5d20f9efce54224d9461f6451a049066b5d75232
   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 <stdarg.h>
   7#include <string.h>
   8#include <assert.h>
   9#include <sys/wait.h>
  10#include <sys/types.h>
  11#include <sys/stat.h>
  12#include <time.h>
  13#include "cache.h"
  14#include "cache-tree.h"
  15#include "commit.h"
  16#include "blob.h"
  17#include "tree-walk.h"
  18#include "diff.h"
  19#include "diffcore.h"
  20#include "run-command.h"
  21#include "tag.h"
  22
  23#include "path-list.h"
  24
  25/*#define DEBUG*/
  26
  27#ifdef DEBUG
  28#define debug(...) fprintf(stderr, __VA_ARGS__)
  29#else
  30#define debug(...) do { ; /* nothing */ } while (0)
  31#endif
  32
  33#ifdef DEBUG
  34#include "quote.h"
  35static void show_ce_entry(const char *tag, struct cache_entry *ce)
  36{
  37        if (tag && *tag &&
  38            (ce->ce_flags & htons(CE_VALID))) {
  39                static char alttag[4];
  40                memcpy(alttag, tag, 3);
  41                if (isalpha(tag[0]))
  42                        alttag[0] = tolower(tag[0]);
  43                else if (tag[0] == '?')
  44                        alttag[0] = '!';
  45                else {
  46                        alttag[0] = 'v';
  47                        alttag[1] = tag[0];
  48                        alttag[2] = ' ';
  49                        alttag[3] = 0;
  50                }
  51                tag = alttag;
  52        }
  53
  54        fprintf(stderr,"%s%06o %s %d\t",
  55                        tag,
  56                        ntohl(ce->ce_mode),
  57                        sha1_to_hex(ce->sha1),
  58                        ce_stage(ce));
  59        write_name_quoted("", 0, ce->name,
  60                        '\n', stderr);
  61        fputc('\n', stderr);
  62}
  63
  64static void ls_files(void) {
  65        int i;
  66        for (i = 0; i < active_nr; i++) {
  67                struct cache_entry *ce = active_cache[i];
  68                show_ce_entry("", ce);
  69        }
  70        fprintf(stderr, "---\n");
  71        if (0) ls_files(); /* avoid "unused" warning */
  72}
  73#endif
  74
  75/*
  76 * A virtual commit has
  77 * - (const char *)commit->util set to the name, and
  78 * - *(int *)commit->object.sha1 set to the virtual id.
  79 */
  80
  81static unsigned commit_list_count(const struct commit_list *l)
  82{
  83        unsigned c = 0;
  84        for (; l; l = l->next )
  85                c++;
  86        return c;
  87}
  88
  89static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  90{
  91        struct commit *commit = xcalloc(1, sizeof(struct commit));
  92        static unsigned virtual_id = 1;
  93        commit->tree = tree;
  94        commit->util = (void*)comment;
  95        *(int*)commit->object.sha1 = virtual_id++;
  96        return commit;
  97}
  98
  99/*
 100 * TODO: we should not have to copy the SHA1s around, but rather reference
 101 * them. That way, sha_eq() is just sha1 == sha2.
 102 */
 103static int sha_eq(const unsigned char *a, const unsigned char *b)
 104{
 105        if (!a && !b)
 106                return 2;
 107        return a && b && memcmp(a, b, 20) == 0;
 108}
 109
 110/*
 111 * TODO: check if we can just reuse the active_cache structure: it is already
 112 * sorted (by name, stage).
 113 * Only problem: do not write it when flushing the cache.
 114 */
 115struct stage_data
 116{
 117        struct
 118        {
 119                unsigned mode;
 120                unsigned char sha[20];
 121        } stages[4];
 122        unsigned processed:1;
 123};
 124
 125static struct path_list current_file_set = {NULL, 0, 0, 1};
 126static struct path_list current_directory_set = {NULL, 0, 0, 1};
 127
 128static int output_indent = 0;
 129
 130static void output(const char *fmt, ...)
 131{
 132        va_list args;
 133        int i;
 134        for (i = output_indent; i--;)
 135                fputs("  ", stdout);
 136        va_start(args, fmt);
 137        vfprintf(stdout, fmt, args);
 138        va_end(args);
 139        fputc('\n', stdout);
 140}
 141
 142static void output_commit_title(struct commit *commit)
 143{
 144        int i;
 145        for (i = output_indent; i--;)
 146                fputs("  ", stdout);
 147        if (commit->util)
 148                printf("virtual %s\n", (char *)commit->util);
 149        else {
 150                printf("%s ", sha1_to_hex(commit->object.sha1));
 151                if (parse_commit(commit) != 0)
 152                        printf("(bad commit)\n");
 153                else {
 154                        const char *s;
 155                        int len;
 156                        for (s = commit->buffer; *s; s++)
 157                                if (*s == '\n' && s[1] == '\n') {
 158                                        s += 2;
 159                                        break;
 160                                }
 161                        for (len = 0; s[len] && '\n' != s[len]; len++)
 162                                ; /* do nothing */
 163                        printf("%.*s\n", len, s);
 164                }
 165        }
 166}
 167
 168static const char *original_index_file;
 169static const char *temporary_index_file;
 170static int cache_dirty = 0;
 171
 172static int flush_cache(void)
 173{
 174        /* flush temporary index */
 175        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 176        int fd = hold_lock_file_for_update(lock, getenv("GIT_INDEX_FILE"));
 177        if (fd < 0)
 178                die("could not lock %s", temporary_index_file);
 179        if (write_cache(fd, active_cache, active_nr) ||
 180                        close(fd) || commit_lock_file(lock))
 181                die ("unable to write %s", getenv("GIT_INDEX_FILE"));
 182        discard_cache();
 183        cache_dirty = 0;
 184        return 0;
 185}
 186
 187static void setup_index(int temp)
 188{
 189        const char *idx = temp ? temporary_index_file: original_index_file;
 190        if (cache_dirty)
 191                die("fatal: cache changed flush_cache();");
 192        unlink(temporary_index_file);
 193        setenv("GIT_INDEX_FILE", idx, 1);
 194        discard_cache();
 195}
 196
 197static struct cache_entry *make_cache_entry(unsigned int mode,
 198                const unsigned char *sha1, const char *path, int stage, int refresh)
 199{
 200        int size, len;
 201        struct cache_entry *ce;
 202
 203        if (!verify_path(path))
 204                return NULL;
 205
 206        len = strlen(path);
 207        size = cache_entry_size(len);
 208        ce = xcalloc(1, size);
 209
 210        memcpy(ce->sha1, sha1, 20);
 211        memcpy(ce->name, path, len);
 212        ce->ce_flags = create_ce_flags(len, stage);
 213        ce->ce_mode = create_ce_mode(mode);
 214
 215        if (refresh)
 216                return refresh_cache_entry(ce, 0);
 217
 218        return ce;
 219}
 220
 221static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 222                const char *path, int stage, int refresh, int options)
 223{
 224        struct cache_entry *ce;
 225        if (!cache_dirty)
 226                read_cache_from(getenv("GIT_INDEX_FILE"));
 227        cache_dirty++;
 228        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 229        if (!ce)
 230                return error("cache_addinfo failed: %s", strerror(cache_errno));
 231        return add_cache_entry(ce, options);
 232}
 233
 234/*
 235 * This is a global variable which is used in a number of places but
 236 * only written to in the 'merge' function.
