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 {
  88         struct
  89         {
  90                 unsigned mode;
  91                 unsigned char sha[20];
  92         } stages[4];
  93         struct rename_df_conflict_info *rename_df_conflict_info;
  94         unsigned processed:1;
  95 };
  96
  97 static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
  98                                                  struct diff_filepair *pair1,
  99                                                  struct diff_filepair *pair2,
 100                                                  const char *branch1,
 101                                                  const char *branch2,
 102                                                  struct stage_data *dst_entry1,
 103                                                  struct stage_data *dst_entry2)
 104 {
 105         struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
 106         ci->rename_type = rename_type;
 107         ci->pair1 = pair1;
 108         ci->branch1 = branch1;
 109         ci->branch2 = branch2;
 110
 111         ci->dst_entry1 = dst_entry1;
 112         dst_entry1->rename_df_conflict_info = ci;
 113         dst_entry1->processed = 0;
 114
 115         assert(!pair2 == !dst_entry2);
 116         if (dst_entry2) {
 117                 ci->dst_entry2 = dst_entry2;
 118                 ci->pair2 = pair2;
 119                 dst_entry2->rename_df_conflict_info = ci;
 120                 dst_entry2->processed = 0;
 121         }
 122 }
 123
 124 static int show(struct merge_options *o, int v)
 125 {
 126         return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 127 }
 128
 129 static void flush_output(struct merge_options *o)
 130 {
 131         if (o->obuf.len) {
 132                 fputs(o->obuf.buf, stdout);
 133                 strbuf_reset(&o->obuf);
 134         }
 135 }
 136
 137 __attribute__((format (printf, 3, 4)))
 138 static void output(struct merge_options *o, int v, const char *fmt, ...)
 139 {
 140         va_list ap;
 141
 142         if (!show(o, v))
 143                 return;
 144
 145         strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 146         memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 147         strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 148
 149         va_start(ap, fmt);
 150         strbuf_vaddf(&o->obuf, fmt, ap);
 151         va_end(ap);
 152
 153         strbuf_add(&o->obuf, "\n", 1);
 154         if (!o->buffer_output)
 155                 flush_output(o);
 156 }
 157
 158 static void output_commit_title(struct merge_options *o, struct commit *commit)
 159 {
 160         int i;
 161         flush_output(o);
 162         for (i = o->call_depth; i--;)
 163                 fputs("  ", stdout);
 164         if (commit->util)
 165                 printf("virtual %s\n", (char *)commit->util);
 166         else {
 167                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 168                 if (parse_commit(commit) != 0)
 169                         printf("(bad commit)\n");
 170                 else {
 171                         const char *title;
 172                         int len = find_commit_subject(commit->buffer, &title);
 173                         if (len)
 174                                 printf("%.*s\n", len, title);
 175                 }
 176         }
 177 }
 178
 179 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 180                 const char *path, int stage, int refresh, int options)
 181 {
 182         struct cache_entry *ce;
 183         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 184         if (!ce)
 185                 return error("addinfo_cache failed for path '%s'", path);
 186         return add_cache_entry(ce, options);
 187 }
 188
 189 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 190 {
 191         parse_tree(tree);
 192         init_tree_desc(desc, tree->buffer, tree->size);
 193 }
 194
 195 static int git_merge_trees(int index_only,
 196                            struct tree *common,
 197                            struct tree *head,
 198                            struct tree *merge)
 199 {
 200         int rc;
 201         struct tree_desc t[3];
 202         struct unpack_trees_options opts;
 203
 204         memset(&opts, 0, sizeof(opts));
 205         if (index_only)
 206                 opts.index_only = 1;
 207         else
 208                 opts.update = 1;
 209         opts.merge = 1;
 210         opts.head_idx = 2;
 211         opts.fn = threeway_merge;
 212         opts.src_index = &the_index;
 213         opts.dst_index = &the_index;
 214         setup_unpack_trees_porcelain(&opts, "merge");
 215
 216         init_tree_desc_from_tree(t+0, common);
 217         init_tree_desc_from_tree(t+1, head);
 218         init_tree_desc_from_tree(t+2, merge);
 219
 220         rc = unpack_trees(3, t, &opts);
 221         cache_tree_free(&active_cache_tree);
 222         return rc;
 223 }
 224
 225 struct tree *write_tree_from_memory(struct merge_options *o)
 226 {
 227         struct tree *result = NULL;
 228
 229         if (unmerged_cache()) {
 230                 int i;
 231                 fprintf(stderr, "BUG: There are unmerged index entries:\n");
 232                 for (i = 0; i < active_nr; i++) {
 233                         struct cache_entry *ce = active_cache[i];
 234                         if (ce_stage(ce))
 235                                 fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
 236                                         (int)ce_namelen(ce), ce->name);
 237                 }
 238                 die("Bug in merge-recursive.c");
 239         }
 240
 241         if (!active_cache_tree)
 242                 active_cache_tree = cache_tree();
 243
 244         if (!cache_tree_fully_valid(active_cache_tree) &&
 245             cache_tree_update(active_cache_tree,
 246                               active_cache, active_nr, 0, 0) < 0)
 247                 die("error building trees");
 248
 249         result = lookup_tree(active_cache_tree->sha1);
 250
 251         return result;
 252 }
 253
 254 static int save_files_dirs(const unsigned char *sha1,
 255                 const char *base, int baselen, const char *path,
 256                 unsigned int mode, int stage, void *context)
 257 {
 258         int len = strlen(path);
 259         char *newpath = xmalloc(baselen + len + 1);
 260         struct merge_options *o = context;
 261
 262         memcpy(newpath, base, baselen);
 263         memcpy(newpath + baselen, path, len);
 264         newpath[baselen + len] = '\0';
 265
 266         if (S_ISDIR(mode))
 267                 string_list_insert(&o->current_directory_set, newpath);
 268         else
 269                 string_list_insert(&o->current_file_set, newpath);
 270         free(newpath);
 271
 272         return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 273 }
 274
 275 static int get_files_dirs(struct merge_options *o, struct tree *tree)
 276 {
 277         int n;
 278         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 279                 return 0;
 280         n = o->current_file_set.nr + o->current_directory_set.nr;
 281         return n;
 282 }
 283
 284 /*
 285  * Returns an index_entry instance which doesn't have to correspond to
 286  * a real cache entry in Git's index.
 287  */
 288 static struct stage_data *insert_stage_data(const char *path,
 289                 struct tree *o, struct tree *a, struct tree *b,
 290                 struct string_list *entries)
 291 {
 292         struct string_list_item *item;
 293         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 294         get_tree_entry(o->object.sha1, path,
 295                         e->stages[1].sha, &e->stages[1].mode);
 296         get_tree_entry(a->object.sha1, path,
 297                         e->stages[2].sha, &e->stages[2].mode);
 298         get_tree_entry(b->object.sha1, path,
 299                         e->stages[3].sha, &e->stages[3].mode);
 300         item = string_list_insert(entries, path);
 301         item->util = e;
 302         return e;
 303 }
 304
 305 /*
 306  * Create a dictionary mapping file names to stage_data objects. The
 307  * dictionary contains one entry for every path with a non-zero stage entry.
