merge-recursive.con commit Merge branch 'en/merge-recursive-2' (96b7c4d)
   1/*
   2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
   3 * Fredrik Kuivinen.
   4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
   5 */
   6#include "advice.h"
   7#include "cache.h"
   8#include "cache-tree.h"
   9#include "commit.h"
  10#include "blob.h"
  11#include "builtin.h"
  12#include "tree-walk.h"
  13#include "diff.h"
  14#include "diffcore.h"
  15#include "tag.h"
  16#include "unpack-trees.h"
  17#include "string-list.h"
  18#include "xdiff-interface.h"
  19#include "ll-merge.h"
  20#include "attr.h"
  21#include "merge-recursive.h"
  22#include "dir.h"
  23#include "submodule.h"
  24
  25static struct tree *shift_tree_object(struct tree *one, struct tree *two,
  26                                      const char *subtree_shift)
  27{
  28        unsigned char shifted[20];
  29
  30        if (!*subtree_shift) {
  31                shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
  32        } else {
  33                shift_tree_by(one->object.sha1, two->object.sha1, shifted,
  34                              subtree_shift);
  35        }
  36        if (!hashcmp(two->object.sha1, shifted))
  37                return two;
  38        return lookup_tree(shifted);
  39}
  40
  41/*
  42 * A virtual commit has (const char *)commit->util set to the name.
  43 */
  44
  45static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  46{
  47        struct commit *commit = xcalloc(1, sizeof(struct commit));
  48        commit->tree = tree;
  49        commit->util = (void*)comment;
  50        /* avoid warnings */
  51        commit->object.parsed = 1;
  52        return commit;
  53}
  54
  55/*
  56 * Since we use get_tree_entry(), which does not put the read object into
  57 * the object pool, we cannot rely on a == b.
  58 */
  59static int sha_eq(const unsigned char *a, const unsigned char *b)
  60{
  61        if (!a && !b)
  62                return 2;
  63        return a && b && hashcmp(a, b) == 0;
  64}
  65
  66enum rename_type {
  67        RENAME_NORMAL = 0,
  68        RENAME_DELETE,
  69        RENAME_ONE_FILE_TO_ONE,
  70        RENAME_ONE_FILE_TO_TWO,
  71        RENAME_TWO_FILES_TO_ONE
  72};
  73
  74struct rename_conflict_info {
  75        enum rename_type rename_type;
  76        struct diff_filepair *pair1;
  77        struct diff_filepair *pair2;
  78        const char *branch1;
  79        const char *branch2;
  80        struct stage_data *dst_entry1;
  81        struct stage_data *dst_entry2;
  82        struct diff_filespec ren1_other;
  83        struct diff_filespec ren2_other;
  84};
  85
  86/*
  87 * Since we want to write the index eventually, we cannot reuse the index
  88 * for these (temporary) data.
  89 */
  90struct stage_data {
  91        struct {
  92                unsigned mode;
  93                unsigned char sha[20];
  94        } stages[4];
  95        struct rename_conflict_info *rename_conflict_info;
  96        unsigned processed:1;
  97};
  98
  99static inline void setup_rename_conflict_info(enum rename_type rename_type,
 100                                              struct diff_filepair *pair1,
 101                                              struct diff_filepair *pair2,
 102                                              const char *branch1,
 103                                              const char *branch2,
 104                                              struct stage_data *dst_entry1,
 105                                              struct stage_data *dst_entry2,
 106                                              struct merge_options *o,
 107                                              struct stage_data *src_entry1,
 108                                              struct stage_data *src_entry2)
 109{
 110        struct rename_conflict_info *ci = xcalloc(1, sizeof(struct rename_conflict_info));
 111        ci->rename_type = rename_type;
 112        ci->pair1 = pair1;
 113        ci->branch1 = branch1;
 114        ci->branch2 = branch2;
 115
 116        ci->dst_entry1 = dst_entry1;
 117        dst_entry1->rename_conflict_info = ci;
 118        dst_entry1->processed = 0;
 119
 120        assert(!pair2 == !dst_entry2);
 121        if (dst_entry2) {
 122                ci->dst_entry2 = dst_entry2;
 123                ci->pair2 = pair2;
 124                dst_entry2->rename_conflict_info = ci;
 125        }
 126
 127        if (rename_type == RENAME_TWO_FILES_TO_ONE) {
 128                /*
 129                 * For each rename, there could have been
 130                 * modifications on the side of history where that
 131                 * file was not renamed.
 132                 */
 133                int ostage1 = o->branch1 == branch1 ? 3 : 2;
 134                int ostage2 = ostage1 ^ 1;
 135
 136                ci->ren1_other.path = pair1->one->path;
 137                hashcpy(ci->ren1_other.sha1, src_entry1->stages[ostage1].sha);
 138                ci->ren1_other.mode = src_entry1->stages[ostage1].mode;
 139
 140                ci->ren2_other.path = pair2->one->path;
 141                hashcpy(ci->ren2_other.sha1, src_entry2->stages[ostage2].sha);
 142                ci->ren2_other.mode = src_entry2->stages[ostage2].mode;
 143        }
 144}
 145
 146static int show(struct merge_options *o, int v)
 147{
 148        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 149}
 150
 151static void flush_output(struct merge_options *o)
 152{
 153        if (o->obuf.len) {
 154                fputs(o->obuf.buf, stdout);
 155                strbuf_reset(&o->obuf);
 156        }
 157}
 158
 159__attribute__((format (printf, 3, 4)))
 160static void output(struct merge_options *o, int v, const char *fmt, ...)
 161{
 162        va_list ap;
 163
 164        if (!show(o, v))
 165                return;
 166
 167        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 168        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 169        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 170
 171        va_start(ap, fmt);
 172        strbuf_vaddf(&o->obuf, fmt, ap);
 173        va_end(ap);
 174
 175        strbuf_add(&o->obuf, "\n", 1);
 176        if (!o->buffer_output)
 177                flush_output(o);
 178}
 179
 180static void output_commit_title(struct merge_options *o, struct commit *commit)
 181{
 182        int i;
 183        flush_output(o);
 184        for (i = o->call_depth; i--;)
 185                fputs("  ", stdout);
 186        if (commit->util)
 187                printf("virtual %s\n", (char *)commit->util);
 188        else {
 189                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 190                if (parse_commit(commit) != 0)
 191                        printf("(bad commit)\n");
 192                else {
 193                        const char *title;
 194                        int len = find_commit_subject(commit->buffer, &title);
 195                        if (len)
 196                                printf("%.*s\n", len, title);
 197                }
 198        }
 199}
 200
 201static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 202                const char *path, int stage, int refresh, int options)
 203{
 204        struct cache_entry *ce;
 205        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 206        if (!ce)
 207                return error("addinfo_cache failed for path '%s'", path);
 208        return add_cache_entry(ce, options);
 209}
 210
 211static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 212{
 213        parse_tree(tree);
 214        init_tree_desc(desc, tree->buffer, tree->size);
 215}
 216
 217static int git_merge_trees(int index_only,
 218                           struct tree *common,
 219                           struct tree *head,
 220                           struct tree *merge)
 221{
 222        int rc;
 223        struct tree_desc t[3];
 224        struct unpack_trees_options opts;
 225
 226        memset(&opts, 0, sizeof(opts));
 227        if (index_only)
 228                opts.index_only = 1;
 229        else
 230                opts.update = 1;
 231        opts.merge = 1;
 232        opts.head_idx = 2;
 233        opts.fn = threeway_merge;
 234        opts.src_index = &the_index;
 235        opts.dst_index = &the_index;
 236        setup_unpack_trees_porcelain(&opts, "merge");
 237
 238        init_tree_desc_from_tree(t+0, common);
 239        init_tree_desc_from_tree(t+1, head);
 240        init_tree_desc_from_tree(t+2, merge);
 241
 242        rc = unpack_trees(3, t, &opts);
 243        cache_tree_free(&active_cache_tree);
 244        return rc;
 245}
 246
 247struct tree *write_tree_from_memory(struct merge_options *o)
 248{
 249        struct tree *result = NULL;
 250
 251        if (unmerged_cache()) {
 252                int i;
 253                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 254                for (i = 0; i < active_nr; i++) {
 255                        struct cache_entry *ce = active_cache[i];
 256                        if (ce_stage(ce))
 257                                fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
 258                                        (int)ce_namelen(ce), ce->name);
 259                }
 260                die("Bug in merge-recursive.c");
 261        }
 262
 263        if (!active_cache_tree)
 264                active_cache_tree = cache_tree();
 265
 266        if (!cache_tree_fully_valid(active_cache_tree) &&
 267            cache_tree_update(active_cache_tree,
 268                              active_cache, active_nr, 0, 0) < 0)
 269                die("error building trees");
 270
 271        result = lookup_tree(active_cache_tree->sha1);
 272
 273        return result;
 274}
 275
 276static int save_files_dirs(const unsigned char *sha1,
 277                const char *base, int baselen, const char *path,
 278                unsigned int mode, int stage, void *context)
 279{
 280        int len = strlen(path);
 281        char *newpath = xmalloc(baselen + len + 1);
 282        struct merge_options *o = context;
 283
 284        memcpy(newpath, base, baselen);
 285        memcpy(newpath + baselen, path, len);
 286        newpath[baselen + len] = '\0';
 287
 288        if (S_ISDIR(mode))
 289                string_list_insert(&o->current_directory_set, newpath);
 290        else
 291                string_list_insert(&o->current_file_set, newpath);
 292        free(newpath);
 293
 294        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 295}
 296
 297static int get_files_dirs(struct merge_options *o, struct tree *tree)
 298{
 299        int n;
 300        struct pathspec match_all;
 301        init_pathspec(&match_all, NULL);
 302        if (read_tree_recursive(tree, "", 0, 0, &match_all, save_files_dirs, o))
 303                return 0;
 304        n = o->current_file_set.nr + o->current_directory_set.nr;
 305        return n;
 306}
 307
 308/*
 309 * Returns an index_entry instance which doesn't have to correspond to
 310 * a real cache entry in Git's index.
