merge-recursive.con commit Document that merge strategies can now take their own options (566c511)
   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
  24static struct tree *shift_tree_object(struct tree *one, struct tree *two,
  25                                      const char *subtree_shift)
  26{
  27        unsigned char shifted[20];
  28
  29        if (!*subtree_shift) {
  30                shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
  31        } else {
  32                shift_tree_by(one->object.sha1, two->object.sha1, shifted,
  33                              subtree_shift);
  34        }
  35        if (!hashcmp(two->object.sha1, shifted))
  36                return two;
  37        return lookup_tree(shifted);
  38}
  39
  40/*
  41 * A virtual commit has (const char *)commit->util set to the name.
  42 */
  43
  44static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  45{
  46        struct commit *commit = xcalloc(1, sizeof(struct commit));
  47        commit->tree = tree;
  48        commit->util = (void*)comment;
  49        /* avoid warnings */
  50        commit->object.parsed = 1;
  51        return commit;
  52}
  53
  54/*
  55 * Since we use get_tree_entry(), which does not put the read object into
  56 * the object pool, we cannot rely on a == b.
  57 */
  58static int sha_eq(const unsigned char *a, const unsigned char *b)
  59{
  60        if (!a && !b)
  61                return 2;
  62        return a && b && hashcmp(a, b) == 0;
  63}
  64
  65/*
  66 * Since we want to write the index eventually, we cannot reuse the index
  67 * for these (temporary) data.
  68 */
  69struct stage_data
  70{
  71        struct
  72        {
  73                unsigned mode;
  74                unsigned char sha[20];
  75        } stages[4];
  76        unsigned processed:1;
  77};
  78
  79static int show(struct merge_options *o, int v)
  80{
  81        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
  82}
  83
  84static void flush_output(struct merge_options *o)
  85{
  86        if (o->obuf.len) {
  87                fputs(o->obuf.buf, stdout);
  88                strbuf_reset(&o->obuf);
  89        }
  90}
  91
  92__attribute__((format (printf, 3, 4)))
  93static void output(struct merge_options *o, int v, const char *fmt, ...)
  94{
  95        int len;
  96        va_list ap;
  97
  98        if (!show(o, v))
  99                return;
 100
 101        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 102        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 103        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 104
 105        va_start(ap, fmt);
 106        len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 107        va_end(ap);
 108
 109        if (len < 0)
 110                len = 0;
 111        if (len >= strbuf_avail(&o->obuf)) {
 112                strbuf_grow(&o->obuf, len + 2);
 113                va_start(ap, fmt);
 114                len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 115                va_end(ap);
 116                if (len >= strbuf_avail(&o->obuf)) {
 117                        die("this should not happen, your snprintf is broken");
 118                }
 119        }
 120        strbuf_setlen(&o->obuf, o->obuf.len + len);
 121        strbuf_add(&o->obuf, "\n", 1);
 122        if (!o->buffer_output)
 123                flush_output(o);
 124}
 125
 126static void output_commit_title(struct merge_options *o, struct commit *commit)
 127{
 128        int i;
 129        flush_output(o);
 130        for (i = o->call_depth; i--;)
 131                fputs("  ", stdout);
 132        if (commit->util)
 133                printf("virtual %s\n", (char *)commit->util);
 134        else {
 135                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 136                if (parse_commit(commit) != 0)
 137                        printf("(bad commit)\n");
 138                else {
 139                        const char *s;
 140                        int len;
 141                        for (s = commit->buffer; *s; s++)
 142                                if (*s == '\n' && s[1] == '\n') {
 143                                        s += 2;
 144                                        break;
 145                                }
 146                        for (len = 0; s[len] && '\n' != s[len]; len++)
 147                                ; /* do nothing */
 148                        printf("%.*s\n", len, s);
 149                }
 150        }
 151}
 152
 153static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 154                const char *path, int stage, int refresh, int options)
 155{
 156        struct cache_entry *ce;
 157        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 158        if (!ce)
 159                return error("addinfo_cache failed for path '%s'", path);
 160        return add_cache_entry(ce, options);
 161}
 162
 163static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 164{
 165        parse_tree(tree);
 166        init_tree_desc(desc, tree->buffer, tree->size);
 167}
 168
 169static int git_merge_trees(int index_only,
 170                           struct tree *common,
 171                           struct tree *head,
 172                           struct tree *merge)
 173{
 174        int rc;
 175        struct tree_desc t[3];
 176        struct unpack_trees_options opts;
 177        struct unpack_trees_error_msgs msgs = {
 178                /* would_overwrite */
 179                "Your local changes to '%s' would be overwritten by merge.  Aborting.",
 180                /* not_uptodate_file */
 181                "Your local changes to '%s' would be overwritten by merge.  Aborting.",
 182                /* not_uptodate_dir */
 183                "Updating '%s' would lose untracked files in it.  Aborting.",
 184                /* would_lose_untracked */
 185                "Untracked working tree file '%s' would be %s by merge.  Aborting",
 186                /* bind_overlap -- will not happen here */
 187                NULL,
 188        };
 189        if (advice_commit_before_merge) {
 190                msgs.would_overwrite = msgs.not_uptodate_file =
 191                        "Your local changes to '%s' would be overwritten by merge.  Aborting.\n"
 192                        "Please, commit your changes or stash them before you can merge.";
 193        }
 194
 195        memset(&opts, 0, sizeof(opts));
 196        if (index_only)
 197                opts.index_only = 1;
 198        else
 199                opts.update = 1;
 200        opts.merge = 1;
 201        opts.head_idx = 2;
 202        opts.fn = threeway_merge;