 308  */
 309 static struct string_list *get_unmerged(void)
 310 {
 311         struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 312         int i;
 313
 314         unmerged->strdup_strings = 1;
 315
 316         for (i = 0; i < active_nr; i++) {
 317                 struct string_list_item *item;
 318                 struct stage_data *e;
 319                 struct cache_entry *ce = active_cache[i];
 320                 if (!ce_stage(ce))
 321                         continue;
 322
 323                 item = string_list_lookup(unmerged, ce->name);
 324                 if (!item) {
 325                         item = string_list_insert(unmerged, ce->name);
 326                         item->util = xcalloc(1, sizeof(struct stage_data));
 327                 }
 328                 e = item->util;
 329                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
 330                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 331         }
 332
 333         return unmerged;
 334 }
 335
 336 static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 337                                                       struct string_list *entries)
 338 {
 339         /* If there are D/F conflicts, and the paths currently exist
 340          * in the working copy as a file, we want to remove them to
 341          * make room for the corresponding directory.  Such paths will
 342          * later be processed in process_df_entry() at the end.  If
 343          * the corresponding directory ends up being removed by the
 344          * merge, then the file will be reinstated at that time;
 345          * otherwise, if the file is not supposed to be removed by the
 346          * merge, the contents of the file will be placed in another
 347          * unique filename.
 348          *
 349          * NOTE: This function relies on the fact that entries for a
 350          * D/F conflict will appear adjacent in the index, with the
 351          * entries for the file appearing before entries for paths
 352          * below the corresponding directory.
 353          */
 354         const char *last_file = NULL;
 355         int last_len = 0;
 356         struct stage_data *last_e;
 357         int i;
 358
 359         for (i = 0; i < entries->nr; i++) {
 360                 const char *path = entries->items[i].string;
 361                 int len = strlen(path);
 362                 struct stage_data *e = entries->items[i].util;
 363
 364                 /*
 365                  * Check if last_file & path correspond to a D/F conflict;
 366                  * i.e. whether path is last_file+'/'+<something>.
 367                  * If so, remove last_file to make room for path and friends.
 368                  */
 369                 if (last_file &&
 370                     len > last_len &&
 371                     memcmp(path, last_file, last_len) == 0 &&
 372                     path[last_len] == '/') {
 373                         output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 374                         unlink(last_file);
 375                 }
 376
 377                 /*
 378                  * Determine whether path could exist as a file in the
 379                  * working directory as a possible D/F conflict.  This
 380                  * will only occur when it exists in stage 2 as a
 381                  * file.
 382                  */
 383                 if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 384                         last_file = path;
 385                         last_len = len;
 386                         last_e = e;
 387                 } else {
 388                         last_file = NULL;
 389                 }
 390         }
 391 }
 392
 393 struct rename
 394 {
 395         struct diff_filepair *pair;
 396         struct stage_data *src_entry;
 397         struct stage_data *dst_entry;
 398         unsigned processed:1;
 399 };
 400
 401 /*
 402  * Get information of all renames which occurred between 'o_tree' and
 403  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 404  * 'b_tree') to be able to associate the correct cache entries with
 405  * the rename information. 'tree' is always equal to either a_tree or b_tree.
 406  */
 407 static struct string_list *get_renames(struct merge_options *o,
 408                                        struct tree *tree,
 409                                        struct tree *o_tree,
 410                                        struct tree *a_tree,
 411                                        struct tree *b_tree,
 412                                        struct string_list *entries)
 413 {
 414         int i;
 415         struct string_list *renames;
 416         struct diff_options opts;
 417
 418         renames = xcalloc(1, sizeof(struct string_list));
 419         diff_setup(&opts);
 420         DIFF_OPT_SET(&opts, RECURSIVE);
 421         opts.detect_rename = DIFF_DETECT_RENAME;
 422         opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 423                             o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 424                             500;
 425         opts.rename_score = o->rename_score;
 426         opts.warn_on_too_large_rename = 1;
 427         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 428         if (diff_setup_done(&opts) < 0)
 429                 die("diff setup failed");
 430         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 431         diffcore_std(&opts);
 432         for (i = 0; i < diff_queued_diff.nr; ++i) {
 433                 struct string_list_item *item;
 434                 struct rename *re;
 435                 struct diff_filepair *pair = diff_queued_diff.queue[i];
 436                 if (pair->status != 'R') {
 437                         diff_free_filepair(pair);
 438                         continue;
 439                 }
 440                 re = xmalloc(sizeof(*re));
 441                 re->processed = 0;
 442                 re->pair = pair;
 443                 item = string_list_lookup(entries, re->pair->one->path);
 444                 if (!item)
 445                         re->src_entry = insert_stage_data(re->pair->one->path,
 446                                         o_tree, a_tree, b_tree, entries);
 447                 else
 448                         re->src_entry = item->util;
 449
 450                 item = string_list_lookup(entries, re->pair->two->path);
 451                 if (!item)
 452                         re->dst_entry = insert_stage_data(re->pair->two->path,
 453                                         o_tree, a_tree, b_tree, entries);
 454                 else
 455                         re->dst_entry = item->util;
 456                 item = string_list_insert(renames, pair->one->path);
 457                 item->util = re;
 458         }
 459         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 460         diff_queued_diff.nr = 0;
 461         diff_flush(&opts);
 462         return renames;
 463 }
 464
 465 static int update_stages_options(const char *path, struct diff_filespec *o,
 466                          struct diff_filespec *a, struct diff_filespec *b,
 467                          int clear, int options)
 468 {
 469         if (clear)
 470                 if (remove_file_from_cache(path))
 471                         return -1;
 472         if (o)
 473                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 474                         return -1;
 475         if (a)
 476                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 477                         return -1;
 478         if (b)
 479                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 480                         return -1;
 481         return 0;
 482 }
 483
 484 static int update_stages(const char *path, struct diff_filespec *o,
 485                          struct diff_filespec *a, struct diff_filespec *b,
 486                          int clear)
 487 {
 488         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 489         return update_stages_options(path, o, a, b, clear, options);
 490 }
 491
 492 static int update_stages_and_entry(const char *path,
 493                                    struct stage_data *entry,
 494                                    struct diff_filespec *o,
 495                                    struct diff_filespec *a,
 496                                    struct diff_filespec *b,
 497                                    int clear)
 498 {
 499         int options;
 500
 501         entry->processed = 0;
 502         entry->stages[1].mode = o->mode;
 503         entry->stages[2].mode = a->mode;
 504         entry->stages[3].mode = b->mode;
 505         hashcpy(entry->stages[1].sha, o->sha1);
 506         hashcpy(entry->stages[2].sha, a->sha1);
 507         hashcpy(entry->stages[3].sha, b->sha1);
 508         options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 509         return update_stages_options(path, o, a, b, clear, options);
 510 }
 511
 512 static int remove_file(struct merge_options *o, int clean,
 513                        const char *path, int no_wd)
 514 {
 515         int update_cache = o->call_depth || clean;
 516         int update_working_directory = !o->call_depth && !no_wd;
 517
 518         if (update_cache) {
 519                 if (remove_file_from_cache(path))
 520                         return -1;
 521         }
 522         if (update_working_directory) {
 523                 if (remove_path(path))
 524                         return -1;
 525         }
 526         return 0;
 527 }
 528
 529 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 530 {
 531         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 532         int suffix = 0;
 533         struct stat st;
 534         char *p = newpath + strlen(path);
 535         strcpy(newpath, path);
 536         *(p++) = '~';
 537         strcpy(p, branch);
 538         for (; *p; ++p)
 539                 if ('/' == *p)
 540                         *p = '_';
 541         while (string_list_has_string(&o->current_file_set, newpath) ||
 542                string_list_has_string(&o->current_directory_set, newpath) ||
 543                lstat(newpath, &st) == 0)
 544                 sprintf(p, "_%d", suffix++);
 545
 546         string_list_insert(&o->current_file_set, newpath);
 547         return newpath;
 548 }
 549
 550 static void flush_buffer(int fd, const char *buf, unsigned long size)
 551 {
 552         while (size > 0) {
 553                 long ret = write_in_full(fd, buf, size);
 554                 if (ret < 0) {
 555                         /* Ignore epipe */
 556                         if (errno == EPIPE)
 557                                 break;
 558                         die_errno("merge-recursive");
 559                 } else if (!ret) {
 560                         die("merge-recursive: disk full?");
 561                 }
 562                 size -= ret;
 563                 buf += ret;
 564         }
 565 }
 566
 567 static int would_lose_untracked(const char *path)
 568 {
 569         int pos = cache_name_pos(path, strlen(path));
 570
 571         if (pos < 0)
 572                 pos = -1 - pos;
 573         while (pos < active_nr &&
 574                !strcmp(path, active_cache[pos]->name)) {
 575                 /*
 576                  * If stage #0, it is definitely tracked.
