, null_sha1)) {
 582                 mm->ptr = xstrdup("");
 583                 mm->size = 0;
 584                 return;
 585         }
 586
 587         mm->ptr = read_sha1_file(sha1, &type, &size);
 588         if (!mm->ptr || type != OBJ_BLOB)
 589                 die("unable to read blob object %s", sha1_to_hex(sha1));
 590         mm->size = size;
 591 }
 592
 593 static int merge_3way(struct merge_options *o,
 594                       mmbuffer_t *result_buf,
 595                       struct diff_filespec *one,
 596                       struct diff_filespec *a,
 597                       struct diff_filespec *b,
 598                       const char *branch1,
 599                       const char *branch2)
 600 {
 601         mmfile_t orig, src1, src2;
 602         char *name1, *name2;
 603         int merge_status;
 604
 605         name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 606         name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 607
 608         fill_mm(one->sha1, &orig);
 609         fill_mm(a->sha1, &src1);
 610         fill_mm(b->sha1, &src2);
 611
 612         merge_status = ll_merge(result_buf, a->path, &orig,
 613                                 &src1, name1, &src2, name2,
 614                                 o->call_depth);
 615
 616         free(name1);
 617         free(name2);
 618         free(orig.ptr);
 619         free(src1.ptr);
 620         free(src2.ptr);
 621         return merge_status;
 622 }
 623
 624 static struct merge_file_info merge_file(struct merge_options *o,
 625                                          struct diff_filespec *one,
 626                                          struct diff_filespec *a,
 627                                          struct diff_filespec *b,
 628                                          const char *branch1,
 629                                          const char *branch2)
 630 {
 631         struct merge_file_info result;
 632         result.merge = 0;
 633         result.clean = 1;
 634
 635         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 636                 result.clean = 0;
 637                 if (S_ISREG(a->mode)) {
 638                         result.mode = a->mode;
 639                         hashcpy(result.sha, a->sha1);
 640                 } else {
 641                         result.mode = b->mode;
 642                         hashcpy(result.sha, b->sha1);
 643                 }
 644         } else {
 645                 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 646                         result.merge = 1;
 647
 648                 /*
 649                  * Merge modes
 650                  */
 651                 if (a->mode == b->mode || a->mode == one->mode)
 652                         result.mode = b->mode;
 653                 else {
 654                         result.mode = a->mode;
 655                         if (b->mode != one->mode) {
 656                                 result.clean = 0;
 657                                 result.merge = 1;
 658                         }
 659                 }
 660
 661                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 662                         hashcpy(result.sha, b->sha1);
 663                 else if (sha_eq(b->sha1, one->sha1))
 664                         hashcpy(result.sha, a->sha1);
 665                 else if (S_ISREG(a->mode)) {
 666                         mmbuffer_t result_buf;
 667                         int merge_status;
 668
 669                         merge_status = merge_3way(o, &result_buf, one, a, b,
 670                                                   branch1, branch2);
 671
 672                         if ((merge_status < 0) || !result_buf.ptr)
 673                                 die("Failed to execute internal merge");
 674
 675                         if (write_sha1_file(result_buf.ptr, result_buf.size,
 676                                             blob_type, result.sha))
 677                                 die("Unable to add %s to database",
 678                                     a->path);
 679
 680                         free(result_buf.ptr);
 681                         result.clean = (merge_status == 0);
 682                 } else if (S_ISGITLINK(a->mode)) {
 683                         result.clean = 0;
 684                         hashcpy(result.sha, a->sha1);
 685                 } else if (S_ISLNK(a->mode)) {
 686                         hashcpy(result.sha, a->sha1);
 687
 688                         if (!sha_eq(a->sha1, b->sha1))
 689                                 result.clean = 0;
 690                 } else {
 691                         die("unsupported object type in the tree");
 692                 }
 693         }
 694
 695         return result;
 696 }
 697
 698 static void conflict_rename_rename(struct merge_options *o,
 699                                    struct rename *ren1,
 700                                    const char *branch1,
 701                                    struct rename *ren2,
 702                                    const char *branch2)
 703 {
 704         char *del[2];
 705         int delp = 0;
 706         const char *ren1_dst = ren1->pair->two->path;
 707         const char *ren2_dst = ren2->pair->two->path;
 708         const char *dst_name1 = ren1_dst;
 709         const char *dst_name2 = ren2_dst;
 710         if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