 203        opts.src_index = &the_index;
 204        opts.dst_index = &the_index;
 205        opts.msgs = msgs;
 206
 207        init_tree_desc_from_tree(t+0, common);
 208        init_tree_desc_from_tree(t+1, head);
 209        init_tree_desc_from_tree(t+2, merge);
 210
 211        rc = unpack_trees(3, t, &opts);
 212        cache_tree_free(&active_cache_tree);
 213        return rc;
 214}
 215
 216struct tree *write_tree_from_memory(struct merge_options *o)
 217{
 218        struct tree *result = NULL;
 219
 220        if (unmerged_cache()) {
 221                int i;
 222                output(o, 0, "There are unmerged index entries:");
 223                for (i = 0; i < active_nr; i++) {
 224                        struct cache_entry *ce = active_cache[i];
 225                        if (ce_stage(ce))
 226                                output(o, 0, "%d %.*s", ce_stage(ce),
 227                                       (int)ce_namelen(ce), ce->name);
 228                }
 229                return NULL;
 230        }
 231
 232        if (!active_cache_tree)
 233                active_cache_tree = cache_tree();
 234
 235        if (!cache_tree_fully_valid(active_cache_tree) &&
 236            cache_tree_update(active_cache_tree,
 237                              active_cache, active_nr, 0, 0) < 0)
 238                die("error building trees");
 239
 240        result = lookup_tree(active_cache_tree->sha1);
 241
 242        return result;
 243}
 244
 245static int save_files_dirs(const unsigned char *sha1,
 246                const char *base, int baselen, const char *path,
 247                unsigned int mode, int stage, void *context)
 248{
 249        int len = strlen(path);
 250        char *newpath = xmalloc(baselen + len + 1);
 251        struct merge_options *o = context;
 252
 253        memcpy(newpath, base, baselen);
 254        memcpy(newpath + baselen, path, len);
 255        newpath[baselen + len] = '\0';
 256
 257        if (S_ISDIR(mode))
 258                string_list_insert(newpath, &o->current_directory_set);
 259        else
 260                string_list_insert(newpath, &o->current_file_set);
 261        free(newpath);
 262
 263        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 264}
 265
 266static int get_files_dirs(struct merge_options *o, struct tree *tree)
 267{
 268        int n;
 269        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 270                return 0;
 271        n = o->current_file_set.nr + o->current_directory_set.nr;
 272        return n;
 273}
 274
 275/*
 276 * Returns an index_entry instance which doesn't have to correspond to
 277 * a real cache entry in Git's index.
 278 */
 279static struct stage_data *insert_stage_data(const char *path,
 280                struct tree *o, struct tree *a, struct tree *b,
 281                struct string_list *entries)
 282{
 283        struct string_list_item *item;
 284        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 285        get_tree_entry(o->object.sha1, path,
 286                        e->stages[1].sha, &e->stages[1].mode);
 287        get_tree_entry(a->object.sha1, path,
 288                        e->stages[2].sha, &e->stages[2].mode);
 289        get_tree_entry(b->object.sha1, path,
 290                        e->stages[3].sha, &e->stages[3].mode);
 291        item = string_list_insert(path, entries);
 292        item->util = e;
 293        return e;
 294}
 295
 296/*
 297 * Create a dictionary mapping file names to stage_data objects. The
 298 * dictionary contains one entry for every path with a non-zero stage entry.
 299 */
 300static struct string_list *get_unmerged(void)
 301{
 302        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 303        int i;
 304
 305        unmerged->strdup_strings = 1;
 306
 307        for (i = 0; i < active_nr; i++) {
 308                struct string_list_item *item;
 309                struct stage_data *e;
 310                struct cache_entry *ce = active_cache[i];
 311                if (!ce_stage(ce))
 312                        continue;
 313
 314                item = string_list_lookup(ce->name, unmerged);
 315                if (!item) {
 316                        item = string_list_insert(ce->name, unmerged);
 317                        item->util = xcalloc(1, sizeof(struct stage_data));
 318                }
 319                e = item->util;
 320                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 321                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 322        }
 323
 324        return unmerged;
 325}
 326
 327struct rename
 328{
 329        struct diff_filepair *pair;
 330        struct stage_data *src_entry;
 331        struct stage_data *dst_entry;
 332        unsigned processed:1;
 333};
 334
 335/*
 336 * Get information of all renames which occurred between 'o_tree' and
 337 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 338 * 'b_tree') to be able to associate the correct cache entries with
 339 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 340 */
 341static struct string_list *get_renames(struct merge_options *o,
 342                                       struct tree *tree,
 343                                       struct tree *o_tree,
 344                                       struct tree *a_tree,
 345                                       struct tree *b_tree,
 346                                       struct string_list *entries)
 347{
 348        int i;
 349        struct string_list *renames;
 350        struct diff_options opts;
 351
 352        renames = xcalloc(1, sizeof(struct string_list));
 353        diff_setup(&opts);
 354        DIFF_OPT_SET(&opts, RECURSIVE);
 355        opts.detect_rename = DIFF_DETECT_RENAME;
 356        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 357                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 358                            500;
 359        opts.warn_on_too_large_rename = 1;
 360        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 361        if (diff_setup_done(&opts) < 0)
 362                die("diff setup failed");
 363        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 364        diffcore_std(&opts);
 365        for (i = 0; i < diff_queued_diff.nr; ++i) {
 366                struct string_list_item *item;
 367                struct rename *re;
 368                struct diff_filepair *pair = diff_queued_diff.queue[i];
 369                if (pair->status != 'R') {
 370                        diff_free_filepair(pair);
 371                        continue;
 372                }
 373                re = xmalloc(sizeof(*re));
 374                re->processed = 0;