 311 */
 312static struct stage_data *insert_stage_data(const char *path,
 313                struct tree *o, struct tree *a, struct tree *b,
 314                struct string_list *entries)
 315{
 316        struct string_list_item *item;
 317        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 318        get_tree_entry(o->object.sha1, path,
 319                        e->stages[1].sha, &e->stages[1].mode);
 320        get_tree_entry(a->object.sha1, path,
 321                        e->stages[2].sha, &e->stages[2].mode);
 322        get_tree_entry(b->object.sha1, path,
 323                        e->stages[3].sha, &e->stages[3].mode);
 324        item = string_list_insert(entries, path);
 325        item->util = e;
 326        return e;
 327}
 328
 329/*
 330 * Create a dictionary mapping file names to stage_data objects. The
 331 * dictionary contains one entry for every path with a non-zero stage entry.
 332 */
 333static struct string_list *get_unmerged(void)
 334{
 335        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 336        int i;
 337
 338        unmerged->strdup_strings = 1;
 339
 340        for (i = 0; i < active_nr; i++) {
 341                struct string_list_item *item;
 342                struct stage_data *e;
 343                struct cache_entry *ce = active_cache[i];
 344                if (!ce_stage(ce))
 345                        continue;
 346
 347                item = string_list_lookup(unmerged, ce->name);
 348                if (!item) {
 349                        item = string_list_insert(unmerged, ce->name);
 350                        item->util = xcalloc(1, sizeof(struct stage_data));
 351                }
 352                e = item->util;
 353                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 354                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 355        }
 356
 357        return unmerged;
 358}
 359
 360static int string_list_df_name_compare(const void *a, const void *b)
 361{
 362        const struct string_list_item *one = a;
 363        const struct string_list_item *two = b;
 364        int onelen = strlen(one->string);
 365        int twolen = strlen(two->string);
 366        /*
 367         * Here we only care that entries for D/F conflicts are
 368         * adjacent, in particular with the file of the D/F conflict
 369         * appearing before files below the corresponding directory.
 370         * The order of the rest of the list is irrelevant for us.
 371         *
 372         * To achieve this, we sort with df_name_compare and provide
 373         * the mode S_IFDIR so that D/F conflicts will sort correctly.
 374         * We use the mode S_IFDIR for everything else for simplicity,
 375         * since in other cases any changes in their order due to
 376         * sorting cause no problems for us.
 377         */
 378        int cmp = df_name_compare(one->string, onelen, S_IFDIR,
 379                                  two->string, twolen, S_IFDIR);
 380        /*
 381         * Now that 'foo' and 'foo/bar' compare equal, we have to make sure
 382         * that 'foo' comes before 'foo/bar'.
 383         */
 384        if (cmp)
 385                return cmp;
 386        return onelen - twolen;
 387}
 388
 389static void record_df_conflict_files(struct merge_options *o,
 390                                     struct string_list *entries)
 391{
 392        /* If there is a D/F conflict and the file for such a conflict
 393         * currently exist in the working copy, we want to allow it to be
 394         * removed to make room for the corresponding directory if needed.
 395         * The files underneath the directories of such D/F conflicts will
 396         * be processed before the corresponding file involved in the D/F
 397         * conflict.  If the D/F directory ends up being removed by the
 398         * merge, then we won't have to touch the D/F file.  If the D/F
 399         * directory needs to be written to the working copy, then the D/F
 400         * file will simply be removed (in make_room_for_path()) to make
 401         * room for the necessary paths.  Note that if both the directory
 402         * and the file need to be present, then the D/F file will be
 403         * reinstated with a new unique name at the time it is processed.
 404         */
 405        struct string_list df_sorted_entries;
 406        const char *last_file = NULL;
 407        int last_len = 0;
 408        int i;
 409
 410        /*
 411         * If we're merging merge-bases, we don't want to bother with
 412         * any working directory changes.
 413         */
 414        if (o->call_depth)
 415                return;
 416
 417        /* Ensure D/F conflicts are adjacent in the entries list. */
 418        memset(&df_sorted_entries, 0, sizeof(struct string_list));
 419        for (i = 0; i < entries->nr; i++) {
 420                struct string_list_item *next = &entries->items[i];
 421                string_list_append(&df_sorted_entries, next->string)->util =
 422                                   next->util;
 423        }
 424        qsort(df_sorted_entries.items, entries->nr, sizeof(*entries->items),
 425              string_list_df_name_compare);
 426
 427        string_list_clear(&o->df_conflict_file_set, 1);
 428        for (i = 0; i < df_sorted_entries.nr; i++) {
 429                const char *path = df_sorted_entries.items[i].string;
 430                int len = strlen(path);
 431                struct stage_data *e = df_sorted_entries.items[i].util;
 432
 433                /*
 434                 * Check if last_file & path correspond to a D/F conflict;
 435                 * i.e. whether path is last_file+'/'+<something>.
 436                 * If so, record that it's okay to remove last_file to make
 437                 * room for path and friends if needed.
 438                 */
 439                if (last_file &&
 440                    len > last_len &&
 441                    memcmp(path, last_file, last_len) == 0 &&
 442                    path[last_len] == '/') {
 443                        string_list_insert(&o->df_conflict_file_set, last_file);
 444                }
 445
 446                /*
 447                 * Determine whether path could exist as a file in the
 448                 * working directory as a possible D/F conflict.  This
 449                 * will only occur when it exists in stage 2 as a
 450                 * file.
 451                 */
 452                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 453                        last_file = path;
 454                        last_len = len;
 455                } else {
 456                        last_file = NULL;
 457                }
 458        }
 459        string_list_clear(&df_sorted_entries, 0);
 460}
 461
 462struct rename {
 463        struct diff_filepair *pair;
 464        struct stage_data *src_entry;
 465        struct stage_data *dst_entry;
 466        unsigned processed:1;
 467};
 468
 469/*
 470 * Get information of all renames which occurred between 'o_tree' and
 471 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 472 * 'b_tree') to be able to associate the correct cache entries with
 473 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 474 */
 475static struct string_list *get_renames(struct merge_options *o,
 476                                       struct tree *tree,
 477                                       struct tree *o_tree,
 478                                       struct tree *a_tree,
 479                                       struct tree *b_tree,
 480                                       struct string_list *entries)
 481{
 482        int i;
 483        struct string_list *renames;
 484        struct diff_options opts;
 485
 486        renames = xcalloc(1, sizeof(struct string_list));
 487        diff_setup(&opts);
 488        DIFF_OPT_SET(&opts, RECURSIVE);
 489        opts.detect_rename = DIFF_DETECT_RENAME;
 490        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 491                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 492                            1000;
 493        opts.rename_score = o->rename_score;
 494        opts.show_rename_progress = o->show_rename_progress;
 495        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 496        if (diff_setup_done(&opts) < 0)
 497                die("diff setup failed");
 498        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 499        diffcore_std(&opts);
 500        if (opts.needed_rename_limit > o->needed_rename_limit)
 501                o->needed_rename_limit = opts.needed_rename_limit;
 502        for (i = 0; i < diff_queued_diff.nr; ++i) {
 503                struct string_list_item *item;
 504                struct rename *re;
 505                struct diff_filepair *pair = diff_queued_diff.queue[i];
 506                if (pair->status != 'R') {
 507                        diff_free_filepair(pair);
 508                        continue;
 509                }
 510                re = xmalloc(sizeof(*re));
 511                re->processed = 0;
 512                re->pair = pair;
 513                item = string_list_lookup(entries, re->pair->one->path);
 514                if (!item)
 515                        re->src_entry = insert_stage_data(re->pair->one->path,
 516                                        o_tree, a_tree, b_tree, entries);
 517                else
 518                        re->src_entry = item->util;
 519
 520                item = string_list_lookup(entries, re->pair->two->path);
 521                if (!item)
 522                        re->dst_entry = insert_stage_data(re->pair->two->path,
 523                                        o_tree, a_tree, b_tree, entries);
 524                else
 525                        re->dst_entry = item->util;
 526                item = string_list_insert(renames, pair->one->path);
 527                item->util = re;
 528        }
 529        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 530        diff_queued_diff.nr = 0;
 531        diff_flush(&opts);
 532        return renames;
 533}
 534
 535static int update_stages(const char *path, const struct diff_filespec *o,
 536                         const struct diff_filespec *a,
 537                         const struct diff_filespec *b)
 538{
 539
 540        /*
 541         * NOTE: It is usually a bad idea to call update_stages on a path
 542         * before calling update_file on that same path, since it can
 543         * sometimes lead to spurious "refusing to lose untracked file..."