 237 *
 238 * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
 239 *                       don't update the working directory.
 240 *               0    => Leave unmerged entries in the cache and update
 241 *                       the working directory.
 242 */
 243static int index_only = 0;
 244
 245/*
 246 * TODO: this can be streamlined by refactoring builtin-read-tree.c
 247 */
 248static int git_read_tree(const struct tree *tree)
 249{
 250#if 0
 251        fprintf(stderr, "GIT_INDEX_FILE='%s' git-read-tree %s\n",
 252                getenv("GIT_INDEX_FILE"),
 253                sha1_to_hex(tree->object.sha1));
 254#endif
 255        int rc;
 256        const char *argv[] = { "git-read-tree", NULL, NULL, };
 257        if (cache_dirty)
 258                die("read-tree with dirty cache");
 259        argv[1] = sha1_to_hex(tree->object.sha1);
 260        rc = run_command_v(2, argv);
 261        return rc < 0 ? -1: rc;
 262}
 263
 264/*
 265 * TODO: this can be streamlined by refactoring builtin-read-tree.c
 266 */
 267static int git_merge_trees(const char *update_arg,
 268                           struct tree *common,
 269                           struct tree *head,
 270                           struct tree *merge)
 271{
 272#if 0
 273        fprintf(stderr, "GIT_INDEX_FILE='%s' git-read-tree %s -m %s %s %s\n",
 274                getenv("GIT_INDEX_FILE"),
 275                update_arg,
 276                sha1_to_hex(common->object.sha1),
 277                sha1_to_hex(head->object.sha1),
 278                sha1_to_hex(merge->object.sha1));
 279#endif
 280        int rc;
 281        const char *argv[] = {
 282                "git-read-tree", NULL, "-m", NULL, NULL, NULL,
 283                NULL,
 284        };
 285        if (cache_dirty)
 286                flush_cache();
 287        argv[1] = update_arg;
 288        argv[3] = sha1_to_hex(common->object.sha1);
 289        argv[4] = sha1_to_hex(head->object.sha1);
 290        argv[5] = sha1_to_hex(merge->object.sha1);
 291        rc = run_command_v(6, argv);
 292        return rc < 0 ? -1: rc;
 293}
 294
 295/*
 296 * TODO: this can be streamlined by refactoring builtin-write-tree.c
 297 */
 298static struct tree *git_write_tree(void)
 299{
 300#if 0
 301        fprintf(stderr, "GIT_INDEX_FILE='%s' git-write-tree\n",
 302                getenv("GIT_INDEX_FILE"));
 303#endif
 304        FILE *fp;
 305        int rc;
 306        char buf[41];
 307        unsigned char sha1[20];
 308        int ch;
 309        unsigned i = 0;
 310        if (cache_dirty)
 311                flush_cache();
 312        fp = popen("git-write-tree 2>/dev/null", "r");
 313        while ((ch = fgetc(fp)) != EOF)
 314                if (i < sizeof(buf)-1 && ch >= '0' && ch <= 'f')
 315                        buf[i++] = ch;
 316                else
 317                        break;
 318        rc = pclose(fp);
 319        if (rc == -1 || WEXITSTATUS(rc))
 320                return NULL;
 321        buf[i] = '\0';
 322        if (get_sha1(buf, sha1) != 0)
 323                return NULL;
 324        return lookup_tree(sha1);
 325}
 326
 327static int save_files_dirs(const unsigned char *sha1,
 328                const char *base, int baselen, const char *path,
 329                unsigned int mode, int stage)
 330{
 331        int len = strlen(path);
 332        char *newpath = malloc(baselen + len + 1);
 333        memcpy(newpath, base, baselen);
 334        memcpy(newpath + baselen, path, len);
 335        newpath[baselen + len] = '\0';
 336
 337        if (S_ISDIR(mode))
 338                path_list_insert(newpath, &current_directory_set);
 339        else
 340                path_list_insert(newpath, &current_file_set);
 341        free(newpath);
 342
 343        return READ_TREE_RECURSIVE;
 344}
 345
 346static int get_files_dirs(struct tree *tree)
 347{
 348        int n;
 349        debug("get_files_dirs ...\n");
 350        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0) {
 351                debug("  get_files_dirs done (0)\n");
 352                return 0;
 353        }
 354        n = current_file_set.nr + current_directory_set.nr;
 355        debug("  get_files_dirs done (%d)\n", n);
 356        return n;
 357}
 358
 359/*
 360 * Returns a index_entry instance which doesn't have to correspond to
 361 * a real cache entry in Git's index.