 375                re->pair = pair;
 376                item = string_list_lookup(re->pair->one->path, entries);
 377                if (!item)
 378                        re->src_entry = insert_stage_data(re->pair->one->path,
 379                                        o_tree, a_tree, b_tree, entries);
 380                else
 381                        re->src_entry = item->util;
 382
 383                item = string_list_lookup(re->pair->two->path, entries);
 384                if (!item)
 385                        re->dst_entry = insert_stage_data(re->pair->two->path,
 386                                        o_tree, a_tree, b_tree, entries);
 387                else
 388                        re->dst_entry = item->util;
 389                item = string_list_insert(pair->one->path, renames);
 390                item->util = re;
 391        }
 392        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 393        diff_queued_diff.nr = 0;
 394        diff_flush(&opts);
 395        return renames;
 396}
 397
 398static int update_stages(const char *path, struct diff_filespec *o,
 399                         struct diff_filespec *a, struct diff_filespec *b,
 400                         int clear)
 401{
 402        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 403        if (clear)
 404                if (remove_file_from_cache(path))
 405                        return -1;
 406        if (o)
 407                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 408                        return -1;
 409        if (a)
 410                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 411                        return -1;
 412        if (b)
 413                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 414                        return -1;
 415        return 0;
 416}
 417
 418static int remove_file(struct merge_options *o, int clean,
 419                       const char *path, int no_wd)
 420{
 421        int update_cache = o->call_depth || clean;
 422        int update_working_directory = !o->call_depth && !no_wd;
 423
 424        if (update_cache) {
 425                if (remove_file_from_cache(path))
 426                        return -1;
 427        }
 428        if (update_working_directory) {
 429                if (remove_path(path) && errno != ENOENT)
 430                        return -1;
 431        }
 432        return 0;
 433}
 434
 435static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 436{
 437        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 438        int suffix = 0;
 439        struct stat st;
 440        char *p = newpath + strlen(path);
 441        strcpy(newpath, path);
 442        *(p++) = '~';
 443        strcpy(p, branch);
 444        for (; *p; ++p)
 445                if ('/' == *p)
 446                        *p = '_';
 447        while (string_list_has_string(&o->current_file_set, newpath) ||
 448               string_list_has_string(&o->current_directory_set, newpath) ||
 449               lstat(newpath, &st) == 0)
 450                sprintf(p, "_%d", suffix++);
 451
 452        string_list_insert(newpath, &o->current_file_set);
 453        return newpath;
 454}
 455
 456static void flush_buffer(int fd, const char *buf, unsigned long size)
 457{
 458        while (size > 0) {
 459                long ret = write_in_full(fd, buf, size);
 460                if (ret < 0) {
 461                        /* Ignore epipe */
 462                        if (errno == EPIPE)
 463                                break;
 464                        die_errno("merge-recursive");
 465                } else if (!ret) {
 466                        die("merge-recursive: disk full?");
 467                }
 468                size -= ret;
 469                buf += ret;
 470        }
 471}
 472
 473static int would_lose_untracked(const char *path)
 474{
 475        int pos = cache_name_pos(path, strlen(path));
 476
 477        if (pos < 0)
 478                pos = -1 - pos;
 479        while (pos < active_nr &&
 480               !strcmp(path, active_cache[pos]->name)) {
 481                /*
 482                 * If stage #0, it is definitely tracked.
 483                 * If it has stage #2 then it was tracked
 484                 * before this merge started.  All other
 485                 * cases the path was not tracked.
 486                 */
 487                switch (ce_stage(active_cache[pos])) {
 488                case 0:
 489                case 2:
 490                        return 0;
 491                }
 492                pos++;
 493        }
 494        return file_exists(path);
 495}
 496
 497static int make_room_for_path(const char *path)
 498{
 499        int status;
 500        const char *msg = "failed to create path '%s'%s";
 501
 502        status = safe_create_leading_directories_const(path);
 503        if (status) {
 504                if (status == -3) {
 505                        /* something else exists */
 506                        error(msg, path, ": perhaps a D/F conflict?");
 507                        return -1;
 508                }
 509                die(msg, path, "");
 510        }
 511
 512        /*
 513         * Do not unlink a file in the work tree if we are not
 514         * tracking it.
 515         */
 516        if (would_lose_untracked(path))
 517                return error("refusing to lose untracked file at '%s'",
 518                             path);
 519
 520        /* Successful unlink is good.. */
 521        if (!unlink(path))
 522                return 0;
 523        /* .. and so is no existing file */
 524        if (errno == ENOENT)
 525                return 0;
 526        /* .. but not some other error (who really cares what?) */
 527        return error(msg, path, ": perhaps a D/F conflict?");
 528}
 529
 530static void update_file_flags(struct merge_options *o,
 531                              const unsigned char *sha,
 532                              unsigned mode,
 533                              const char *path,
 534                              int update_cache,
 535                              int update_wd)
 536{
 537        if (o->call_depth)
 538                update_wd = 0;
 539
 540        if (update_wd) {
 541                enum object_type type;
 542                void *buf;
 543                unsigned long size;
 544
 545                if (S_ISGITLINK(mode))
 546                        /*
 547                         * We may later decide to recursively descend into
 548                         * the submodule directory and update its index
 549                         * and/or work tree, but we do not do that now.
