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 "advice.h"
   7 #include "cache.h"
   8 #include "cache-tree.h"
   9 #include "commit.h"
  10 #include "blob.h"
  11 #include "builtin.h"
  12 #include "tree-walk.h"
  13 #include "diff.h"
  14 #include "diffcore.h"
  15 #include "tag.h"
  16 #include "unpack-trees.h"
  17 #include "string-list.h"
  18 #include "xdiff-interface.h"
  19 #include "ll-merge.h"
  20 #include "attr.h"
  21 #include "merge-recursive.h"
  22 #include "dir.h"
  23 #include "submodule.h"
  24
  25 static struct tree *shift_tree_object(struct tree *one, struct tree *two,
  26                                       const char *subtree_shift)
  27 {
  28         unsigned char shifted[20];
  29
  30         if (!*subtree_shift) {
  31                 shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
  32         } else {
  33                 shift_tree_by(one->object.sha1, two->object.sha1, shifted,
  34                               subtree_shift);
  35         }
  36         if (!hashcmp(two->object.sha1, shifted))
  37                 return two;
  38         return lookup_tree(shifted);
  39 }
  40
  41 /*
  42  * A virtual commit has (const char *)commit->util set to the name.
  43  */
  44
  45 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  46 {
  47         struct commit *commit = xcalloc(1, sizeof(struct commit));
  48         commit->tree = tree;
  49         commit->util = (void*)comment;
  50         /* avoid warnings */
  51         commit->object.parsed = 1;
  52         return commit;
  53 }
  54
  55 /*
  56  * Since we use get_tree_entry(), which does not put the read object into
  57  * the object pool, we cannot rely on a == b.
  58  */
  59 static int sha_eq(const unsigned char *a, const unsigned char *b)
  60 {
  61         if (!a && !b)
  62                 return 2;
  63         return a && b && hashcmp(a, b) == 0;
  64 }
  65
  66 enum rename_type {
  67         RENAME_NORMAL = 0,
  68         RENAME_DELETE,
  69         RENAME_ONE_FILE_TO_TWO
  70 };
  71
  72 struct rename_df_conflict_info {
  73         enum rename_type rename_type;
  74         struct diff_filepair *pair1;
  75         struct diff_filepair *pair2;
  76         const char *branch1;
  77         const char *branch2;
  78         struct stage_data *dst_entry1;
  79         struct stage_data *dst_entry2;
  80 };
  81
  82 /*
  83  * Since we want to write the index eventually, we cannot reuse the index
  84  * for these (temporary) data.
  85  */
  86 struct stage_data {
  87         struct {
  88                 unsigned mode;
  89                 unsigned char sha[20];
  90         } stages[4];
  91         struct rename_df_conflict_info *rename_df_conflict_info;
  92         unsigned processed:1;
  93 };
  94
  95 static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
  96                                                  struct diff_filepair *pair1,
  97                                                  struct diff_filepair *pair2,
  98                                                  const char *branch1,
  99                                                  const char *branch2,
 100                                                  struct stage_data *dst_entry1,
 101                                                  struct stage_data *dst_entry2)
 102 {
 103         struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
 104         ci->rename_type = rename_type;
 105         ci->pair1 = pair1;
 106         ci->branch1 = branch1;
 107         ci->branch2 = branch2;
 108
 109         ci->dst_entry1 = dst_entry1;
 110         dst_entry1->rename_df_conflict_info = ci;
 111         dst_entry1->processed = 0;
 112
 113         assert(!pair2 == !dst_entry2);
 114         if (dst_entry2) {
 115                 ci->dst_entry2 = dst_entry2;
 116                 ci->pair2 = pair2;
 117                 dst_entry2->rename_df_conflict_info = ci;
 118                 dst_entry2->processed = 0;
 119         }
 120 }
 121
 122 static int show(struct merge_options *o, int v)
 123 {
 124         return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 125 }
 126
 127 static void flush_output(struct merge_options *o)
 128 {
 129         if (o->obuf.len) {
 130                 fputs(o->obuf.buf, stdout);
 131                 strbuf_reset(&o->obuf);
 132         }
 133 }
 134
 135 __attribute__((format (printf, 3, 4)))
 136 static void output(struct merge_options *o, int v, const char *fmt, ...)
 137 {
 138         va_list ap;
 139
 140         if (!show(o, v))
 141                 return;
 142
 143         strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 144         memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 145         strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 146
 147         va_start(ap, fmt);
 148         strbuf_vaddf(&o->obuf, fmt, ap);
 149         va_end(ap);
 150
 151         strbuf_add(&o->obuf, "\n", 1);
 152         if (!o->buffer_output)
 153                 flush_output(o);
 154 }
 155
 156 static void output_commit_title(struct merge_options *o, struct commit *commit)
 157 {
 158         int i;
 159         flush_output(o);
 160         for (i = o->call_depth; i--;)
 161                 fputs("  ", stdout);
 162         if (commit->util)
 163                 printf("virtual %s\n", (char *)commit->util);
 164         else {
 165                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 166                 if (parse_commit(commit) != 0)
 167                         printf("(bad commit)\n");
 168                 else {
 169                         const char *title;
 170                         int len = find_commit_subject(commit->buffer, &title);
 171                         if (len)
 172                                 printf("%.*s\n", len, title);
 173                 }
 174         }
 175 }
 176
 177 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 178                 const char *path, int stage, int refresh, int options)
 179 {
 180         struct cache_entry *ce;
 181         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 182         if (!ce)
 183                 return error("addinfo_cache failed for path '%s'", path);
 184         return add_cache_entry(ce, options);
 185 }
 186
 187 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 188 {
 189         parse_tree(tree);
 190         init_tree_desc(desc, tree->buffer, tree->size);
 191 }
 192
 193 static int git_merge_trees(int index_only,
 194                            struct tree *common,
 195                            struct tree *head,
 196                            struct tree *merge)
 197 {
 198         int rc;
 199         struct tree_desc t[3];
 200         struct unpack_trees_options opts;
 201
 202         memset(&opts, 0, sizeof(opts));
 203         if (index_only)
 204                 opts.index_only = 1;
 205         else
 206                 opts.update = 1;
 207         opts.merge = 1;
 208         opts.head_idx = 2;
 209         opts.fn = threeway_merge;
 210         opts.src_index = &the_index;
 211         opts.dst_index = &the_index;
 212         setup_unpack_trees_porcelain(&opts, "merge");
 213
 214         init_tree_desc_from_tree(t+0, common);
 215         init_tree_desc_from_tree(t+1, head);
 216         init_tree_desc_from_tree(t+2, merge);
 217
 218         rc = unpack_trees(3, t, &opts);
 219         cache_tree_free(&active_cache_tree);
 220         return rc;
 221 }
 222
 223 struct tree *write_tree_from_memory(struct merge_options *o)
 224 {
 225         struct tree *result = NULL;
 226
 227         if (unmerged_cache()) {
 228                 int i;
 229                 fprintf(stderr, "BUG: There are unmerged index entries:\n");
 230                 for (i = 0; i < active_nr; i++) {
 231                         struct cache_entry *ce = active_cache[i];
 232                         if (ce_stage(ce))
 233                                 fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
 234                                         (int)ce_namelen(ce), ce->name);
 235                 }
 236                 die("Bug in merge-recursive.c");
 237         }
 238
 239         if (!active_cache_tree)
 240                 active_cache_tree = cache_tree();
 241
 242         if (!cache_tree_fully_valid(active_cache_tree) &&
 243             cache_tree_update(active_cache_tree,
 244                               active_cache, active_nr, 0, 0) < 0)
 245                 die("error building trees");
 246
 247         result = lookup_tree(active_cache_tree->sha1);
 248
 249         return result;
 250 }
 251
 252 static int save_files_dirs(const unsigned char *sha1,
 253                 const char *base, int baselen, const char *path,
 254                 unsigned int mode, int stage, void *context)
 255 {
 256         int len = strlen(path);
 257         char *newpath = xmalloc(baselen + len + 1);
 258         struct merge_options *o = context;
 259
 260         memcpy(newpath, base, baselen);
 261         memcpy(newpath + baselen, path, len);
 262         newpath[baselen + len] = '\0';
 263
 264         if (S_ISDIR(mode))
 265                 string_list_insert(&o->current_directory_set, newpath);
 266         else
 267                 string_list_insert(&o->current_file_set, newpath);
 268         free(newpath);
 269
 270         return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 271 }
 272
 273 static int get_files_dirs(struct merge_options *o, struct tree *tree)
 274 {
 275         int n;
 276         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 277                 return 0;
 278         n = o->current_file_set.nr + o->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 string_list *entries)
 289 {
 290         struct string_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 = string_list_insert(entries, path);
 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 string_list *get_unmerged(void)
 308 {
 309         struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 310         int i;
 311
 312         unmerged->strdup_strings = 1;
 313
 314         for (i = 0; i < active_nr; i++) {
 315                 struct string_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 = string_list_lookup(unmerged, ce->name);
 322                 if (!item) {
 323                         item = string_list_insert(unmerged, ce->name);
 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 static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 335                                                       struct string_list *entries)
 336 {
 337         /* If there are D/F conflicts, and the paths currently exist
 338          * in the working copy as a file, we want to remove them to
 339          * make room for the corresponding directory.  Such paths will
 340          * later be processed in process_df_entry() at the end.  If
 341          * the corresponding directory ends up being removed by the
 342          * merge, then the file will be reinstated at that time;
 343          * otherwise, if the file is not supposed to be removed by the
 344          * merge, the contents of the file will be placed in another
 345          * unique filename.