 544         * messages from update_file (via make_room_for path via
 545         * would_lose_untracked).  Instead, reverse the order of the calls
 546         * (executing update_file first and then update_stages).
 547         */
 548        int clear = 1;
 549        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 550        if (clear)
 551                if (remove_file_from_cache(path))
 552                        return -1;
 553        if (o)
 554                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 555                        return -1;
 556        if (a)
 557                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 558                        return -1;
 559        if (b)
 560                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 561                        return -1;
 562        return 0;
 563}
 564
 565static void update_entry(struct stage_data *entry,
 566                         struct diff_filespec *o,
 567                         struct diff_filespec *a,
 568                         struct diff_filespec *b)
 569{
 570        entry->processed = 0;
 571        entry->stages[1].mode = o->mode;
 572        entry->stages[2].mode = a->mode;
 573        entry->stages[3].mode = b->mode;
 574        hashcpy(entry->stages[1].sha, o->sha1);
 575        hashcpy(entry->stages[2].sha, a->sha1);
 576        hashcpy(entry->stages[3].sha, b->sha1);
 577}
 578
 579static int remove_file(struct merge_options *o, int clean,
 580                       const char *path, int no_wd)
 581{
 582        int update_cache = o->call_depth || clean;
 583        int update_working_directory = !o->call_depth && !no_wd;
 584
 585        if (update_cache) {
 586                if (remove_file_from_cache(path))
 587                        return -1;
 588        }
 589        if (update_working_directory) {
 590                if (remove_path(path))
 591                        return -1;
 592        }
 593        return 0;
 594}
 595
 596static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 597{
 598        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 599        int suffix = 0;
 600        struct stat st;
 601        char *p = newpath + strlen(path);
 602        strcpy(newpath, path);
 603        *(p++) = '~';
 604        strcpy(p, branch);
 605        for (; *p; ++p)
 606                if ('/' == *p)
 607                        *p = '_';
 608        while (string_list_has_string(&o->current_file_set, newpath) ||
 609               string_list_has_string(&o->current_directory_set, newpath) ||
 610               lstat(newpath, &st) == 0)
 611                sprintf(p, "_%d", suffix++);
 612
 613        string_list_insert(&o->current_file_set, newpath);
 614        return newpath;
 615}
 616
 617static void flush_buffer(int fd, const char *buf, unsigned long size)
 618{
 619        while (size > 0) {
 620                long ret = write_in_full(fd, buf, size);
 621                if (ret < 0) {
 622                        /* Ignore epipe */
 623                        if (errno == EPIPE)
 624                                break;
 625                        die_errno("merge-recursive");
 626                } else if (!ret) {
 627                        die("merge-recursive: disk full?");
 628                }
 629                size -= ret;
 630                buf += ret;
 631        }
 632}
 633
 634static int dir_in_way(const char *path, int check_working_copy)
 635{
 636        int pos, pathlen = strlen(path);
 637        char *dirpath = xmalloc(pathlen + 2);
 638        struct stat st;
 639
 640        strcpy(dirpath, path);
 641        dirpath[pathlen] = '/';
 642        dirpath[pathlen+1] = '\0';
 643
 644        pos = cache_name_pos(dirpath, pathlen+1);
 645
 646        if (pos < 0)
 647                pos = -1 - pos;
 648        if (pos < active_nr &&
 649            !strncmp(dirpath, active_cache[pos]->name, pathlen+1)) {
 650                free(dirpath);
 651                return 1;
 652        }
 653
 654        free(dirpath);
 655        return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode);
 656}
 657
 658static int was_tracked(const char *path)
 659{
 660        int pos = cache_name_pos(path, strlen(path));
 661
 662        if (pos < 0)
 663                pos = -1 - pos;
 664        while (pos < active_nr &&
 665               !strcmp(path, active_cache[pos]->name)) {
 666                /*
 667                 * If stage #0, it is definitely tracked.
 668                 * If it has stage #2 then it was tracked
 669                 * before this merge started.  All other
 670                 * cases the path was not tracked.
 671                 */
 672                switch (ce_stage(active_cache[pos])) {
 673                case 0:
 674                case 2:
 675                        return 1;
 676                }
 677                pos++;
 678        }
 679        return 0;
 680}
 681
 682static int would_lose_untracked(const char *path)
 683{
 684        return !was_tracked(path) && file_exists(path);
 685}
 686
 687static int make_room_for_path(struct merge_options *o, const char *path)
 688{
 689        int status, i;
 690        const char *msg = "failed to create path '%s'%s";
 691
 692        /* Unlink any D/F conflict files that are in the way */
 693        for (i = 0; i < o->df_conflict_file_set.nr; i++) {
 694                const char *df_path = o->df_conflict_file_set.items[i].string;
 695                size_t pathlen = strlen(path);
 696                size_t df_pathlen = strlen(df_path);
 697                if (df_pathlen < pathlen &&
 698                    path[df_pathlen] == '/' &&
 699                    strncmp(path, df_path, df_pathlen) == 0) {
 700                        output(o, 3,
 701                               "Removing %s to make room for subdirectory\n",
 702                               df_path);
 703                        unlink(df_path);
 704                        unsorted_string_list_delete_item(&o->df_conflict_file_set,
 705                                                         i, 0);
 706                        break;
 707                }
 708        }
 709
 710        /* Make sure leading directories are created */
 711        status = safe_create_leading_directories_const(path);
 712        if (status) {
 713                if (status == -3) {
 714                        /* something else exists */
 715                        error(msg, path, ": perhaps a D/F conflict?");
 716                        return -1;
 717                }
 718                die(msg, path, "");
 719        }
 720
 721        /*
 722         * Do not unlink a file in the work tree if we are not
 723         * tracking it.
 724         */
 725        if (would_lose_untracked(path))
 726                return error("refusing to lose untracked file at '%s'",
 727                             path);
 728
 729        /* Successful unlink is good.. */
 730        if (!unlink(path))
 731                return 0;
 732        /* .. and so is no existing file */
 733        if (errno == ENOENT)
 734                return 0;
 735        /* .. but not some other error (who really cares what?) */
 736        return error(msg, path, ": perhaps a D/F conflict?");
 737}
 738
 739static void update_file_flags(struct merge_options *o,
 740                              const unsigned char *sha,
 741                              unsigned mode,
 742                              const char *path,
 743                              int update_cache,
 744                              int update_wd)
 745{
 746        if (o->call_depth)
 747                update_wd = 0;
 748
 749        if (update_wd) {
 750                enum object_type type;
 751                void *buf;
 752                unsigned long size;
 753
 754                if (S_ISGITLINK(mode)) {
 755                        /*
 756                         * We may later decide to recursively descend into
 757                         * the submodule directory and update its index
 758                         * and/or work tree, but we do not do that now.