 550                         */
 551                        goto update_index;
 552
 553                buf = read_sha1_file(sha, &type, &size);
 554                if (!buf)
 555                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 556                if (type != OBJ_BLOB)
 557                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 558                if (S_ISREG(mode)) {
 559                        struct strbuf strbuf = STRBUF_INIT;
 560                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 561                                free(buf);
 562                                size = strbuf.len;
 563                                buf = strbuf_detach(&strbuf, NULL);
 564                        }
 565                }
 566
 567                if (make_room_for_path(path) < 0) {
 568                        update_wd = 0;
 569                        free(buf);
 570                        goto update_index;
 571                }
 572                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 573                        int fd;
 574                        if (mode & 0100)
 575                                mode = 0777;
 576                        else
 577                                mode = 0666;
 578                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 579                        if (fd < 0)
 580                                die_errno("failed to open '%s'", path);
 581                        flush_buffer(fd, buf, size);
 582                        close(fd);
 583                } else if (S_ISLNK(mode)) {
 584                        char *lnk = xmemdupz(buf, size);
 585                        safe_create_leading_directories_const(path);
 586                        unlink(path);
 587                        if (symlink(lnk, path))
 588                                die_errno("failed to symlink '%s'", path);
 589                        free(lnk);
 590                } else
 591                        die("do not know what to do with %06o %s '%s'",
 592                            mode, sha1_to_hex(sha), path);
 593                free(buf);
 594        }
 595 update_index:
 596        if (update_cache)
 597                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 598}
 599
 600static void update_file(struct merge_options *o,
 601                        int clean,
 602                        const unsigned char *sha,
 603                        unsigned mode,
 604                        const char *path)
 605{
 606        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 607}
 608
 609/* Low level file merging, update and removal */
 610
 611struct merge_file_info
 612{
 613        unsigned char sha[20];
 614        unsigned mode;
 615        unsigned clean:1,
 616                 merge:1;
 617};
 618
 619static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
 620{
 621        unsigned long size;
 622        enum object_type type;
 623
 624        if (!hashcmp(sha1, null_sha1)) {
 625                mm->ptr = xstrdup("");
 626                mm->size = 0;
 627                return;
 628        }
 629
 630        mm->ptr = read_sha1_file(sha1, &type, &size);
 631        if (!mm->ptr || type != OBJ_BLOB)
 632                die("unable to read blob object %s", sha1_to_hex(sha1));
 633        mm->size = size;
 634}
 635
 636static int merge_3way(struct merge_options *o,
 637                      mmbuffer_t *result_buf,
 638                      struct diff_filespec *one,
 639                      struct diff_filespec *a,
 640                      struct diff_filespec *b,
 641                      const char *branch1,
 642                      const char *branch2)
 643{
 644        mmfile_t orig, src1, src2;
 645        char *name1, *name2;
 646        int merge_status;
 647        int favor;
 648
 649        if (o->call_depth)
 650                favor = 0;
 651        else {
 652                switch (o->recursive_variant) {
 653                case MERGE_RECURSIVE_OURS:
 654                        favor = XDL_MERGE_FAVOR_OURS;
 655                        break;
 656                case MERGE_RECURSIVE_THEIRS:
 657                        favor = XDL_MERGE_FAVOR_THEIRS;
 658                        break;
 659                default:
 660                        favor = 0;
 661                        break;
 662                }
 663        }
 664
 665        if (strcmp(a->path, b->path)) {
 666                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 667                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 668        } else {
 669                name1 = xstrdup(mkpath("%s", branch1));
 670                name2 = xstrdup(mkpath("%s", branch2));
 671        }
 672
 673        fill_mm(one->sha1, &orig);
 674        fill_mm(a->sha1, &src1);
 675        fill_mm(b->sha1, &src2);
 676
 677        merge_status = ll_merge(result_buf, a->path, &orig,
 678                                &src1, name1, &src2, name2,
 679                                (!!o->call_depth) | (favor << 1));
 680
 681        free(name1);
 682        free(name2);
 683        free(orig.ptr);
 684        free(src1.ptr);
 685        free(src2.ptr);
 686        return merge_status;
 687}
 688
 689static struct merge_file_info merge_file(struct merge_options *o,
 690                                         struct diff_filespec *one,
 691                                         struct diff_filespec *a,
 692                                         struct diff_filespec *b,
 693                                         const char *branch1,
 694                                         const char *branch2)
 695{
 696        struct merge_file_info result;
 697        result.merge = 0;
 698        result.clean = 1;
 699
 700        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 701                result.clean = 0;
 702                if (S_ISREG(a->mode)) {
 703                        result.mode = a->mode;
 704                        hashcpy(result.sha, a->sha1);
 705                } else {
 706                        result.mode = b->mode;
 707                        hashcpy(result.sha, b->sha1);
 708                }
 709        } else {
 710                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 711                        result.merge = 1;
 712
 713                /*
 714                 * Merge modes
 715                 */
 716                if (a->mode == b->mode || a->mode == one->mode)
 717                        result.mode = b->mode;
 718                else {
 719                        result.mode = a->mode;
 720                        if (b->mode != one->mode) {
 721                                result.clean = 0;
 722                                result.merge = 1;
 723                        }
 724                }
 725
 726                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 727                        hashcpy(result.sha, b->sha1);
 728                else if (sha_eq(b->sha1, one->sha1))
 729                        hashcpy(result.sha, a->sha1);
 730                else if (S_ISREG(a->mode)) {
 731                        mmbuffer_t result_buf;
 732                        int merge_status;
 733
 734                        merge_status = merge_3way(o, &result_buf, one, a, b,
 735                                                  branch1, branch2);
 736
 737                        if ((merge_status < 0) || !result_buf.ptr)
 738                                die("Failed to execute internal merge");
 739
 740                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 741                                            blob_type, result.sha))
 742                                die("Unable to add %s to database",
 743                                    a->path);
 744
 745                        free(result_buf.ptr);
 746                        result.clean = (merge_status == 0);
 747                } else if (S_ISGITLINK(a->mode)) {
 748                        result.clean = 0;
 749                        hashcpy(result.sha, a->sha1);
 750                } else if (S_ISLNK(a->mode)) {
 751                        hashcpy(result.sha, a->sha1);
 752
 753                        if (!sha_eq(a->sha1, b->sha1))
 754                                result.clean = 0;
 755                } else {
 756                        die("unsupported object type in the tree");
 757                }
 758        }
 759
 760        return result;
 761}
 762
 763static void conflict_rename_rename(struct merge_options *o,
 764                                   struct rename *ren1,
 765                                   const char *branch1,
 766                                   struct rename *ren2,
 767                                   const char *branch2)
 768{
 769        char *del[2];
 770        int delp = 0;
 771        const char *ren1_dst = ren1->pair->two->path;
 772        const char *ren2_dst = ren2->pair->two->path;
 773        const char *dst_name1 = ren1_dst;
 774        const char *dst_name2 = ren2_dst;
 775        if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
 776                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 777                output(o, 1, "%s is a directory in %s adding as %s instead",
 778                       ren1_dst, branch2, dst_name1);
 779                remove_file(o, 0, ren1_dst, 0);
 780        }
 781        if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
 782                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 783                output(o, 1, "%s is a directory in %s adding as %s instead",
 784                       ren2_dst, branch1, dst_name2);
 785                remove_file(o, 0, ren2_dst, 0);
 786        }
 787        if (o->call_depth) {
 788                remove_file_from_cache(dst_name1);
 789                remove_file_from_cache(dst_name2);
 790                /*
 791                 * Uncomment to leave the conflicting names in the resulting tree
 792                 *
 793                 * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
