builtin-merge-recursive.con commit Merge git://repo.or.cz/git-gui (1500f7b)
   1/*
   2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
   3 * Fredrik Kuivinen.
   4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
   5 */
   6#include "cache.h"
   7#include "cache-tree.h"
   8#include "commit.h"
   9#include "blob.h"
  10#include "builtin.h"
  11#include "tree-walk.h"
  12#include "diff.h"
  13#include "diffcore.h"
  14#include "tag.h"
  15#include "unpack-trees.h"
  16#include "string-list.h"
  17#include "xdiff-interface.h"
  18#include "ll-merge.h"
  19#include "interpolate.h"
  20#include "attr.h"
  21#include "merge-recursive.h"
  22
  23static int subtree_merge;
  24
  25static struct tree *shift_tree_object(struct tree *one, struct tree *two)
  26{
  27        unsigned char shifted[20];
  28
  29        /*
  30         * NEEDSWORK: this limits the recursion depth to hardcoded
  31         * value '2' to avoid excessive overhead.
  32         */
  33        shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
  34        if (!hashcmp(two->object.sha1, shifted))
  35                return two;
  36        return lookup_tree(shifted);
  37}
  38
  39/*
  40 * A virtual commit has
  41 * - (const char *)commit->util set to the name, and
  42 * - *(int *)commit->object.sha1 set to the virtual id.
  43 */
  44
  45static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  46{
  47        struct commit *commit = xcalloc(1, sizeof(struct commit));
  48        static unsigned virtual_id = 1;
  49        commit->tree = tree;
  50        commit->util = (void*)comment;
  51        *(int*)commit->object.sha1 = virtual_id++;
  52        /* avoid warnings */
  53        commit->object.parsed = 1;
  54        return commit;
  55}
  56
  57/*
  58 * Since we use get_tree_entry(), which does not put the read object into
  59 * the object pool, we cannot rely on a == b.
  60 */
  61static int sha_eq(const unsigned char *a, const unsigned char *b)
  62{
  63        if (!a && !b)
  64                return 2;
  65        return a && b && hashcmp(a, b) == 0;
  66}
  67
  68/*
  69 * Since we want to write the index eventually, we cannot reuse the index
  70 * for these (temporary) data.
  71 */
  72struct stage_data
  73{
  74        struct
  75        {
  76                unsigned mode;
  77                unsigned char sha[20];
  78        } stages[4];
  79        unsigned processed:1;
  80};
  81
  82static struct string_list current_file_set = {NULL, 0, 0, 1};
  83static struct string_list current_directory_set = {NULL, 0, 0, 1};
  84
  85static int call_depth = 0;
  86static int verbosity = 2;
  87static int diff_rename_limit = -1;
  88static int merge_rename_limit = -1;
  89static int buffer_output = 1;
  90static struct strbuf obuf = STRBUF_INIT;
  91
  92static int show(int v)
  93{
  94        return (!call_depth && verbosity >= v) || verbosity >= 5;
  95}
  96
  97static void flush_output(void)
  98{
  99        if (obuf.len) {
 100                fputs(obuf.buf, stdout);
 101                strbuf_reset(&obuf);
 102        }
 103}
 104
 105static void output(int v, const char *fmt, ...)
 106{
 107        int len;
 108        va_list ap;
 109
 110        if (!show(v))
 111                return;
 112
 113        strbuf_grow(&obuf, call_depth * 2 + 2);
 114        memset(obuf.buf + obuf.len, ' ', call_depth * 2);
 115        strbuf_setlen(&obuf, obuf.len + call_depth * 2);
 116
 117        va_start(ap, fmt);
 118        len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
 119        va_end(ap);
 120
 121        if (len < 0)
 122                len = 0;
 123        if (len >= strbuf_avail(&obuf)) {
 124                strbuf_grow(&obuf, len + 2);
 125                va_start(ap, fmt);
 126                len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
 127                va_end(ap);
 128                if (len >= strbuf_avail(&obuf)) {
 129                        die("this should not happen, your snprintf is broken");
 130                }
 131        }
 132        strbuf_setlen(&obuf, obuf.len + len);
 133        strbuf_add(&obuf, "\n", 1);
 134        if (!buffer_output)
 135                flush_output();
 136}
 137
 138static void output_commit_title(struct commit *commit)
 139{
 140        int i;
 141        flush_output();
 142        for (i = call_depth; i--;)
 143                fputs("  ", stdout);
 144        if (commit->util)
 145                printf("virtual %s\n", (char *)commit->util);
 146        else {
 147                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 148                if (parse_commit(commit) != 0)
 149                        printf("(bad commit)\n");
 150                else {
 151                        const char *s;
 152                        int len;
 153                        for (s = commit->buffer; *s; s++)
 154                                if (*s == '\n' && s[1] == '\n') {
 155                                        s += 2;
 156                                        break;
 157                                }
 158                        for (len = 0; s[len] && '\n' != s[len]; len++)
 159                                ; /* do nothing */
 160                        printf("%.*s\n", len, s);
 161                }
 162        }
 163}
 164
 165static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 166                const char *path, int stage, int refresh, int options)
 167{
 168        struct cache_entry *ce;
 169        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 170        if (!ce)
 171                return error("addinfo_cache failed for path '%s'", path);
 172        return add_cache_entry(ce, options);
 173}
 174
 175/*
 176 * This is a global variable which is used in a number of places but
 177 * only written to in the 'merge' function.
 178 *
 179 * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
 180 *                       don't update the working directory.
 181 *               0    => Leave unmerged entries in the cache and update
 182 *                       the working directory.