 711                 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 712                 output(o, 1, "%s is a directory in %s adding as %s instead",
 713                        ren1_dst, branch2, dst_name1);
 714                 remove_file(o, 0, ren1_dst, 0);
 715         }
 716         if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
 717                 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 718                 output(o, 1, "%s is a directory in %s adding as %s instead",
 719                        ren2_dst, branch1, dst_name2);
 720                 remove_file(o, 0, ren2_dst, 0);
 721         }
 722         if (o->call_depth) {
 723                 remove_file_from_cache(dst_name1);
 724                 remove_file_from_cache(dst_name2);
 725                 /*
 726                  * Uncomment to leave the conflicting names in the resulting tree
 727                  *
 728                  * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
 729                  * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
 730                  */
 731         } else {
 732                 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
 733                 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
 734         }
 735         while (delp--)
 736                 free(del[delp]);
 737 }
 738
 739 static void conflict_rename_dir(struct merge_options *o,
 740                                 struct rename *ren1,
 741                                 const char *branch1)
 742 {
 743         char *new_path = unique_path(o, ren1->pair->two->path, branch1);
 744         output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
 745         remove_file(o, 0, ren1->pair->two->path, 0);
 746         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 747         free(new_path);
 748 }
 749
 750 static void conflict_rename_rename_2(struct merge_options *o,
 751                                      struct rename *ren1,
 752                                      const char *branch1,
 753                                      struct rename *ren2,
 754                                      const char *branch2)
 755 {
 756         char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 757         char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 758         output(o, 1, "Renaming %s to %s and %s to %s instead",
 759                ren1->pair->one->path, new_path1,
 760                ren2->pair->one->path, new_path2);
 761         remove_file(o, 0, ren1->pair->two->path, 0);
 762         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 763         update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 764         free(new_path2);
 765         free(new_path1);
 766 }
 767
 768 static int process_renames(struct merge_options *o,
 769                            struct string_list *a_renames,
 770                            struct string_list *b_renames)
 771 {
 772         int clean_merge = 1, i, j;
 773         struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
 774         const struct rename *sre;
 775
 776         for (i = 0; i < a_renames->nr; i++) {
 777                 sre = a_renames->items[i].util;
 778                 string_list_insert(sre->pair->two->path, &a_by_dst)->util
 779                         = sre->dst_entry;
 780         }
 781         for (i = 0; i < b_renames->nr; i++) {
 782                 sre = b_renames->items[i].util;
 783                 string_list_insert(sre->pair->two->path, &b_by_dst)->util
 784                         = sre->dst_entry;
 785         }
 786
 787         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 788                 int compare;
 789                 char *src;
 790                 struct string_list *renames1, *renames2, *renames2Dst;
 791                 struct rename *ren1 = NULL, *ren2 = NULL;
 792                 const char *branch1, *branch2;
 793                 const char *ren1_src, *ren1_dst;
 794
 795                 if (i >= a_renames->nr) {
 796                         compare = 1;
 797                         ren2 = b_renames->items[j++].util;
 798                 } else if (j >= b_renames->nr) {
 799                         compare = -1;
 800                         ren1 = a_renames->items[i++].util;
 801                 } else {
 802                         compare = strcmp(a_renames->items[i].string,
 803                                         b_renames->items[j].string);
 804                         if (compare <= 0)
 805                                 ren1 = a_renames->items[i++].util;
 806                         if (compare >= 0)
 807                                 ren2 = b_renames->items[j++].util;
 808                 }
 809
 810                 /* TODO: refactor, so that 1/2 are not needed */
 811                 if (ren1) {
 812                         renames1 = a_renames;
 813                         renames2 = b_renames;
 814                         renames2Dst = &b_by_dst;
 815                         branch1 = o->branch1;
 816                         branch2 = o->branch2;
 817                 } else {
 818                         struct rename *tmp;
 819                         renames1 = b_renames;
 820                         renames2 = a_renames;
 821                         renames2Dst = &a_by_dst;
 822                         branch1 = o->branch2;
 823                         branch2 = o->branch1;
 824                         tmp = ren2;
 825                         ren2 = ren1;
 826                         ren1 = tmp;
 827                 }