 794                 * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
 795                 */
 796        } else {
 797                update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
 798                update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
 799        }
 800        while (delp--)
 801                free(del[delp]);
 802}
 803
 804static void conflict_rename_dir(struct merge_options *o,
 805                                struct rename *ren1,
 806                                const char *branch1)
 807{
 808        char *new_path = unique_path(o, ren1->pair->two->path, branch1);
 809        output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
 810        remove_file(o, 0, ren1->pair->two->path, 0);
 811        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 812        free(new_path);
 813}
 814
 815static void conflict_rename_rename_2(struct merge_options *o,
 816                                     struct rename *ren1,
 817                                     const char *branch1,
 818                                     struct rename *ren2,
 819                                     const char *branch2)
 820{
 821        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 822        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 823        output(o, 1, "Renaming %s to %s and %s to %s instead",
 824               ren1->pair->one->path, new_path1,
 825               ren2->pair->one->path, new_path2);
 826        remove_file(o, 0, ren1->pair->two->path, 0);
 827        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 828        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 829        free(new_path2);
 830        free(new_path1);
 831}
 832
 833static int process_renames(struct merge_options *o,
 834                           struct string_list *a_renames,
 835                           struct string_list *b_renames)
 836{
 837        int clean_merge = 1, i, j;
 838        struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
 839        const struct rename *sre;
 840
 841        for (i = 0; i < a_renames->nr; i++) {
 842                sre = a_renames->items[i].util;
 843                string_list_insert(sre->pair->two->path, &a_by_dst)->util
 844                        = sre->dst_entry;
 845        }
 846        for (i = 0; i < b_renames->nr; i++) {
 847                sre = b_renames->items[i].util;
 848                string_list_insert(sre->pair->two->path, &b_by_dst)->util
 849                        = sre->dst_entry;
 850        }
 851
 852        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 853                char *src;
 854                struct string_list *renames1, *renames2Dst;
 855                struct rename *ren1 = NULL, *ren2 = NULL;
 856                const char *branch1, *branch2;
 857                const char *ren1_src, *ren1_dst;
 858
 859                if (i >= a_renames->nr) {
 860                        ren2 = b_renames->items[j++].util;
 861                } else if (j >= b_renames->nr) {
 862                        ren1 = a_renames->items[i++].util;
 863                } else {
 864                        int compare = strcmp(a_renames->items[i].string,
 865                                             b_renames->items[j].string);
 866                        if (compare <= 0)
 867                                ren1 = a_renames->items[i++].util;
 868                        if (compare >= 0)
 869                                ren2 = b_renames->items[j++].util;
 870                }
 871
 872                /* TODO: refactor, so that 1/2 are not needed */
 873                if (ren1) {
 874                        renames1 = a_renames;
 875                        renames2Dst = &b_by_dst;
 876                        branch1 = o->branch1;
 877                        branch2 = o->branch2;
 878                } else {
 879                        struct rename *tmp;
 880                        renames1 = b_renames;
 881                        renames2Dst = &a_by_dst;
 882                        branch1 = o->branch2;
 883                        branch2 = o->branch1;
 884                        tmp = ren2;
 885                        ren2 = ren1;
 886                        ren1 = tmp;
 887                }
 888                src = ren1->pair->one->path;
 889
 890                ren1->dst_entry->processed = 1;
 891                ren1->src_entry->processed = 1;
 892
 893                if (ren1->processed)
 894                        continue;
 895                ren1->processed = 1;
 896
 897                ren1_src = ren1->pair->one->path;
 898                ren1_dst = ren1->pair->two->path;
 899
 900                if (ren2) {
 901                        const char *ren2_src = ren2->pair->one->path;
 902                        const char *ren2_dst = ren2->pair->two->path;
 903                        /* Renamed in 1 and renamed in 2 */
 904                        if (strcmp(ren1_src, ren2_src) != 0)
 905                                die("ren1.src != ren2.src");
 906                        ren2->dst_entry->processed = 1;
 907                        ren2->processed = 1;
 908                        if (strcmp(ren1_dst, ren2_dst) != 0) {
 909                                clean_merge = 0;
 910                                output(o, 1, "CONFLICT (rename/rename): "
 911                                       "Rename \"%s\"->\"%s\" in branch \"%s\" "
 912                                       "rename \"%s\"->\"%s\" in \"%s\"%s",
 913                                       src, ren1_dst, branch1,
 914                                       src, ren2_dst, branch2,
 915                                       o->call_depth ? " (left unresolved)": "");
 916                                if (o->call_depth) {
 917                                        remove_file_from_cache(src);
 918                                        update_file(o, 0, ren1->pair->one->sha1,
 919                                                    ren1->pair->one->mode, src);
 920                                }
 921                                conflict_rename_rename(o, ren1, branch1, ren2, branch2);
 922                        } else {
 923                                struct merge_file_info mfi;
 924                                remove_file(o, 1, ren1_src, 1);
 925                                mfi = merge_file(o,
 926                                                 ren1->pair->one,
 927                                                 ren1->pair->two,
 928                                                 ren2->pair->two,
 929                                                 branch1,
 930                                                 branch2);
 931                                if (mfi.merge || !mfi.clean)
 932                                        output(o, 1, "Renaming %s->%s", src, ren1_dst);
 933
 934                                if (mfi.merge)
 935                                        output(o, 2, "Auto-merging %s", ren1_dst);
 936
 937                                if (!mfi.clean) {
 938                                        output(o, 1, "CONFLICT (content): merge conflict in %s",
 939                                               ren1_dst);
 940                                        clean_merge = 0;
 941
 942                                        if (!o->call_depth)
 943                                                update_stages(ren1_dst,
 944                                                              ren1->pair->one,
 945                                                              ren1->pair->two,
 946                                                              ren2->pair->two,
 947                                                              1 /* clear */);
 948                                }
 949                                update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 950                        }
 951                } else {
 952                        /* Renamed in 1, maybe changed in 2 */
 953                        struct string_list_item *item;
 954                        /* we only use sha1 and mode of these */
 955                        struct diff_filespec src_other, dst_other;
 956                        int try_merge, stage = a_renames == renames1 ? 3: 2;
 957
 958                        remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
 959
 960                        hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
 961                        src_other.mode = ren1->src_entry->stages[stage].mode;
 962                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
 963                        dst_other.mode = ren1->dst_entry->stages[stage].mode;
 964
 965                        try_merge = 0;
 966
 967                        if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
 968                                clean_merge = 0;
 969                                output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
 970                                       " directory %s added in %s",
 971                                       ren1_src, ren1_dst, branch1,
 972                                       ren1_dst, branch2);
 973                                conflict_rename_dir(o, ren1, branch1);
 974                        } else if (sha_eq(src_other.sha1, null_sha1)) {
 975                                clean_merge = 0;
 976                                output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 977                                       "and deleted in %s",
 978                                       ren1_src, ren1_dst, branch1,
 979                                       branch2);
 980                                update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 981                                if (!o->call_depth)
 982                                        update_stages(ren1_dst, NULL,
 983                                                        branch1 == o->branch1 ?