 759                         */
 760                        update_wd = 0;
 761                        goto update_index;
 762                }
 763
 764                buf = read_sha1_file(sha, &type, &size);
 765                if (!buf)
 766                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 767                if (type != OBJ_BLOB)
 768                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 769                if (S_ISREG(mode)) {
 770                        struct strbuf strbuf = STRBUF_INIT;
 771                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 772                                free(buf);
 773                                size = strbuf.len;
 774                                buf = strbuf_detach(&strbuf, NULL);
 775                        }
 776                }
 777
 778                if (make_room_for_path(o, path) < 0) {
 779                        update_wd = 0;
 780                        free(buf);
 781                        goto update_index;
 782                }
 783                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 784                        int fd;
 785                        if (mode & 0100)
 786                                mode = 0777;
 787                        else
 788                                mode = 0666;
 789                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 790                        if (fd < 0)
 791                                die_errno("failed to open '%s'", path);
 792                        flush_buffer(fd, buf, size);
 793                        close(fd);
 794                } else if (S_ISLNK(mode)) {
 795                        char *lnk = xmemdupz(buf, size);
 796                        safe_create_leading_directories_const(path);
 797                        unlink(path);
 798                        if (symlink(lnk, path))
 799                                die_errno("failed to symlink '%s'", path);
 800                        free(lnk);
 801                } else
 802                        die("do not know what to do with %06o %s '%s'",
 803                            mode, sha1_to_hex(sha), path);
 804                free(buf);
 805        }
 806 update_index:
 807        if (update_cache)
 808                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 809}
 810
 811static void update_file(struct merge_options *o,
 812                        int clean,
 813                        const unsigned char *sha,
 814                        unsigned mode,
 815                        const char *path)
 816{
 817        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 818}
 819
 820/* Low level file merging, update and removal */
 821
 822struct merge_file_info {
 823        unsigned char sha[20];
 824        unsigned mode;
 825        unsigned clean:1,
 826                 merge:1;
 827};
 828
 829static int merge_3way(struct merge_options *o,
 830                      mmbuffer_t *result_buf,
 831                      const struct diff_filespec *one,
 832                      const struct diff_filespec *a,
 833                      const struct diff_filespec *b,
 834                      const char *branch1,
 835                      const char *branch2)
 836{
 837        mmfile_t orig, src1, src2;
 838        struct ll_merge_options ll_opts = {0};
 839        char *base_name, *name1, *name2;
 840        int merge_status;
 841
 842        ll_opts.renormalize = o->renormalize;
 843        ll_opts.xdl_opts = o->xdl_opts;
 844
 845        if (o->call_depth) {
 846                ll_opts.virtual_ancestor = 1;
 847                ll_opts.variant = 0;
 848        } else {
 849                switch (o->recursive_variant) {
 850                case MERGE_RECURSIVE_OURS:
 851                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 852                        break;
 853                case MERGE_RECURSIVE_THEIRS:
 854                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 855                        break;
 856                default:
 857                        ll_opts.variant = 0;
 858                        break;
 859                }
 860        }
 861
 862        if (strcmp(a->path, b->path) ||
 863            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 864                base_name = o->ancestor == NULL ? NULL :
 865                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 866                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 867                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 868        } else {
 869                base_name = o->ancestor == NULL ? NULL :
 870                        xstrdup(mkpath("%s", o->ancestor));
 871                name1 = xstrdup(mkpath("%s", branch1));
 872                name2 = xstrdup(mkpath("%s", branch2));
 873        }
 874
 875        read_mmblob(&orig, one->sha1);
 876        read_mmblob(&src1, a->sha1);
 877        read_mmblob(&src2, b->sha1);
 878
 879        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 880                                &src1, name1, &src2, name2, &ll_opts);
 881
 882        free(name1);
 883        free(name2);
 884        free(orig.ptr);
 885        free(src1.ptr);
 886        free(src2.ptr);
 887        return merge_status;
 888}
 889
 890static struct merge_file_info merge_file_1(struct merge_options *o,
 891                                           const struct diff_filespec *one,
 892                                           const struct diff_filespec *a,
 893                                           const struct diff_filespec *b,
 894                                           const char *branch1,
 895                                           const char *branch2)
 896{
 897        struct merge_file_info result;
 898        result.merge = 0;
 899        result.clean = 1;
 900
 901        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 902                result.clean = 0;
 903                if (S_ISREG(a->mode)) {
 904                        result.mode = a->mode;
 905                        hashcpy(result.sha, a->sha1);
 906                } else {
 907                        result.mode = b->mode;
 908                        hashcpy(result.sha, b->sha1);
 909                }
 910        } else {
 911                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 912                        result.merge = 1;
 913
 914                /*
 915                 * Merge modes
 916                 */
 917                if (a->mode == b->mode || a->mode == one->mode)
 918                        result.mode = b->mode;
 919                else {
 920                        result.mode = a->mode;
 921                        if (b->mode != one->mode) {
 922                                result.clean = 0;
 923                                result.merge = 1;
 924                        }
 925                }
 926
 927                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 928                        hashcpy(result.sha, b->sha1);
 929                else if (sha_eq(b->sha1, one->sha1))
 930                        hashcpy(result.sha, a->sha1);
 931                else if (S_ISREG(a->mode)) {
 932                        mmbuffer_t result_buf;
 933                        int merge_status;
 934
 935                        merge_status = merge_3way(o, &result_buf, one, a, b,
 936                                                  branch1, branch2);
 937
 938                        if ((merge_status < 0) || !result_buf.ptr)
 939                                die("Failed to execute internal merge");
 940
 941                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 942                                            blob_type, result.sha))
 943                                die("Unable to add %s to database",
 944                                    a->path);
 945
 946                        free(result_buf.ptr);
 947                        result.clean = (merge_status == 0);
 948                } else if (S_ISGITLINK(a->mode)) {
 949                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 950                                                       a->sha1, b->sha1);
 951                } else if (S_ISLNK(a->mode)) {
 952                        hashcpy(result.sha, a->sha1);
 953
 954                        if (!sha_eq(a->sha1, b->sha1))
 955                                result.clean = 0;
 956                } else {
 957                        die("unsupported object type in the tree");
 958                }
 959        }
 960
 961        return result;
 962}
 963
 964static struct merge_file_info
 965merge_file_special_markers(struct merge_options *o,
 966                           const struct diff_filespec *one,
 967                           const struct diff_filespec *a,
 968                           const struct diff_filespec *b,
 969                           const char *branch1,
 970                           const char *filename1,
 971                           const char *branch2,
 972                           const char *filename2)
 973{
 974        char *side1 = NULL;
 975        char *side2 = NULL;
 976        struct merge_file_info mfi;
 977
 978        if (filename1) {
 979                side1 = xmalloc(strlen(branch1) + strlen(filename1) + 2);
 980                sprintf(side1, "%s:%s", branch1, filename1);
 981        }
 982        if (filename2) {
 983                side2 = xmalloc(strlen(branch2) + strlen(filename2) + 2);
 984                sprintf(side2, "%s:%s", branch2, filename2);
 985        }
 986
 987        mfi = merge_file_1(o, one, a, b,
 988                           side1 ? side1 : branch1, side2 ? side2 : branch2);
 989        free(side1);
 990        free(side2);
 991        return mfi;
 992}
 993
 994static struct merge_file_info merge_file(struct merge_options *o,
 995                                         const char *path,
 996                                         const unsigned char *o_sha, int o_mode,
 997                                         const unsigned char *a_sha, int a_mode,
 998                                         const unsigned char *b_sha, int b_mode,
 999                                         const char *branch1,
1000                                         const char *branch2)
1001{
1002        struct diff_filespec one, a, b;
1003
1004        one.path = a.path = b.path = (char *)path;
1005        hashcpy(one.sha1, o_sha);
1006        one.mode = o_mode;
1007        hashcpy(a.sha1, a_sha);
1008        a.mode = a_mode;
1009        hashcpy(b.sha1, b_sha);
1010        b.mode = b_mode;
1011        return merge_file_1(o, &one, &a, &b, branch1, branch2);
1012}
1013
1014static void handle_change_delete(struct merge_options *o,
1015                                 const char *path,
1016                                 const unsigned char *o_sha, int o_mode,
1017                                 const unsigned char *a_sha, int a_mode,
1018                                 const unsigned char *b_sha, int b_mode,
1019                                 const char *change, const char *change_past)
1020{
1021        char *renamed = NULL;
1022        if (dir_in_way(path, !o->call_depth)) {
1023                renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1024        }
1025
1026        if (o->call_depth) {
1027                /*
1028                 * We cannot arbitrarily accept either a_sha or b_sha as
1029                 * correct; since there is no true "middle point" between
1030                 * them, simply reuse the base version for virtual merge base.
1031                 */
1032                remove_file_from_cache(path);
1033                update_file(o, 0, o_sha, o_mode, renamed ? renamed : path);
1034        } else if (!a_sha) {
1035                output(o, 1, "CONFLICT (%s/delete): %s deleted in %s "
1036                       "and %s in %s. Version %s of %s left in tree%s%s.",
1037                       change, path, o->branch1,
1038                       change_past, o->branch2, o->branch2, path,
1039                       NULL == renamed ? "" : " at ",
1040                       NULL == renamed ? "" : renamed);
1041                update_file(o, 0, b_sha, b_mode, renamed ? renamed : path);
1042        } else {
1043                output(o, 1, "CONFLICT (%s/delete): %s deleted in %s "
1044                       "and %s in %s. Version %s of %s left in tree%s%s.",
1045                       change, path, o->branch2,
1046                       change_past, o->branch1, o->branch1, path,
1047                       NULL == renamed ? "" : " at ",
1048                       NULL == renamed ? "" : renamed);
1049                if (renamed)
1050                        update_file(o, 0, a_sha, a_mode, renamed);
1051                /*
1052                 * No need to call update_file() on path when !renamed, since
1053                 * that would needlessly touch path.  We could call
1054                 * update_file_flags() with update_cache=0 and update_wd=0,
1055                 * but that's a no-op.