 346          *
 347          * NOTE: This function relies on the fact that entries for a
 348          * D/F conflict will appear adjacent in the index, with the
 349          * entries for the file appearing before entries for paths
 350          * below the corresponding directory.
 351          */
 352         const char *last_file = NULL;
 353         int last_len = 0;
 354         int i;
 355
 356         for (i = 0; i < entries->nr; i++) {
 357                 const char *path = entries->items[i].string;
 358                 int len = strlen(path);
 359                 struct stage_data *e = entries->items[i].util;
 360
 361                 /*
 362                  * Check if last_file & path correspond to a D/F conflict;
 363                  * i.e. whether path is last_file+'/'+<something>.
 364                  * If so, remove last_file to make room for path and friends.
 365                  */
 366                 if (last_file &&
 367                     len > last_len &&
 368                     memcmp(path, last_file, last_len) == 0 &&
 369                     path[last_len] == '/') {
 370                         output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 371                         unlink(last_file);
 372                 }
 373
 374                 /*
 375                  * Determine whether path could exist as a file in the
 376                  * working directory as a possible D/F conflict.  This
 377                  * will only occur when it exists in stage 2 as a
 378                  * file.
 379                  */
 380                 if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 381                         last_file = path;
 382                         last_len = len;
 383                 } else {
 384                         last_file = NULL;
 385                 }
 386         }
 387 }
 388
 389 struct rename {
 390         struct diff_filepair *pair;
 391         struct stage_data *src_entry;
 392         struct stage_data *dst_entry;
 393         unsigned processed:1;
 394 };
 395
 396 /*
 397  * Get information of all renames which occurred between 'o_tree' and
 398  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 399  * 'b_tree') to be able to associate the correct cache entries with
 400  * the rename information. 'tree' is always equal to either a_tree or b_tree.
 401  */
 402 static struct string_list *get_renames(struct merge_options *o,
 403                                        struct tree *tree,
 404                                        struct tree *o_tree,
 405                                        struct tree *a_tree,
 406                                        struct tree *b_tree,
 407                                        struct string_list *entries)
 408 {
 409         int i;
 410         struct string_list *renames;
 411         struct diff_options opts;
 412
 413         renames = xcalloc(1, sizeof(struct string_list));
 414         diff_setup(&opts);
 415         DIFF_OPT_SET(&opts, RECURSIVE);
 416         opts.detect_rename = DIFF_DETECT_RENAME;
 417         opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 418                             o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 419                             1000;
 420         opts.rename_score = o->rename_score;
 421         opts.show_rename_progress = o->show_rename_progress;
 422         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 423         if (diff_setup_done(&opts) < 0)
 424                 die("diff setup failed");
 425         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 426         diffcore_std(&opts);
 427         if (opts.needed_rename_limit > o->needed_rename_limit)
 428                 o->needed_rename_limit = opts.needed_rename_limit;
 429         for (i = 0; i < diff_queued_diff.nr; ++i) {
 430                 struct string_list_item *item;
 431                 struct rename *re;
 432                 struct diff_filepair *pair = diff_queued_diff.queue[i];
 433                 if (pair->status != 'R') {
 434                         diff_free_filepair(pair);
 435                         continue;
 436                 }
 437                 re = xmalloc(sizeof(*re));
 438                 re->processed = 0;
 439                 re->pair = pair;
 440                 item = string_list_lookup(entries, re->pair->one->path);
 441                 if (!item)
 442                         re->src_entry = insert_stage_data(re->pair->one->path,
 443                                         o_tree, a_tree, b_tree, entries);
 444                 else
 445                         re->src_entry = item->util;
 446
 447                 item = string_list_lookup(entries, re->pair->two->path);
 448                 if (!item)
 449                         re->dst_entry = insert_stage_data(re->pair->two->path,
 450                                         o_tree, a_tree, b_tree, entries);
 451                 else
 452                         re->dst_entry = item->util;
 453                 item = string_list_insert(renames, pair->one->path);
 454                 item->util = re;
 455         }
 456         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 457         diff_queued_diff.nr = 0;
 458         diff_flush(&opts);
 459         return renames;
 460 }
 461
 462 static int update_stages_options(const char *path, struct diff_filespec *o,
 463                          struct diff_filespec *a, struct diff_filespec *b,
 464                          int clear, int options)
 465 {
 466         if (clear)
 467                 if (remove_file_from_cache(path))
 468                         return -1;
 469         if (o)
 470                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 471                         return -1;
 472         if (a)
 473                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 474                         return -1;
 475         if (b)
 476                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 477                         return -1;
 478         return 0;
 479 }
 480
 481 static int update_stages(const char *path, struct diff_filespec *o,
 482                          struct diff_filespec *a, struct diff_filespec *b,
 483                          int clear)
 484 {
 485         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 486         return update_stages_options(path, o, a, b, clear, options);
 487 }
 488
 489 static int update_stages_and_entry(const char *path,
 490                                    struct stage_data *entry,
 491                                    struct diff_filespec *o,
 492                                    struct diff_filespec *a,
 493                                    struct diff_filespec *b,
 494                                    int clear)
 495 {
 496         int options;
 497
 498         entry->processed = 0;
 499         entry->stages[1].mode = o->mode;
 500         entry->stages[2].mode = a->mode;
 501         entry->stages[3].mode = b->mode;
 502         hashcpy(entry->stages[1].sha, o->sha1);
 503         hashcpy(entry->stages[2].sha, a->sha1);
 504         hashcpy(entry->stages[3].sha, b->sha1);
 505         options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 506         return update_stages_options(path, o, a, b, clear, options);
 507 }
 508
 509 static int remove_file(struct merge_options *o, int clean,
 510                        const char *path, int no_wd)
 511 {
 512         int update_cache = o->call_depth || clean;
 513         int update_working_directory = !o->call_depth && !no_wd;
 514
 515         if (update_cache) {
 516                 if (remove_file_from_cache(path))
 517                         return -1;
 518         }
 519         if (update_working_directory) {
 520                 if (remove_path(path))
 521                         return -1;
 522         }
 523         return 0;
 524 }
 525
 526 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 527 {
 528         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 529         int suffix = 0;
 530         struct stat st;
 531         char *p = newpath + strlen(path);
 532         strcpy(newpath, path);
 533         *(p++) = '~';
 534         strcpy(p, branch);
 535         for (; *p; ++p)
 536                 if ('/' == *p)
 537                         *p = '_';
 538         while (string_list_has_string(&o->current_file_set, newpath) ||
 539                string_list_has_string(&o->current_directory_set, newpath) ||
 540                lstat(newpath, &st) == 0)
 541                 sprintf(p, "_%d", suffix++);
 542
 543         string_list_insert(&o->current_file_set, newpath);
 544         return newpath;
 545 }
 546
 547 static void flush_buffer(int fd, const char *buf, unsigned long size)
 548 {
 549         while (size > 0) {
 550                 long ret = write_in_full(fd, buf, size);
 551                 if (ret < 0) {
 552                         /* Ignore epipe */
 553                         if (errno == EPIPE)
 554                                 break;
 555                         die_errno("merge-recursive");
 556                 } else if (!ret) {
 557                         die("merge-recursive: disk full?");
 558                 }
 559                 size -= ret;
 560                 buf += ret;
 561         }
 562 }
 563
 564 static int would_lose_untracked(const char *path)
 565 {
 566         int pos = cache_name_pos(path, strlen(path));
 567
 568         if (pos < 0)
 569                 pos = -1 - pos;
 570         while (pos < active_nr &&
 571                !strcmp(path, active_cache[pos]->name)) {
 572                 /*
 573                  * If stage #0, it is definitely tracked.
 574                  * If it has stage #2 then it was tracked
 575                  * before this merge started.  All other
 576                  * cases the path was not tracked.