 183 */
 184static int index_only = 0;
 185
 186static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 187{
 188        parse_tree(tree);
 189        init_tree_desc(desc, tree->buffer, tree->size);
 190}
 191
 192static int git_merge_trees(int index_only,
 193                           struct tree *common,
 194                           struct tree *head,
 195                           struct tree *merge)
 196{
 197        int rc;
 198        struct tree_desc t[3];
 199        struct unpack_trees_options opts;
 200
 201        memset(&opts, 0, sizeof(opts));
 202        if (index_only)
 203                opts.index_only = 1;
 204        else
 205                opts.update = 1;
 206        opts.merge = 1;
 207        opts.head_idx = 2;
 208        opts.fn = threeway_merge;
 209        opts.src_index = &the_index;
 210        opts.dst_index = &the_index;
 211
 212        init_tree_desc_from_tree(t+0, common);
 213        init_tree_desc_from_tree(t+1, head);
 214        init_tree_desc_from_tree(t+2, merge);
 215
 216        rc = unpack_trees(3, t, &opts);
 217        cache_tree_free(&active_cache_tree);
 218        return rc;
 219}
 220
 221struct tree *write_tree_from_memory(void)
 222{
 223        struct tree *result = NULL;
 224
 225        if (unmerged_cache()) {
 226                int i;
 227                output(0, "There are unmerged index entries:");
 228                for (i = 0; i < active_nr; i++) {
 229                        struct cache_entry *ce = active_cache[i];
 230                        if (ce_stage(ce))
 231                                output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
 232                }
 233                return NULL;
 234        }
 235
 236        if (!active_cache_tree)
 237                active_cache_tree = cache_tree();
 238
 239        if (!cache_tree_fully_valid(active_cache_tree) &&
 240            cache_tree_update(active_cache_tree,
 241                              active_cache, active_nr, 0, 0) < 0)
 242                die("error building trees");
 243
 244        result = lookup_tree(active_cache_tree->sha1);
 245
 246        return result;
 247}
 248
 249static int save_files_dirs(const unsigned char *sha1,
 250                const char *base, int baselen, const char *path,
 251                unsigned int mode, int stage, void *context)
 252{
 253        int len = strlen(path);
 254        char *newpath = xmalloc(baselen + len + 1);
 255        memcpy(newpath, base, baselen);
 256        memcpy(newpath + baselen, path, len);
 257        newpath[baselen + len] = '\0';
 258
 259        if (S_ISDIR(mode))
 260                string_list_insert(newpath, &current_directory_set);
 261        else
 262                string_list_insert(newpath, &current_file_set);
 263        free(newpath);
 264
 265        return READ_TREE_RECURSIVE;
 266}
 267
 268static int get_files_dirs(struct tree *tree)
 269{
 270        int n;
 271        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, NULL))
 272                return 0;
 273        n = current_file_set.nr + current_directory_set.nr;
 274        return n;
 275}
 276
 277/*
 278 * Returns an index_entry instance which doesn't have to correspond to
 279 * a real cache entry in Git's index.
 280 */
 281static struct stage_data *insert_stage_data(const char *path,
 282                struct tree *o, struct tree *a, struct tree *b,
 283                struct string_list *entries)
 284{
 285        struct string_list_item *item;
 286        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 287        get_tree_entry(o->object.sha1, path,
 288                        e->stages[1].sha, &e->stages[1].mode);
 289        get_tree_entry(a->object.sha1, path,
 290                        e->stages[2].sha, &e->stages[2].mode);
 291        get_tree_entry(b->object.sha1, path,
 292                        e->stages[3].sha, &e->stages[3].mode);
 293        item = string_list_insert(path, entries);
 294        item->util = e;
 295        return e;
 296}
 297
 298/*
 299 * Create a dictionary mapping file names to stage_data objects. The
 300 * dictionary contains one entry for every path with a non-zero stage entry.
 301 */
 302static struct string_list *get_unmerged(void)
 303{
 304        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 305        int i;
 306
 307        unmerged->strdup_strings = 1;
 308
 309        for (i = 0; i < active_nr; i++) {
 310                struct string_list_item *item;
 311                struct stage_data *e;
 312                struct cache_entry *ce = active_cache[i];
 313                if (!ce_stage(ce))
 314                        continue;
 315
 316                item = string_list_lookup(ce->name, unmerged);
 317                if (!item) {
 318                        item = string_list_insert(ce->name, unmerged);
 319                        item->util = xcalloc(1, sizeof(struct stage_data));
 320                }
 321                e = item->util;
 322                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 323                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 324        }
 325
 326        return unmerged;
 327}
 328
 329struct rename
 330{
 331        struct diff_filepair *pair;
 332        struct stage_data *src_entry;
 333        struct stage_data *dst_entry;
 334        unsigned processed:1;
 335};
 336
 337/*
 338 * Get information of all renames which occurred between 'o_tree' and
 339 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 340 * 'b_tree') to be able to associate the correct cache entries with
 341 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 342 */
 343static struct string_list *get_renames(struct tree *tree,
 344                                        struct tree *o_tree,
 345                                        struct tree *a_tree,
 346                                        struct tree *b_tree,
 347                                        struct string_list *entries)
 348{
 349        int i;
 350        struct string_list *renames;
 351        struct diff_options opts;
 352
 353        renames = xcalloc(1, sizeof(struct string_list));
 354        diff_setup(&opts);
 355        DIFF_OPT_SET(&opts, RECURSIVE);
 356        opts.detect_rename = DIFF_DETECT_RENAME;
 357        opts.rename_limit = merge_rename_limit >= 0 ? merge_rename_limit :
 358                            diff_rename_limit >= 0 ? diff_rename_limit :
 359                            500;
 360        opts.warn_on_too_large_rename = 1;
 361        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 362        if (diff_setup_done(&opts) < 0)
 363                die("diff setup failed");
 364        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 365        diffcore_std(&opts);
 366        for (i = 0; i < diff_queued_diff.nr; ++i) {
 367                struct string_list_item *item;
 368                struct rename *re;
 369                struct diff_filepair *pair = diff_queued_diff.queue[i];
 370                if (pair->status != 'R') {
 371                        diff_free_filepair(pair);
 372                        continue;
 373                }
 374                re = xmalloc(sizeof(*re));
 375                re->processed = 0;
 376                re->pair = pair;
 377                item = string_list_lookup(re->pair->one->path, entries);
 378                if (!item)
 379                        re->src_entry = insert_stage_data(re->pair->one->path,
 380                                        o_tree, a_tree, b_tree, entries);
 381                else