1056                 */
1057        }
1058        free(renamed);
1059}
1060
1061static void conflict_rename_delete(struct merge_options *o,
1062                                   struct diff_filepair *pair,
1063                                   const char *rename_branch,
1064                                   const char *other_branch)
1065{
1066        const struct diff_filespec *orig = pair->one;
1067        const struct diff_filespec *dest = pair->two;
1068        const unsigned char *a_sha = NULL;
1069        const unsigned char *b_sha = NULL;
1070        int a_mode = 0;
1071        int b_mode = 0;
1072
1073        if (rename_branch == o->branch1) {
1074                a_sha = dest->sha1;
1075                a_mode = dest->mode;
1076        } else {
1077                b_sha = dest->sha1;
1078                b_mode = dest->mode;
1079        }
1080
1081        handle_change_delete(o,
1082                             o->call_depth ? orig->path : dest->path,
1083                             orig->sha1, orig->mode,
1084                             a_sha, a_mode,
1085                             b_sha, b_mode,
1086                             "rename", "renamed");
1087
1088        if (o->call_depth) {
1089                remove_file_from_cache(dest->path);
1090        } else {
1091                update_stages(dest->path, NULL,
1092                              rename_branch == o->branch1 ? dest : NULL,
1093                              rename_branch == o->branch1 ? NULL : dest);
1094        }
1095
1096}
1097
1098static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
1099                                                 struct stage_data *entry,
1100                                                 int stage)
1101{
1102        unsigned char *sha = entry->stages[stage].sha;
1103        unsigned mode = entry->stages[stage].mode;
1104        if (mode == 0 || is_null_sha1(sha))
1105                return NULL;
1106        hashcpy(target->sha1, sha);
1107        target->mode = mode;
1108        return target;
1109}
1110
1111static void handle_file(struct merge_options *o,
1112                        struct diff_filespec *rename,
1113                        int stage,
1114                        struct rename_conflict_info *ci)
1115{
1116        char *dst_name = rename->path;
1117        struct stage_data *dst_entry;
1118        const char *cur_branch, *other_branch;
1119        struct diff_filespec other;
1120        struct diff_filespec *add;
1121
1122        if (stage == 2) {
1123                dst_entry = ci->dst_entry1;
1124                cur_branch = ci->branch1;
1125                other_branch = ci->branch2;
1126        } else {
1127                dst_entry = ci->dst_entry2;
1128                cur_branch = ci->branch2;
1129                other_branch = ci->branch1;
1130        }
1131
1132        add = filespec_from_entry(&other, dst_entry, stage ^ 1);
1133        if (add) {
1134                char *add_name = unique_path(o, rename->path, other_branch);
1135                update_file(o, 0, add->sha1, add->mode, add_name);
1136
1137                remove_file(o, 0, rename->path, 0);
1138                dst_name = unique_path(o, rename->path, cur_branch);
1139        } else {
1140                if (dir_in_way(rename->path, !o->call_depth)) {
1141                        dst_name = unique_path(o, rename->path, cur_branch);
1142                        output(o, 1, "%s is a directory in %s adding as %s instead",
1143                               rename->path, other_branch, dst_name);
1144                }
1145        }
1146        update_file(o, 0, rename->sha1, rename->mode, dst_name);
1147        if (stage == 2)
1148                update_stages(rename->path, NULL, rename, add);
1149        else
1150                update_stages(rename->path, NULL, add, rename);
1151
1152        if (dst_name != rename->path)
1153                free(dst_name);
1154}
1155
1156static void conflict_rename_rename_1to2(struct merge_options *o,
1157                                        struct rename_conflict_info *ci)
1158{
1159        /* One file was renamed in both branches, but to different names. */
1160        struct diff_filespec *one = ci->pair1->one;
1161        struct diff_filespec *a = ci->pair1->two;
1162        struct diff_filespec *b = ci->pair2->two;
1163
1164        output(o, 1, "CONFLICT (rename/rename): "
1165               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1166               "rename \"%s\"->\"%s\" in \"%s\"%s",
1167               one->path, a->path, ci->branch1,
1168               one->path, b->path, ci->branch2,
1169               o->call_depth ? " (left unresolved)" : "");
1170        if (o->call_depth) {
1171                struct merge_file_info mfi;
1172                struct diff_filespec other;
1173                struct diff_filespec *add;
1174                mfi = merge_file(o, one->path,
1175                                 one->sha1, one->mode,
1176                                 a->sha1, a->mode,
1177                                 b->sha1, b->mode,
1178                                 ci->branch1, ci->branch2);
1179                /*
1180                 * FIXME: For rename/add-source conflicts (if we could detect
1181                 * such), this is wrong.  We should instead find a unique
1182                 * pathname and then either rename the add-source file to that
1183                 * unique path, or use that unique path instead of src here.
1184                 */
1185                update_file(o, 0, mfi.sha, mfi.mode, one->path);
1186
1187                /*
1188                 * Above, we put the merged content at the merge-base's
1189                 * path.  Now we usually need to delete both a->path and
1190                 * b->path.  However, the rename on each side of the merge
1191                 * could also be involved in a rename/add conflict.  In
1192                 * such cases, we should keep the added file around,
1193                 * resolving the conflict at that path in its favor.
1194                 */
1195                add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
1196                if (add)
1197                        update_file(o, 0, add->sha1, add->mode, a->path);
1198                else
1199                        remove_file_from_cache(a->path);
1200                add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
1201                if (add)
1202                        update_file(o, 0, add->sha1, add->mode, b->path);
1203                else
1204                        remove_file_from_cache(b->path);
1205        } else {
1206                handle_file(o, a, 2, ci);
1207                handle_file(o, b, 3, ci);
1208        }
1209}
1210
1211static void conflict_rename_rename_2to1(struct merge_options *o,
1212                                        struct rename_conflict_info *ci)
1213{
1214        /* Two files, a & b, were renamed to the same thing, c. */
1215        struct diff_filespec *a = ci->pair1->one;
1216        struct diff_filespec *b = ci->pair2->one;
1217        struct diff_filespec *c1 = ci->pair1->two;
1218        struct diff_filespec *c2 = ci->pair2->two;
1219        char *path = c1->path; /* == c2->path */
1220        struct merge_file_info mfi_c1;
1221        struct merge_file_info mfi_c2;
1222
1223        output(o, 1, "CONFLICT (rename/rename): "
1224               "Rename %s->%s in %s. "
1225               "Rename %s->%s in %s",
1226               a->path, c1->path, ci->branch1,
1227               b->path, c2->path, ci->branch2);
1228
1229        remove_file(o, 1, a->path, would_lose_untracked(a->path));
1230        remove_file(o, 1, b->path, would_lose_untracked(b->path));
1231
1232        mfi_c1 = merge_file_special_markers(o, a, c1, &ci->ren1_other,
1233                                            o->branch1, c1->path,
1234                                            o->branch2, ci->ren1_other.path);
1235        mfi_c2 = merge_file_special_markers(o, b, &ci->ren2_other, c2,
1236                                            o->branch1, ci->ren2_other.path,
1237                                            o->branch2, c2->path);
1238
1239        if (o->call_depth) {
1240                /*
1241                 * If mfi_c1.clean && mfi_c2.clean, then it might make
1242                 * sense to do a two-way merge of those results.  But, I
1243                 * think in all cases, it makes sense to have the virtual
1244                 * merge base just undo the renames; they can be detected
1245                 * again later for the non-recursive merge.
1246                 */
1247                remove_file(o, 0, path, 0);
1248                update_file(o, 0, mfi_c1.sha, mfi_c1.mode, a->path);
1249                update_file(o, 0, mfi_c2.sha, mfi_c2.mode, b->path);
1250        } else {
1251                char *new_path1 = unique_path(o, path, ci->branch1);
1252                char *new_path2 = unique_path(o, path, ci->branch2);
1253                output(o, 1, "Renaming %s to %s and %s to %s instead",
1254                       a->path, new_path1, b->path, new_path2);
1255                remove_file(o, 0, path, 0);
1256                update_file(o, 0, mfi_c1.sha, mfi_c1.mode, new_path1);
1257                update_file(o, 0, mfi_c2.sha, mfi_c2.mode, new_path2);
1258                free(new_path2);
1259                free(new_path1);
1260        }
1261}
1262
1263static int process_renames(struct merge_options *o,
1264                           struct string_list *a_renames,
1265                           struct string_list *b_renames)
1266{
1267        int clean_merge = 1, i, j;
1268        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
1269        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
1270        const struct rename *sre;
1271
1272        for (i = 0; i < a_renames->nr; i++) {
1273                sre = a_renames->items[i].util;
1274                string_list_insert(&a_by_dst, sre->pair->two->path)->util
1275                        = (void *)sre;
1276        }
1277        for (i = 0; i < b_renames->nr; i++) {
1278                sre = b_renames->items[i].util;
1279                string_list_insert(&b_by_dst, sre->pair->two->path)->util
1280                        = (void *)sre;
1281        }
1282
1283        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1284                struct string_list *renames1, *renames2Dst;
1285                struct rename *ren1 = NULL, *ren2 = NULL;
1286                const char *branch1, *branch2;
1287                const char *ren1_src, *ren1_dst;
1288                struct string_list_item *lookup;
1289
1290                if (i >= a_renames->nr) {
1291                        ren2 = b_renames->items[j++].util;
1292                } else if (j >= b_renames->nr) {
1293                        ren1 = a_renames->items[i++].util;
1294                } else {
1295                        int compare = strcmp(a_renames->items[i].string,
1296                                             b_renames->items[j].string);
1297                        if (compare <= 0)
1298                                ren1 = a_renames->items[i++].util;
1299                        if (compare >= 0)
1300                                ren2 = b_renames->items[j++].util;
1301                }
1302
1303                /* TODO: refactor, so that 1/2 are not needed */
1304                if (ren1) {
1305                        renames1 = a_renames;
1306                        renames2Dst = &b_by_dst;
1307                        branch1 = o->branch1;
1308                        branch2 = o->branch2;
1309                } else {
1310                        struct rename *tmp;
1311                        renames1 = b_renames;
1312                        renames2Dst = &a_by_dst;
1313                        branch1 = o->branch2;
1314                        branch2 = o->branch1;
1315                        tmp = ren2;
1316                        ren2 = ren1;
1317                        ren1 = tmp;
1318                }
1319
1320                if (ren1->processed)
1321                        continue;
1322                ren1->processed = 1;
1323                ren1->dst_entry->processed = 1;
1324                /* BUG: We should only mark src_entry as processed if we
1325                 * are not dealing with a rename + add-source case.