 577                  * If it has stage #2 then it was tracked
 578                  * before this merge started.  All other
 579                  * cases the path was not tracked.
 580                  */
 581                 switch (ce_stage(active_cache[pos])) {
 582                 case 0:
 583                 case 2:
 584                         return 0;
 585                 }
 586                 pos++;
 587         }
 588         return file_exists(path);
 589 }
 590
 591 static int make_room_for_path(const char *path)
 592 {
 593         int status;
 594         const char *msg = "failed to create path '%s'%s";
 595
 596         status = safe_create_leading_directories_const(path);
 597         if (status) {
 598                 if (status == -3) {
 599                         /* something else exists */
 600                         error(msg, path, ": perhaps a D/F conflict?");
 601                         return -1;
 602                 }
 603                 die(msg, path, "");
 604         }
 605
 606         /*
 607          * Do not unlink a file in the work tree if we are not
 608          * tracking it.
 609          */
 610         if (would_lose_untracked(path))
 611                 return error("refusing to lose untracked file at '%s'",
 612                              path);
 613
 614         /* Successful unlink is good.. */
 615         if (!unlink(path))
 616                 return 0;
 617         /* .. and so is no existing file */
 618         if (errno == ENOENT)
 619                 return 0;
 620         /* .. but not some other error (who really cares what?) */
 621         return error(msg, path, ": perhaps a D/F conflict?");
 622 }
 623
 624 static void update_file_flags(struct merge_options *o,
 625                               const unsigned char *sha,
 626                               unsigned mode,
 627                               const char *path,
 628                               int update_cache,
 629                               int update_wd)
 630 {
 631         if (o->call_depth)
 632                 update_wd = 0;
 633
 634         if (update_wd) {
 635                 enum object_type type;
 636                 void *buf;
 637                 unsigned long size;
 638
 639                 if (S_ISGITLINK(mode)) {
 640                         /*
 641                          * We may later decide to recursively descend into
 642                          * the submodule directory and update its index
 643                          * and/or work tree, but we do not do that now.
 644                          */
 645                         update_wd = 0;
 646                         goto update_index;
 647                 }
 648
 649                 buf = read_sha1_file(sha, &type, &size);
 650                 if (!buf)
 651                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 652                 if (type != OBJ_BLOB)
 653                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 654                 if (S_ISREG(mode)) {
 655                         struct strbuf strbuf = STRBUF_INIT;
 656                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
 657                                 free(buf);
 658                                 size = strbuf.len;
 659                                 buf = strbuf_detach(&strbuf, NULL);
 660                         }
 661                 }
 662
 663                 if (make_room_for_path(path) < 0) {
 664                         update_wd = 0;
 665                         free(buf);
 666                         goto update_index;
 667                 }
 668                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 669                         int fd;
 670                         if (mode & 0100)
 671                                 mode = 0777;
 672                         else
 673                                 mode = 0666;
 674                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 675                         if (fd < 0)
 676                                 die_errno("failed to open '%s'", path);
 677                         flush_buffer(fd, buf, size);
 678                         close(fd);
 679                 } else if (S_ISLNK(mode)) {
 680                         char *lnk = xmemdupz(buf, size);
 681                         safe_create_leading_directories_const(path);
 682                         unlink(path);
 683                         if (symlink(lnk, path))
 684                                 die_errno("failed to symlink '%s'", path);
 685                         free(lnk);
 686                 } else
 687                         die("do not know what to do with %06o %s '%s'",
 688                             mode, sha1_to_hex(sha), path);
 689                 free(buf);
 690         }
 691  update_index:
 692         if (update_cache)
 693                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 694 }
 695
 696 static void update_file(struct merge_options *o,
 697                         int clean,
 698                         const unsigned char *sha,
 699                         unsigned mode,
 700                         const char *path)
 701 {
 702         update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 703 }
 704
 705 /* Low level file merging, update and removal */
 706
 707 struct merge_file_info
 708 {
 709         unsigned char sha[20];
 710         unsigned mode;
 711         unsigned clean:1,
 712                  merge:1;
 713 };
 714
 715 static int merge_3way(struct merge_options *o,
 716                       mmbuffer_t *result_buf,
 717                       struct diff_filespec *one,
 718                       struct diff_filespec *a,
 719                       struct diff_filespec *b,
 720                       const char *branch1,
 721                       const char *branch2)
 722 {
 723         mmfile_t orig, src1, src2;
 724         struct ll_merge_options ll_opts = {0};
 725         char *base_name, *name1, *name2;
 726         int merge_status;
 727
 728         ll_opts.renormalize = o->renormalize;
 729         ll_opts.xdl_opts = o->xdl_opts;
 730
 731         if (o->call_depth) {
 732                 ll_opts.virtual_ancestor = 1;
 733                 ll_opts.variant = 0;
 734         } else {
 735                 switch (o->recursive_variant) {
 736                 case MERGE_RECURSIVE_OURS:
 737                         ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 738                         break;
 739                 case MERGE_RECURSIVE_THEIRS:
 740                         ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 741                         break;
 742                 default:
 743                         ll_opts.variant = 0;
 744                         break;
 745                 }
 746         }
 747
 748         if (strcmp(a->path, b->path) ||
 749             (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 750                 base_name = o->ancestor == NULL ? NULL :
 751                         xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 752                 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 753                 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 754         } else {
 755                 base_name = o->ancestor == NULL ? NULL :
 756                         xstrdup(mkpath("%s", o->ancestor));
 757                 name1 = xstrdup(mkpath("%s", branch1));
 758                 name2 = xstrdup(mkpath("%s", branch2));
 759         }
 760
 761         read_mmblob(&orig, one->sha1);
 762         read_mmblob(&src1, a->sha1);
 763         read_mmblob(&src2, b->sha1);
 764
 765         merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 766                                 &src1, name1, &src2, name2, &ll_opts);
 767
 768         free(name1);
 769         free(name2);
 770         free(orig.ptr);
 771         free(src1.ptr);
 772         free(src2.ptr);
 773         return merge_status;
 774 }
 775
 776 static struct merge_file_info merge_file(struct merge_options *o,
 777                                          struct diff_filespec *one,
 778                                          struct diff_filespec *a,
 779                                          struct diff_filespec *b,
 780                                          const char *branch1,
 781                                          const char *branch2)
 782 {
 783         struct merge_file_info result;
 784         result.merge = 0;
 785         result.clean = 1;
 786
 787         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 788                 result.clean = 0;
 789                 if (S_ISREG(a->mode)) {
 790                         result.mode = a->mode;
 791                         hashcpy(result.sha, a->sha1);
 792                 } else {
 793                         result.mode = b->mode;
 794                         hashcpy(result.sha, b->sha1);
 795                 }
 796         } else {
 797                 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 798                         result.merge = 1;
 799
 800                 /*
 801                  * Merge modes
 802                  */
 803                 if (a->mode == b->mode || a->mode == one->mode)
 804                         result.mode = b->mode;
 805                 else {
 806                         result.mode = a->mode;
 807                         if (b->mode != one->mode) {
 808                                 result.clean = 0;
 809                                 result.merge = 1;
 810                         }
 811                 }
 812
 813                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 814                         hashcpy(result.sha, b->sha1);
 815                 else if (sha_eq(b->sha1, one->sha1))
 816                         hashcpy(result.sha, a->sha1);
 817                 else if (S_ISREG(a->mode)) {
 818                         mmbuffer_t result_buf;