 362 */
 363static struct stage_data *insert_stage_data(const char *path,
 364                struct tree *o, struct tree *a, struct tree *b,
 365                struct path_list *entries)
 366{
 367        struct path_list_item *item;
 368        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 369        get_tree_entry(o->object.sha1, path,
 370                        e->stages[1].sha, &e->stages[1].mode);
 371        get_tree_entry(a->object.sha1, path,
 372                        e->stages[2].sha, &e->stages[2].mode);
 373        get_tree_entry(b->object.sha1, path,
 374                        e->stages[3].sha, &e->stages[3].mode);
 375        item = path_list_insert(path, entries);
 376        item->util = e;
 377        return e;
 378}
 379
 380/*
 381 * Create a dictionary mapping file names to stage_data objects. The
 382 * dictionary contains one entry for every path with a non-zero stage entry.
 383 */
 384static struct path_list *get_unmerged(void)
 385{
 386        struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
 387        int i;
 388
 389        unmerged->strdup_paths = 1;
 390        if (!cache_dirty) {
 391                read_cache_from(getenv("GIT_INDEX_FILE"));
 392                cache_dirty++;
 393        }
 394        for (i = 0; i < active_nr; i++) {
 395                struct path_list_item *item;
 396                struct stage_data *e;
 397                struct cache_entry *ce = active_cache[i];
 398                if (!ce_stage(ce))
 399                        continue;
 400
 401                item = path_list_lookup(ce->name, unmerged);
 402                if (!item) {
 403                        item = path_list_insert(ce->name, unmerged);
 404                        item->util = xcalloc(1, sizeof(struct stage_data));
 405                }
 406                e = item->util;
 407                e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
 408                memcpy(e->stages[ce_stage(ce)].sha, ce->sha1, 20);
 409        }
 410
 411        return unmerged;
 412}
 413
 414struct rename
 415{
 416        struct diff_filepair *pair;
 417        struct stage_data *src_entry;
 418        struct stage_data *dst_entry;
 419        unsigned processed:1;
 420};
 421
 422/*
 423 * Get information of all renames which occured between 'o_tree' and
 424 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 425 * 'b_tree') to be able to associate the correct cache entries with
 426 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 427 */
 428static struct path_list *get_renames(struct tree *tree,
 429                                        struct tree *o_tree,
 430                                        struct tree *a_tree,
 431                                        struct tree *b_tree,
 432                                        struct path_list *entries)
 433{
 434        int i;
 435        struct path_list *renames;
 436        struct diff_options opts;
 437#ifdef DEBUG
 438        time_t t = time(0);
 439
 440        debug("get_renames ...\n");
 441#endif
 442
 443        renames = xcalloc(1, sizeof(struct path_list));
 444        diff_setup(&opts);
 445        opts.recursive = 1;
 446        opts.detect_rename = DIFF_DETECT_RENAME;
 447        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 448        if (diff_setup_done(&opts) < 0)
 449                die("diff setup failed");
 450        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 451        diffcore_std(&opts);
 452        for (i = 0; i < diff_queued_diff.nr; ++i) {
 453                struct path_list_item *item;
 454                struct rename *re;
 455                struct diff_filepair *pair = diff_queued_diff.queue[i];
 456                if (pair->status != 'R') {
 457                        diff_free_filepair(pair);
 458                        continue;
 459                }
 460                re = xmalloc(sizeof(*re));
 461                re->processed = 0;
 462                re->pair = pair;
 463                item = path_list_lookup(re->pair->one->path, entries);
 464                if (!item)
 465                        re->src_entry = insert_stage_data(re->pair->one->path,
 466                                        o_tree, a_tree, b_tree, entries);
 467                else
 468                        re->src_entry = item->util;
 469
 470                item = path_list_lookup(re->pair->two->path, entries);
 471                if (!item)
 472                        re->dst_entry = insert_stage_data(re->pair->two->path,
 473                                        o_tree, a_tree, b_tree, entries);
 474                else
 475                        re->dst_entry = item->util;
 476                item = path_list_insert(pair->one->path, renames);
 477                item->util = re;
 478        }
 479        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 480        diff_queued_diff.nr = 0;
 481        diff_flush(&opts);
 482#ifdef DEBUG
 483        debug("  get_renames done in %ld\n", time(0)-t);
 484#endif
 485        return renames;
 486}
 487
 488int update_stages(const char *path, struct diff_filespec *o,
 489                struct diff_filespec *a, struct diff_filespec *b, int clear)
 490{
 491        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 492        if (clear)
 493                if (remove_file_from_cache(path))
 494                        return -1;
 495        if (o)
 496                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 497                        return -1;
 498        if (a)
 499                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 500                        return -1;
 501        if (b)
 502                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 503                        return -1;
 504        return 0;
 505}
 506
 507static int remove_path(const char *name)
 508{
 509        int ret, len;
 510        char *slash, *dirs;
 511
 512        ret = unlink(name);
 513        if (ret)
 514                return ret;
 515        len = strlen(name);
 516        dirs = malloc(len+1);
 517        memcpy(dirs, name, len);
 518        dirs[len] = '\0';
 519        while ((slash = strrchr(name, '/'))) {
 520                *slash = '\0';
 521                len = slash - name;
 522                if (rmdir(name) != 0)
 523                        break;
 524        }
 525        free(dirs);
 526        return ret;
 527}
 528
 529/*
 530 * TODO: once we no longer call external programs, we'd probably be better off
 531 * not setting / getting the environment variable GIT_INDEX_FILE all the time.