 984                                                        ren1->pair->two : NULL,
 985                                                        branch1 == o->branch1 ?
 986                                                        NULL : ren1->pair->two, 1);
 987                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
 988                                const char *new_path;
 989                                clean_merge = 0;
 990                                try_merge = 1;
 991                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
 992                                       "%s added in %s",
 993                                       ren1_src, ren1_dst, branch1,
 994                                       ren1_dst, branch2);
 995                                if (o->call_depth) {
 996                                        struct merge_file_info mfi;
 997                                        struct diff_filespec one, a, b;
 998
 999                                        one.path = a.path = b.path =
1000                                                (char *)ren1_dst;
1001                                        hashcpy(one.sha1, null_sha1);
1002                                        one.mode = 0;
1003                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1004                                        a.mode = ren1->pair->two->mode;
1005                                        hashcpy(b.sha1, dst_other.sha1);
1006                                        b.mode = dst_other.mode;
1007                                        mfi = merge_file(o, &one, &a, &b,
1008                                                         branch1,
1009                                                         branch2);
1010                                        output(o, 1, "Adding merged %s", ren1_dst);
1011                                        update_file(o, 0,
1012                                                    mfi.sha,
1013                                                    mfi.mode,
1014                                                    ren1_dst);
1015                                } else {
1016                                        new_path = unique_path(o, ren1_dst, branch2);
1017                                        output(o, 1, "Adding as %s instead", new_path);
1018                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1019                                }
1020                        } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
1021                                ren2 = item->util;
1022                                clean_merge = 0;
1023                                ren2->processed = 1;
1024                                output(o, 1, "CONFLICT (rename/rename): "
1025                                       "Rename %s->%s in %s. "
1026                                       "Rename %s->%s in %s",
1027                                       ren1_src, ren1_dst, branch1,
1028                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1029                                conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
1030                        } else
1031                                try_merge = 1;
1032
1033                        if (try_merge) {
1034                                struct diff_filespec *one, *a, *b;
1035                                struct merge_file_info mfi;
1036                                src_other.path = (char *)ren1_src;
1037
1038                                one = ren1->pair->one;
1039                                if (a_renames == renames1) {
1040                                        a = ren1->pair->two;
1041                                        b = &src_other;
1042                                } else {
1043                                        b = ren1->pair->two;
1044                                        a = &src_other;
1045                                }
1046                                mfi = merge_file(o, one, a, b,
1047                                                o->branch1, o->branch2);
1048
1049                                if (mfi.clean &&
1050                                    sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1051                                    mfi.mode == ren1->pair->two->mode)
1052                                        /*
1053                                         * This messaged is part of
1054                                         * t6022 test. If you change
1055                                         * it update the test too.
1056                                         */
1057                                        output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
1058                                else {
1059                                        if (mfi.merge || !mfi.clean)
1060                                                output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
1061                                        if (mfi.merge)
1062                                                output(o, 2, "Auto-merging %s", ren1_dst);
1063                                        if (!mfi.clean) {
1064                                                output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
1065                                                       ren1_dst);
1066                                                clean_merge = 0;
1067
1068                                                if (!o->call_depth)
1069                                                        update_stages(ren1_dst,
1070                                                                      one, a, b, 1);
1071                                        }
1072                                        update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1073                                }
1074                        }
1075                }
1076        }
1077        string_list_clear(&a_by_dst, 0);
1078        string_list_clear(&b_by_dst, 0);
1079
1080        return clean_merge;
1081}
1082
1083static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1084{
1085        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1086}
1087
1088/* Per entry merge function */
1089static int process_entry(struct merge_options *o,
1090                         const char *path, struct stage_data *entry)
1091{
1092        /*
1093        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1094        print_index_entry("\tpath: ", entry);
1095        */
1096        int clean_merge = 1;
1097        unsigned o_mode = entry->stages[1].mode;
1098        unsigned a_mode = entry->stages[2].mode;
1099        unsigned b_mode = entry->stages[3].mode;
1100        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1101        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1102        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1103
1104        if (o_sha && (!a_sha || !b_sha)) {
1105                /* Case A: Deleted in one */
1106                if ((!a_sha && !b_sha) ||
1107                    (sha_eq(a_sha, o_sha) && !b_sha) ||
1108                    (!a_sha && sha_eq(b_sha, o_sha))) {
1109                        /* Deleted in both or deleted in one and
1110                         * unchanged in the other */
1111                        if (a_sha)
1112                                output(o, 2, "Removing %s", path);
1113                        /* do not touch working file if it did not exist */
1114                        remove_file(o, 1, path, !a_sha);
1115                } else {