 382                        re->src_entry = item->util;
 383
 384                item = string_list_lookup(re->pair->two->path, entries);
 385                if (!item)
 386                        re->dst_entry = insert_stage_data(re->pair->two->path,
 387                                        o_tree, a_tree, b_tree, entries);
 388                else
 389                        re->dst_entry = item->util;
 390                item = string_list_insert(pair->one->path, renames);
 391                item->util = re;
 392        }
 393        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 394        diff_queued_diff.nr = 0;
 395        diff_flush(&opts);
 396        return renames;
 397}
 398
 399static int update_stages(const char *path, struct diff_filespec *o,
 400                         struct diff_filespec *a, struct diff_filespec *b,
 401                         int clear)
 402{
 403        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 404        if (clear)
 405                if (remove_file_from_cache(path))
 406                        return -1;
 407        if (o)
 408                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 409                        return -1;
 410        if (a)
 411                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 412                        return -1;
 413        if (b)
 414                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 415                        return -1;
 416        return 0;
 417}
 418
 419static int remove_path(const char *name)
 420{
 421        int ret;
 422        char *slash, *dirs;
 423
 424        ret = unlink(name);
 425        if (ret)
 426                return ret;
 427        dirs = xstrdup(name);
 428        while ((slash = strrchr(name, '/'))) {
 429                *slash = '\0';
 430                if (rmdir(name) != 0)
 431                        break;
 432        }
 433        free(dirs);
 434        return ret;
 435}
 436
 437static int remove_file(int clean, const char *path, int no_wd)
 438{
 439        int update_cache = index_only || clean;
 440        int update_working_directory = !index_only && !no_wd;
 441
 442        if (update_cache) {
 443                if (remove_file_from_cache(path))
 444                        return -1;
 445        }
 446        if (update_working_directory) {
 447                unlink(path);
 448                if (errno != ENOENT || errno != EISDIR)
 449                        return -1;
 450                remove_path(path);
 451        }
 452        return 0;
 453}
 454
 455static char *unique_path(const char *path, const char *branch)
 456{
 457        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 458        int suffix = 0;
 459        struct stat st;
 460        char *p = newpath + strlen(path);
 461        strcpy(newpath, path);
 462        *(p++) = '~';
 463        strcpy(p, branch);
 464        for (; *p; ++p)
 465                if ('/' == *p)
 466                        *p = '_';
 467        while (string_list_has_string(&current_file_set, newpath) ||
 468               string_list_has_string(&current_directory_set, newpath) ||
 469               lstat(newpath, &st) == 0)
 470                sprintf(p, "_%d", suffix++);
 471
 472        string_list_insert(newpath, &current_file_set);
 473        return newpath;
 474}
 475
 476static void flush_buffer(int fd, const char *buf, unsigned long size)
 477{
 478        while (size > 0) {
 479                long ret = write_in_full(fd, buf, size);
 480                if (ret < 0) {
 481                        /* Ignore epipe */
 482                        if (errno == EPIPE)
 483                                break;
 484                        die("merge-recursive: %s", strerror(errno));
 485                } else if (!ret) {
 486                        die("merge-recursive: disk full?");
 487                }
 488                size -= ret;
 489                buf += ret;
 490        }
 491}
 492
 493static int make_room_for_path(const char *path)
 494{
 495        int status;
 496        const char *msg = "failed to create path '%s'%s";
 497
 498        status = safe_create_leading_directories_const(path);
 499        if (status) {
 500                if (status == -3) {
 501                        /* something else exists */
 502                        error(msg, path, ": perhaps a D/F conflict?");
 503                        return -1;
 504                }
 505                die(msg, path, "");
 506        }
 507
 508        /* Successful unlink is good.. */
 509        if (!unlink(path))
 510                return 0;
 511        /* .. and so is no existing file */
 512        if (errno == ENOENT)
 513                return 0;
 514        /* .. but not some other error (who really cares what?) */
 515        return error(msg, path, ": perhaps a D/F conflict?");
 516}
 517
 518static void update_file_flags(const unsigned char *sha,
 519                              unsigned mode,
 520                              const char *path,
 521                              int update_cache,
 522                              int update_wd)
 523{
 524        if (index_only)
 525                update_wd = 0;
 526
 527        if (update_wd) {
 528                enum object_type type;
 529                void *buf;
 530                unsigned long size;
 531
 532                if (S_ISGITLINK(mode))
 533                        die("cannot read object %s '%s': It is a submodule!",
 534                            sha1_to_hex(sha), path);
 535
 536                buf = read_sha1_file(sha, &type, &size);
 537                if (!buf)
 538                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 539                if (type != OBJ_BLOB)
 540                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 541                if (S_ISREG(mode)) {
 542                        struct strbuf strbuf;
 543                        strbuf_init(&strbuf, 0);
 544                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 545                                free(buf);
 546                                size = strbuf.len;
 547                                buf = strbuf_detach(&strbuf, NULL);
 548                        }
 549                }
 550
 551                if (make_room_for_path(path) < 0) {
 552                        update_wd = 0;
 553                        free(buf);
 554                        goto update_index;
 555                }
 556                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 557                        int fd;
 558                        if (mode & 0100)
 559                                mode = 0777;
 560                        else
 561                                mode = 0666;
 562                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 563                        if (fd < 0)
 564                                die("failed to open %s: %s", path, strerror(errno));
 565                        flush_buffer(fd, buf, size);
 566                        close(fd);
 567                } else if (S_ISLNK(mode)) {
 568                        char *lnk = xmemdupz(buf, size);
 569                        safe_create_leading_directories_const(path);
 570                        unlink(path);
 571                        symlink(lnk, path);
 572                        free(lnk);
 573                } else
 574                        die("do not know what to do with %06o %s '%s'",
 575                            mode, sha1_to_hex(sha), path);
 576                free(buf);
 577        }
 578 update_index:
 579        if (update_cache)