 532 */
 533int remove_file(int clean, const char *path)
 534{
 535        int update_cache = index_only || clean;
 536        int update_working_directory = !index_only;
 537
 538        if (update_cache) {
 539                if (!cache_dirty)
 540                        read_cache_from(getenv("GIT_INDEX_FILE"));
 541                cache_dirty++;
 542                if (remove_file_from_cache(path))
 543                        return -1;
 544        }
 545        if (update_working_directory)
 546        {
 547                unlink(path);
 548                if (errno != ENOENT || errno != EISDIR)
 549                        return -1;
 550                remove_path(path);
 551        }
 552        return 0;
 553}
 554
 555static char *unique_path(const char *path, const char *branch)
 556{
 557        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 558        int suffix = 0;
 559        struct stat st;
 560        char *p = newpath + strlen(newpath);
 561        strcpy(newpath, path);
 562        strcat(newpath, "~");
 563        strcpy(p, branch);
 564        for (; *p; ++p)
 565                if ('/' == *p)
 566                        *p = '_';
 567        while (path_list_has_path(&current_file_set, newpath) ||
 568               path_list_has_path(&current_directory_set, newpath) ||
 569               lstat(newpath, &st) == 0)
 570                sprintf(p, "_%d", suffix++);
 571
 572        path_list_insert(newpath, &current_file_set);
 573        return newpath;
 574}
 575
 576static int mkdir_p(const char *path, unsigned long mode)
 577{
 578        /* path points to cache entries, so strdup before messing with it */
 579        char *buf = strdup(path);
 580        int result = safe_create_leading_directories(buf);
 581        free(buf);
 582        return result;
 583}
 584
 585static void flush_buffer(int fd, const char *buf, unsigned long size)
 586{
 587        while (size > 0) {
 588                long ret = xwrite(fd, buf, size);
 589                if (ret < 0) {
 590                        /* Ignore epipe */
 591                        if (errno == EPIPE)
 592                                break;
 593                        die("merge-recursive: %s", strerror(errno));
 594                } else if (!ret) {
 595                        die("merge-recursive: disk full?");
 596                }
 597                size -= ret;
 598                buf += ret;
 599        }
 600}
 601
 602void update_file_flags(const unsigned char *sha,
 603                       unsigned mode,
 604                       const char *path,
 605                       int update_cache,
 606                       int update_wd)
 607{
 608        if (index_only)
 609                update_wd = 0;
 610
 611        if (update_wd) {
 612                char type[20];
 613                void *buf;
 614                unsigned long size;
 615
 616                buf = read_sha1_file(sha, type, &size);
 617                if (!buf)
 618                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 619                if (strcmp(type, blob_type) != 0)
 620                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 621
 622                if (S_ISREG(mode)) {
 623                        int fd;
 624                        if (mkdir_p(path, 0777))
 625                                die("failed to create path %s: %s", path, strerror(errno));
 626                        unlink(path);
 627                        if (mode & 0100)
 628                                mode = 0777;
 629                        else
 630                                mode = 0666;
 631                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 632                        if (fd < 0)
 633                                die("failed to open %s: %s", path, strerror(errno));
 634                        flush_buffer(fd, buf, size);
 635                        close(fd);
 636                } else if (S_ISLNK(mode)) {
 637                        char *lnk = malloc(size + 1);
 638                        memcpy(lnk, buf, size);
 639                        lnk[size] = '\0';
 640                        mkdir_p(path, 0777);
 641                        unlink(lnk);
 642                        symlink(lnk, path);
 643                } else
 644                        die("do not know what to do with %06o %s '%s'",
 645                            mode, sha1_to_hex(sha), path);
 646        }
 647        if (update_cache)
 648                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 649}
 650
 651void update_file(int clean,
 652                const unsigned char *sha,
 653                unsigned mode,
 654                const char *path)
 655{
 656        update_file_flags(sha, mode, path, index_only || clean, !index_only);
 657}
 658
 659/* Low level file merging, update and removal */
 660
 661struct merge_file_info
 662{
 663        unsigned char sha[20];
 664        unsigned mode;
 665        unsigned clean:1,
 666                 merge:1;
 667};
 668
 669static char *git_unpack_file(const unsigned char *sha1, char *path)
 670{
 671        void *buf;
 672        char type[20];
 673        unsigned long size;
 674        int fd;
 675
 676        buf = read_sha1_file(sha1, type, &size);
 677        if (!buf || strcmp(type, blob_type))
 678                die("unable to read blob object %s", sha1_to_hex(sha1));
 679
 680        strcpy(path, ".merge_file_XXXXXX");
 681        fd = mkstemp(path);
 682        if (fd < 0)
 683                die("unable to create temp-file");
 684        flush_buffer(fd, buf, size);
 685        close(fd);
 686        return path;
 687}
 688
 689static struct merge_file_info merge_file(struct diff_filespec *o,
 690                struct diff_filespec *a, struct diff_filespec *b,
 691                const char *branch1Name, const char *branch2Name)
 692{
 693        struct merge_file_info result;
 694        result.merge = 0;
 695        result.clean = 1;
 696
 697        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 698                result.clean = 0;
 699                if (S_ISREG(a->mode)) {
 700                        result.mode = a->mode;
 701                        memcpy(result.sha, a->sha1, 20);
 702                } else {
 703                        result.mode = b->mode;
 704                        memcpy(result.sha, b->sha1, 20);
 705                }
 706        } else {
 707                if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
 708                        result.merge = 1;
 709
 710                result.mode = a->mode == o->mode ? b->mode: a->mode;
 711
 712                if (sha_eq(a->sha1, o->sha1))
 713                        memcpy(result.sha, b->sha1, 20);
 714                else if (sha_eq(b->sha1, o->sha1))
 715                        memcpy(result.sha, a->sha1, 20);
 716                else if (S_ISREG(a->mode)) {
 717                        int code = 1, fd;
 718                        struct stat st;
 719                        char orig[PATH_MAX];
 720                        char src1[PATH_MAX];
 721                        char src2[PATH_MAX];
 722                        const char *argv[] = {
 723                                "merge", "-L", NULL, "-L", NULL, "-L", NULL,
 724                                src1, orig, src2,
 725                                NULL
 726                        };
 727                        char *la, *lb, *lo;
 728
 729                        git_unpack_file(o->sha1, orig);
 730                        git_unpack_file(a->sha1, src1);
 731                        git_unpack_file(b->sha1, src2);
 732
 733                        argv[2] = la = strdup(mkpath("%s/%s", branch1Name, a->path));
 734                        argv[6] = lb = strdup(mkpath("%s/%s", branch2Name, b->path));
 735                        argv[4] = lo = strdup(mkpath("orig/%s", o->path));
 736
 737#if 0
 738                        printf("%s %s %s %s %s %s %s %s %s %s\n",
 739                               argv[0], argv[1], argv[2], argv[3], argv[4],
 740                               argv[5], argv[6], argv[7], argv[8], argv[9]);
 741#endif
 742                        code = run_command_v(10, argv);
 743
 744                        free(la);
 745                        free(lb);
 746                        free(lo);
 747                        if (code && code < -256) {
 748                                die("Failed to execute 'merge'. merge(1) is used as the "