 828                 src = ren1->pair->one->path;
 829
 830                 ren1->dst_entry->processed = 1;
 831                 ren1->src_entry->processed = 1;
 832
 833                 if (ren1->processed)
 834                         continue;
 835                 ren1->processed = 1;
 836
 837                 ren1_src = ren1->pair->one->path;
 838                 ren1_dst = ren1->pair->two->path;
 839
 840                 if (ren2) {
 841                         const char *ren2_src = ren2->pair->one->path;
 842                         const char *ren2_dst = ren2->pair->two->path;
 843                         /* Renamed in 1 and renamed in 2 */
 844                         if (strcmp(ren1_src, ren2_src) != 0)
 845                                 die("ren1.src != ren2.src");
 846                         ren2->dst_entry->processed = 1;
 847                         ren2->processed = 1;
 848                         if (strcmp(ren1_dst, ren2_dst) != 0) {
 849                                 clean_merge = 0;
 850                                 output(o, 1, "CONFLICT (rename/rename): "
 851                                        "Rename \"%s\"->\"%s\" in branch \"%s\" "
 852                                        "rename \"%s\"->\"%s\" in \"%s\"%s",
 853                                        src, ren1_dst, branch1,
 854                                        src, ren2_dst, branch2,
 855                                        o->call_depth ? " (left unresolved)": "");
 856                                 if (o->call_depth) {
 857                                         remove_file_from_cache(src);
 858                                         update_file(o, 0, ren1->pair->one->sha1,
 859                                                     ren1->pair->one->mode, src);
 860                                 }
 861                                 conflict_rename_rename(o, ren1, branch1, ren2, branch2);
 862                         } else {
 863                                 struct merge_file_info mfi;
 864                                 remove_file(o, 1, ren1_src, 1);
 865                                 mfi = merge_file(o,
 866                                                  ren1->pair->one,
 867                                                  ren1->pair->two,
 868                                                  ren2->pair->two,
 869                                                  branch1,
 870                                                  branch2);
 871                                 if (mfi.merge || !mfi.clean)
 872                                         output(o, 1, "Renaming %s->%s", src, ren1_dst);
 873
 874                                 if (mfi.merge)
 875                                         output(o, 2, "Auto-merging %s", ren1_dst);
 876
 877                                 if (!mfi.clean) {
 878                                         output(o, 1, "CONFLICT (content): merge conflict in %s",
 879                                                ren1_dst);
 880                                         clean_merge = 0;
 881
 882                                         if (!o->call_depth)
 883                                                 update_stages(ren1_dst,
 884                                                               ren1->pair->one,
 885                                                               ren1->pair->two,
 886                                                               ren2->pair->two,
 887                                                               1 /* clear */);
 888                                 }
 889                                 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 890                         }
 891                 } else {
 892                         /* Renamed in 1, maybe changed in 2 */
 893                         struct string_list_item *item;
 894                         /* we only use sha1 and mode of these */
 895                         struct diff_filespec src_other, dst_other;
 896                         int try_merge, stage = a_renames == renames1 ? 3: 2;
 897
 898                         remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
 899
 900                         hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
 901                         src_other.mode = ren1->src_entry->stages[stage].mode;
 902                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
 903                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
 904
 905                         try_merge = 0;
 906
 907                         if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
 908                                 clean_merge = 0;
 909                                 output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
 910                                        " directory %s added in %s",
 911                                        ren1_src, ren1_dst, branch1,
 912                                        ren1_dst, branch2);
 913                                 conflict_rename_dir(o, ren1, branch1);
 914                         } else if (sha_eq(src_other.sha1, null_sha1)) {
 915                                 clean_merge = 0;
 916                                 output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 917                                        "and deleted in %s",
 918                                        ren1_src, ren1_dst, branch1,
 919                                        branch2);