 580                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 581}
 582
 583static void update_file(int clean,
 584                        const unsigned char *sha,
 585                        unsigned mode,
 586                        const char *path)
 587{
 588        update_file_flags(sha, mode, path, index_only || clean, !index_only);
 589}
 590
 591/* Low level file merging, update and removal */
 592
 593struct merge_file_info
 594{
 595        unsigned char sha[20];
 596        unsigned mode;
 597        unsigned clean:1,
 598                 merge:1;
 599};
 600
 601static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
 602{
 603        unsigned long size;
 604        enum object_type type;
 605
 606        if (!hashcmp(sha1, null_sha1)) {
 607                mm->ptr = xstrdup("");
 608                mm->size = 0;
 609                return;
 610        }
 611
 612        mm->ptr = read_sha1_file(sha1, &type, &size);
 613        if (!mm->ptr || type != OBJ_BLOB)
 614                die("unable to read blob object %s", sha1_to_hex(sha1));
 615        mm->size = size;
 616}
 617
 618static int merge_3way(mmbuffer_t *result_buf,
 619                      struct diff_filespec *o,
 620                      struct diff_filespec *a,
 621                      struct diff_filespec *b,
 622                      const char *branch1,
 623                      const char *branch2)
 624{
 625        mmfile_t orig, src1, src2;
 626        char *name1, *name2;
 627        int merge_status;
 628
 629        name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 630        name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 631
 632        fill_mm(o->sha1, &orig);
 633        fill_mm(a->sha1, &src1);
 634        fill_mm(b->sha1, &src2);
 635
 636        merge_status = ll_merge(result_buf, a->path, &orig,
 637                                &src1, name1, &src2, name2,
 638                                index_only);
 639
 640        free(name1);
 641        free(name2);
 642        free(orig.ptr);
 643        free(src1.ptr);
 644        free(src2.ptr);
 645        return merge_status;
 646}
 647
 648static struct merge_file_info merge_file(struct diff_filespec *o,
 649                struct diff_filespec *a, struct diff_filespec *b,
 650                const char *branch1, const char *branch2)
 651{
 652        struct merge_file_info result;
 653        result.merge = 0;
 654        result.clean = 1;
 655
 656        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 657                result.clean = 0;
 658                if (S_ISREG(a->mode)) {
 659                        result.mode = a->mode;
 660                        hashcpy(result.sha, a->sha1);
 661                } else {
 662                        result.mode = b->mode;
 663                        hashcpy(result.sha, b->sha1);
 664                }
 665        } else {
 666                if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
 667                        result.merge = 1;
 668
 669                /*
 670                 * Merge modes
 671                 */
 672                if (a->mode == b->mode || a->mode == o->mode)
 673                        result.mode = b->mode;
 674                else {
 675                        result.mode = a->mode;
 676                        if (b->mode != o->mode) {
 677                                result.clean = 0;
 678                                result.merge = 1;
 679                        }
 680                }
 681
 682                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, o->sha1))
 683                        hashcpy(result.sha, b->sha1);
 684                else if (sha_eq(b->sha1, o->sha1))
 685                        hashcpy(result.sha, a->sha1);
 686                else if (S_ISREG(a->mode)) {
 687                        mmbuffer_t result_buf;
 688                        int merge_status;
 689
 690                        merge_status = merge_3way(&result_buf, o, a, b,
 691                                                  branch1, branch2);
 692
 693                        if ((merge_status < 0) || !result_buf.ptr)
 694                                die("Failed to execute internal merge");
 695
 696                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 697                                            blob_type, result.sha))
 698                                die("Unable to add %s to database",
 699                                    a->path);
 700
 701                        free(result_buf.ptr);
 702                        result.clean = (merge_status == 0);
 703                } else if (S_ISGITLINK(a->mode)) {
 704                        result.clean = 0;
 705                        hashcpy(result.sha, a->sha1);
 706                } else if (S_ISLNK(a->mode)) {
 707                        hashcpy(result.sha, a->sha1);
 708
 709                        if (!sha_eq(a->sha1, b->sha1))
 710                                result.clean = 0;
 711                } else {
 712                        die("unsupported object type in the tree");
 713                }
 714        }
 715
 716        return result;
 717}
 718
 719static void conflict_rename_rename(struct rename *ren1,
 720                                   const char *branch1,
 721                                   struct rename *ren2,
 722                                   const char *branch2)
 723{
 724        char *del[2];
 725        int delp = 0;
 726        const char *ren1_dst = ren1->pair->two->path;
 727        const char *ren2_dst = ren2->pair->two->path;
 728        const char *dst_name1 = ren1_dst;
 729        const char *dst_name2 = ren2_dst;
 730        if (string_list_has_string(&current_directory_set, ren1_dst)) {
 731                dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
 732                output(1, "%s is a directory in %s adding as %s instead",
 733                       ren1_dst, branch2, dst_name1);
 734                remove_file(0, ren1_dst, 0);
 735        }
 736        if (string_list_has_string(&current_directory_set, ren2_dst)) {
 737                dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
 738                output(1, "%s is a directory in %s adding as %s instead",
 739                       ren2_dst, branch1, dst_name2);
 740                remove_file(0, ren2_dst, 0);
 741        }
 742        if (index_only) {
 743                remove_file_from_cache(dst_name1);
 744                remove_file_from_cache(dst_name2);
 745                /*
 746                 * Uncomment to leave the conflicting names in the resulting tree
 747                 *
 748                 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
 749                 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
 750                 */
 751        } else {
 752                update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
 753                update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
 754        }
 755        while (delp--)
 756                free(del[delp]);
 757}
 758
 759static void conflict_rename_dir(struct rename *ren1,
 760                                const char *branch1)
 761{
 762        char *new_path = unique_path(ren1->pair->two->path, branch1);
 763        output(1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
 764        remove_file(0, ren1->pair->two->path, 0);
 765        update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 766        free(new_path);
 767}
 768
 769static void conflict_rename_rename_2(struct rename *ren1,