 819                         int merge_status;
 820
 821                         merge_status = merge_3way(o, &result_buf, one, a, b,
 822                                                   branch1, branch2);
 823
 824                         if ((merge_status < 0) || !result_buf.ptr)
 825                                 die("Failed to execute internal merge");
 826
 827                         if (write_sha1_file(result_buf.ptr, result_buf.size,
 828                                             blob_type, result.sha))
 829                                 die("Unable to add %s to database",
 830                                     a->path);
 831
 832                         free(result_buf.ptr);
 833                         result.clean = (merge_status == 0);
 834                 } else if (S_ISGITLINK(a->mode)) {
 835                         result.clean = merge_submodule(result.sha, one->path, one->sha1,
 836                                                        a->sha1, b->sha1);
 837                 } else if (S_ISLNK(a->mode)) {
 838                         hashcpy(result.sha, a->sha1);
 839
 840                         if (!sha_eq(a->sha1, b->sha1))
 841                                 result.clean = 0;
 842                 } else {
 843                         die("unsupported object type in the tree");
 844                 }
 845         }
 846
 847         return result;
 848 }
 849
 850 static void conflict_rename_delete(struct merge_options *o,
 851                                    struct diff_filepair *pair,
 852                                    const char *rename_branch,
 853                                    const char *other_branch)
 854 {
 855         char *dest_name = pair->two->path;
 856         int df_conflict = 0;
 857         struct stat st;
 858
 859         output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 860                "and deleted in %s",
 861                pair->one->path, pair->two->path, rename_branch,
 862                other_branch);
 863         if (!o->call_depth)
 864                 update_stages(dest_name, NULL,
 865                               rename_branch == o->branch1 ? pair->two : NULL,
 866                               rename_branch == o->branch1 ? NULL : pair->two,
 867                               1);
 868         if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 869                 dest_name = unique_path(o, dest_name, rename_branch);
 870                 df_conflict = 1;
 871         }
 872         update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 873         if (df_conflict)
 874                 free(dest_name);
 875 }
 876
 877 static void conflict_rename_rename_1to2(struct merge_options *o,
 878                                         struct diff_filepair *pair1,
 879                                         const char *branch1,
 880                                         struct diff_filepair *pair2,
 881                                         const char *branch2)
 882 {
 883         /* One file was renamed in both branches, but to different names. */
 884         char *del[2];
 885         int delp = 0;
 886         const char *ren1_dst = pair1->two->path;
 887         const char *ren2_dst = pair2->two->path;
 888         const char *dst_name1 = ren1_dst;
 889         const char *dst_name2 = ren2_dst;
 890         struct stat st;
 891         if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 892                 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 893                 output(o, 1, "%s is a directory in %s adding as %s instead",
 894                        ren1_dst, branch2, dst_name1);
 895         }
 896         if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 897                 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 898                 output(o, 1, "%s is a directory in %s adding as %s instead",
 899                        ren2_dst, branch1, dst_name2);
 900         }
 901         if (o->call_depth) {
 902                 remove_file_from_cache(dst_name1);
 903                 remove_file_from_cache(dst_name2);
 904                 /*
 905                  * Uncomment to leave the conflicting names in the resulting tree
 906                  *
 907                  * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 908                  * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 909                  */
 910         } else {
 911                 update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 912                 update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 913
 914                 update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 915                 update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 916         }
 917         while (delp--)
 918                 free(del[delp]);
 919 }
 920
 921 static void conflict_rename_rename_2to1(struct merge_options *o,
 922                                         struct rename *ren1,
 923                                         const char *branch1,
 924                                         struct rename *ren2,
 925                                         const char *branch2)
 926 {
 927         /* Two files were renamed to the same thing. */
 928         char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 929         char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 930         output(o, 1, "Renaming %s to %s and %s to %s instead",
 931                ren1->pair->one->path, new_path1,
 932                ren2->pair->one->path, new_path2);
 933         remove_file(o, 0, ren1->pair->two->path, 0);
 934         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 935         update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 936         free(new_path2);
 937         free(new_path1);
 938 }
 939
 940 static int process_renames(struct merge_options *o,
 941                            struct string_list *a_renames,
 942                            struct string_list *b_renames)
 943 {
 944         int clean_merge = 1, i, j;
 945         struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 946         struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 947         const struct rename *sre;
 948
 949         for (i = 0; i < a_renames->nr; i++) {
 950                 sre = a_renames->items[i].util;
 951                 string_list_insert(&a_by_dst, sre->pair->two->path)->util
 952                         = sre->dst_entry;
 953         }
 954         for (i = 0; i < b_renames->nr; i++) {
 955                 sre = b_renames->items[i].util;
 956                 string_list_insert(&b_by_dst, sre->pair->two->path)->util
 957                         = sre->dst_entry;
 958         }
 959
 960         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 961                 char *src;
 962                 struct string_list *renames1, *renames2Dst;
 963                 struct rename *ren1 = NULL, *ren2 = NULL;
 964                 const char *branch1, *branch2;
 965                 const char *ren1_src, *ren1_dst;
 966
 967                 if (i >= a_renames->nr) {
 968                         ren2 = b_renames->items[j++].util;
 969                 } else if (j >= b_renames->nr) {
 970                         ren1 = a_renames->items[i++].util;
 971                 } else {
 972                         int compare = strcmp(a_renames->items[i].string,
 973                                              b_renames->items[j].string);
 974                         if (compare <= 0)
 975                                 ren1 = a_renames->items[i++].util;
 976                         if (compare >= 0)
 977                                 ren2 = b_renames->items[j++].util;
 978                 }
 979
 980                 /* TODO: refactor, so that 1/2 are not needed */
 981                 if (ren1) {
 982                         renames1 = a_renames;
 983                         renames2Dst = &b_by_dst;
 984                         branch1 = o->branch1;
 985                         branch2 = o->branch2;
 986                 } else {
 987                         struct rename *tmp;
 988                         renames1 = b_renames;
 989                         renames2Dst = &a_by_dst;
 990                         branch1 = o->branch2;
 991                         branch2 = o->branch1;
 992                         tmp = ren2;
 993                         ren2 = ren1;
 994                         ren1 = tmp;
 995                 }
 996                 src = ren1->pair->one->path;
 997
 998                 ren1->dst_entry->processed = 1;
 999                 ren1->src_entry->processed = 1;
1000
1001                 if (ren1->processed)
1002                         continue;
1003                 ren1->processed = 1;
1004
1005                 ren1_src = ren1->pair->one->path;
1006                 ren1_dst = ren1->pair->two->path;
1007
1008                 if (ren2) {
1009                         const char *ren2_src = ren2->pair->one->path;
1010                         const char *ren2_dst = ren2->pair->two->path;
1011                         /* Renamed in 1 and renamed in 2 */
1012                         if (strcmp(ren1_src, ren2_src) != 0)
1013                                 die("ren1.src != ren2.src");
1014                         ren2->dst_entry->processed = 1;
1015                         ren2->processed = 1;
1016                         if (strcmp(ren1_dst, ren2_dst) != 0) {
1017                                 setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1018                                                               ren1->pair,
1019                                                               ren2->pair,
1020                                                               branch1,
1021                                                               branch2,
1022                                                               ren1->dst_entry,