 577                  */
 578                 switch (ce_stage(active_cache[pos])) {
 579                 case 0:
 580                 case 2:
 581                         return 0;
 582                 }
 583                 pos++;
 584         }
 585         return file_exists(path);
 586 }
 587
 588 static int make_room_for_path(const char *path)
 589 {
 590         int status;
 591         const char *msg = "failed to create path '%s'%s";
 592
 593         status = safe_create_leading_directories_const(path);
 594         if (status) {
 595                 if (status == -3) {
 596                         /* something else exists */
 597                         error(msg, path, ": perhaps a D/F conflict?");
 598                         return -1;
 599                 }
 600                 die(msg, path, "");
 601         }
 602
 603         /*
 604          * Do not unlink a file in the work tree if we are not
 605          * tracking it.
 606          */
 607         if (would_lose_untracked(path))
 608                 return error("refusing to lose untracked file at '%s'",
 609                              path);
 610
 611         /* Successful unlink is good.. */
 612         if (!unlink(path))
 613                 return 0;
 614         /* .. and so is no existing file */
 615         if (errno == ENOENT)
 616                 return 0;
 617         /* .. but not some other error (who really cares what?) */
 618         return error(msg, path, ": perhaps a D/F conflict?");
 619 }
 620
 621 static void update_file_flags(struct merge_options *o,
 622                               const unsigned char *sha,
 623                               unsigned mode,
 624                               const char *path,
 625                               int update_cache,
 626                               int update_wd)
 627 {
 628         if (o->call_depth)
 629                 update_wd = 0;
 630
 631         if (update_wd) {
 632                 enum object_type type;
 633                 void *buf;
 634                 unsigned long size;
 635
 636                 if (S_ISGITLINK(mode)) {
 637                         /*
 638                          * We may later decide to recursively descend into
 639                          * the submodule directory and update its index
 640                          * and/or work tree, but we do not do that now.
 641                          */
 642                         update_wd = 0;
 643                         goto update_index;
 644                 }
 645
 646                 buf = read_sha1_file(sha, &type, &size);
 647                 if (!buf)
 648                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 649                 if (type != OBJ_BLOB)
 650                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 651                 if (S_ISREG(mode)) {
 652                         struct strbuf strbuf = STRBUF_INIT;
 653                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
 654                                 free(buf);
 655                                 size = strbuf.len;
 656                                 buf = strbuf_detach(&strbuf, NULL);
 657                         }
 658                 }
 659
 660                 if (make_room_for_path(path) < 0) {
 661                         update_wd = 0;
 662                         free(buf);
 663                         goto update_index;
 664                 }
 665                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 666                         int fd;
 667                         if (mode & 0100)
 668                                 mode = 0777;
 669                         else
 670                                 mode = 0666;
 671                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 672                         if (fd < 0)
 673                                 die_errno("failed to open '%s'", path);
 674                         flush_buffer(fd, buf, size);
 675                         close(fd);
 676                 } else if (S_ISLNK(mode)) {
 677                         char *lnk = xmemdupz(buf, size);
 678                         safe_create_leading_directories_const(path);
 679                         unlink(path);
 680                         if (symlink(lnk, path))
 681                                 die_errno("failed to symlink '%s'", path);
 682                         free(lnk);
 683                 } else
 684                         die("do not know what to do with %06o %s '%s'",
 685                             mode, sha1_to_hex(sha), path);
 686                 free(buf);
 687         }
 688  update_index:
 689         if (update_cache)
 690                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 691 }
 692
 693 static void update_file(struct merge_options *o,
 694                         int clean,
 695                         const unsigned char *sha,
 696                         unsigned mode,
 697                         const char *path)
 698 {
 699         update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 700 }
 701
 702 /* Low level file merging, update and removal */
 703
 704 struct merge_file_info {
 705         unsigned char sha[20];
 706         unsigned mode;
 707         unsigned clean:1,
 708                  merge:1;
 709 };
 710
 711 static int merge_3way(struct merge_options *o,
 712                       mmbuffer_t *result_buf,
 713                       struct diff_filespec *one,
 714                       struct diff_filespec *a,
 715                       struct diff_filespec *b,
 716                       const char *branch1,
 717                       const char *branch2)
 718 {
 719         mmfile_t orig, src1, src2;
 720         struct ll_merge_options ll_opts = {0};
 721         char *base_name, *name1, *name2;
 722         int merge_status;
 723
 724         ll_opts.renormalize = o->renormalize;
 725         ll_opts.xdl_opts = o->xdl_opts;
 726
 727         if (o->call_depth) {
 728                 ll_opts.virtual_ancestor = 1;
 729                 ll_opts.variant = 0;
 730         } else {
 731                 switch (o->recursive_variant) {
 732                 case MERGE_RECURSIVE_OURS:
 733                         ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 734                         break;
 735                 case MERGE_RECURSIVE_THEIRS:
 736                         ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 737                         break;
 738                 default:
 739                         ll_opts.variant = 0;
 740                         break;
 741                 }
 742         }
 743
 744         if (strcmp(a->path, b->path) ||
 745             (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 746                 base_name = o->ancestor == NULL ? NULL :
 747                         xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 748                 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 749                 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 750         } else {
 751                 base_name = o->ancestor == NULL ? NULL :
 752                         xstrdup(mkpath("%s", o->ancestor));
 753                 name1 = xstrdup(mkpath("%s", branch1));
 754                 name2 = xstrdup(mkpath("%s", branch2));
 755         }
 756
 757         read_mmblob(&orig, one->sha1);
 758         read_mmblob(&src1, a->sha1);
 759         read_mmblob(&src2, b->sha1);
 760
 761         merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 762                                 &src1, name1, &src2, name2, &ll_opts);
 763
 764         free(name1);
 765         free(name2);
 766         free(orig.ptr);
 767         free(src1.ptr);
 768         free(src2.ptr);
 769         return merge_status;
 770 }
 771
 772 static struct merge_file_info merge_file(struct merge_options *o,
 773                                          struct diff_filespec *one,
 774                                          struct diff_filespec *a,
 775                                          struct diff_filespec *b,
 776                                          const char *branch1,
 777                                          const char *branch2)
 778 {
 779         struct merge_file_info result;
 780         result.merge = 0;
 781         result.clean = 1;
 782
 783         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 784                 result.clean = 0;
 785                 if (S_ISREG(a->mode)) {
 786                         result.mode = a->mode;
 787                         hashcpy(result.sha, a->sha1);
 788                 } else {
 789                         result.mode = b->mode;
 790                         hashcpy(result.sha, b->sha1);
 791                 }
 792         } else {
 793                 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 794                         result.merge = 1;
 795
 796                 /*
 797                  * Merge modes
 798                  */
 799                 if (a->mode == b->mode || a->mode == one->mode)
 800                         result.mode = b->mode;
 801                 else {
 802                         result.mode = a->mode;
 803                         if (b->mode != one->mode) {
 804                                 result.clean = 0;
 805                                 result.merge = 1;
 806                         }
 807                 }
 808
 809                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 810                         hashcpy(result.sha, b->sha1);
 811                 else if (sha_eq(b->sha1, one->sha1))
 812                         hashcpy(result.sha, a->sha1);
 813                 else if (S_ISREG(a->mode)) {
 814                         mmbuffer_t result_buf;
 815                         int merge_status;
 816