 920                                 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 921                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
 922                                 const char *new_path;
 923                                 clean_merge = 0;
 924                                 try_merge = 1;
 925                                 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
 926                                        "%s added in %s",
 927                                        ren1_src, ren1_dst, branch1,
 928                                        ren1_dst, branch2);
 929                                 new_path = unique_path(o, ren1_dst, branch2);
 930                                 output(o, 1, "Adding as %s instead", new_path);
 931                                 update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
 932                         } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
 933                                 ren2 = item->util;
 934                                 clean_merge = 0;
 935                                 ren2->processed = 1;
 936                                 output(o, 1, "CONFLICT (rename/rename): "
 937                                        "Rename %s->%s in %s. "
 938                                        "Rename %s->%s in %s",
 939                                        ren1_src, ren1_dst, branch1,
 940                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
 941                                 conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
 942                         } else
 943                                 try_merge = 1;
 944
 945                         if (try_merge) {
 946                                 struct diff_filespec *one, *a, *b;
 947                                 struct merge_file_info mfi;
 948                                 src_other.path = (char *)ren1_src;
 949
 950                                 one = ren1->pair->one;
 951                                 if (a_renames == renames1) {
 952                                         a = ren1->pair->two;
 953                                         b = &src_other;
 954                                 } else {
 955                                         b = ren1->pair->two;
 956                                         a = &src_other;
 957                                 }
 958                                 mfi = merge_file(o, one, a, b,
 959                                                 o->branch1, o->branch2);
 960
 961                                 if (mfi.clean &&
 962                                     sha_eq(mfi.sha, ren1->pair->two->sha1) &&
 963                                     mfi.mode == ren1->pair->two->mode)
 964                                         /*
 965                                          * This messaged is part of
 966                                          * t6022 test. If you change
 967                                          * it update the test too.
 968                                          */
 969                                         output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
 970                                 else {
 971                                         if (mfi.merge || !mfi.clean)
 972                                                 output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
 973                                         if (mfi.merge)
 974                                                 output(o, 2, "Auto-merging %s", ren1_dst);
 975                                         if (!mfi.clean) {
 976                                                 output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
 977                                                        ren1_dst);
 978                                                 clean_merge = 0;
 979
 980                                                 if (!o->call_depth)
 981                                                         update_stages(ren1_dst,
 982                                                                       one, a, b, 1);
 983                                         }
 984                                         update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 985                                 }
 986                         }
 987                 }
 988         }
 989         string_list_clear(&a_by_dst, 0);
 990         string_list_clear(&b_by_dst, 0);
 991
 992         return clean_merge;
 993 }
 994
 995 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
 996 {
 997         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
 998 }
 999
1000 /* Per entry merge function */
1001 static int process_entry(struct merge_options *o,
1002                          const char *path, struct stage_data *entry)
1003 {
1004         /*
1005         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1006         print_index_entry("\tpath: ", entry);
1007         */
1008         int clean_merge = 1;
1009         unsigned o_mode = entry->stages[1].mode;
1010         unsigned a_mode = entry->stages[2].mode;
1011         unsigned b_mode = entry->stages[3].mode;
1012         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1013         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1014         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1015
1016         if (o_sha && (!a_sha || !b_sha)) {
1017                 /* Case A: Deleted in one */
1018                 if ((!a_sha && !b_sha) ||