1023                                                               ren2->dst_entry);
1024                         } else {
1025                                 remove_file(o, 1, ren1_src, 1);
1026                                 update_stages_and_entry(ren1_dst,
1027                                                         ren1->dst_entry,
1028                                                         ren1->pair->one,
1029                                                         ren1->pair->two,
1030                                                         ren2->pair->two,
1031                                                         1 /* clear */);
1032                         }
1033                 } else {
1034                         /* Renamed in 1, maybe changed in 2 */
1035                         struct string_list_item *item;
1036                         /* we only use sha1 and mode of these */
1037                         struct diff_filespec src_other, dst_other;
1038                         int try_merge;
1039
1040                         /*
1041                          * unpack_trees loads entries from common-commit
1042                          * into stage 1, from head-commit into stage 2, and
1043                          * from merge-commit into stage 3.  We keep track
1044                          * of which side corresponds to the rename.
1045                          */
1046                         int renamed_stage = a_renames == renames1 ? 2 : 3;
1047                         int other_stage =   a_renames == renames1 ? 3 : 2;
1048
1049                         remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1050
1051                         hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1052                         src_other.mode = ren1->src_entry->stages[other_stage].mode;
1053                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1054                         dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1055                         try_merge = 0;
1056
1057                         if (sha_eq(src_other.sha1, null_sha1)) {
1058                                 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1059                                         ren1->dst_entry->processed = 0;
1060                                         setup_rename_df_conflict_info(RENAME_DELETE,
1061                                                                       ren1->pair,
1062                                                                       NULL,
1063                                                                       branch1,
1064                                                                       branch2,
1065                                                                       ren1->dst_entry,
1066                                                                       NULL);
1067                                 } else {
1068                                         clean_merge = 0;
1069                                         conflict_rename_delete(o, ren1->pair, branch1, branch2);
1070                                 }
1071                         } else if ((dst_other.mode == ren1->pair->two->mode) &&
1072                                    sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1073                                 /* Added file on the other side
1074                                    identical to the file being
1075                                    renamed: clean merge */
1076                                 update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1077                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1078                                 const char *new_path;
1079                                 clean_merge = 0;
1080                                 try_merge = 1;
1081                                 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1082                                        "%s added in %s",
1083                                        ren1_src, ren1_dst, branch1,
1084                                        ren1_dst, branch2);
1085                                 if (o->call_depth) {
1086                                         struct merge_file_info mfi;
1087                                         struct diff_filespec one, a, b;
1088
1089                                         one.path = a.path = b.path =
1090                                                 (char *)ren1_dst;
1091                                         hashcpy(one.sha1, null_sha1);
1092                                         one.mode = 0;
1093                                         hashcpy(a.sha1, ren1->pair->two->sha1);
1094                                         a.mode = ren1->pair->two->mode;
1095                                         hashcpy(b.sha1, dst_other.sha1);
1096                                         b.mode = dst_other.mode;
1097                                         mfi = merge_file(o, &one, &a, &b,
1098                                                          branch1,
1099                                                          branch2);
1100                                         output(o, 1, "Adding merged %s", ren1_dst);
1101                                         update_file(o, 0,
1102                                                     mfi.sha,
1103                                                     mfi.mode,
1104                                                     ren1_dst);
1105                                         try_merge = 0;
1106                                 } else {
1107                                         new_path = unique_path(o, ren1_dst, branch2);
1108                                         output(o, 1, "Adding as %s instead", new_path);
1109                                         update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1110                                 }
1111                         } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1112                                 ren2 = item->util;
1113                                 clean_merge = 0;
1114                                 ren2->processed = 1;
1115                                 output(o, 1, "CONFLICT (rename/rename): "
1116                                        "Rename %s->%s in %s. "
1117                                        "Rename %s->%s in %s",
1118                                        ren1_src, ren1_dst, branch1,
1119                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
1120                                 conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1121                         } else
1122                                 try_merge = 1;
1123
1124                         if (try_merge) {
1125                                 struct diff_filespec *one, *a, *b;
1126                                 src_other.path = (char *)ren1_src;
1127
1128                                 one = ren1->pair->one;
1129                                 if (a_renames == renames1) {
1130                                         a = ren1->pair->two;
1131                                         b = &src_other;
1132                                 } else {
1133                                         b = ren1->pair->two;
1134                                         a = &src_other;
1135                                 }
1136                                 update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1137                                 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1138                                         setup_rename_df_conflict_info(RENAME_NORMAL,
1139                                                                       ren1->pair,
1140                                                                       NULL,
1141                                                                       branch1,
1142                                                                       NULL,
1143                                                                       ren1->dst_entry,
1144                                                                       NULL);
1145                                 }
1146                         }
1147                 }
1148         }
1149         string_list_clear(&a_by_dst, 0);
1150         string_list_clear(&b_by_dst, 0);
1151
1152         return clean_merge;
1153 }
1154
1155 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1156 {
1157         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1158 }
1159
1160 static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1161 {
1162         void *buf;
1163         enum object_type type;
1164         unsigned long size;
1165         buf = read_sha1_file(sha1, &type, &size);
1166         if (!buf)
1167                 return error("cannot read object %s", sha1_to_hex(sha1));
1168         if (type != OBJ_BLOB) {
1169                 free(buf);
1170                 return error("object %s is not a blob", sha1_to_hex(sha1));
1171         }
1172         strbuf_attach(dst, buf, size, size + 1);
1173         return 0;
1174 }
1175
1176 static int blob_unchanged(const unsigned char *o_sha,
1177                           const unsigned char *a_sha,
1178                           int renormalize, const char *path)
1179 {
1180         struct strbuf o = STRBUF_INIT;
1181         struct strbuf a = STRBUF_INIT;
1182         int ret = 0; /* assume changed for safety */
1183
1184         if (sha_eq(o_sha, a_sha))
1185                 return 1;
1186         if (!renormalize)
1187                 return 0;
1188
1189         assert(o_sha && a_sha);
1190         if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1191                 goto error_return;
1192         /*
1193          * Note: binary | is used so that both renormalizations are
1194          * performed.  Comparison can be skipped if both files are
1195          * unchanged since their sha1s have already been compared.