 817                         merge_status = merge_3way(o, &result_buf, one, a, b,
 818                                                   branch1, branch2);
 819
 820                         if ((merge_status < 0) || !result_buf.ptr)
 821                                 die("Failed to execute internal merge");
 822
 823                         if (write_sha1_file(result_buf.ptr, result_buf.size,
 824                                             blob_type, result.sha))
 825                                 die("Unable to add %s to database",
 826                                     a->path);
 827
 828                         free(result_buf.ptr);
 829                         result.clean = (merge_status == 0);
 830                 } else if (S_ISGITLINK(a->mode)) {
 831                         result.clean = merge_submodule(result.sha, one->path, one->sha1,
 832                                                        a->sha1, b->sha1);
 833                 } else if (S_ISLNK(a->mode)) {
 834                         hashcpy(result.sha, a->sha1);
 835
 836                         if (!sha_eq(a->sha1, b->sha1))
 837                                 result.clean = 0;
 838                 } else {
 839                         die("unsupported object type in the tree");
 840                 }
 841         }
 842
 843         return result;
 844 }
 845
 846 static void conflict_rename_delete(struct merge_options *o,
 847                                    struct diff_filepair *pair,
 848                                    const char *rename_branch,
 849                                    const char *other_branch)
 850 {
 851         char *dest_name = pair->two->path;
 852         int df_conflict = 0;
 853         struct stat st;
 854
 855         output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 856                "and deleted in %s",
 857                pair->one->path, pair->two->path, rename_branch,
 858                other_branch);
 859         if (!o->call_depth)
 860                 update_stages(dest_name, NULL,
 861                               rename_branch == o->branch1 ? pair->two : NULL,
 862                               rename_branch == o->branch1 ? NULL : pair->two,
 863                               1);
 864         if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 865                 dest_name = unique_path(o, dest_name, rename_branch);
 866                 df_conflict = 1;
 867         }
 868         update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 869         if (df_conflict)
 870                 free(dest_name);
 871 }
 872
 873 static void conflict_rename_rename_1to2(struct merge_options *o,
 874                                         struct diff_filepair *pair1,
 875                                         const char *branch1,
 876                                         struct diff_filepair *pair2,
 877                                         const char *branch2)
 878 {
 879         /* One file was renamed in both branches, but to different names. */
 880         char *del[2];
 881         int delp = 0;
 882         const char *ren1_dst = pair1->two->path;
 883         const char *ren2_dst = pair2->two->path;
 884         const char *dst_name1 = ren1_dst;
 885         const char *dst_name2 = ren2_dst;
 886         struct stat st;
 887         if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 888                 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 889                 output(o, 1, "%s is a directory in %s adding as %s instead",
 890                        ren1_dst, branch2, dst_name1);
 891         }
 892         if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 893                 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 894                 output(o, 1, "%s is a directory in %s adding as %s instead",
 895                        ren2_dst, branch1, dst_name2);
 896         }
 897         if (o->call_depth) {
 898                 remove_file_from_cache(dst_name1);
 899                 remove_file_from_cache(dst_name2);
 900                 /*
 901                  * Uncomment to leave the conflicting names in the resulting tree
 902                  *
 903                  * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 904                  * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 905                  */
 906         } else {
 907                 update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 908                 update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 909
 910                 update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 911                 update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 912         }
 913         while (delp--)
 914                 free(del[delp]);
 915 }
 916
 917 static void conflict_rename_rename_2to1(struct merge_options *o,
 918                                         struct rename *ren1,
 919                                         const char *branch1,
 920                                         struct rename *ren2,
 921                                         const char *branch2)
 922 {
 923         /* Two files were renamed to the same thing. */
 924         char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 925         char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 926         output(o, 1, "Renaming %s to %s and %s to %s instead",
 927                ren1->pair->one->path, new_path1,
 928                ren2->pair->one->path, new_path2);
 929         remove_file(o, 0, ren1->pair->two->path, 0);
 930         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 931         update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 932         free(new_path2);
 933         free(new_path1);
 934 }
 935
 936 static int process_renames(struct merge_options *o,
 937                            struct string_list *a_renames,
 938                            struct string_list *b_renames)
 939 {
 940         int clean_merge = 1, i, j;
 941         struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 942         struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 943         const struct rename *sre;
 944
 945         for (i = 0; i < a_renames->nr; i++) {
 946                 sre = a_renames->items[i].util;
 947                 string_list_insert(&a_by_dst, sre->pair->two->path)->util
 948                         = sre->dst_entry;
 949         }
 950         for (i = 0; i < b_renames->nr; i++) {
 951                 sre = b_renames->items[i].util;
 952                 string_list_insert(&b_by_dst, sre->pair->two->path)->util
 953                         = sre->dst_entry;
 954         }
 955
 956         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 957                 struct string_list *renames1, *renames2Dst;
 958                 struct rename *ren1 = NULL, *ren2 = NULL;
 959                 const char *branch1, *branch2;
 960                 const char *ren1_src, *ren1_dst;
 961
 962                 if (i >= a_renames->nr) {
 963                         ren2 = b_renames->items[j++].util;
 964                 } else if (j >= b_renames->nr) {
 965                         ren1 = a_renames->items[i++].util;
 966                 } else {
 967                         int compare = strcmp(a_renames->items[i].string,
 968                                              b_renames->items[j].string);
 969                         if (compare <= 0)
 970                                 ren1 = a_renames->items[i++].util;
 971                         if (compare >= 0)
 972                                 ren2 = b_renames->items[j++].util;
 973                 }
 974
 975                 /* TODO: refactor, so that 1/2 are not needed */
 976                 if (ren1) {
 977                         renames1 = a_renames;
 978                         renames2Dst = &b_by_dst;
 979                         branch1 = o->branch1;
 980                         branch2 = o->branch2;
 981                 } else {
 982                         struct rename *tmp;
 983                         renames1 = b_renames;
 984                         renames2Dst = &a_by_dst;
 985                         branch1 = o->branch2;
 986                         branch2 = o->branch1;
 987                         tmp = ren2;
 988                         ren2 = ren1;
 989                         ren1 = tmp;
 990                 }
 991
 992                 ren1->dst_entry->processed = 1;
 993                 ren1->src_entry->processed = 1;
 994
 995                 if (ren1->processed)
 996                         continue;
 997                 ren1->processed = 1;
 998
 999                 ren1_src = ren1->pair->one->path;
1000                 ren1_dst = ren1->pair->two->path;
1001
1002                 if (ren2) {
1003                         const char *ren2_src = ren2->pair->one->path;
1004                         const char *ren2_dst = ren2->pair->two->path;
1005                         /* Renamed in 1 and renamed in 2 */
1006                         if (strcmp(ren1_src, ren2_src) != 0)
1007                                 die("ren1.src != ren2.src");
1008                         ren2->dst_entry->processed = 1;
1009                         ren2->processed = 1;
1010                         if (strcmp(ren1_dst, ren2_dst) != 0) {
1011                                 setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1012                                                               ren1->pair,
1013                                                               ren2->pair,
1014                                                               branch1,
1015                                                               branch2,
1016                                                               ren1->dst_entry,
1017                                                               ren2->dst_entry);