1326                 */
1327                ren1->src_entry->processed = 1;
1328
1329                ren1_src = ren1->pair->one->path;
1330                ren1_dst = ren1->pair->two->path;
1331
1332                if (ren2) {
1333                        /* One file renamed on both sides */
1334                        const char *ren2_src = ren2->pair->one->path;
1335                        const char *ren2_dst = ren2->pair->two->path;
1336                        enum rename_type rename_type;
1337                        if (strcmp(ren1_src, ren2_src) != 0)
1338                                die("ren1_src != ren2_src");
1339                        ren2->dst_entry->processed = 1;
1340                        ren2->processed = 1;
1341                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1342                                rename_type = RENAME_ONE_FILE_TO_TWO;
1343                                clean_merge = 0;
1344                        } else {
1345                                rename_type = RENAME_ONE_FILE_TO_ONE;
1346                                /* BUG: We should only remove ren1_src in
1347                                 * the base stage (think of rename +
1348                                 * add-source cases).
1349                                 */
1350                                remove_file(o, 1, ren1_src, 1);
1351                                update_entry(ren1->dst_entry,
1352                                             ren1->pair->one,
1353                                             ren1->pair->two,
1354                                             ren2->pair->two);
1355                        }
1356                        setup_rename_conflict_info(rename_type,
1357                                                   ren1->pair,
1358                                                   ren2->pair,
1359                                                   branch1,
1360                                                   branch2,
1361                                                   ren1->dst_entry,
1362                                                   ren2->dst_entry,
1363                                                   o,
1364                                                   NULL,
1365                                                   NULL);
1366                } else if ((lookup = string_list_lookup(renames2Dst, ren1_dst))) {
1367                        /* Two different files renamed to the same thing */
1368                        char *ren2_dst;
1369                        ren2 = lookup->util;
1370                        ren2_dst = ren2->pair->two->path;
1371                        if (strcmp(ren1_dst, ren2_dst) != 0)
1372                                die("ren1_dst != ren2_dst");
1373
1374                        clean_merge = 0;
1375                        ren2->processed = 1;
1376                        /*
1377                         * BUG: We should only mark src_entry as processed
1378                         * if we are not dealing with a rename + add-source
1379                         * case.
1380                         */
1381                        ren2->src_entry->processed = 1;
1382
1383                        setup_rename_conflict_info(RENAME_TWO_FILES_TO_ONE,
1384                                                   ren1->pair,
1385                                                   ren2->pair,
1386                                                   branch1,
1387                                                   branch2,
1388                                                   ren1->dst_entry,
1389                                                   ren2->dst_entry,
1390                                                   o,
1391                                                   ren1->src_entry,
1392                                                   ren2->src_entry);
1393
1394                } else {
1395                        /* Renamed in 1, maybe changed in 2 */
1396                        /* we only use sha1 and mode of these */
1397                        struct diff_filespec src_other, dst_other;
1398                        int try_merge;
1399
1400                        /*
1401                         * unpack_trees loads entries from common-commit
1402                         * into stage 1, from head-commit into stage 2, and
1403                         * from merge-commit into stage 3.  We keep track
1404                         * of which side corresponds to the rename.
1405                         */
1406                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1407                        int other_stage =   a_renames == renames1 ? 3 : 2;
1408
1409                        /* BUG: We should only remove ren1_src in the base
1410                         * stage and in other_stage (think of rename +
1411                         * add-source case).
1412                         */
1413                        remove_file(o, 1, ren1_src,
1414                                    renamed_stage == 2 || !was_tracked(ren1_src));
1415
1416                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1417                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1418                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1419                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1420                        try_merge = 0;
1421
1422                        if (sha_eq(src_other.sha1, null_sha1)) {
1423                                setup_rename_conflict_info(RENAME_DELETE,
1424                                                           ren1->pair,
1425                                                           NULL,
1426                                                           branch1,
1427                                                           branch2,
1428                                                           ren1->dst_entry,
1429                                                           NULL,
1430                                                           o,
1431                                                           NULL,
1432                                                           NULL);
1433                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1434                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1435                                /*
1436                                 * Added file on the other side identical to
1437                                 * the file being renamed: clean merge.
1438                                 * Also, there is no need to overwrite the
1439                                 * file already in the working copy, so call
1440                                 * update_file_flags() instead of
1441                                 * update_file().
1442                                 */
1443                                update_file_flags(o,
1444                                                  ren1->pair->two->sha1,
1445                                                  ren1->pair->two->mode,
1446                                                  ren1_dst,
1447                                                  1, /* update_cache */
1448                                                  0  /* update_wd    */);
1449                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1450                                clean_merge = 0;
1451                                try_merge = 1;
1452                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1453                                       "%s added in %s",
1454                                       ren1_src, ren1_dst, branch1,
1455                                       ren1_dst, branch2);
1456                                if (o->call_depth) {
1457                                        struct merge_file_info mfi;
1458                                        mfi = merge_file(o, ren1_dst, null_sha1, 0,
1459                                                         ren1->pair->two->sha1, ren1->pair->two->mode,
1460                                                         dst_other.sha1, dst_other.mode,
1461                                                         branch1, branch2);
1462                                        output(o, 1, "Adding merged %s", ren1_dst);
1463                                        update_file(o, 0, mfi.sha, mfi.mode, ren1_dst);
1464                                        try_merge = 0;
1465                                } else {
1466                                        char *new_path = unique_path(o, ren1_dst, branch2);
1467                                        output(o, 1, "Adding as %s instead", new_path);
1468                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1469                                        free(new_path);
1470                                }
1471                        } else
1472                                try_merge = 1;
1473
1474                        if (try_merge) {
1475                                struct diff_filespec *one, *a, *b;
1476                                src_other.path = (char *)ren1_src;
1477
1478                                one = ren1->pair->one;
1479                                if (a_renames == renames1) {
1480                                        a = ren1->pair->two;
1481                                        b = &src_other;
1482                                } else {
1483                                        b = ren1->pair->two;
1484                                        a = &src_other;
1485                                }
1486                                update_entry(ren1->dst_entry, one, a, b);
1487                                setup_rename_conflict_info(RENAME_NORMAL,
1488                                                           ren1->pair,
1489                                                           NULL,
1490                                                           branch1,
1491                                                           NULL,
1492                                                           ren1->dst_entry,
1493                                                           NULL,
1494                                                           o,
1495                                                           NULL,
1496                                                           NULL);
1497                        }
1498                }
1499        }
1500        string_list_clear(&a_by_dst, 0);
1501        string_list_clear(&b_by_dst, 0);
1502
1503        return clean_merge;
1504}
1505
1506static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1507{
1508        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1509}
1510
1511static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1512{
1513        void *buf;
1514        enum object_type type;
1515        unsigned long size;
1516        buf = read_sha1_file(sha1, &type, &size);
1517        if (!buf)
1518                return error("cannot read object %s", sha1_to_hex(sha1));
1519        if (type != OBJ_BLOB) {
1520                free(buf);
1521                return error("object %s is not a blob", sha1_to_hex(sha1));
1522        }
1523        strbuf_attach(dst, buf, size, size + 1);
1524        return 0;
1525}
1526
1527static int blob_unchanged(const unsigned char *o_sha,
1528                          const unsigned char *a_sha,
1529                          int renormalize, const char *path)
1530{
1531        struct strbuf o = STRBUF_INIT;
1532        struct strbuf a = STRBUF_INIT;
1533        int ret = 0; /* assume changed for safety */
1534
1535        if (sha_eq(o_sha, a_sha))
1536                return 1;
1537        if (!renormalize)
1538                return 0;
1539
1540        assert(o_sha && a_sha);
1541        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1542                goto error_return;
1543        /*
1544         * Note: binary | is used so that both renormalizations are
1545         * performed.  Comparison can be skipped if both files are
1546         * unchanged since their sha1s have already been compared.
1547         */
1548        if (renormalize_buffer(path, o.buf, o.len, &o) |
1549            renormalize_buffer(path, a.buf, o.len, &a))
1550                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1551
1552error_return:
1553        strbuf_release(&o);
1554        strbuf_release(&a);
1555        return ret;
1556}
1557
1558static void handle_modify_delete(struct merge_options *o,
1559                                 const char *path,
1560                                 unsigned char *o_sha, int o_mode,
1561                                 unsigned char *a_sha, int a_mode,
1562                                 unsigned char *b_sha, int b_mode)
1563{
1564        handle_change_delete(o,
1565                             path,
1566                             o_sha, o_mode,
1567                             a_sha, a_mode,
1568                             b_sha, b_mode,
1569                             "modify", "modified");
1570}
1571
1572static int merge_content(struct merge_options *o,
1573                         const char *path,
1574                         unsigned char *o_sha, int o_mode,
1575                         unsigned char *a_sha, int a_mode,
1576                         unsigned char *b_sha, int b_mode,
1577                         struct rename_conflict_info *rename_conflict_info)
1578{
1579        const char *reason = "content";
1580        const char *path1 = NULL, *path2 = NULL;
1581        struct merge_file_info mfi;
1582        struct diff_filespec one, a, b;
1583        unsigned df_conflict_remains = 0;
1584
1585        if (!o_sha) {
1586                reason = "add/add";
1587                o_sha = (unsigned char *)null_sha1;
1588        }
1589        one.path = a.path = b.path = (char *)path;
1590        hashcpy(one.sha1, o_sha);
1591        one.mode = o_mode;
1592        hashcpy(a.sha1, a_sha);
1593        a.mode = a_mode;
1594        hashcpy(b.sha1, b_sha);
1595        b.mode = b_mode;
1596
1597        if (rename_conflict_info) {
1598                struct diff_filepair *pair1 = rename_conflict_info->pair1;
1599
1600                path1 = (o->branch1 == rename_conflict_info->branch1) ?