 749                                    "file-level merge tool. Is 'merge' in your path?");
 750                        }
 751                        fd = open(src1, O_RDONLY);
 752                        if (fd < 0 || fstat(fd, &st) < 0 ||
 753                                        index_fd(result.sha, fd, &st, 1,
 754                                                "blob"))
 755                                die("Unable to add %s to database", src1);
 756
 757                        unlink(orig);
 758                        unlink(src1);
 759                        unlink(src2);
 760
 761                        result.clean = WEXITSTATUS(code) == 0;
 762                } else {
 763                        if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
 764                                die("cannot merge modes?");
 765
 766                        memcpy(result.sha, a->sha1, 20);
 767
 768                        if (!sha_eq(a->sha1, b->sha1))
 769                                result.clean = 0;
 770                }
 771        }
 772
 773        return result;
 774}
 775
 776static void conflict_rename_rename(struct rename *ren1,
 777                                   const char *branch1,
 778                                   struct rename *ren2,
 779                                   const char *branch2)
 780{
 781        char *del[2];
 782        int delp = 0;
 783        const char *ren1_dst = ren1->pair->two->path;
 784        const char *ren2_dst = ren2->pair->two->path;
 785        const char *dst_name1 = ren1_dst;
 786        const char *dst_name2 = ren2_dst;
 787        if (path_list_has_path(&current_directory_set, ren1_dst)) {
 788                dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
 789                output("%s is a directory in %s adding as %s instead",
 790                       ren1_dst, branch2, dst_name1);
 791                remove_file(0, ren1_dst);
 792        }
 793        if (path_list_has_path(&current_directory_set, ren2_dst)) {
 794                dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
 795                output("%s is a directory in %s adding as %s instead",
 796                       ren2_dst, branch1, dst_name2);
 797                remove_file(0, ren2_dst);
 798        }
 799        update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
 800        update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
 801        while (delp--)
 802                free(del[delp]);
 803}
 804
 805static void conflict_rename_dir(struct rename *ren1,
 806                                const char *branch1)
 807{
 808        char *new_path = unique_path(ren1->pair->two->path, branch1);
 809        output("Renaming %s to %s instead", ren1->pair->one->path, new_path);
 810        remove_file(0, ren1->pair->two->path);
 811        update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 812        free(new_path);
 813}
 814
 815static void conflict_rename_rename_2(struct rename *ren1,
 816                                     const char *branch1,
 817                                     struct rename *ren2,
 818                                     const char *branch2)
 819{
 820        char *new_path1 = unique_path(ren1->pair->two->path, branch1);
 821        char *new_path2 = unique_path(ren2->pair->two->path, branch2);
 822        output("Renaming %s to %s and %s to %s instead",
 823               ren1->pair->one->path, new_path1,
 824               ren2->pair->one->path, new_path2);
 825        remove_file(0, ren1->pair->two->path);
 826        update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 827        update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 828        free(new_path2);
 829        free(new_path1);
 830}
 831
 832/* General TODO: get rid of all the debug messages */
 833static int process_renames(struct path_list *a_renames,
 834                           struct path_list *b_renames,
 835                           const char *a_branch,
 836                           const char *b_branch)
 837{
 838        int clean_merge = 1, i, j;
 839        struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
 840        const struct rename *sre;
 841
 842        for (i = 0; i < a_renames->nr; i++) {
 843                sre = a_renames->items[i].util;
 844                path_list_insert(sre->pair->two->path, &a_by_dst)->util
 845                        = sre->dst_entry;
 846        }
 847        for (i = 0; i < b_renames->nr; i++) {
 848                sre = b_renames->items[i].util;
 849                path_list_insert(sre->pair->two->path, &b_by_dst)->util
 850                        = sre->dst_entry;
 851        }
 852
 853        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 854                int compare;
 855                char *src;
 856                struct path_list *renames1, *renames2, *renames2Dst;
 857                struct rename *ren1 = NULL, *ren2 = NULL;
 858                const char *branch1, *branch2;
 859                const char *ren1_src, *ren1_dst;
 860
 861                if (i >= a_renames->nr) {
 862                        compare = 1;
 863                        ren2 = b_renames->items[j++].util;
 864                } else if (j >= b_renames->nr) {
 865                        compare = -1;
 866                        ren1 = a_renames->items[i++].util;
 867                } else {
 868                        compare = strcmp(a_renames->items[i].path,
 869                                        b_renames->items[j].path);
 870                        ren1 = a_renames->items[i++].util;
 871                        ren2 = b_renames->items[j++].util;
 872                }
 873
 874                /* TODO: refactor, so that 1/2 are not needed */
 875                if (ren1) {
 876                        renames1 = a_renames;
 877                        renames2 = b_renames;
 878                        renames2Dst = &b_by_dst;
 879                        branch1 = a_branch;
 880                        branch2 = b_branch;
 881                } else {
 882                        struct rename *tmp;
 883                        renames1 = b_renames;
 884                        renames2 = a_renames;
 885                        renames2Dst = &a_by_dst;
 886                        branch1 = b_branch;
 887                        branch2 = a_branch;
 888                        tmp = ren2;
 889                        ren2 = ren1;
 890                        ren1 = tmp;
 891                }
 892                src = ren1->pair->one->path;
 893
 894                ren1->dst_entry->processed = 1;
 895                ren1->src_entry->processed = 1;
 896
 897                if (ren1->processed)
 898                        continue;
 899                ren1->processed = 1;
 900
 901                ren1_src = ren1->pair->one->path;
 902                ren1_dst = ren1->pair->two->path;
 903
 904                if (ren2) {
 905                        const char *ren2_src = ren2->pair->one->path;
 906                        const char *ren2_dst = ren2->pair->two->path;
 907                        /* Renamed in 1 and renamed in 2 */
 908                        if (strcmp(ren1_src, ren2_src) != 0)
 909                                die("ren1.src != ren2.src");
 910                        ren2->dst_entry->processed = 1;
 911                        ren2->processed = 1;
 912                        if (strcmp(ren1_dst, ren2_dst) != 0) {
 913                                clean_merge = 0;
 914                                output("CONFLICT (rename/rename): "
 915                                       "Rename %s->%s in branch %s "
 916                                       "rename %s->%s in %s",
 917                                       src, ren1_dst, branch1,
 918                                       src, ren2_dst, branch2);
 919                                conflict_rename_rename(ren1, branch1, ren2, branch2);
 920                        } else {
 921                                struct merge_file_info mfi;
 922                                remove_file(1, ren1_src);
 923                                mfi = merge_file(ren1->pair->one,
 924                                                 ren1->pair->two,
 925                                                 ren2->pair->two,
 926                                                 branch1,
 927                                                 branch2);