1018                         } else {
1019                                 remove_file(o, 1, ren1_src, 1);
1020                                 update_stages_and_entry(ren1_dst,
1021                                                         ren1->dst_entry,
1022                                                         ren1->pair->one,
1023                                                         ren1->pair->two,
1024                                                         ren2->pair->two,
1025                                                         1 /* clear */);
1026                         }
1027                 } else {
1028                         /* Renamed in 1, maybe changed in 2 */
1029                         struct string_list_item *item;
1030                         /* we only use sha1 and mode of these */
1031                         struct diff_filespec src_other, dst_other;
1032                         int try_merge;
1033
1034                         /*
1035                          * unpack_trees loads entries from common-commit
1036                          * into stage 1, from head-commit into stage 2, and
1037                          * from merge-commit into stage 3.  We keep track
1038                          * of which side corresponds to the rename.
1039                          */
1040                         int renamed_stage = a_renames == renames1 ? 2 : 3;
1041                         int other_stage =   a_renames == renames1 ? 3 : 2;
1042
1043                         remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1044
1045                         hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1046                         src_other.mode = ren1->src_entry->stages[other_stage].mode;
1047                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1048                         dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1049                         try_merge = 0;
1050
1051                         if (sha_eq(src_other.sha1, null_sha1)) {
1052                                 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1053                                         ren1->dst_entry->processed = 0;
1054                                         setup_rename_df_conflict_info(RENAME_DELETE,
1055                                                                       ren1->pair,
1056                                                                       NULL,
1057                                                                       branch1,
1058                                                                       branch2,
1059                                                                       ren1->dst_entry,
1060                                                                       NULL);
1061                                 } else {
1062                                         clean_merge = 0;
1063                                         conflict_rename_delete(o, ren1->pair, branch1, branch2);
1064                                 }
1065                         } else if ((dst_other.mode == ren1->pair->two->mode) &&
1066                                    sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1067                                 /* Added file on the other side
1068                                    identical to the file being
1069                                    renamed: clean merge */
1070                                 update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1071                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1072                                 const char *new_path;
1073                                 clean_merge = 0;
1074                                 try_merge = 1;
1075                                 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1076                                        "%s added in %s",
1077                                        ren1_src, ren1_dst, branch1,
1078                                        ren1_dst, branch2);
1079                                 if (o->call_depth) {
1080                                         struct merge_file_info mfi;
1081                                         struct diff_filespec one, a, b;
1082
1083                                         one.path = a.path = b.path =
1084                                                 (char *)ren1_dst;
1085                                         hashcpy(one.sha1, null_sha1);
1086                                         one.mode = 0;
1087                                         hashcpy(a.sha1, ren1->pair->two->sha1);
1088                                         a.mode = ren1->pair->two->mode;
1089                                         hashcpy(b.sha1, dst_other.sha1);
1090                                         b.mode = dst_other.mode;
1091                                         mfi = merge_file(o, &one, &a, &b,
1092                                                          branch1,
1093                                                          branch2);
1094                                         output(o, 1, "Adding merged %s", ren1_dst);
1095                                         update_file(o, 0,
1096                                                     mfi.sha,
1097                                                     mfi.mode,
1098                                                     ren1_dst);
1099                                         try_merge = 0;
1100                                 } else {
1101                                         new_path = unique_path(o, ren1_dst, branch2);
1102                                         output(o, 1, "Adding as %s instead", new_path);
1103                                         update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1104                                 }
1105                         } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1106                                 ren2 = item->util;
1107                                 clean_merge = 0;
1108                                 ren2->processed = 1;
1109                                 output(o, 1, "CONFLICT (rename/rename): "
1110                                        "Rename %s->%s in %s. "
1111                                        "Rename %s->%s in %s",
1112                                        ren1_src, ren1_dst, branch1,
1113                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
1114                                 conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1115                         } else
1116                                 try_merge = 1;
1117
1118                         if (try_merge) {
1119                                 struct diff_filespec *one, *a, *b;
1120                                 src_other.path = (char *)ren1_src;
1121
1122                                 one = ren1->pair->one;
1123                                 if (a_renames == renames1) {
1124                                         a = ren1->pair->two;
1125                                         b = &src_other;
1126                                 } else {
1127                                         b = ren1->pair->two;
1128                                         a = &src_other;
1129                                 }
1130                                 update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1131                                 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1132                                         setup_rename_df_conflict_info(RENAME_NORMAL,
1133                                                                       ren1->pair,
1134                                                                       NULL,
1135                                                                       branch1,
1136                                                                       NULL,
1137                                                                       ren1->dst_entry,
1138                                                                       NULL);
1139                                 }
1140                         }
1141                 }
1142         }
1143         string_list_clear(&a_by_dst, 0);
1144         string_list_clear(&b_by_dst, 0);
1145
1146         return clean_merge;
1147 }
1148
1149 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1150 {
1151         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1152 }
1153
1154 static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1155 {
1156         void *buf;
1157         enum object_type type;
1158         unsigned long size;
1159         buf = read_sha1_file(sha1, &type, &size);
1160         if (!buf)
1161                 return error("cannot read object %s", sha1_to_hex(sha1));
1162         if (type != OBJ_BLOB) {
1163                 free(buf);
1164                 return error("object %s is not a blob", sha1_to_hex(sha1));
1165         }
1166         strbuf_attach(dst, buf, size, size + 1);
1167         return 0;
1168 }
1169
1170 static int blob_unchanged(const unsigned char *o_sha,
1171                           const unsigned char *a_sha,
1172                           int renormalize, const char *path)
1173 {
1174         struct strbuf o = STRBUF_INIT;
1175         struct strbuf a = STRBUF_INIT;
1176         int ret = 0; /* assume changed for safety */
1177
1178         if (sha_eq(o_sha, a_sha))
1179                 return 1;
1180         if (!renormalize)
1181                 return 0;
1182
1183         assert(o_sha && a_sha);
1184         if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1185                 goto error_return;
1186         /*
1187          * Note: binary | is used so that both renormalizations are
1188          * performed.  Comparison can be skipped if both files are
1189          * unchanged since their sha1s have already been compared.