1196          */
1197         if (renormalize_buffer(path, o.buf, o.len, &o) |
1198             renormalize_buffer(path, a.buf, o.len, &a))
1199                 ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1200
1201 error_return:
1202         strbuf_release(&o);
1203         strbuf_release(&a);
1204         return ret;
1205 }
1206
1207 static void handle_delete_modify(struct merge_options *o,
1208                                  const char *path,
1209                                  const char *new_path,
1210                                  unsigned char *a_sha, int a_mode,
1211                                  unsigned char *b_sha, int b_mode)
1212 {
1213         if (!a_sha) {
1214                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1215                        "and modified in %s. Version %s of %s left in tree%s%s.",
1216                        path, o->branch1,
1217                        o->branch2, o->branch2, path,
1218                        path == new_path ? "" : " at ",
1219                        path == new_path ? "" : new_path);
1220                 update_file(o, 0, b_sha, b_mode, new_path);
1221         } else {
1222                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1223                        "and modified in %s. Version %s of %s left in tree%s%s.",
1224                        path, o->branch2,
1225                        o->branch1, o->branch1, path,
1226                        path == new_path ? "" : " at ",
1227                        path == new_path ? "" : new_path);
1228                 update_file(o, 0, a_sha, a_mode, new_path);
1229         }
1230 }
1231
1232 static int merge_content(struct merge_options *o,
1233                          const char *path,
1234                          unsigned char *o_sha, int o_mode,
1235                          unsigned char *a_sha, int a_mode,
1236                          unsigned char *b_sha, int b_mode,
1237                          const char *df_rename_conflict_branch)
1238 {
1239         const char *reason = "content";
1240         struct merge_file_info mfi;
1241         struct diff_filespec one, a, b;
1242         struct stat st;
1243         unsigned df_conflict_remains = 0;
1244
1245         if (!o_sha) {
1246                 reason = "add/add";
1247                 o_sha = (unsigned char *)null_sha1;
1248         }
1249         one.path = a.path = b.path = (char *)path;
1250         hashcpy(one.sha1, o_sha);
1251         one.mode = o_mode;
1252         hashcpy(a.sha1, a_sha);
1253         a.mode = a_mode;
1254         hashcpy(b.sha1, b_sha);
1255         b.mode = b_mode;
1256
1257         mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1258         if (df_rename_conflict_branch &&
1259             lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1260                 df_conflict_remains = 1;
1261         }
1262
1263         if (mfi.clean && !df_conflict_remains &&
1264             sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1265                 output(o, 3, "Skipped %s (merged same as existing)", path);
1266         else
1267                 output(o, 2, "Auto-merging %s", path);
1268
1269         if (!mfi.clean) {
1270                 if (S_ISGITLINK(mfi.mode))
1271                         reason = "submodule";
1272                 output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1273                                 reason, path);
1274         }
1275
1276         if (df_conflict_remains) {
1277                 const char *new_path;
1278                 update_file_flags(o, mfi.sha, mfi.mode, path,
1279                                   o->call_depth || mfi.clean, 0);
1280                 new_path = unique_path(o, path, df_rename_conflict_branch);
1281                 mfi.clean = 0;
1282                 output(o, 1, "Adding as %s instead", new_path);
1283                 update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1284         } else {
1285                 update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1286         }
1287         return mfi.clean;
1288
1289 }
1290
1291 /* Per entry merge function */
1292 static int process_entry(struct merge_options *o,
1293                          const char *path, struct stage_data *entry)
1294 {
1295         /*
1296         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1297         print_index_entry("\tpath: ", entry);
1298         */
1299         int clean_merge = 1;
1300         int normalize = o->renormalize;
1301         unsigned o_mode = entry->stages[1].mode;
1302         unsigned a_mode = entry->stages[2].mode;
1303         unsigned b_mode = entry->stages[3].mode;
1304         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1305         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1306         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1307
1308         if (entry->rename_df_conflict_info)
1309                 return 1; /* Such cases are handled elsewhere. */
1310
1311         entry->processed = 1;
1312         if (o_sha && (!a_sha || !b_sha)) {
1313                 /* Case A: Deleted in one */
1314                 if ((!a_sha && !b_sha) ||
1315                     (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1316                     (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1317                         /* Deleted in both or deleted in one and
1318                          * unchanged in the other */
1319                         if (a_sha)
1320                                 output(o, 2, "Removing %s", path);
1321                         /* do not touch working file if it did not exist */
1322                         remove_file(o, 1, path, !a_sha);
1323                 } else if (string_list_has_string(&o->current_directory_set,
1324                                                   path)) {
1325                         entry->processed = 0;
1326                         return 1; /* Assume clean until processed */
1327                 } else {
1328                         /* Deleted in one and changed in the other */
1329                         clean_merge = 0;
1330                         handle_delete_modify(o, path, path,
1331                                              a_sha, a_mode, b_sha, b_mode);
1332                 }
1333
1334         } else if ((!o_sha && a_sha && !b_sha) ||
1335                    (!o_sha && !a_sha && b_sha)) {
1336                 /* Case B: Added in one. */
1337                 unsigned mode;
1338                 const unsigned char *sha;
1339
1340                 if (a_sha) {
1341                         mode = a_mode;
1342                         sha = a_sha;
1343                 } else {
1344                         mode = b_mode;
1345                         sha = b_sha;
1346                 }
1347                 if (string_list_has_string(&o->current_directory_set, path)) {
1348                         /* Handle D->F conflicts after all subfiles */
1349                         entry->processed = 0;
1350                         return 1; /* Assume clean until processed */
1351                 } else {
1352                         output(o, 2, "Adding %s", path);
1353                         update_file(o, 1, sha, mode, path);
1354                 }
1355         } else if (a_sha && b_sha) {
1356                 /* Case C: Added in both (check for same permissions) and */
1357                 /* case D: Modified in both, but differently. */
1358                 clean_merge = merge_content(o, path,
1359                                             o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1360                                             NULL);
1361         } else if (!o_sha && !a_sha && !b_sha) {
1362                 /*
1363                  * this entry was deleted altogether. a_mode == 0 means
1364                  * we had that path and want to actively remove it.
1365                  */
1366                 remove_file(o, 1, path, !a_mode);
1367         } else
1368                 die("Fatal merge failure, shouldn't happen.");
1369
1370         return clean_merge;
1371 }
1372
1373 /*
1374  * Per entry merge function for D/F (and/or rename) conflicts.  In the
1375  * cases we can cleanly resolve D/F conflicts, process_entry() can
1376  * clean out all the files below the directory for us.  All D/F
1377  * conflict cases must be handled here at the end to make sure any
1378  * directories that can be cleaned out, are.
1379  *
1380  * Some rename conflicts may also be handled here that don't necessarily
1381  * involve D/F conflicts, since the code to handle them is generic enough
1382  * to handle those rename conflicts with or without D/F conflicts also
1383  * being involved.