1019                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1020                     (!a_sha && sha_eq(b_sha, o_sha))) {
1021                         /* Deleted in both or deleted in one and
1022                          * unchanged in the other */
1023                         if (a_sha)
1024                                 output(o, 2, "Removing %s", path);
1025                         /* do not touch working file if it did not exist */
1026                         remove_file(o, 1, path, !a_sha);
1027                 } else {
1028                         /* Deleted in one and changed in the other */
1029                         clean_merge = 0;
1030                         if (!a_sha) {
1031                                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1032                                        "and modified in %s. Version %s of %s left in tree.",
1033                                        path, o->branch1,
1034                                        o->branch2, o->branch2, path);
1035                                 update_file(o, 0, b_sha, b_mode, path);
1036                         } else {
1037                                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1038                                        "and modified in %s. Version %s of %s left in tree.",
1039                                        path, o->branch2,
1040                                        o->branch1, o->branch1, path);
1041                                 update_file(o, 0, a_sha, a_mode, path);
1042                         }
1043                 }
1044
1045         } else if ((!o_sha && a_sha && !b_sha) ||
1046                    (!o_sha && !a_sha && b_sha)) {
1047                 /* Case B: Added in one. */
1048                 const char *add_branch;
1049                 const char *other_branch;
1050                 unsigned mode;
1051                 const unsigned char *sha;
1052                 const char *conf;
1053
1054                 if (a_sha) {
1055                         add_branch = o->branch1;
1056                         other_branch = o->branch2;
1057                         mode = a_mode;
1058                         sha = a_sha;
1059                         conf = "file/directory";
1060                 } else {
1061                         add_branch = o->branch2;
1062                         other_branch = o->branch1;
1063                         mode = b_mode;
1064                         sha = b_sha;
1065                         conf = "directory/file";
1066                 }
1067                 if (string_list_has_string(&o->current_directory_set, path)) {
1068                         const char *new_path = unique_path(o, path, add_branch);
1069                         clean_merge = 0;
1070                         output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1071                                "Adding %s as %s",
1072                                conf, path, other_branch, path, new_path);
1073                         remove_file(o, 0, path, 0);
1074                         update_file(o, 0, sha, mode, new_path);
1075                 } else {
1076                         output(o, 2, "Adding %s", path);
1077                         update_file(o, 1, sha, mode, path);
1078                 }
1079         } else if (a_sha && b_sha) {
1080                 /* Case C: Added in both (check for same permissions) and */
1081                 /* case D: Modified in both, but differently. */
1082                 const char *reason = "content";
1083                 struct merge_file_info mfi;
1084                 struct diff_filespec one, a, b;
1085
1086                 if (!o_sha) {
1087                         reason = "add/add";
1088                         o_sha = (unsigned char *)null_sha1;
1089                 }
1090                 output(o, 2, "Auto-merging %s", path);
1091                 one.path = a.path = b.path = (char *)path;
1092                 hashcpy(one.sha1, o_sha);
1093                 one.mode = o_mode;
1094                 hashcpy(a.sha1, a_sha);
1095                 a.mode = a_mode;
1096                 hashcpy(b.sha1, b_sha);
1097                 b.mode = b_mode;
1098
1099                 mfi = merge_file(o, &one, &a, &b,
1100                                  o->branch1, o->branch2);
1101
1102                 clean_merge = mfi.clean;
1103                 if (mfi.clean)
1104                         update_file(o, 1, mfi.sha, mfi.mode, path);
1105                 else if (S_ISGITLINK(mfi.mode))
1106                         output(o, 1, "CONFLICT (submodule): Merge conflict in %s "
1107                                "- needs %s", path, sha1_to_hex(b.sha1));
1108                 else {
1109                         output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1110                                         reason, path);
1111
1112                         if (o->call_depth)
1113                                 update_file(o, 0, mfi.sha, mfi.mode, path);
1114                         else
1115                                 update_file_flags(o, mfi.sha, mfi.mode, path,
1116                                               0 /* update_cache */, 1 /* update_working_directory */);
1117                 }
1118         } else if (!o_sha && !a_sha && !b_sha) {
1119                 /*
1120                  * this entry was deleted altogether. a_mode == 0 means
1121                  * we had that path and want to actively remove it.