1190          */
1191         if (renormalize_buffer(path, o.buf, o.len, &o) |
1192             renormalize_buffer(path, a.buf, o.len, &a))
1193                 ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1194
1195 error_return:
1196         strbuf_release(&o);
1197         strbuf_release(&a);
1198         return ret;
1199 }
1200
1201 static void handle_delete_modify(struct merge_options *o,
1202                                  const char *path,
1203                                  const char *new_path,
1204                                  unsigned char *a_sha, int a_mode,
1205                                  unsigned char *b_sha, int b_mode)
1206 {
1207         if (!a_sha) {
1208                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1209                        "and modified in %s. Version %s of %s left in tree%s%s.",
1210                        path, o->branch1,
1211                        o->branch2, o->branch2, path,
1212                        path == new_path ? "" : " at ",
1213                        path == new_path ? "" : new_path);
1214                 update_file(o, 0, b_sha, b_mode, new_path);
1215         } else {
1216                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1217                        "and modified in %s. Version %s of %s left in tree%s%s.",
1218                        path, o->branch2,
1219                        o->branch1, o->branch1, path,
1220                        path == new_path ? "" : " at ",
1221                        path == new_path ? "" : new_path);
1222                 update_file(o, 0, a_sha, a_mode, new_path);
1223         }
1224 }
1225
1226 static int merge_content(struct merge_options *o,
1227                          const char *path,
1228                          unsigned char *o_sha, int o_mode,
1229                          unsigned char *a_sha, int a_mode,
1230                          unsigned char *b_sha, int b_mode,
1231                          const char *df_rename_conflict_branch)
1232 {
1233         const char *reason = "content";
1234         struct merge_file_info mfi;
1235         struct diff_filespec one, a, b;
1236         struct stat st;
1237         unsigned df_conflict_remains = 0;
1238
1239         if (!o_sha) {
1240                 reason = "add/add";
1241                 o_sha = (unsigned char *)null_sha1;
1242         }
1243         one.path = a.path = b.path = (char *)path;
1244         hashcpy(one.sha1, o_sha);
1245         one.mode = o_mode;
1246         hashcpy(a.sha1, a_sha);
1247         a.mode = a_mode;
1248         hashcpy(b.sha1, b_sha);
1249         b.mode = b_mode;
1250
1251         mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1252         if (df_rename_conflict_branch &&
1253             lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1254                 df_conflict_remains = 1;
1255         }
1256
1257         if (mfi.clean && !df_conflict_remains &&
1258             sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1259                 output(o, 3, "Skipped %s (merged same as existing)", path);
1260         else
1261                 output(o, 2, "Auto-merging %s", path);
1262
1263         if (!mfi.clean) {
1264                 if (S_ISGITLINK(mfi.mode))
1265                         reason = "submodule";
1266                 output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1267                                 reason, path);
1268         }
1269
1270         if (df_conflict_remains) {
1271                 const char *new_path;
1272                 update_file_flags(o, mfi.sha, mfi.mode, path,
1273                                   o->call_depth || mfi.clean, 0);
1274                 new_path = unique_path(o, path, df_rename_conflict_branch);
1275                 mfi.clean = 0;
1276                 output(o, 1, "Adding as %s instead", new_path);
1277                 update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1278         } else {
1279                 update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1280         }
1281         return mfi.clean;
1282
1283 }
1284
1285 /* Per entry merge function */
1286 static int process_entry(struct merge_options *o,
1287                          const char *path, struct stage_data *entry)
1288 {
1289         /*
1290         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1291         print_index_entry("\tpath: ", entry);
1292         */
1293         int clean_merge = 1;
1294         int normalize = o->renormalize;
1295         unsigned o_mode = entry->stages[1].mode;
1296         unsigned a_mode = entry->stages[2].mode;
1297         unsigned b_mode = entry->stages[3].mode;
1298         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1299         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1300         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1301
1302         if (entry->rename_df_conflict_info)
1303                 return 1; /* Such cases are handled elsewhere. */
1304
1305         entry->processed = 1;
1306         if (o_sha && (!a_sha || !b_sha)) {
1307                 /* Case A: Deleted in one */
1308                 if ((!a_sha && !b_sha) ||
1309                     (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1310                     (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1311                         /* Deleted in both or deleted in one and
1312                          * unchanged in the other */
1313                         if (a_sha)
1314                                 output(o, 2, "Removing %s", path);
1315                         /* do not touch working file if it did not exist */
1316                         remove_file(o, 1, path, !a_sha);
1317                 } else if (string_list_has_string(&o->current_directory_set,
1318                                                   path)) {
1319                         entry->processed = 0;
1320                         return 1; /* Assume clean until processed */
1321                 } else {
1322                         /* Deleted in one and changed in the other */
1323                         clean_merge = 0;
1324                         handle_delete_modify(o, path, path,
1325                                              a_sha, a_mode, b_sha, b_mode);
1326                 }
1327
1328         } else if ((!o_sha && a_sha && !b_sha) ||
1329                    (!o_sha && !a_sha && b_sha)) {
1330                 /* Case B: Added in one. */
1331                 unsigned mode;
1332                 const unsigned char *sha;
1333
1334                 if (a_sha) {
1335                         mode = a_mode;
1336                         sha = a_sha;
1337                 } else {
1338                         mode = b_mode;
1339                         sha = b_sha;
1340                 }
1341                 if (string_list_has_string(&o->current_directory_set, path)) {
1342                         /* Handle D->F conflicts after all subfiles */
1343                         entry->processed = 0;
1344                         return 1; /* Assume clean until processed */
1345                 } else {
1346                         output(o, 2, "Adding %s", path);
1347                         update_file(o, 1, sha, mode, path);
1348                 }
1349         } else if (a_sha && b_sha) {
1350                 /* Case C: Added in both (check for same permissions) and */
1351                 /* case D: Modified in both, but differently. */
1352                 clean_merge = merge_content(o, path,
1353                                             o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1354                                             NULL);
1355         } else if (!o_sha && !a_sha && !b_sha) {
1356                 /*
1357                  * this entry was deleted altogether. a_mode == 0 means
1358                  * we had that path and want to actively remove it.
1359                  */
1360                 remove_file(o, 1, path, !a_mode);
1361         } else
1362                 die("Fatal merge failure, shouldn't happen.");
1363
1364         return clean_merge;
1365 }
1366
1367 /*
1368  * Per entry merge function for D/F (and/or rename) conflicts.  In the
1369  * cases we can cleanly resolve D/F conflicts, process_entry() can
1370  * clean out all the files below the directory for us.  All D/F
1371  * conflict cases must be handled here at the end to make sure any
1372  * directories that can be cleaned out, are.