1384  */
1385 static int process_df_entry(struct merge_options *o,
1386                             const char *path, struct stage_data *entry)
1387 {
1388         int clean_merge = 1;
1389         unsigned o_mode = entry->stages[1].mode;
1390         unsigned a_mode = entry->stages[2].mode;
1391         unsigned b_mode = entry->stages[3].mode;
1392         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1393         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1394         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1395         struct stat st;
1396
1397         entry->processed = 1;
1398         if (entry->rename_df_conflict_info) {
1399                 struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1400                 char *src;
1401                 switch (conflict_info->rename_type) {
1402                 case RENAME_NORMAL:
1403                         clean_merge = merge_content(o, path,
1404                                                     o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1405                                                     conflict_info->branch1);
1406                         break;
1407                 case RENAME_DELETE:
1408                         clean_merge = 0;
1409                         conflict_rename_delete(o, conflict_info->pair1,
1410                                                conflict_info->branch1,
1411                                                conflict_info->branch2);
1412                         break;
1413                 case RENAME_ONE_FILE_TO_TWO:
1414                         src = conflict_info->pair1->one->path;
1415                         clean_merge = 0;
1416                         output(o, 1, "CONFLICT (rename/rename): "
1417                                "Rename \"%s\"->\"%s\" in branch \"%s\" "
1418                                "rename \"%s\"->\"%s\" in \"%s\"%s",
1419                                src, conflict_info->pair1->two->path, conflict_info->branch1,
1420                                src, conflict_info->pair2->two->path, conflict_info->branch2,
1421                                o->call_depth ? " (left unresolved)" : "");
1422                         if (o->call_depth) {
1423                                 remove_file_from_cache(src);
1424                                 update_file(o, 0, conflict_info->pair1->one->sha1,
1425                                             conflict_info->pair1->one->mode, src);
1426                         }
1427                         conflict_rename_rename_1to2(o, conflict_info->pair1,
1428                                                     conflict_info->branch1,
1429                                                     conflict_info->pair2,
1430                                                     conflict_info->branch2);
1431                         conflict_info->dst_entry2->processed = 1;
1432                         break;
1433                 default:
1434                         entry->processed = 0;
1435                         break;
1436                 }
1437         } else if (o_sha && (!a_sha || !b_sha)) {
1438                 /* Modify/delete; deleted side may have put a directory in the way */
1439                 const char *new_path = path;
1440                 if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1441                         new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1442                 clean_merge = 0;
1443                 handle_delete_modify(o, path, new_path,
1444                                      a_sha, a_mode, b_sha, b_mode);
1445         } else if (!o_sha && !!a_sha != !!b_sha) {
1446                 /* directory -> (directory, file) */
1447                 const char *add_branch;
1448                 const char *other_branch;
1449                 unsigned mode;
1450                 const unsigned char *sha;
1451                 const char *conf;
1452
1453                 if (a_sha) {
1454                         add_branch = o->branch1;
1455                         other_branch = o->branch2;
1456                         mode = a_mode;
1457                         sha = a_sha;
1458                         conf = "file/directory";
1459                 } else {
1460                         add_branch = o->branch2;
1461                         other_branch = o->branch1;
1462                         mode = b_mode;
1463                         sha = b_sha;
1464                         conf = "directory/file";
1465                 }
1466                 if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1467                         const char *new_path = unique_path(o, path, add_branch);
1468                         clean_merge = 0;
1469                         output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1470                                "Adding %s as %s",
1471                                conf, path, other_branch, path, new_path);
1472                         update_file(o, 0, sha, mode, new_path);
1473                 } else {
1474                         output(o, 2, "Adding %s", path);
1475                         update_file(o, 1, sha, mode, path);
1476                 }
1477         } else {
1478                 entry->processed = 0;
1479                 return 1; /* not handled; assume clean until processed */
1480         }
1481
1482         return clean_merge;
1483 }
1484
1485 int merge_trees(struct merge_options *o,
1486                 struct tree *head,
1487                 struct tree *merge,
1488                 struct tree *common,
1489                 struct tree **result)
1490 {
1491         int code, clean;
1492
1493         if (o->subtree_shift) {
1494                 merge = shift_tree_object(head, merge, o->subtree_shift);
1495                 common = shift_tree_object(head, common, o->subtree_shift);
1496         }
1497
1498         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1499                 output(o, 0, "Already up-to-date!");
1500                 *result = head;
1501                 return 1;
1502         }
1503
1504         code = git_merge_trees(o->call_depth, common, head, merge);
1505
1506         if (code != 0) {
1507                 if (show(o, 4) || o->call_depth)
1508                         die("merging of trees %s and %s failed",
1509                             sha1_to_hex(head->object.sha1),
1510                             sha1_to_hex(merge->object.sha1));
1511                 else
1512                         exit(128);
1513         }
1514
1515         if (unmerged_cache()) {
1516                 struct string_list *entries, *re_head, *re_merge;
1517                 int i;
1518                 string_list_clear(&o->current_file_set, 1);
1519                 string_list_clear(&o->current_directory_set, 1);
1520                 get_files_dirs(o, head);
1521                 get_files_dirs(o, merge);
1522
1523                 entries = get_unmerged();
1524                 make_room_for_directories_of_df_conflicts(o, entries);
1525                 re_head  = get_renames(o, head, common, head, merge, entries);
1526                 re_merge = get_renames(o, merge, common, head, merge, entries);
1527                 clean = process_renames(o, re_head, re_merge);
1528                 for (i = 0; i < entries->nr; i++) {
1529                         const char *path = entries->items[i].string;
1530                         struct stage_data *e = entries->items[i].util;
1531                         if (!e->processed
1532                                 && !process_entry(o, path, e))
1533                                 clean = 0;
1534                 }
1535                 for (i = 0; i < entries->nr; i++) {
1536                         const char *path = entries->items[i].string;
1537                         struct stage_data *e = entries->items[i].util;
1538                         if (!e->processed
1539                                 && !process_df_entry(o, path, e))
1540                                 clean = 0;
1541                 }
1542                 for (i = 0; i < entries->nr; i++) {
1543                         struct stage_data *e = entries->items[i].util;
1544                         if (!e->processed)
1545                                 die("Unprocessed path??? %s",
1546                                     entries->items[i].string);
1547                 }
1548
1549                 string_list_clear(re_merge, 0);
1550                 string_list_clear(re_head, 0);
1551                 string_list_clear(entries, 1);
1552
1553         }
1554         else
1555                 clean = 1;
1556
1557         if (o->call_depth)
1558                 *result = write_tree_from_memory(o);
1559
1560         return clean;
1561 }
1562
1563 static struct commit_list *reverse_commit_list(struct commit_list *list)
1564 {
1565         struct commit_list *next = NULL, *current, *backup;
1566         for (current = list; current; current = backup) {
1567                 backup = current->next;
1568                 current->next = next;
1569                 next = current;
1570         }
1571         return next;
1572 }
1573
1574 /*
1575  * Merge the commits h1 and h2, return the resulting virtual
1576  * commit object and a flag indicating the cleanness of the merge.