1601                        pair1->two->path : pair1->one->path;
1602                /* If rename_conflict_info->pair2 != NULL, we are in
1603                 * RENAME_ONE_FILE_TO_ONE case.  Otherwise, we have a
1604                 * normal rename.
1605                 */
1606                path2 = (rename_conflict_info->pair2 ||
1607                         o->branch2 == rename_conflict_info->branch1) ?
1608                        pair1->two->path : pair1->one->path;
1609
1610                if (dir_in_way(path, !o->call_depth))
1611                        df_conflict_remains = 1;
1612        }
1613        mfi = merge_file_special_markers(o, &one, &a, &b,
1614                                         o->branch1, path1,
1615                                         o->branch2, path2);
1616
1617        if (mfi.clean && !df_conflict_remains &&
1618            sha_eq(mfi.sha, a_sha) && mfi.mode == a_mode) {
1619                int path_renamed_outside_HEAD;
1620                output(o, 3, "Skipped %s (merged same as existing)", path);
1621                /*
1622                 * The content merge resulted in the same file contents we
1623                 * already had.  We can return early if those file contents
1624                 * are recorded at the correct path (which may not be true
1625                 * if the merge involves a rename).
1626                 */
1627                path_renamed_outside_HEAD = !path2 || !strcmp(path, path2);
1628                if (!path_renamed_outside_HEAD) {
1629                        add_cacheinfo(mfi.mode, mfi.sha, path,
1630                                      0 /*stage*/, 1 /*refresh*/, 0 /*options*/);
1631                        return mfi.clean;
1632                }
1633        } else
1634                output(o, 2, "Auto-merging %s", path);
1635
1636        if (!mfi.clean) {
1637                if (S_ISGITLINK(mfi.mode))
1638                        reason = "submodule";
1639                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1640                                reason, path);
1641                if (rename_conflict_info && !df_conflict_remains)
1642                        update_stages(path, &one, &a, &b);
1643        }
1644
1645        if (df_conflict_remains) {
1646                char *new_path;
1647                if (o->call_depth) {
1648                        remove_file_from_cache(path);
1649                } else {
1650                        if (!mfi.clean)
1651                                update_stages(path, &one, &a, &b);
1652                        else {
1653                                int file_from_stage2 = was_tracked(path);
1654                                struct diff_filespec merged;
1655                                hashcpy(merged.sha1, mfi.sha);
1656                                merged.mode = mfi.mode;
1657
1658                                update_stages(path, NULL,
1659                                              file_from_stage2 ? &merged : NULL,
1660                                              file_from_stage2 ? NULL : &merged);
1661                        }
1662
1663                }
1664                new_path = unique_path(o, path, rename_conflict_info->branch1);
1665                output(o, 1, "Adding as %s instead", new_path);
1666                update_file(o, 0, mfi.sha, mfi.mode, new_path);
1667                free(new_path);
1668                mfi.clean = 0;
1669        } else {
1670                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1671        }
1672        return mfi.clean;
1673
1674}
1675
1676/* Per entry merge function */
1677static int process_entry(struct merge_options *o,
1678                         const char *path, struct stage_data *entry)
1679{
1680        /*
1681        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1682        print_index_entry("\tpath: ", entry);
1683        */
1684        int clean_merge = 1;
1685        int normalize = o->renormalize;
1686        unsigned o_mode = entry->stages[1].mode;
1687        unsigned a_mode = entry->stages[2].mode;
1688        unsigned b_mode = entry->stages[3].mode;
1689        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1690        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1691        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1692
1693        entry->processed = 1;
1694        if (entry->rename_conflict_info) {
1695                struct rename_conflict_info *conflict_info = entry->rename_conflict_info;
1696                switch (conflict_info->rename_type) {
1697                case RENAME_NORMAL:
1698                case RENAME_ONE_FILE_TO_ONE:
1699                        clean_merge = merge_content(o, path,
1700                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1701                                                    conflict_info);
1702                        break;
1703                case RENAME_DELETE:
1704                        clean_merge = 0;
1705                        conflict_rename_delete(o, conflict_info->pair1,
1706                                               conflict_info->branch1,
1707                                               conflict_info->branch2);
1708                        break;
1709                case RENAME_ONE_FILE_TO_TWO:
1710                        clean_merge = 0;
1711                        conflict_rename_rename_1to2(o, conflict_info);
1712                        break;
1713                case RENAME_TWO_FILES_TO_ONE:
1714                        clean_merge = 0;
1715                        conflict_rename_rename_2to1(o, conflict_info);
1716                        break;
1717                default:
1718                        entry->processed = 0;
1719                        break;
1720                }
1721        } else if (o_sha && (!a_sha || !b_sha)) {
1722                /* Case A: Deleted in one */
1723                if ((!a_sha && !b_sha) ||
1724                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1725                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1726                        /* Deleted in both or deleted in one and
1727                         * unchanged in the other */
1728                        if (a_sha)
1729                                output(o, 2, "Removing %s", path);
1730                        /* do not touch working file if it did not exist */
1731                        remove_file(o, 1, path, !a_sha);
1732                } else {
1733                        /* Modify/delete; deleted side may have put a directory in the way */
1734                        clean_merge = 0;
1735                        handle_modify_delete(o, path, o_sha, o_mode,
1736                                             a_sha, a_mode, b_sha, b_mode);
1737                }
1738        } else if ((!o_sha && a_sha && !b_sha) ||
1739                   (!o_sha && !a_sha && b_sha)) {
1740                /* Case B: Added in one. */
1741                /* [nothing|directory] -> ([nothing|directory], file) */
1742
1743                const char *add_branch;
1744                const char *other_branch;
1745                unsigned mode;
1746                const unsigned char *sha;
1747                const char *conf;
1748
1749                if (a_sha) {
1750                        add_branch = o->branch1;
1751                        other_branch = o->branch2;
1752                        mode = a_mode;
1753                        sha = a_sha;
1754                        conf = "file/directory";
1755                } else {
1756                        add_branch = o->branch2;
1757                        other_branch = o->branch1;
1758                        mode = b_mode;
1759                        sha = b_sha;
1760                        conf = "directory/file";
1761                }
1762                if (dir_in_way(path, !o->call_depth)) {
1763                        char *new_path = unique_path(o, path, add_branch);
1764                        clean_merge = 0;
1765                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1766                               "Adding %s as %s",
1767                               conf, path, other_branch, path, new_path);
1768                        if (o->call_depth)
1769                                remove_file_from_cache(path);
1770                        update_file(o, 0, sha, mode, new_path);
1771                        if (o->call_depth)
1772                                remove_file_from_cache(path);
1773                        free(new_path);
1774                } else {
1775                        output(o, 2, "Adding %s", path);
1776                        /* do not overwrite file if already present */
1777                        update_file_flags(o, sha, mode, path, 1, !a_sha);
1778                }
1779        } else if (a_sha && b_sha) {
1780                /* Case C: Added in both (check for same permissions) and */
1781                /* case D: Modified in both, but differently. */
1782                clean_merge = merge_content(o, path,
1783                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1784                                            NULL);
1785        } else if (!o_sha && !a_sha && !b_sha) {
1786                /*
1787                 * this entry was deleted altogether. a_mode == 0 means
1788                 * we had that path and want to actively remove it.