 770                                     const char *branch1,
 771                                     struct rename *ren2,
 772                                     const char *branch2)
 773{
 774        char *new_path1 = unique_path(ren1->pair->two->path, branch1);
 775        char *new_path2 = unique_path(ren2->pair->two->path, branch2);
 776        output(1, "Renaming %s to %s and %s to %s instead",
 777               ren1->pair->one->path, new_path1,
 778               ren2->pair->one->path, new_path2);
 779        remove_file(0, ren1->pair->two->path, 0);
 780        update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 781        update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 782        free(new_path2);
 783        free(new_path1);
 784}
 785
 786static int process_renames(struct string_list *a_renames,
 787                           struct string_list *b_renames,
 788                           const char *a_branch,
 789                           const char *b_branch)
 790{
 791        int clean_merge = 1, i, j;
 792        struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
 793        const struct rename *sre;
 794
 795        for (i = 0; i < a_renames->nr; i++) {
 796                sre = a_renames->items[i].util;
 797                string_list_insert(sre->pair->two->path, &a_by_dst)->util
 798                        = sre->dst_entry;
 799        }
 800        for (i = 0; i < b_renames->nr; i++) {
 801                sre = b_renames->items[i].util;
 802                string_list_insert(sre->pair->two->path, &b_by_dst)->util
 803                        = sre->dst_entry;
 804        }
 805
 806        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 807                int compare;
 808                char *src;
 809                struct string_list *renames1, *renames2, *renames2Dst;
 810                struct rename *ren1 = NULL, *ren2 = NULL;
 811                const char *branch1, *branch2;
 812                const char *ren1_src, *ren1_dst;
 813
 814                if (i >= a_renames->nr) {
 815                        compare = 1;
 816                        ren2 = b_renames->items[j++].util;
 817                } else if (j >= b_renames->nr) {
 818                        compare = -1;
 819                        ren1 = a_renames->items[i++].util;
 820                } else {
 821                        compare = strcmp(a_renames->items[i].string,
 822                                        b_renames->items[j].string);
 823                        if (compare <= 0)
 824                                ren1 = a_renames->items[i++].util;
 825                        if (compare >= 0)
 826                                ren2 = b_renames->items[j++].util;
 827                }
 828
 829                /* TODO: refactor, so that 1/2 are not needed */
 830                if (ren1) {
 831                        renames1 = a_renames;
 832                        renames2 = b_renames;
 833                        renames2Dst = &b_by_dst;
 834                        branch1 = a_branch;
 835                        branch2 = b_branch;
 836                } else {
 837                        struct rename *tmp;
 838                        renames1 = b_renames;
 839                        renames2 = a_renames;
 840                        renames2Dst = &a_by_dst;
 841                        branch1 = b_branch;
 842                        branch2 = a_branch;
 843                        tmp = ren2;
 844                        ren2 = ren1;
 845                        ren1 = tmp;
 846                }
 847                src = ren1->pair->one->path;
 848
 849                ren1->dst_entry->processed = 1;
 850                ren1->src_entry->processed = 1;
 851
 852                if (ren1->processed)
 853                        continue;
 854                ren1->processed = 1;
 855
 856                ren1_src = ren1->pair->one->path;
 857                ren1_dst = ren1->pair->two->path;
 858
 859                if (ren2) {
 860                        const char *ren2_src = ren2->pair->one->path;
 861                        const char *ren2_dst = ren2->pair->two->path;
 862                        /* Renamed in 1 and renamed in 2 */
 863                        if (strcmp(ren1_src, ren2_src) != 0)
 864                                die("ren1.src != ren2.src");
 865                        ren2->dst_entry->processed = 1;
 866                        ren2->processed = 1;
 867                        if (strcmp(ren1_dst, ren2_dst) != 0) {
 868                                clean_merge = 0;
 869                                output(1, "CONFLICT (rename/rename): "
 870                                       "Rename \"%s\"->\"%s\" in branch \"%s\" "
 871                                       "rename \"%s\"->\"%s\" in \"%s\"%s",
 872                                       src, ren1_dst, branch1,
 873                                       src, ren2_dst, branch2,
 874                                       index_only ? " (left unresolved)": "");
 875                                if (index_only) {
 876                                        remove_file_from_cache(src);
 877                                        update_file(0, ren1->pair->one->sha1,
 878                                                    ren1->pair->one->mode, src);
 879                                }
 880                                conflict_rename_rename(ren1, branch1, ren2, branch2);
 881                        } else {
 882                                struct merge_file_info mfi;
 883                                remove_file(1, ren1_src, 1);
 884                                mfi = merge_file(ren1->pair->one,
 885                                                 ren1->pair->two,
 886                                                 ren2->pair->two,
 887                                                 branch1,
 888                                                 branch2);
 889                                if (mfi.merge || !mfi.clean)
 890                                        output(1, "Renaming %s->%s", src, ren1_dst);
 891
 892                                if (mfi.merge)
 893                                        output(2, "Auto-merging %s", ren1_dst);
 894
 895                                if (!mfi.clean) {
 896                                        output(1, "CONFLICT (content): merge conflict in %s",
 897                                               ren1_dst);
 898                                        clean_merge = 0;
 899
 900                                        if (!index_only)
 901                                                update_stages(ren1_dst,
 902                                                              ren1->pair->one,
 903                                                              ren1->pair->two,
 904                                                              ren2->pair->two,
 905                                                              1 /* clear */);
 906                                }
 907                                update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 908                        }
 909                } else {
 910                        /* Renamed in 1, maybe changed in 2 */
 911                        struct string_list_item *item;
 912                        /* we only use sha1 and mode of these */
 913                        struct diff_filespec src_other, dst_other;
 914                        int try_merge, stage = a_renames == renames1 ? 3: 2;
 915