 928                                if (mfi.merge || !mfi.clean)
 929                                        output("Renaming %s->%s", src, ren1_dst);
 930
 931                                if (mfi.merge)
 932                                        output("Auto-merging %s", ren1_dst);
 933
 934                                if (!mfi.clean) {
 935                                        output("CONFLICT (content): merge conflict in %s",
 936                                               ren1_dst);
 937                                        clean_merge = 0;
 938
 939                                        if (!index_only)
 940                                                update_stages(ren1_dst,
 941                                                              ren1->pair->one,
 942                                                              ren1->pair->two,
 943                                                              ren2->pair->two,
 944                                                              1 /* clear */);
 945                                }
 946                                update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 947                        }
 948                } else {
 949                        /* Renamed in 1, maybe changed in 2 */
 950                        struct path_list_item *item;
 951                        /* we only use sha1 and mode of these */
 952                        struct diff_filespec src_other, dst_other;
 953                        int try_merge, stage = a_renames == renames1 ? 3: 2;
 954
 955                        remove_file(1, ren1_src);
 956
 957                        memcpy(src_other.sha1,
 958                                        ren1->src_entry->stages[stage].sha, 20);
 959                        src_other.mode = ren1->src_entry->stages[stage].mode;
 960                        memcpy(dst_other.sha1,
 961                                        ren1->dst_entry->stages[stage].sha, 20);
 962                        dst_other.mode = ren1->dst_entry->stages[stage].mode;
 963
 964                        try_merge = 0;
 965
 966                        if (path_list_has_path(&current_directory_set, ren1_dst)) {
 967                                clean_merge = 0;
 968                                output("CONFLICT (rename/directory): Rename %s->%s in %s "
 969                                       " directory %s added in %s",
 970                                       ren1_src, ren1_dst, branch1,
 971                                       ren1_dst, branch2);
 972                                conflict_rename_dir(ren1, branch1);
 973                        } else if (sha_eq(src_other.sha1, null_sha1)) {
 974                                clean_merge = 0;
 975                                output("CONFLICT (rename/delete): Rename %s->%s in %s "
 976                                       "and deleted in %s",
 977                                       ren1_src, ren1_dst, branch1,
 978                                       branch2);
 979                                update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 980                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
 981                                const char *new_path;
 982                                clean_merge = 0;
 983                                try_merge = 1;
 984                                output("CONFLICT (rename/add): Rename %s->%s in %s. "
 985                                       "%s added in %s",
 986                                       ren1_src, ren1_dst, branch1,
 987                                       ren1_dst, branch2);
 988                                new_path = unique_path(ren1_dst, branch2);
 989                                output("Adding as %s instead", new_path);
 990                                update_file(0, dst_other.sha1, dst_other.mode, new_path);
 991                        } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
 992                                ren2 = item->util;
 993                                clean_merge = 0;
 994                                ren2->processed = 1;
 995                                output("CONFLICT (rename/rename): Rename %s->%s in %s. "
 996                                       "Rename %s->%s in %s",
 997                                       ren1_src, ren1_dst, branch1,
 998                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
 999                                conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1000                        } else
1001                                try_merge = 1;
1002
1003                        if (try_merge) {
1004                                struct diff_filespec *o, *a, *b;
1005                                struct merge_file_info mfi;
1006                                src_other.path = (char *)ren1_src;
1007
1008                                o = ren1->pair->one;
1009                                if (a_renames == renames1) {
1010                                        a = ren1->pair->two;
1011                                        b = &src_other;
1012                                } else {
1013                                        b = ren1->pair->two;
1014                                        a = &src_other;
1015                                }
1016                                mfi = merge_file(o, a, b,
1017                                                a_branch, b_branch);
1018
1019                                if (mfi.merge || !mfi.clean)
1020                                        output("Renaming %s => %s", ren1_src, ren1_dst);
1021                                if (mfi.merge)
1022                                        output("Auto-merging %s", ren1_dst);
1023                                if (!mfi.clean) {
1024                                        output("CONFLICT (rename/modify): Merge conflict in %s",
1025                                               ren1_dst);
1026                                        clean_merge = 0;
1027
1028                                        if (!index_only)
1029                                                update_stages(ren1_dst,
1030                                                                o, a, b, 1);
1031                                }
1032                                update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1033                        }
1034                }
1035        }
1036        path_list_clear(&a_by_dst, 0);
1037        path_list_clear(&b_by_dst, 0);
1038
1039        if (cache_dirty)
1040                flush_cache();
1041        return clean_merge;
1042}
1043
1044static unsigned char *has_sha(const unsigned char *sha)
1045{
1046        return memcmp(sha, null_sha1, 20) == 0 ? NULL: (unsigned char *)sha;
1047}
1048
1049/* Per entry merge function */
1050static int process_entry(const char *path, struct stage_data *entry,
1051                         const char *branch1Name,
1052                         const char *branch2Name)
1053{
1054        /*
1055        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1056        print_index_entry("\tpath: ", entry);
1057        */
1058        int clean_merge = 1;
1059        unsigned char *o_sha = has_sha(entry->stages[1].sha);
1060        unsigned char *a_sha = has_sha(entry->stages[2].sha);
1061        unsigned char *b_sha = has_sha(entry->stages[3].sha);
1062        unsigned o_mode = entry->stages[1].mode;
1063        unsigned a_mode = entry->stages[2].mode;
1064        unsigned b_mode = entry->stages[3].mode;
1065
1066        if (o_sha && (!a_sha || !b_sha)) {
1067                /* Case A: Deleted in one */
1068                if ((!a_sha && !b_sha) ||
1069                    (sha_eq(a_sha, o_sha) && !b_sha) ||
1070                    (!a_sha && sha_eq(b_sha, o_sha))) {
1071                        /* Deleted in both or deleted in one and
1072                         * unchanged in the other */
1073                        if (a_sha)
1074                                output("Removing %s", path);
1075                        remove_file(1, path);
1076                } else {
1077                        /* Deleted in one and changed in the other */
1078                        clean_merge = 0;
1079                        if (!a_sha) {
1080                                output("CONFLICT (delete/modify): %s deleted in %s "