1122                  */
1123                 remove_file(o, 1, path, !a_mode);
1124         } else
1125                 die("Fatal merge failure, shouldn't happen.");
1126
1127         return clean_merge;
1128 }
1129
1130 int merge_trees(struct merge_options *o,
1131                 struct tree *head,
1132                 struct tree *merge,
1133                 struct tree *common,
1134                 struct tree **result)
1135 {
1136         int code, clean;
1137
1138         if (o->subtree_merge) {
1139                 merge = shift_tree_object(head, merge);
1140                 common = shift_tree_object(head, common);
1141         }
1142
1143         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1144                 output(o, 0, "Already uptodate!");
1145                 *result = head;
1146                 return 1;
1147         }
1148
1149         code = git_merge_trees(o->call_depth, common, head, merge);
1150
1151         if (code != 0)
1152                 die("merging of trees %s and %s failed",
1153                     sha1_to_hex(head->object.sha1),
1154                     sha1_to_hex(merge->object.sha1));
1155
1156         if (unmerged_cache()) {
1157                 struct string_list *entries, *re_head, *re_merge;
1158                 int i;
1159                 string_list_clear(&o->current_file_set, 1);
1160                 string_list_clear(&o->current_directory_set, 1);
1161                 get_files_dirs(o, head);
1162                 get_files_dirs(o, merge);
1163
1164                 entries = get_unmerged();
1165                 re_head  = get_renames(o, head, common, head, merge, entries);
1166                 re_merge = get_renames(o, merge, common, head, merge, entries);
1167                 clean = process_renames(o, re_head, re_merge);
1168                 for (i = 0; i < entries->nr; i++) {
1169                         const char *path = entries->items[i].string;
1170                         struct stage_data *e = entries->items[i].util;
1171                         if (!e->processed
1172                                 && !process_entry(o, path, e))
1173                                 clean = 0;
1174                 }
1175
1176                 string_list_clear(re_merge, 0);
1177                 string_list_clear(re_head, 0);
1178                 string_list_clear(entries, 1);
1179
1180         }
1181         else
1182                 clean = 1;
1183
1184         if (o->call_depth)
1185                 *result = write_tree_from_memory(o);
1186
1187         return clean;
1188 }
1189
1190 static struct commit_list *reverse_commit_list(struct commit_list *list)
1191 {
1192         struct commit_list *next = NULL, *current, *backup;
1193         for (current = list; current; current = backup) {
1194                 backup = current->next;
1195                 current->next = next;
1196                 next = current;
1197         }
1198         return next;
1199 }
1200
1201 /*
1202  * Merge the commits h1 and h2, return the resulting virtual
1203  * commit object and a flag indicating the cleanness of the merge.
1204  */
1205 int merge_recursive(struct merge_options *o,
1206                     struct commit *h1,
1207                     struct commit *h2,
1208                     struct commit_list *ca,
1209                     struct commit **result)
1210 {
1211         struct commit_list *iter;
1212         struct commit *merged_common_ancestors;
1213         struct tree *mrtree = mrtree;
1214         int clean;
1215
1216         if (show(o, 4)) {
1217                 output(o, 4, "Merging:");
1218                 output_commit_title(o, h1);
1219                 output_commit_title(o, h2);
1220         }
1221
1222         if (!ca) {
1223                 ca = get_merge_bases(h1, h2, 1);
1224                 ca = reverse_commit_list(ca);
1225         }
1226
1227         if (show(o, 5)) {
1228                 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1229                 for (iter = ca; iter; iter = iter->next)
1230                         output_commit_title(o, iter->item);
1231         }
1232
1233         merged_common_ancestors = pop_commit(&ca);
1234         if (merged_common_ancestors == NULL) {
1235                 /* if there is no common ancestor, make an empty tree */
1236                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1237
1238                 tree->object.parsed = 1;
1239                 tree->object.type = OBJ_TREE;
1240                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1241                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1242         }
1243
1244         for (iter = ca; iter; iter = iter->next) {
1245                 const char *saved_b1, *saved_b2;
1246                 o->call_depth++;
1247                 /*
1248                  * When the merge fails, the result contains files
1249                  * with conflict markers. The cleanness flag is
1250                  * ignored, it was never actually used, as result of
1251                  * merge_trees has always overwritten it: the committed
1252                  * "conflicts" were already resolved.