 916                        remove_file(1, ren1_src, index_only || stage == 3);
 917
 918                        hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
 919                        src_other.mode = ren1->src_entry->stages[stage].mode;
 920                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
 921                        dst_other.mode = ren1->dst_entry->stages[stage].mode;
 922
 923                        try_merge = 0;
 924
 925                        if (string_list_has_string(&current_directory_set, ren1_dst)) {
 926                                clean_merge = 0;
 927                                output(1, "CONFLICT (rename/directory): Rename %s->%s in %s "
 928                                       " directory %s added in %s",
 929                                       ren1_src, ren1_dst, branch1,
 930                                       ren1_dst, branch2);
 931                                conflict_rename_dir(ren1, branch1);
 932                        } else if (sha_eq(src_other.sha1, null_sha1)) {
 933                                clean_merge = 0;
 934                                output(1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 935                                       "and deleted in %s",
 936                                       ren1_src, ren1_dst, branch1,
 937                                       branch2);
 938                                update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 939                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
 940                                const char *new_path;
 941                                clean_merge = 0;
 942                                try_merge = 1;
 943                                output(1, "CONFLICT (rename/add): Rename %s->%s in %s. "
 944                                       "%s added in %s",
 945                                       ren1_src, ren1_dst, branch1,
 946                                       ren1_dst, branch2);
 947                                new_path = unique_path(ren1_dst, branch2);
 948                                output(1, "Adding as %s instead", new_path);
 949                                update_file(0, dst_other.sha1, dst_other.mode, new_path);
 950                        } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
 951                                ren2 = item->util;
 952                                clean_merge = 0;
 953                                ren2->processed = 1;
 954                                output(1, "CONFLICT (rename/rename): Rename %s->%s in %s. "
 955                                       "Rename %s->%s in %s",
 956                                       ren1_src, ren1_dst, branch1,
 957                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
 958                                conflict_rename_rename_2(ren1, branch1, ren2, branch2);
 959                        } else
 960                                try_merge = 1;
 961
 962                        if (try_merge) {
 963                                struct diff_filespec *o, *a, *b;
 964                                struct merge_file_info mfi;
 965                                src_other.path = (char *)ren1_src;
 966
 967                                o = ren1->pair->one;
 968                                if (a_renames == renames1) {
 969                                        a = ren1->pair->two;
 970                                        b = &src_other;
 971                                } else {
 972                                        b = ren1->pair->two;
 973                                        a = &src_other;
 974                                }
 975                                mfi = merge_file(o, a, b,
 976                                                a_branch, b_branch);
 977
 978                                if (mfi.clean &&
 979                                    sha_eq(mfi.sha, ren1->pair->two->sha1) &&
 980                                    mfi.mode == ren1->pair->two->mode)
 981                                        /*
 982                                         * This messaged is part of
 983                                         * t6022 test. If you change
 984                                         * it update the test too.
 985                                         */
 986                                        output(3, "Skipped %s (merged same as existing)", ren1_dst);
 987                                else {
 988                                        if (mfi.merge || !mfi.clean)
 989                                                output(1, "Renaming %s => %s", ren1_src, ren1_dst);
 990                                        if (mfi.merge)
 991                                                output(2, "Auto-merging %s", ren1_dst);
 992                                        if (!mfi.clean) {
 993                                                output(1, "CONFLICT (rename/modify): Merge conflict in %s",
 994                                                       ren1_dst);
 995                                                clean_merge = 0;
 996
 997                                                if (!index_only)
 998                                                        update_stages(ren1_dst,
 999                                                                      o, a, b, 1);
1000                                        }
1001                                        update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1002                                }
1003                        }
1004                }
1005        }
1006        string_list_clear(&a_by_dst, 0);
1007        string_list_clear(&b_by_dst, 0);
1008
1009        return clean_merge;
1010}
1011
1012static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1013{
1014        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1015}
1016
1017/* Per entry merge function */
1018static int process_entry(const char *path, struct stage_data *entry,
1019                         const char *branch1,
1020                         const char *branch2)
1021{
1022        /*
1023        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1024        print_index_entry("\tpath: ", entry);
1025        */
1026        int clean_merge = 1;
1027        unsigned o_mode = entry->stages[1].mode;
1028        unsigned a_mode = entry->stages[2].mode;
1029        unsigned b_mode = entry->stages[3].mode;
1030        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1031        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1032        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1033
1034        if (o_sha && (!a_sha || !b_sha)) {
1035                /* Case A: Deleted in one */
1036                if ((!a_sha && !b_sha) ||
1037                    (sha_eq(a_sha, o_sha) && !b_sha) ||
1038                    (!a_sha && sha_eq(b_sha, o_sha))) {
1039                        /* Deleted in both or deleted in one and
1040                         * unchanged in the other */
1041                        if (a_sha)
1042                                output(2, "Removing %s", path);
1043                        /* do not touch working file if it did not exist */
1044                        remove_file(1, path, !a_sha);
1045                } else {
1046                        /* Deleted in one and changed in the other */
1047                        clean_merge = 0;
1048                        if (!a_sha) {
1049                                output(1, "CONFLICT (delete/modify): %s deleted in %s "