1081                                       "and modified in %s. Version %s of %s left in tree.",
1082                                       path, branch1Name,
1083                                       branch2Name, branch2Name, path);
1084                                update_file(0, b_sha, b_mode, path);
1085                        } else {
1086                                output("CONFLICT (delete/modify): %s deleted in %s "
1087                                       "and modified in %s. Version %s of %s left in tree.",
1088                                       path, branch2Name,
1089                                       branch1Name, branch1Name, path);
1090                                update_file(0, a_sha, a_mode, path);
1091                        }
1092                }
1093
1094        } else if ((!o_sha && a_sha && !b_sha) ||
1095                   (!o_sha && !a_sha && b_sha)) {
1096                /* Case B: Added in one. */
1097                const char *add_branch;
1098                const char *other_branch;
1099                unsigned mode;
1100                const unsigned char *sha;
1101                const char *conf;
1102
1103                if (a_sha) {
1104                        add_branch = branch1Name;
1105                        other_branch = branch2Name;
1106                        mode = a_mode;
1107                        sha = a_sha;
1108                        conf = "file/directory";
1109                } else {
1110                        add_branch = branch2Name;
1111                        other_branch = branch1Name;
1112                        mode = b_mode;
1113                        sha = b_sha;
1114                        conf = "directory/file";
1115                }
1116                if (path_list_has_path(&current_directory_set, path)) {
1117                        const char *new_path = unique_path(path, add_branch);
1118                        clean_merge = 0;
1119                        output("CONFLICT (%s): There is a directory with name %s in %s. "
1120                               "Adding %s as %s",
1121                               conf, path, other_branch, path, new_path);
1122                        remove_file(0, path);
1123                        update_file(0, sha, mode, new_path);
1124                } else {
1125                        output("Adding %s", path);
1126                        update_file(1, sha, mode, path);
1127                }
1128        } else if (!o_sha && a_sha && b_sha) {
1129                /* Case C: Added in both (check for same permissions). */
1130                if (sha_eq(a_sha, b_sha)) {
1131                        if (a_mode != b_mode) {
1132                                clean_merge = 0;
1133                                output("CONFLICT: File %s added identically in both branches, "
1134                                       "but permissions conflict %06o->%06o",
1135                                       path, a_mode, b_mode);
1136                                output("CONFLICT: adding with permission: %06o", a_mode);
1137                                update_file(0, a_sha, a_mode, path);
1138                        } else {
1139                                /* This case is handled by git-read-tree */
1140                                assert(0 && "This case must be handled by git-read-tree");
1141                        }
1142                } else {
1143                        const char *new_path1, *new_path2;
1144                        clean_merge = 0;
1145                        new_path1 = unique_path(path, branch1Name);
1146                        new_path2 = unique_path(path, branch2Name);
1147                        output("CONFLICT (add/add): File %s added non-identically "
1148                               "in both branches. Adding as %s and %s instead.",
1149                               path, new_path1, new_path2);
1150                        remove_file(0, path);
1151                        update_file(0, a_sha, a_mode, new_path1);
1152                        update_file(0, b_sha, b_mode, new_path2);
1153                }
1154
1155        } else if (o_sha && a_sha && b_sha) {
1156                /* case D: Modified in both, but differently. */
1157                struct merge_file_info mfi;
1158                struct diff_filespec o, a, b;
1159
1160                output("Auto-merging %s", path);
1161                o.path = a.path = b.path = (char *)path;
1162                memcpy(o.sha1, o_sha, 20);
1163                o.mode = o_mode;
1164                memcpy(a.sha1, a_sha, 20);
1165                a.mode = a_mode;
1166                memcpy(b.sha1, b_sha, 20);
1167                b.mode = b_mode;
1168
1169                mfi = merge_file(&o, &a, &b,
1170                                 branch1Name, branch2Name);
1171
1172                if (mfi.clean)
1173                        update_file(1, mfi.sha, mfi.mode, path);
1174                else {
1175                        clean_merge = 0;
1176                        output("CONFLICT (content): Merge conflict in %s", path);
1177
1178                        if (index_only)
1179                                update_file(0, mfi.sha, mfi.mode, path);
1180                        else
1181                                update_file_flags(mfi.sha, mfi.mode, path,
1182                                              0 /* update_cache */, 1 /* update_working_directory */);
1183                }
1184        } else
1185                die("Fatal merge failure, shouldn't happen.");
1186
1187        if (cache_dirty)
1188                flush_cache();
1189
1190        return clean_merge;
1191}
1192
1193static int merge_trees(struct tree *head,
1194                       struct tree *merge,
1195                       struct tree *common,
1196                       const char *branch1Name,
1197                       const char *branch2Name,
1198                       struct tree **result)
1199{
1200        int code, clean;
1201        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1202                output("Already uptodate!");
1203                *result = head;
1204                return 1;
1205        }
1206
1207        code = git_merge_trees(index_only ? "-i": "-u", common, head, merge);
1208
1209        if (code != 0)
1210                die("merging of trees %s and %s failed",
1211                    sha1_to_hex(head->object.sha1),
1212                    sha1_to_hex(merge->object.sha1));
1213
1214        *result = git_write_tree();
1215
1216        if (!*result) {
1217                struct path_list *entries, *re_head, *re_merge;
1218                int i;
1219                path_list_clear(&current_file_set, 1);
1220                path_list_clear(&current_directory_set, 1);
1221                get_files_dirs(head);
1222                get_files_dirs(merge);
1223
1224                entries = get_unmerged();
1225                re_head  = get_renames(head, common, head, merge, entries);
1226                re_merge = get_renames(merge, common, head, merge, entries);
1227                clean = process_renames(re_head, re_merge,
1228                                branch1Name, branch2Name);
1229                for (i = 0; i < entries->nr; i++) {
1230                        const char *path = entries->items[i].path;
1231                        struct stage_data *e = entries->items[i].util;
1232                        if (e->processed)
1233                                continue;
1234                        if (!process_entry(path, e, branch1Name, branch2Name))
1235                                clean = 0;
1236                }
1237
1238                path_list_clear(re_merge, 0);
1239                path_list_clear(re_head, 0);
1240                path_list_clear(entries, 1);
1241
1242                if (clean || index_only)
1243                        *result = git_write_tree();
1244                else
1245                        *result = NULL;
1246        } else {
1247                clean = 1;
1248                printf("merging of trees %s and %s resulted in %s\n",
1249                       sha1_to_hex(head->object.sha1),
1250                       sha1_to_hex(merge->object.sha1),
1251                       sha1_to_hex((*result)->object.sha1));
1252        }
1253
1254        return clean;
1255}
1256
1257/*
1258 * Merge the commits h1 and h2, return the resulting virtual
1259 * commit object and a flag indicating the cleaness of the merge.