1789                 */
1790                remove_file(o, 1, path, !a_mode);
1791        } else
1792                die("Fatal merge failure, shouldn't happen.");
1793
1794        return clean_merge;
1795}
1796
1797int merge_trees(struct merge_options *o,
1798                struct tree *head,
1799                struct tree *merge,
1800                struct tree *common,
1801                struct tree **result)
1802{
1803        int code, clean;
1804
1805        if (o->subtree_shift) {
1806                merge = shift_tree_object(head, merge, o->subtree_shift);
1807                common = shift_tree_object(head, common, o->subtree_shift);
1808        }
1809
1810        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1811                output(o, 0, "Already up-to-date!");
1812                *result = head;
1813                return 1;
1814        }
1815
1816        code = git_merge_trees(o->call_depth, common, head, merge);
1817
1818        if (code != 0) {
1819                if (show(o, 4) || o->call_depth)
1820                        die("merging of trees %s and %s failed",
1821                            sha1_to_hex(head->object.sha1),
1822                            sha1_to_hex(merge->object.sha1));
1823                else
1824                        exit(128);
1825        }
1826
1827        if (unmerged_cache()) {
1828                struct string_list *entries, *re_head, *re_merge;
1829                int i;
1830                string_list_clear(&o->current_file_set, 1);
1831                string_list_clear(&o->current_directory_set, 1);
1832                get_files_dirs(o, head);
1833                get_files_dirs(o, merge);
1834
1835                entries = get_unmerged();
1836                record_df_conflict_files(o, entries);
1837                re_head  = get_renames(o, head, common, head, merge, entries);
1838                re_merge = get_renames(o, merge, common, head, merge, entries);
1839                clean = process_renames(o, re_head, re_merge);
1840                for (i = entries->nr-1; 0 <= i; i--) {
1841                        const char *path = entries->items[i].string;
1842                        struct stage_data *e = entries->items[i].util;
1843                        if (!e->processed
1844                                && !process_entry(o, path, e))
1845                                clean = 0;
1846                }
1847                for (i = 0; i < entries->nr; i++) {
1848                        struct stage_data *e = entries->items[i].util;
1849                        if (!e->processed)
1850                                die("Unprocessed path??? %s",
1851                                    entries->items[i].string);
1852                }
1853
1854                string_list_clear(re_merge, 0);
1855                string_list_clear(re_head, 0);
1856                string_list_clear(entries, 1);
1857
1858        }
1859        else
1860                clean = 1;
1861
1862        if (o->call_depth)
1863                *result = write_tree_from_memory(o);
1864
1865        return clean;
1866}
1867
1868static struct commit_list *reverse_commit_list(struct commit_list *list)
1869{
1870        struct commit_list *next = NULL, *current, *backup;
1871        for (current = list; current; current = backup) {
1872                backup = current->next;
1873                current->next = next;
1874                next = current;
1875        }
1876        return next;
1877}
1878
1879/*
1880 * Merge the commits h1 and h2, return the resulting virtual
1881 * commit object and a flag indicating the cleanness of the merge.
1882 */
1883int merge_recursive(struct merge_options *o,
1884                    struct commit *h1,
1885                    struct commit *h2,
1886                    struct commit_list *ca,
1887                    struct commit **result)
1888{
1889        struct commit_list *iter;
1890        struct commit *merged_common_ancestors;
1891        struct tree *mrtree = mrtree;
1892        int clean;
1893
1894        if (show(o, 4)) {
1895                output(o, 4, "Merging:");
1896                output_commit_title(o, h1);
1897                output_commit_title(o, h2);
1898        }
1899
1900        if (!ca) {
1901                ca = get_merge_bases(h1, h2, 1);
1902                ca = reverse_commit_list(ca);
1903        }
1904
1905        if (show(o, 5)) {
1906                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1907                for (iter = ca; iter; iter = iter->next)
1908                        output_commit_title(o, iter->item);
1909        }
1910
1911        merged_common_ancestors = pop_commit(&ca);
1912        if (merged_common_ancestors == NULL) {
1913                /* if there is no common ancestor, use an empty tree */
1914                struct tree *tree;
1915
1916                tree = lookup_tree((const unsigned char *)EMPTY_TREE_SHA1_BIN);
1917                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1918        }
1919
1920        for (iter = ca; iter; iter = iter->next) {
1921                const char *saved_b1, *saved_b2;
1922                o->call_depth++;
1923                /*
1924                 * When the merge fails, the result contains files
1925                 * with conflict markers. The cleanness flag is
1926                 * ignored, it was never actually used, as result of
1927                 * merge_trees has always overwritten it: the committed
1928                 * "conflicts" were already resolved.
1929                 */
1930                discard_cache();
1931                saved_b1 = o->branch1;
1932                saved_b2 = o->branch2;
1933                o->branch1 = "Temporary merge branch 1";
1934                o->branch2 = "Temporary merge branch 2";
1935                merge_recursive(o, merged_common_ancestors, iter->item,
1936                                NULL, &merged_common_ancestors);
1937                o->branch1 = saved_b1;
1938                o->branch2 = saved_b2;
1939                o->call_depth--;
1940
1941                if (!merged_common_ancestors)
1942                        die("merge returned no commit");
1943        }
1944
1945        discard_cache();
1946        if (!o->call_depth)
1947                read_cache();
1948
1949        o->ancestor = "merged common ancestors";
1950        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1951                            &mrtree);
1952
1953        if (o->call_depth) {
1954                *result = make_virtual_commit(mrtree, "merged tree");
1955                commit_list_insert(h1, &(*result)->parents);
1956                commit_list_insert(h2, &(*result)->parents->next);
1957        }
1958        flush_output(o);
1959        if (show(o, 2))
1960                diff_warn_rename_limit("merge.renamelimit",
1961                                       o->needed_rename_limit, 0);
1962        return clean;
1963}
1964
1965static struct commit *get_ref(const unsigned char *sha1, const char *name)
1966{
1967        struct object *object;
1968
1969        object = deref_tag(parse_object(sha1), name, strlen(name));
1970        if (!object)
1971                return NULL;
1972        if (object->type == OBJ_TREE)
1973                return make_virtual_commit((struct tree*)object, name);
1974        if (object->type != OBJ_COMMIT)
1975                return NULL;
1976        if (parse_commit((struct commit *)object))
1977                return NULL;
1978        return (struct commit *)object;
1979}
1980
1981int merge_recursive_generic(struct merge_options *o,
1982                            const unsigned char *head,
1983                            const unsigned char *merge,
1984                            int num_base_list,
1985                            const unsigned char **base_list,
1986                            struct commit **result)
1987{
1988        int clean, index_fd;
1989        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1990        struct commit *head_commit = get_ref(head, o->branch1);
1991        struct commit *next_commit = get_ref(merge, o->branch2);
1992        struct commit_list *ca = NULL;
1993
1994        if (base_list) {
1995                int i;
1996                for (i = 0; i < num_base_list; ++i) {
1997                        struct commit *base;
1998                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1999                                return error("Could not parse object '%s'",
2000                                        sha1_to_hex(base_list[i]));
2001                        commit_list_insert(base, &ca);
2002                }
2003        }
2004
2005        index_fd = hold_locked_index(lock, 1);
2006        clean = merge_recursive(o, head_commit, next_commit, ca,
2007                        result);
2008        if (active_cache_changed &&
2009                        (write_cache(index_fd, active_cache, active_nr) ||
2010                         commit_locked_index(lock)))
2011                return error("Unable to write index.");
2012
2013        return clean ? 0 : 1;
2014}
2015
2016static int merge_recursive_config(const char *var, const char *value, void *cb)
2017{
2018        struct merge_options *o = cb;
2019        if (!strcmp(var, "merge.verbosity")) {
2020                o->verbosity = git_config_int(var, value);
2021                return 0;
2022        }
2023        if (!strcmp(var, "diff.renamelimit")) {
2024                o->diff_rename_limit = git_config_int(var, value);
2025                return 0;
2026        }
2027        if (!strcmp(var, "merge.renamelimit")) {
2028                o->merge_rename_limit = git_config_int(var, value);
2029                return 0;
2030        }
2031        return git_xmerge_config(var, value, cb);
2032}
2033
2034void init_merge_options(struct merge_options *o)
2035{
2036        memset(o, 0, sizeof(struct merge_options));
2037        o->verbosity = 2;
2038        o->buffer_output = 1;
2039        o->diff_rename_limit = -1;
2040        o->merge_rename_limit = -1;
2041        o->renormalize = 0;
2042        git_config(merge_recursive_config, o);
2043        if (getenv("GIT_MERGE_VERBOSITY"))
2044                o->verbosity =
2045                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
2046        if (o->verbosity >= 5)
2047                o->buffer_output = 0;
2048        strbuf_init(&o->obuf, 0);
2049        memset(&o->current_file_set, 0, sizeof(struct string_list));
2050        o->current_file_set.strdup_strings = 1;
2051        memset(&o->current_directory_set, 0, sizeof(struct string_list));
2052        o->current_directory_set.strdup_strings = 1;
2053        memset(&o->df_conflict_file_set, 0, sizeof(struct string_list));
2054        o->df_conflict_file_set.strdup_strings = 1;
2055}
2056
2057int parse_merge_opt(struct merge_options *o, const char *s)
2058{
2059        if (!s || !*s)
2060                return -1;
2061        if (!strcmp(s, "ours"))
2062                o->recursive_variant = MERGE_RECURSIVE_OURS;
2063        else if (!strcmp(s, "theirs"))
2064                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
2065        else if (!strcmp(s, "subtree"))
2066                o->subtree_shift = "";
2067        else if (!prefixcmp(s, "subtree="))
2068                o->subtree_shift = s + strlen("subtree=");
2069        else if (!strcmp(s, "patience"))
2070                o->xdl_opts |= XDF_PATIENCE_DIFF;
2071        else if (!strcmp(s, "histogram"))
2072                o->xdl_opts |= XDF_HISTOGRAM_DIFF;
2073        else if (!strcmp(s, "ignore-space-change"))
2074                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2075        else if (!strcmp(s, "ignore-all-space"))
2076                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
2077        else if (!strcmp(s, "ignore-space-at-eol"))
2078                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2079        else if (!strcmp(s, "renormalize"))
2080                o->renormalize = 1;
2081        else if (!strcmp(s, "no-renormalize"))
2082                o->renormalize = 0;
2083        else if (!prefixcmp(s, "rename-threshold=")) {
2084                const char *score = s + strlen("rename-threshold=");
2085                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
2086                        return -1;
2087        }
2088        else
2089                return -1;
2090        return 0;
2091}