1050                                       "and modified in %s. Version %s of %s left in tree.",
1051                                       path, branch1,
1052                                       branch2, branch2, path);
1053                                update_file(0, b_sha, b_mode, path);
1054                        } else {
1055                                output(1, "CONFLICT (delete/modify): %s deleted in %s "
1056                                       "and modified in %s. Version %s of %s left in tree.",
1057                                       path, branch2,
1058                                       branch1, branch1, path);
1059                                update_file(0, a_sha, a_mode, path);
1060                        }
1061                }
1062
1063        } else if ((!o_sha && a_sha && !b_sha) ||
1064                   (!o_sha && !a_sha && b_sha)) {
1065                /* Case B: Added in one. */
1066                const char *add_branch;
1067                const char *other_branch;
1068                unsigned mode;
1069                const unsigned char *sha;
1070                const char *conf;
1071
1072                if (a_sha) {
1073                        add_branch = branch1;
1074                        other_branch = branch2;
1075                        mode = a_mode;
1076                        sha = a_sha;
1077                        conf = "file/directory";
1078                } else {
1079                        add_branch = branch2;
1080                        other_branch = branch1;
1081                        mode = b_mode;
1082                        sha = b_sha;
1083                        conf = "directory/file";
1084                }
1085                if (string_list_has_string(&current_directory_set, path)) {
1086                        const char *new_path = unique_path(path, add_branch);
1087                        clean_merge = 0;
1088                        output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1089                               "Adding %s as %s",
1090                               conf, path, other_branch, path, new_path);
1091                        remove_file(0, path, 0);
1092                        update_file(0, sha, mode, new_path);
1093                } else {
1094                        output(2, "Adding %s", path);
1095                        update_file(1, sha, mode, path);
1096                }
1097        } else if (a_sha && b_sha) {
1098                /* Case C: Added in both (check for same permissions) and */
1099                /* case D: Modified in both, but differently. */
1100                const char *reason = "content";
1101                struct merge_file_info mfi;
1102                struct diff_filespec o, a, b;
1103
1104                if (!o_sha) {
1105                        reason = "add/add";
1106                        o_sha = (unsigned char *)null_sha1;
1107                }
1108                output(2, "Auto-merging %s", path);
1109                o.path = a.path = b.path = (char *)path;
1110                hashcpy(o.sha1, o_sha);
1111                o.mode = o_mode;
1112                hashcpy(a.sha1, a_sha);
1113                a.mode = a_mode;
1114                hashcpy(b.sha1, b_sha);
1115                b.mode = b_mode;
1116
1117                mfi = merge_file(&o, &a, &b,
1118                                 branch1, branch2);
1119
1120                clean_merge = mfi.clean;
1121                if (mfi.clean)
1122                        update_file(1, mfi.sha, mfi.mode, path);
1123                else if (S_ISGITLINK(mfi.mode))
1124                        output(1, "CONFLICT (submodule): Merge conflict in %s "
1125                               "- needs %s", path, sha1_to_hex(b.sha1));
1126                else {
1127                        output(1, "CONFLICT (%s): Merge conflict in %s",
1128                                        reason, path);
1129
1130                        if (index_only)
1131                                update_file(0, mfi.sha, mfi.mode, path);
1132                        else
1133                                update_file_flags(mfi.sha, mfi.mode, path,
1134                                              0 /* update_cache */, 1 /* update_working_directory */);
1135                }
1136        } else if (!o_sha && !a_sha && !b_sha) {
1137                /*
1138                 * this entry was deleted altogether. a_mode == 0 means
1139                 * we had that path and want to actively remove it.
1140                 */
1141                remove_file(1, path, !a_mode);
1142        } else
1143                die("Fatal merge failure, shouldn't happen.");
1144
1145        return clean_merge;
1146}
1147
1148int merge_trees(struct tree *head,
1149                struct tree *merge,
1150                struct tree *common,
1151                const char *branch1,
1152                const char *branch2,
1153                struct tree **result)
1154{
1155        int code, clean;
1156
1157        if (subtree_merge) {
1158                merge = shift_tree_object(head, merge);
1159                common = shift_tree_object(head, common);
1160        }
1161
1162        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1163                output(0, "Already uptodate!");
1164                *result = head;
1165                return 1;
1166        }
1167
1168        code = git_merge_trees(index_only, common, head, merge);
1169
1170        if (code != 0)
1171                die("merging of trees %s and %s failed",
1172                    sha1_to_hex(head->object.sha1),
1173                    sha1_to_hex(merge->object.sha1));
1174
1175        if (unmerged_cache()) {
1176                struct string_list *entries, *re_head, *re_merge;
1177                int i;
1178                string_list_clear(&current_file_set, 1);
1179                string_list_clear(&current_directory_set, 1);
1180                get_files_dirs(head);
1181                get_files_dirs(merge);
1182
1183                entries = get_unmerged();
1184                re_head  = get_renames(head, common, head, merge, entries);
1185                re_merge = get_renames(merge, common, head, merge, entries);
1186                clean = process_renames(re_head, re_merge,
1187                                branch1, branch2);
1188                for (i = 0; i < entries->nr; i++) {
1189                        const char *path = entries->items[i].string;
1190                        struct stage_data *e = entries->items[i].util;
1191                        if (!e->processed
1192                                && !process_entry(path, e, branch1, branch2))
1193                                clean = 0;
1194                }
1195
1196                string_list_clear(re_merge, 0);
1197                string_list_clear(re_head, 0);
1198                string_list_clear(entries, 1);
1199
1200        }
1201        else
1202                clean = 1;
1203
1204        if (index_only)
1205                *result = write_tree_from_memory();
1206
1207        return clean;
1208}
1209
1210static struct commit_list *reverse_commit_list(struct commit_list *list)
1211{
1212        struct commit_list *next = NULL, *current, *backup;
1213        for (current = list; current; current = backup) {
1214                backup = current->next;
1215                current->next = next;
1216                next = current;
1217        }
1218        return next;
1219}
1220
1221/*
1222 * Merge the commits h1 and h2, return the resulting virtual
1223 * commit object and a flag indicating the cleanness of the merge.