1116                        /* Deleted in one and changed in the other */
1117                        clean_merge = 0;
1118                        if (!a_sha) {
1119                                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1120                                       "and modified in %s. Version %s of %s left in tree.",
1121                                       path, o->branch1,
1122                                       o->branch2, o->branch2, path);
1123                                update_file(o, 0, b_sha, b_mode, path);
1124                        } else {
1125                                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1126                                       "and modified in %s. Version %s of %s left in tree.",
1127                                       path, o->branch2,
1128                                       o->branch1, o->branch1, path);
1129                                update_file(o, 0, a_sha, a_mode, path);
1130                        }
1131                }
1132
1133        } else if ((!o_sha && a_sha && !b_sha) ||
1134                   (!o_sha && !a_sha && b_sha)) {
1135                /* Case B: Added in one. */
1136                const char *add_branch;
1137                const char *other_branch;
1138                unsigned mode;
1139                const unsigned char *sha;
1140                const char *conf;
1141
1142                if (a_sha) {
1143                        add_branch = o->branch1;
1144                        other_branch = o->branch2;
1145                        mode = a_mode;
1146                        sha = a_sha;
1147                        conf = "file/directory";
1148                } else {
1149                        add_branch = o->branch2;
1150                        other_branch = o->branch1;
1151                        mode = b_mode;
1152                        sha = b_sha;
1153                        conf = "directory/file";
1154                }
1155                if (string_list_has_string(&o->current_directory_set, path)) {
1156                        const char *new_path = unique_path(o, path, add_branch);
1157                        clean_merge = 0;
1158                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1159                               "Adding %s as %s",
1160                               conf, path, other_branch, path, new_path);
1161                        remove_file(o, 0, path, 0);
1162                        update_file(o, 0, sha, mode, new_path);
1163                } else {
1164                        output(o, 2, "Adding %s", path);
1165                        update_file(o, 1, sha, mode, path);
1166                }
1167        } else if (a_sha && b_sha) {
1168                /* Case C: Added in both (check for same permissions) and */
1169                /* case D: Modified in both, but differently. */
1170                const char *reason = "content";
1171                struct merge_file_info mfi;
1172                struct diff_filespec one, a, b;
1173
1174                if (!o_sha) {
1175                        reason = "add/add";
1176                        o_sha = (unsigned char *)null_sha1;
1177                }
1178                output(o, 2, "Auto-merging %s", path);
1179                one.path = a.path = b.path = (char *)path;
1180                hashcpy(one.sha1, o_sha);
1181                one.mode = o_mode;
1182                hashcpy(a.sha1, a_sha);
1183                a.mode = a_mode;
1184                hashcpy(b.sha1, b_sha);
1185                b.mode = b_mode;
1186
1187                mfi = merge_file(o, &one, &a, &b,
1188                                 o->branch1, o->branch2);
1189
1190                clean_merge = mfi.clean;
1191                if (!mfi.clean) {
1192                        if (S_ISGITLINK(mfi.mode))
1193                                reason = "submodule";
1194                        output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1195                                        reason, path);
1196                }
1197                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1198        } else if (!o_sha && !a_sha && !b_sha) {
1199                /*
1200                 * this entry was deleted altogether. a_mode == 0 means
1201                 * we had that path and want to actively remove it.
1202                 */
1203                remove_file(o, 1, path, !a_mode);
1204        } else
1205                die("Fatal merge failure, shouldn't happen.");
1206
1207        return clean_merge;
1208}
1209
1210int merge_trees(struct merge_options *o,
1211                struct tree *head,
1212                struct tree *merge,
1213                struct tree *common,
1214                struct tree **result)
1215{
1216        int code, clean;
1217
1218        if (o->subtree_shift) {
1219                merge = shift_tree_object(head, merge, o->subtree_shift);
1220                common = shift_tree_object(head, common, o->subtree_shift);
1221        }
1222
1223        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1224                output(o, 0, "Already uptodate!");
1225                *result = head;
1226                return 1;
1227        }
1228
1229        code = git_merge_trees(o->call_depth, common, head, merge);
1230
1231        if (code != 0) {
1232                if (show(o, 4) || o->call_depth)
1233                        die("merging of trees %s and %s failed",
1234                            sha1_to_hex(head->object.sha1),
1235                            sha1_to_hex(merge->object.sha1));
1236                else
1237                        exit(128);
1238        }
1239
1240        if (unmerged_cache()) {
1241                struct string_list *entries, *re_head, *re_merge;
1242                int i;
1243                string_list_clear(&o->current_file_set, 1);
1244                string_list_clear(&o->current_directory_set, 1);
1245                get_files_dirs(o, head);
1246                get_files_dirs(o, merge);
1247
1248                entries = get_unmerged();
1249                re_head  = get_renames(o, head, common, head, merge, entries);
1250                re_merge = get_renames(o, merge, common, head, merge, entries);
1251                clean = process_renames(o, re_head, re_merge);
1252                for (i = 0; i < entries->nr; i++) {
1253                        const char *path = entries->items[i].string;
1254                        struct stage_data *e = entries->items[i].util;
1255                        if (!e->processed
1256                                && !process_entry(o, path, e))
1257                                clean = 0;
1258                }
1259
1260                string_list_clear(re_merge, 0);
1261                string_list_clear(re_head, 0);
1262                string_list_clear(entries, 1);
1263
1264        }
1265        else
1266                clean = 1;
1267
1268        if (o->call_depth)
1269                *result = write_tree_from_memory(o);
1270
1271        return clean;
1272}
1273
1274static struct commit_list *reverse_commit_list(struct commit_list *list)
1275{
1276        struct commit_list *next = NULL, *current, *backup;
1277        for (current = list; current; current = backup) {
1278                backup = current->next;
1279                current->next = next;
1280                next = current;
1281        }
1282        return next;
1283}
1284
1285/*
1286 * Merge the commits h1 and h2, return the resulting virtual
1287 * commit object and a flag indicating the cleanness of the merge.