1373  *
1374  * Some rename conflicts may also be handled here that don't necessarily
1375  * involve D/F conflicts, since the code to handle them is generic enough
1376  * to handle those rename conflicts with or without D/F conflicts also
1377  * being involved.
1378  */
1379 static int process_df_entry(struct merge_options *o,
1380                             const char *path, struct stage_data *entry)
1381 {
1382         int clean_merge = 1;
1383         unsigned o_mode = entry->stages[1].mode;
1384         unsigned a_mode = entry->stages[2].mode;
1385         unsigned b_mode = entry->stages[3].mode;
1386         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1387         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1388         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1389         struct stat st;
1390
1391         entry->processed = 1;
1392         if (entry->rename_df_conflict_info) {
1393                 struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1394                 char *src;
1395                 switch (conflict_info->rename_type) {
1396                 case RENAME_NORMAL:
1397                         clean_merge = merge_content(o, path,
1398                                                     o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1399                                                     conflict_info->branch1);
1400                         break;
1401                 case RENAME_DELETE:
1402                         clean_merge = 0;
1403                         conflict_rename_delete(o, conflict_info->pair1,
1404                                                conflict_info->branch1,
1405                                                conflict_info->branch2);
1406                         break;
1407                 case RENAME_ONE_FILE_TO_TWO:
1408                         src = conflict_info->pair1->one->path;
1409                         clean_merge = 0;
1410                         output(o, 1, "CONFLICT (rename/rename): "
1411                                "Rename \"%s\"->\"%s\" in branch \"%s\" "
1412                                "rename \"%s\"->\"%s\" in \"%s\"%s",
1413                                src, conflict_info->pair1->two->path, conflict_info->branch1,
1414                                src, conflict_info->pair2->two->path, conflict_info->branch2,
1415                                o->call_depth ? " (left unresolved)" : "");
1416                         if (o->call_depth) {
1417                                 remove_file_from_cache(src);
1418                                 update_file(o, 0, conflict_info->pair1->one->sha1,
1419                                             conflict_info->pair1->one->mode, src);
1420                         }
1421                         conflict_rename_rename_1to2(o, conflict_info->pair1,
1422                                                     conflict_info->branch1,
1423                                                     conflict_info->pair2,
1424                                                     conflict_info->branch2);
1425                         conflict_info->dst_entry2->processed = 1;
1426                         break;
1427                 default:
1428                         entry->processed = 0;
1429                         break;
1430                 }
1431         } else if (o_sha && (!a_sha || !b_sha)) {
1432                 /* Modify/delete; deleted side may have put a directory in the way */
1433                 const char *new_path = path;
1434                 if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1435                         new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1436                 clean_merge = 0;
1437                 handle_delete_modify(o, path, new_path,
1438                                      a_sha, a_mode, b_sha, b_mode);
1439         } else if (!o_sha && !!a_sha != !!b_sha) {
1440                 /* directory -> (directory, file) */
1441                 const char *add_branch;
1442                 const char *other_branch;
1443                 unsigned mode;
1444                 const unsigned char *sha;
1445                 const char *conf;
1446
1447                 if (a_sha) {
1448                         add_branch = o->branch1;
1449                         other_branch = o->branch2;
1450                         mode = a_mode;
1451                         sha = a_sha;
1452                         conf = "file/directory";
1453                 } else {
1454                         add_branch = o->branch2;
1455                         other_branch = o->branch1;
1456                         mode = b_mode;
1457                         sha = b_sha;
1458                         conf = "directory/file";
1459                 }
1460                 if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1461                         const char *new_path = unique_path(o, path, add_branch);
1462                         clean_merge = 0;
1463                         output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1464                                "Adding %s as %s",
1465                                conf, path, other_branch, path, new_path);
1466                         update_file(o, 0, sha, mode, new_path);
1467                 } else {
1468                         output(o, 2, "Adding %s", path);
1469                         update_file(o, 1, sha, mode, path);
1470                 }
1471         } else {
1472                 entry->processed = 0;
1473                 return 1; /* not handled; assume clean until processed */
1474         }
1475
1476         return clean_merge;
1477 }
1478
1479 int merge_trees(struct merge_options *o,
1480                 struct tree *head,
1481                 struct tree *merge,
1482                 struct tree *common,
1483                 struct tree **result)
1484 {
1485         int code, clean;
1486
1487         if (o->subtree_shift) {
1488                 merge = shift_tree_object(head, merge, o->subtree_shift);
1489                 common = shift_tree_object(head, common, o->subtree_shift);
1490         }
1491
1492         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1493                 output(o, 0, "Already up-to-date!");
1494                 *result = head;
1495                 return 1;
1496         }
1497
1498         code = git_merge_trees(o->call_depth, common, head, merge);
1499
1500         if (code != 0) {
1501                 if (show(o, 4) || o->call_depth)
1502                         die("merging of trees %s and %s failed",
1503                             sha1_to_hex(head->object.sha1),
1504                             sha1_to_hex(merge->object.sha1));
1505                 else
1506                         exit(128);
1507         }
1508
1509         if (unmerged_cache()) {
1510                 struct string_list *entries, *re_head, *re_merge;
1511                 int i;
1512                 string_list_clear(&o->current_file_set, 1);
1513                 string_list_clear(&o->current_directory_set, 1);
1514                 get_files_dirs(o, head);
1515                 get_files_dirs(o, merge);
1516
1517                 entries = get_unmerged();
1518                 make_room_for_directories_of_df_conflicts(o, entries);
1519                 re_head  = get_renames(o, head, common, head, merge, entries);
1520                 re_merge = get_renames(o, merge, common, head, merge, entries);
1521                 clean = process_renames(o, re_head, re_merge);
1522                 for (i = 0; i < entries->nr; i++) {
1523                         const char *path = entries->items[i].string;
1524                         struct stage_data *e = entries->items[i].util;
1525                         if (!e->processed
1526                                 && !process_entry(o, path, e))
1527                                 clean = 0;
1528                 }
1529                 for (i = 0; i < entries->nr; i++) {
1530                         const char *path = entries->items[i].string;
1531                         struct stage_data *e = entries->items[i].util;
1532                         if (!e->processed
1533                                 && !process_df_entry(o, path, e))
1534                                 clean = 0;
1535                 }
1536                 for (i = 0; i < entries->nr; i++) {
1537                         struct stage_data *e = entries->items[i].util;
1538                         if (!e->processed)
1539                                 die("Unprocessed path??? %s",
1540                                     entries->items[i].string);
1541                 }
1542
1543                 string_list_clear(re_merge, 0);
1544                 string_list_clear(re_head, 0);
1545                 string_list_clear(entries, 1);
1546
1547         }
1548         else
1549                 clean = 1;
1550
1551         if (o->call_depth)
1552                 *result = write_tree_from_memory(o);
1553
1554         return clean;
1555 }
1556
1557 static struct commit_list *reverse_commit_list(struct commit_list *list)
1558 {
1559         struct commit_list *next = NULL, *current, *backup;
1560         for (current = list; current; current = backup) {
1561                 backup = current->next;
1562                 current->next = next;
1563                 next = current;
1564         }
1565         return next;
1566 }
1567
1568 /*
1569  * Merge the commits h1 and h2, return the resulting virtual
1570  * commit object and a flag indicating the cleanness of the merge.