1224 */
1225int merge_recursive(struct commit *h1,
1226                    struct commit *h2,
1227                    const char *branch1,
1228                    const char *branch2,
1229                    struct commit_list *ca,
1230                    struct commit **result)
1231{
1232        struct commit_list *iter;
1233        struct commit *merged_common_ancestors;
1234        struct tree *mrtree = mrtree;
1235        int clean;
1236
1237        if (show(4)) {
1238                output(4, "Merging:");
1239                output_commit_title(h1);
1240                output_commit_title(h2);
1241        }
1242
1243        if (!ca) {
1244                ca = get_merge_bases(h1, h2, 1);
1245                ca = reverse_commit_list(ca);
1246        }
1247
1248        if (show(5)) {
1249                output(5, "found %u common ancestor(s):", commit_list_count(ca));
1250                for (iter = ca; iter; iter = iter->next)
1251                        output_commit_title(iter->item);
1252        }
1253
1254        merged_common_ancestors = pop_commit(&ca);
1255        if (merged_common_ancestors == NULL) {
1256                /* if there is no common ancestor, make an empty tree */
1257                struct tree *tree = xcalloc(1, sizeof(struct tree));
1258
1259                tree->object.parsed = 1;
1260                tree->object.type = OBJ_TREE;
1261                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1262                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1263        }
1264
1265        for (iter = ca; iter; iter = iter->next) {
1266                call_depth++;
1267                /*
1268                 * When the merge fails, the result contains files
1269                 * with conflict markers. The cleanness flag is
1270                 * ignored, it was never actually used, as result of
1271                 * merge_trees has always overwritten it: the committed
1272                 * "conflicts" were already resolved.
1273                 */
1274                discard_cache();
1275                merge_recursive(merged_common_ancestors, iter->item,
1276                                "Temporary merge branch 1",
1277                                "Temporary merge branch 2",
1278                                NULL,
1279                                &merged_common_ancestors);
1280                call_depth--;
1281
1282                if (!merged_common_ancestors)
1283                        die("merge returned no commit");
1284        }
1285
1286        discard_cache();
1287        if (!call_depth) {
1288                read_cache();
1289                index_only = 0;
1290        } else
1291                index_only = 1;
1292
1293        clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1294                            branch1, branch2, &mrtree);
1295
1296        if (index_only) {
1297                *result = make_virtual_commit(mrtree, "merged tree");
1298                commit_list_insert(h1, &(*result)->parents);
1299                commit_list_insert(h2, &(*result)->parents->next);
1300        }
1301        flush_output();
1302        return clean;
1303}
1304
1305static const char *better_branch_name(const char *branch)
1306{
1307        static char githead_env[8 + 40 + 1];
1308        char *name;
1309
1310        if (strlen(branch) != 40)
1311                return branch;
1312        sprintf(githead_env, "GITHEAD_%s", branch);
1313        name = getenv(githead_env);
1314        return name ? name : branch;
1315}
1316
1317static struct commit *get_ref(const char *ref)
1318{
1319        unsigned char sha1[20];
1320        struct object *object;
1321
1322        if (get_sha1(ref, sha1))
1323                die("Could not resolve ref '%s'", ref);
1324        object = deref_tag(parse_object(sha1), ref, strlen(ref));
1325        if (!object)
1326                return NULL;
1327        if (object->type == OBJ_TREE)
1328                return make_virtual_commit((struct tree*)object,
1329                        better_branch_name(ref));
1330        if (object->type != OBJ_COMMIT)
1331                return NULL;
1332        if (parse_commit((struct commit *)object))
1333                die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1334        return (struct commit *)object;
1335}
1336
1337static int merge_config(const char *var, const char *value, void *cb)
1338{
1339        if (!strcasecmp(var, "merge.verbosity")) {
1340                verbosity = git_config_int(var, value);
1341                return 0;
1342        }
1343        if (!strcasecmp(var, "diff.renamelimit")) {
1344                diff_rename_limit = git_config_int(var, value);
1345                return 0;
1346        }
1347        if (!strcasecmp(var, "merge.renamelimit")) {
1348                merge_rename_limit = git_config_int(var, value);
1349                return 0;
1350        }
1351        return git_default_config(var, value, cb);
1352}
1353
1354int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1355{
1356        static const char *bases[20];
1357        static unsigned bases_count = 0;
1358        int i, clean;
1359        const char *branch1, *branch2;
1360        struct commit *result, *h1, *h2;
1361        struct commit_list *ca = NULL;
1362        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1363        int index_fd;
1364
1365        if (argv[0]) {
1366                int namelen = strlen(argv[0]);
1367                if (8 < namelen &&
1368                    !strcmp(argv[0] + namelen - 8, "-subtree"))
1369                        subtree_merge = 1;
1370        }
1371
1372        git_config(merge_config, NULL);
1373        if (getenv("GIT_MERGE_VERBOSITY"))
1374                verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1375
1376        if (argc < 4)
1377                die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1378
1379        for (i = 1; i < argc; ++i) {
1380                if (!strcmp(argv[i], "--"))
1381                        break;
1382                if (bases_count < sizeof(bases)/sizeof(*bases))
1383                        bases[bases_count++] = argv[i];
1384        }
1385        if (argc - i != 3) /* "--" "<head>" "<remote>" */
1386                die("Not handling anything other than two heads merge.");
1387        if (verbosity >= 5)
1388                buffer_output = 0;
1389
1390        branch1 = argv[++i];
1391        branch2 = argv[++i];
1392
1393        h1 = get_ref(branch1);
1394        h2 = get_ref(branch2);
1395
1396        branch1 = better_branch_name(branch1);
1397        branch2 = better_branch_name(branch2);
1398
1399        if (show(3))
1400                printf("Merging %s with %s\n", branch1, branch2);
1401
1402        index_fd = hold_locked_index(lock, 1);
1403
1404        for (i = 0; i < bases_count; i++) {
1405                struct commit *ancestor = get_ref(bases[i]);
1406                ca = commit_list_insert(ancestor, &ca);
1407        }
1408        clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1409
1410        if (active_cache_changed &&
1411            (write_cache(index_fd, active_cache, active_nr) ||
1412             commit_locked_index(lock)))
1413                        die ("unable to write %s", get_index_file());
1414
1415        return clean ? 0: 1;
1416}