1577  */
1578 int merge_recursive(struct merge_options *o,
1579                     struct commit *h1,
1580                     struct commit *h2,
1581                     struct commit_list *ca,
1582                     struct commit **result)
1583 {
1584         struct commit_list *iter;
1585         struct commit *merged_common_ancestors;
1586         struct tree *mrtree = mrtree;
1587         int clean;
1588
1589         if (show(o, 4)) {
1590                 output(o, 4, "Merging:");
1591                 output_commit_title(o, h1);
1592                 output_commit_title(o, h2);
1593         }
1594
1595         if (!ca) {
1596                 ca = get_merge_bases(h1, h2, 1);
1597                 ca = reverse_commit_list(ca);
1598         }
1599
1600         if (show(o, 5)) {
1601                 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1602                 for (iter = ca; iter; iter = iter->next)
1603                         output_commit_title(o, iter->item);
1604         }
1605
1606         merged_common_ancestors = pop_commit(&ca);
1607         if (merged_common_ancestors == NULL) {
1608                 /* if there is no common ancestor, make an empty tree */
1609                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1610
1611                 tree->object.parsed = 1;
1612                 tree->object.type = OBJ_TREE;
1613                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1614                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1615         }
1616
1617         for (iter = ca; iter; iter = iter->next) {
1618                 const char *saved_b1, *saved_b2;
1619                 o->call_depth++;
1620                 /*
1621                  * When the merge fails, the result contains files
1622                  * with conflict markers. The cleanness flag is
1623                  * ignored, it was never actually used, as result of
1624                  * merge_trees has always overwritten it: the committed
1625                  * "conflicts" were already resolved.
1626                  */
1627                 discard_cache();
1628                 saved_b1 = o->branch1;
1629                 saved_b2 = o->branch2;
1630                 o->branch1 = "Temporary merge branch 1";
1631                 o->branch2 = "Temporary merge branch 2";
1632                 merge_recursive(o, merged_common_ancestors, iter->item,
1633                                 NULL, &merged_common_ancestors);
1634                 o->branch1 = saved_b1;
1635                 o->branch2 = saved_b2;
1636                 o->call_depth--;
1637
1638                 if (!merged_common_ancestors)
1639                         die("merge returned no commit");
1640         }
1641
1642         discard_cache();
1643         if (!o->call_depth)
1644                 read_cache();
1645
1646         o->ancestor = "merged common ancestors";
1647         clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1648                             &mrtree);
1649
1650         if (o->call_depth) {
1651                 *result = make_virtual_commit(mrtree, "merged tree");
1652                 commit_list_insert(h1, &(*result)->parents);
1653                 commit_list_insert(h2, &(*result)->parents->next);
1654         }
1655         flush_output(o);
1656         return clean;
1657 }
1658
1659 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1660 {
1661         struct object *object;
1662
1663         object = deref_tag(parse_object(sha1), name, strlen(name));
1664         if (!object)
1665                 return NULL;
1666         if (object->type == OBJ_TREE)
1667                 return make_virtual_commit((struct tree*)object, name);
1668         if (object->type != OBJ_COMMIT)
1669                 return NULL;
1670         if (parse_commit((struct commit *)object))
1671                 return NULL;
1672         return (struct commit *)object;
1673 }
1674
1675 int merge_recursive_generic(struct merge_options *o,
1676                             const unsigned char *head,
1677                             const unsigned char *merge,
1678                             int num_base_list,
1679                             const unsigned char **base_list,
1680                             struct commit **result)
1681 {
1682         int clean, index_fd;
1683         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1684         struct commit *head_commit = get_ref(head, o->branch1);
1685         struct commit *next_commit = get_ref(merge, o->branch2);
1686         struct commit_list *ca = NULL;
1687
1688         if (base_list) {
1689                 int i;
1690                 for (i = 0; i < num_base_list; ++i) {
1691                         struct commit *base;
1692                         if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1693                                 return error("Could not parse object '%s'",
1694                                         sha1_to_hex(base_list[i]));
1695                         commit_list_insert(base, &ca);
1696                 }
1697         }
1698
1699         index_fd = hold_locked_index(lock, 1);
1700         clean = merge_recursive(o, head_commit, next_commit, ca,
1701                         result);
1702         if (active_cache_changed &&
1703                         (write_cache(index_fd, active_cache, active_nr) ||
1704                          commit_locked_index(lock)))
1705                 return error("Unable to write index.");
1706
1707         return clean ? 0 : 1;
1708 }
1709
1710 static int merge_recursive_config(const char *var, const char *value, void *cb)
1711 {
1712         struct merge_options *o = cb;
1713         if (!strcasecmp(var, "merge.verbosity")) {
1714                 o->verbosity = git_config_int(var, value);
1715                 return 0;
1716         }
1717         if (!strcasecmp(var, "diff.renamelimit")) {
1718                 o->diff_rename_limit = git_config_int(var, value);
1719                 return 0;
1720         }
1721         if (!strcasecmp(var, "merge.renamelimit")) {
1722                 o->merge_rename_limit = git_config_int(var, value);
1723                 return 0;
1724         }
1725         return git_xmerge_config(var, value, cb);
1726 }
1727
1728 void init_merge_options(struct merge_options *o)
1729 {
1730         memset(o, 0, sizeof(struct merge_options));
1731         o->verbosity = 2;
1732         o->buffer_output = 1;
1733         o->diff_rename_limit = -1;
1734         o->merge_rename_limit = -1;
1735         o->renormalize = 0;
1736         git_config(merge_recursive_config, o);
1737         if (getenv("GIT_MERGE_VERBOSITY"))
1738                 o->verbosity =
1739                         strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1740         if (o->verbosity >= 5)
1741                 o->buffer_output = 0;
1742         strbuf_init(&o->obuf, 0);
1743         memset(&o->current_file_set, 0, sizeof(struct string_list));
1744         o->current_file_set.strdup_strings = 1;
1745         memset(&o->current_directory_set, 0, sizeof(struct string_list));
1746         o->current_directory_set.strdup_strings = 1;
1747 }
1748
1749 int parse_merge_opt(struct merge_options *o, const char *s)
1750 {
1751         if (!s || !*s)
1752                 return -1;
1753         if (!strcmp(s, "ours"))
1754                 o->recursive_variant = MERGE_RECURSIVE_OURS;
1755         else if (!strcmp(s, "theirs"))
1756                 o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1757         else if (!strcmp(s, "subtree"))
1758                 o->subtree_shift = "";
1759         else if (!prefixcmp(s, "subtree="))
1760                 o->subtree_shift = s + strlen("subtree=");
1761         else if (!strcmp(s, "patience"))
1762                 o->xdl_opts |= XDF_PATIENCE_DIFF;
1763         else if (!strcmp(s, "ignore-space-change"))
1764                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1765         else if (!strcmp(s, "ignore-all-space"))
1766                 o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1767         else if (!strcmp(s, "ignore-space-at-eol"))
1768                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1769         else if (!strcmp(s, "renormalize"))
1770                 o->renormalize = 1;
1771         else if (!strcmp(s, "no-renormalize"))
1772                 o->renormalize = 0;
1773         else if (!prefixcmp(s, "rename-threshold=")) {
1774                 const char *score = s + strlen("rename-threshold=");
1775                 if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1776                         return -1;
1777         }
1778         else
1779                 return -1;
1780         return 0;
1781 }