1288 */
1289int merge_recursive(struct merge_options *o,
1290                    struct commit *h1,
1291                    struct commit *h2,
1292                    struct commit_list *ca,
1293                    struct commit **result)
1294{
1295        struct commit_list *iter;
1296        struct commit *merged_common_ancestors;
1297        struct tree *mrtree = mrtree;
1298        int clean;
1299
1300        if (show(o, 4)) {
1301                output(o, 4, "Merging:");
1302                output_commit_title(o, h1);
1303                output_commit_title(o, h2);
1304        }
1305
1306        if (!ca) {
1307                ca = get_merge_bases(h1, h2, 1);
1308                ca = reverse_commit_list(ca);
1309        }
1310
1311        if (show(o, 5)) {
1312                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1313                for (iter = ca; iter; iter = iter->next)
1314                        output_commit_title(o, iter->item);
1315        }
1316
1317        merged_common_ancestors = pop_commit(&ca);
1318        if (merged_common_ancestors == NULL) {
1319                /* if there is no common ancestor, make an empty tree */
1320                struct tree *tree = xcalloc(1, sizeof(struct tree));
1321
1322                tree->object.parsed = 1;
1323                tree->object.type = OBJ_TREE;
1324                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1325                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1326        }
1327
1328        for (iter = ca; iter; iter = iter->next) {
1329                const char *saved_b1, *saved_b2;
1330                o->call_depth++;
1331                /*
1332                 * When the merge fails, the result contains files
1333                 * with conflict markers. The cleanness flag is
1334                 * ignored, it was never actually used, as result of
1335                 * merge_trees has always overwritten it: the committed
1336                 * "conflicts" were already resolved.
1337                 */
1338                discard_cache();
1339                saved_b1 = o->branch1;
1340                saved_b2 = o->branch2;
1341                o->branch1 = "Temporary merge branch 1";
1342                o->branch2 = "Temporary merge branch 2";
1343                merge_recursive(o, merged_common_ancestors, iter->item,
1344                                NULL, &merged_common_ancestors);
1345                o->branch1 = saved_b1;
1346                o->branch2 = saved_b2;
1347                o->call_depth--;
1348
1349                if (!merged_common_ancestors)
1350                        die("merge returned no commit");
1351        }
1352
1353        discard_cache();
1354        if (!o->call_depth)
1355                read_cache();
1356
1357        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1358                            &mrtree);
1359
1360        if (o->call_depth) {
1361                *result = make_virtual_commit(mrtree, "merged tree");
1362                commit_list_insert(h1, &(*result)->parents);
1363                commit_list_insert(h2, &(*result)->parents->next);
1364        }
1365        flush_output(o);
1366        return clean;
1367}
1368
1369static struct commit *get_ref(const unsigned char *sha1, const char *name)
1370{
1371        struct object *object;
1372
1373        object = deref_tag(parse_object(sha1), name, strlen(name));
1374        if (!object)
1375                return NULL;
1376        if (object->type == OBJ_TREE)
1377                return make_virtual_commit((struct tree*)object, name);
1378        if (object->type != OBJ_COMMIT)
1379                return NULL;
1380        if (parse_commit((struct commit *)object))
1381                return NULL;
1382        return (struct commit *)object;
1383}
1384
1385int merge_recursive_generic(struct merge_options *o,
1386                            const unsigned char *head,
1387                            const unsigned char *merge,
1388                            int num_base_list,
1389                            const unsigned char **base_list,
1390                            struct commit **result)
1391{
1392        int clean, index_fd;
1393        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1394        struct commit *head_commit = get_ref(head, o->branch1);
1395        struct commit *next_commit = get_ref(merge, o->branch2);
1396        struct commit_list *ca = NULL;
1397
1398        if (base_list) {
1399                int i;
1400                for (i = 0; i < num_base_list; ++i) {
1401                        struct commit *base;
1402                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1403                                return error("Could not parse object '%s'",
1404                                        sha1_to_hex(base_list[i]));
1405                        commit_list_insert(base, &ca);
1406                }
1407        }
1408
1409        index_fd = hold_locked_index(lock, 1);
1410        clean = merge_recursive(o, head_commit, next_commit, ca,
1411                        result);
1412        if (active_cache_changed &&
1413                        (write_cache(index_fd, active_cache, active_nr) ||
1414                         commit_locked_index(lock)))
1415                return error("Unable to write index.");
1416
1417        return clean ? 0 : 1;
1418}
1419
1420static int merge_recursive_config(const char *var, const char *value, void *cb)
1421{
1422        struct merge_options *o = cb;
1423        if (!strcasecmp(var, "merge.verbosity")) {
1424                o->verbosity = git_config_int(var, value);
1425                return 0;
1426        }
1427        if (!strcasecmp(var, "diff.renamelimit")) {
1428                o->diff_rename_limit = git_config_int(var, value);
1429                return 0;
1430        }
1431        if (!strcasecmp(var, "merge.renamelimit")) {
1432                o->merge_rename_limit = git_config_int(var, value);
1433                return 0;
1434        }
1435        return git_xmerge_config(var, value, cb);
1436}
1437
1438void init_merge_options(struct merge_options *o)
1439{
1440        memset(o, 0, sizeof(struct merge_options));
1441        o->verbosity = 2;
1442        o->buffer_output = 1;
1443        o->diff_rename_limit = -1;
1444        o->merge_rename_limit = -1;
1445        git_config(merge_recursive_config, o);
1446        if (getenv("GIT_MERGE_VERBOSITY"))
1447                o->verbosity =
1448                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1449        if (o->verbosity >= 5)
1450                o->buffer_output = 0;
1451        strbuf_init(&o->obuf, 0);
1452        memset(&o->current_file_set, 0, sizeof(struct string_list));
1453        o->current_file_set.strdup_strings = 1;
1454        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1455        o->current_directory_set.strdup_strings = 1;
1456}