1253                  */
1254                 discard_cache();
1255                 saved_b1 = o->branch1;
1256                 saved_b2 = o->branch2;
1257                 o->branch1 = "Temporary merge branch 1";
1258                 o->branch2 = "Temporary merge branch 2";
1259                 merge_recursive(o, merged_common_ancestors, iter->item,
1260                                 NULL, &merged_common_ancestors);
1261                 o->branch1 = saved_b1;
1262                 o->branch2 = saved_b2;
1263                 o->call_depth--;
1264
1265                 if (!merged_common_ancestors)
1266                         die("merge returned no commit");
1267         }
1268
1269         discard_cache();
1270         if (!o->call_depth)
1271                 read_cache();
1272
1273         clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1274                             &mrtree);
1275
1276         if (o->call_depth) {
1277                 *result = make_virtual_commit(mrtree, "merged tree");
1278                 commit_list_insert(h1, &(*result)->parents);
1279                 commit_list_insert(h2, &(*result)->parents->next);
1280         }
1281         flush_output(o);
1282         return clean;
1283 }
1284
1285 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1286 {
1287         struct object *object;
1288
1289         object = deref_tag(parse_object(sha1), name, strlen(name));
1290         if (!object)
1291                 return NULL;
1292         if (object->type == OBJ_TREE)
1293                 return make_virtual_commit((struct tree*)object, name);
1294         if (object->type != OBJ_COMMIT)
1295                 return NULL;
1296         if (parse_commit((struct commit *)object))
1297                 return NULL;
1298         return (struct commit *)object;
1299 }
1300
1301 int merge_recursive_generic(struct merge_options *o,
1302                             const unsigned char *head,
1303                             const unsigned char *merge,
1304                             int num_base_list,
1305                             const unsigned char **base_list,
1306                             struct commit **result)
1307 {
1308         int clean, index_fd;
1309         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1310         struct commit *head_commit = get_ref(head, o->branch1);
1311         struct commit *next_commit = get_ref(merge, o->branch2);
1312         struct commit_list *ca = NULL;
1313
1314         if (base_list) {
1315                 int i;
1316                 for (i = 0; i < num_base_list; ++i) {
1317                         struct commit *base;
1318                         if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1319                                 return error("Could not parse object '%s'",
1320                                         sha1_to_hex(base_list[i]));
1321                         commit_list_insert(base, &ca);
1322                 }
1323         }
1324
1325         index_fd = hold_locked_index(lock, 1);
1326         clean = merge_recursive(o, head_commit, next_commit, ca,
1327                         result);
1328         if (active_cache_changed &&
1329                         (write_cache(index_fd, active_cache, active_nr) ||
1330                          commit_locked_index(lock)))
1331                 return error("Unable to write index.");
1332
1333         return clean ? 0 : 1;
1334 }
1335
1336 static int merge_recursive_config(const char *var, const char *value, void *cb)
1337 {
1338         struct merge_options *o = cb;
1339         if (!strcasecmp(var, "merge.verbosity")) {
1340                 o->verbosity = git_config_int(var, value);
1341                 return 0;
1342         }
1343         if (!strcasecmp(var, "diff.renamelimit")) {
1344                 o->diff_rename_limit = git_config_int(var, value);
1345                 return 0;
1346         }
1347         if (!strcasecmp(var, "merge.renamelimit")) {
1348                 o->merge_rename_limit = git_config_int(var, value);
1349                 return 0;
1350         }
1351         return git_default_config(var, value, cb);
1352 }
1353
1354 void init_merge_options(struct merge_options *o)
1355 {
1356         memset(o, 0, sizeof(struct merge_options));
1357         o->verbosity = 2;
1358         o->buffer_output = 1;
1359         o->diff_rename_limit = -1;
1360         o->merge_rename_limit = -1;
1361         git_config(merge_recursive_config, o);
1362         if (getenv("GIT_MERGE_VERBOSITY"))
1363                 o->verbosity =
1364                         strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1365         if (o->verbosity >= 5)
1366                 o->buffer_output = 0;
1367         strbuf_init(&o->obuf, 0);
1368         memset(&o->current_file_set, 0, sizeof(struct string_list));
1369         o->current_file_set.strdup_strings = 1;
1370         memset(&o->current_directory_set, 0, sizeof(struct string_list));
1371         o->current_directory_set.strdup_strings = 1;
1372 }