1571  */
1572 int merge_recursive(struct merge_options *o,
1573                     struct commit *h1,
1574                     struct commit *h2,
1575                     struct commit_list *ca,
1576                     struct commit **result)
1577 {
1578         struct commit_list *iter;
1579         struct commit *merged_common_ancestors;
1580         struct tree *mrtree = mrtree;
1581         int clean;
1582
1583         if (show(o, 4)) {
1584                 output(o, 4, "Merging:");
1585                 output_commit_title(o, h1);
1586                 output_commit_title(o, h2);
1587         }
1588
1589         if (!ca) {
1590                 ca = get_merge_bases(h1, h2, 1);
1591                 ca = reverse_commit_list(ca);
1592         }
1593
1594         if (show(o, 5)) {
1595                 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1596                 for (iter = ca; iter; iter = iter->next)
1597                         output_commit_title(o, iter->item);
1598         }
1599
1600         merged_common_ancestors = pop_commit(&ca);
1601         if (merged_common_ancestors == NULL) {
1602                 /* if there is no common ancestor, make an empty tree */
1603                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1604
1605                 tree->object.parsed = 1;
1606                 tree->object.type = OBJ_TREE;
1607                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1608                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1609         }
1610
1611         for (iter = ca; iter; iter = iter->next) {
1612                 const char *saved_b1, *saved_b2;
1613                 o->call_depth++;
1614                 /*
1615                  * When the merge fails, the result contains files
1616                  * with conflict markers. The cleanness flag is
1617                  * ignored, it was never actually used, as result of
1618                  * merge_trees has always overwritten it: the committed
1619                  * "conflicts" were already resolved.
1620                  */
1621                 discard_cache();
1622                 saved_b1 = o->branch1;
1623                 saved_b2 = o->branch2;
1624                 o->branch1 = "Temporary merge branch 1";
1625                 o->branch2 = "Temporary merge branch 2";
1626                 merge_recursive(o, merged_common_ancestors, iter->item,
1627                                 NULL, &merged_common_ancestors);
1628                 o->branch1 = saved_b1;
1629                 o->branch2 = saved_b2;
1630                 o->call_depth--;
1631
1632                 if (!merged_common_ancestors)
1633                         die("merge returned no commit");
1634         }
1635
1636         discard_cache();
1637         if (!o->call_depth)
1638                 read_cache();
1639
1640         o->ancestor = "merged common ancestors";
1641         clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1642                             &mrtree);
1643
1644         if (o->call_depth) {
1645                 *result = make_virtual_commit(mrtree, "merged tree");
1646                 commit_list_insert(h1, &(*result)->parents);
1647                 commit_list_insert(h2, &(*result)->parents->next);
1648         }
1649         flush_output(o);
1650         if (show(o, 2))
1651                 diff_warn_rename_limit("merge.renamelimit",
1652                                        o->needed_rename_limit, 0);
1653         return clean;
1654 }
1655
1656 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1657 {
1658         struct object *object;
1659
1660         object = deref_tag(parse_object(sha1), name, strlen(name));
1661         if (!object)
1662                 return NULL;
1663         if (object->type == OBJ_TREE)
1664                 return make_virtual_commit((struct tree*)object, name);
1665         if (object->type != OBJ_COMMIT)
1666                 return NULL;
1667         if (parse_commit((struct commit *)object))
1668                 return NULL;
1669         return (struct commit *)object;
1670 }
1671
1672 int merge_recursive_generic(struct merge_options *o,
1673                             const unsigned char *head,
1674                             const unsigned char *merge,
1675                             int num_base_list,
1676                             const unsigned char **base_list,
1677                             struct commit **result)
1678 {
1679         int clean, index_fd;
1680         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1681         struct commit *head_commit = get_ref(head, o->branch1);
1682         struct commit *next_commit = get_ref(merge, o->branch2);
1683         struct commit_list *ca = NULL;
1684
1685         if (base_list) {
1686                 int i;
1687                 for (i = 0; i < num_base_list; ++i) {
1688                         struct commit *base;
1689                         if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1690                                 return error("Could not parse object '%s'",
1691                                         sha1_to_hex(base_list[i]));
1692                         commit_list_insert(base, &ca);
1693                 }
1694         }
1695
1696         index_fd = hold_locked_index(lock, 1);
1697         clean = merge_recursive(o, head_commit, next_commit, ca,
1698                         result);
1699         if (active_cache_changed &&
1700                         (write_cache(index_fd, active_cache, active_nr) ||
1701                          commit_locked_index(lock)))
1702                 return error("Unable to write index.");
1703
1704         return clean ? 0 : 1;
1705 }
1706
1707 static int merge_recursive_config(const char *var, const char *value, void *cb)
1708 {
1709         struct merge_options *o = cb;
1710         if (!strcmp(var, "merge.verbosity")) {
1711                 o->verbosity = git_config_int(var, value);
1712                 return 0;
1713         }
1714         if (!strcmp(var, "diff.renamelimit")) {
1715                 o->diff_rename_limit = git_config_int(var, value);
1716                 return 0;
1717         }
1718         if (!strcmp(var, "merge.renamelimit")) {
1719                 o->merge_rename_limit = git_config_int(var, value);
1720                 return 0;
1721         }
1722         return git_xmerge_config(var, value, cb);
1723 }
1724
1725 void init_merge_options(struct merge_options *o)
1726 {
1727         memset(o, 0, sizeof(struct merge_options));
1728         o->verbosity = 2;
1729         o->buffer_output = 1;
1730         o->diff_rename_limit = -1;
1731         o->merge_rename_limit = -1;
1732         o->renormalize = 0;
1733         git_config(merge_recursive_config, o);
1734         if (getenv("GIT_MERGE_VERBOSITY"))
1735                 o->verbosity =
1736                         strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1737         if (o->verbosity >= 5)
1738                 o->buffer_output = 0;
1739         strbuf_init(&o->obuf, 0);
1740         memset(&o->current_file_set, 0, sizeof(struct string_list));
1741         o->current_file_set.strdup_strings = 1;
1742         memset(&o->current_directory_set, 0, sizeof(struct string_list));
1743         o->current_directory_set.strdup_strings = 1;
1744 }
1745
1746 int parse_merge_opt(struct merge_options *o, const char *s)
1747 {
1748         if (!s || !*s)
1749                 return -1;
1750         if (!strcmp(s, "ours"))
1751                 o->recursive_variant = MERGE_RECURSIVE_OURS;
1752         else if (!strcmp(s, "theirs"))
1753                 o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1754         else if (!strcmp(s, "subtree"))
1755                 o->subtree_shift = "";
1756         else if (!prefixcmp(s, "subtree="))
1757                 o->subtree_shift = s + strlen("subtree=");
1758         else if (!strcmp(s, "patience"))
1759                 o->xdl_opts |= XDF_PATIENCE_DIFF;
1760         else if (!strcmp(s, "ignore-space-change"))
1761                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1762         else if (!strcmp(s, "ignore-all-space"))
1763                 o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1764         else if (!strcmp(s, "ignore-space-at-eol"))
1765                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1766         else if (!strcmp(s, "renormalize"))
1767                 o->renormalize = 1;
1768         else if (!strcmp(s, "no-renormalize"))
1769                 o->renormalize = 0;
1770         else if (!prefixcmp(s, "rename-threshold=")) {
1771                 const char *score = s + strlen("rename-threshold=");
1772                 if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1773                         return -1;
1774         }
1775         else
1776                 return -1;
1777         return 0;
1778 }