1260 */
1261static
1262int merge(struct commit *h1,
1263                          struct commit *h2,
1264                          const char *branch1Name,
1265                          const char *branch2Name,
1266                          int call_depth /* =0 */,
1267                          struct commit *ancestor /* =None */,
1268                          struct commit **result)
1269{
1270        struct commit_list *ca = NULL, *iter;
1271        struct commit *merged_common_ancestors;
1272        struct tree *mrtree;
1273        int clean;
1274
1275        output("Merging:");
1276        output_commit_title(h1);
1277        output_commit_title(h2);
1278
1279        if (ancestor)
1280                commit_list_insert(ancestor, &ca);
1281        else
1282                ca = get_merge_bases(h1, h2, 1);
1283
1284        output("found %u common ancestor(s):", commit_list_count(ca));
1285        for (iter = ca; iter; iter = iter->next)
1286                output_commit_title(iter->item);
1287
1288        merged_common_ancestors = pop_commit(&ca);
1289
1290        for (iter = ca; iter; iter = iter->next) {
1291                output_indent = call_depth + 1;
1292                /*
1293                 * When the merge fails, the result contains files
1294                 * with conflict markers. The cleanness flag is
1295                 * ignored, it was never acutally used, as result of
1296                 * merge_trees has always overwritten it: the commited
1297                 * "conflicts" were already resolved.
1298                 */
1299                merge(merged_common_ancestors, iter->item,
1300                      "Temporary merge branch 1",
1301                      "Temporary merge branch 2",
1302                      call_depth + 1,
1303                      NULL,
1304                      &merged_common_ancestors);
1305                output_indent = call_depth;
1306
1307                if (!merged_common_ancestors)
1308                        die("merge returned no commit");
1309        }
1310
1311        if (call_depth == 0) {
1312                setup_index(0 /* $GIT_DIR/index */);
1313                index_only = 0;
1314        } else {
1315                setup_index(1 /* temporary index */);
1316                git_read_tree(h1->tree);
1317                index_only = 1;
1318        }
1319
1320        clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1321                            branch1Name, branch2Name, &mrtree);
1322
1323        if (!ancestor && (clean || index_only)) {
1324                *result = make_virtual_commit(mrtree, "merged tree");
1325                commit_list_insert(h1, &(*result)->parents);
1326                commit_list_insert(h2, &(*result)->parents->next);
1327        } else
1328                *result = NULL;
1329
1330        return clean;
1331}
1332
1333static struct commit *get_ref(const char *ref)
1334{
1335        unsigned char sha1[20];
1336        struct object *object;
1337
1338        if (get_sha1(ref, sha1))
1339                die("Could not resolve ref '%s'", ref);
1340        object = deref_tag(parse_object(sha1), ref, strlen(ref));
1341        if (object->type != OBJ_COMMIT)
1342                return NULL;
1343        if (parse_commit((struct commit *)object))
1344                die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1345        return (struct commit *)object;
1346}
1347
1348int main(int argc, char *argv[])
1349{
1350        static const char *bases[2];
1351        static unsigned bases_count = 0;
1352        int i, clean;
1353        const char *branch1, *branch2;
1354        struct commit *result, *h1, *h2;
1355
1356        original_index_file = getenv("GIT_INDEX_FILE");
1357
1358        if (!original_index_file)
1359                original_index_file = strdup(git_path("index"));
1360
1361        temporary_index_file = strdup(git_path("mrg-rcrsv-tmp-idx"));
1362
1363        if (argc < 4)
1364                die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1365
1366        for (i = 1; i < argc; ++i) {
1367                if (!strcmp(argv[i], "--"))
1368                        break;
1369                if (bases_count < sizeof(bases)/sizeof(*bases))
1370                        bases[bases_count++] = argv[i];
1371        }
1372        if (argc - i != 3) /* "--" "<head>" "<remote>" */
1373                die("Not handling anything other than two heads merge.");
1374
1375        branch1 = argv[++i];
1376        branch2 = argv[++i];
1377        printf("Merging %s with %s\n", branch1, branch2);
1378
1379        h1 = get_ref(branch1);
1380        h2 = get_ref(branch2);
1381
1382        if (bases_count == 1) {
1383                struct commit *ancestor = get_ref(bases[0]);
1384                clean = merge(h1, h2, branch1, branch2, 0, ancestor, &result);
1385        } else
1386                clean = merge(h1, h2, branch1, branch2, 0, NULL, &result);
1387
1388        if (cache_dirty)
1389                flush_cache();
1390
1391        return clean ? 0: 1;
1392}
1393
1394/*
1395vim: sw=8 noet
1396*/