merge-recursive.con commit Merge branch 'jt/itimer-autoconf' (7dded66)
   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
  41static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  42{
  43        struct commit *commit = alloc_commit_node();
  44        struct merge_remote_desc *desc = xmalloc(sizeof(*desc));
  45
  46        desc->name = comment;
  47        desc->obj = (struct object *)commit;
  48        commit->tree = tree;
  49        commit->util = desc;
  50        commit->object.parsed = 1;
  51        return commit;
  52}
  53
  54/*
  55 * Since we use get_tree_entry(), which does not put the read object into
  56 * the object pool, we cannot rely on a == b.
  57 */
  58static int sha_eq(const unsigned char *a, const unsigned char *b)
  59{
  60        if (!a && !b)
  61                return 2;
  62        return a && b && hashcmp(a, b) == 0;
  63}
  64
  65enum rename_type {
  66        RENAME_NORMAL = 0,
  67        RENAME_DELETE,
  68        RENAME_ONE_FILE_TO_ONE,
  69        RENAME_ONE_FILE_TO_TWO,
  70        RENAME_TWO_FILES_TO_ONE
  71};
  72
  73struct rename_conflict_info {
  74        enum rename_type rename_type;
  75        struct diff_filepair *pair1;
  76        struct diff_filepair *pair2;
  77        const char *branch1;
  78        const char *branch2;
  79        struct stage_data *dst_entry1;
  80        struct stage_data *dst_entry2;
  81        struct diff_filespec ren1_other;
  82        struct diff_filespec ren2_other;
  83};
  84
  85/*
  86 * Since we want to write the index eventually, we cannot reuse the index
  87 * for these (temporary) data.
  88 */
  89struct stage_data {
  90        struct {
  91                unsigned mode;
  92                unsigned char sha[20];
  93        } stages[4];
  94        struct rename_conflict_info *rename_conflict_info;
  95        unsigned processed:1;
  96};
  97
  98static inline void setup_rename_conflict_info(enum rename_type rename_type,
  99                                              struct diff_filepair *pair1,
 100                                              struct diff_filepair *pair2,
 101                                              const char *branch1,
 102                                              const char *branch2,
 103                                              struct stage_data *dst_entry1,
 104                                              struct stage_data *dst_entry2,
 105                                              struct merge_options *o,
 106                                              struct stage_data *src_entry1,
 107                                              struct stage_data *src_entry2)
 108{
 109        struct rename_conflict_info *ci = xcalloc(1, sizeof(struct rename_conflict_info));
 110        ci->rename_type = rename_type;
 111        ci->pair1 = pair1;
 112        ci->branch1 = branch1;
 113        ci->branch2 = branch2;
 114
 115        ci->dst_entry1 = dst_entry1;
 116        dst_entry1->rename_conflict_info = ci;
 117        dst_entry1->processed = 0;
 118
 119        assert(!pair2 == !dst_entry2);
 120        if (dst_entry2) {
 121                ci->dst_entry2 = dst_entry2;
 122                ci->pair2 = pair2;
 123                dst_entry2->rename_conflict_info = ci;
 124        }
 125
 126        if (rename_type == RENAME_TWO_FILES_TO_ONE) {
 127                /*
 128                 * For each rename, there could have been
 129                 * modifications on the side of history where that
 130                 * file was not renamed.
 131                 */
 132                int ostage1 = o->branch1 == branch1 ? 3 : 2;
 133                int ostage2 = ostage1 ^ 1;
 134
 135                ci->ren1_other.path = pair1->one->path;
 136                hashcpy(ci->ren1_other.sha1, src_entry1->stages[ostage1].sha);
 137                ci->ren1_other.mode = src_entry1->stages[ostage1].mode;
 138
 139                ci->ren2_other.path = pair2->one->path;
 140                hashcpy(ci->ren2_other.sha1, src_entry2->stages[ostage2].sha);
 141                ci->ren2_other.mode = src_entry2->stages[ostage2].mode;
 142        }
 143}
 144
 145static int show(struct merge_options *o, int v)
 146{
 147        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 148}
 149
 150static void flush_output(struct merge_options *o)
 151{
 152        if (o->obuf.len) {
 153                fputs(o->obuf.buf, stdout);
 154                strbuf_reset(&o->obuf);
 155        }
 156}
 157
 158__attribute__((format (printf, 3, 4)))
 159static void output(struct merge_options *o, int v, const char *fmt, ...)
 160{
 161        va_list ap;
 162
 163        if (!show(o, v))
 164                return;
 165
 166        strbuf_addchars(&o->obuf, ' ', o->call_depth * 2);
 167
 168        va_start(ap, fmt);
 169        strbuf_vaddf(&o->obuf, fmt, ap);
 170        va_end(ap);
 171
 172        strbuf_addch(&o->obuf, '\n');
 173        if (!o->buffer_output)
 174                flush_output(o);
 175}
 176
 177static void output_commit_title(struct merge_options *o, struct commit *commit)
 178{
 179        int i;
 180        flush_output(o);
 181        for (i = o->call_depth; i--;)
 182                fputs("  ", stdout);
 183        if (commit->util)
 184                printf("virtual %s\n", merge_remote_util(commit)->name);
 185        else {
 186                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 187                if (parse_commit(commit) != 0)
 188                        printf(_("(bad commit)\n"));
 189                else {
 190                        const char *title;
 191                        const char *msg = get_commit_buffer(commit, NULL);
 192                        int len = find_commit_subject(msg, &title);
 193                        if (len)
 194                                printf("%.*s\n", len, title);
 195                        unuse_commit_buffer(commit, msg);
 196                }
 197        }
 198}
 199
 200static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 201                const char *path, int stage, int refresh, int options)
 202{
 203        struct cache_entry *ce;
 204        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage,
 205                              (refresh ? (CE_MATCH_REFRESH |
 206                                          CE_MATCH_IGNORE_MISSING) : 0 ));
 207        if (!ce)
 208                return error(_("addinfo_cache failed for path '%s'"), path);
 209        return add_cache_entry(ce, options);
 210}
 211
 212static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 213{
 214        parse_tree(tree);
 215        init_tree_desc(desc, tree->buffer, tree->size);
 216}
 217
 218static int git_merge_trees(int index_only,
 219                           struct tree *common,
 220                           struct tree *head,
 221                           struct tree *merge)
 222{
 223        int rc;
 224        struct tree_desc t[3];
 225        struct unpack_trees_options opts;
 226
 227        memset(&opts, 0, sizeof(opts));
 228        if (index_only)
 229                opts.index_only = 1;
 230        else
 231                opts.update = 1;
 232        opts.merge = 1;
 233        opts.head_idx = 2;
 234        opts.fn = threeway_merge;
 235        opts.src_index = &the_index;
 236        opts.dst_index = &the_index;
 237        setup_unpack_trees_porcelain(&opts, "merge");
 238
 239        init_tree_desc_from_tree(t+0, common);
 240        init_tree_desc_from_tree(t+1, head);
 241        init_tree_desc_from_tree(t+2, merge);
 242
 243        rc = unpack_trees(3, t, &opts);
 244        cache_tree_free(&active_cache_tree);
 245        return rc;
 246}
 247
 248struct tree *write_tree_from_memory(struct merge_options *o)
 249{
 250        struct tree *result = NULL;
 251
 252        if (unmerged_cache()) {
 253                int i;
 254                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 255                for (i = 0; i < active_nr; i++) {
 256                        const struct cache_entry *ce = active_cache[i];
 257                        if (ce_stage(ce))
 258                                fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
 259                                        (int)ce_namelen(ce), ce->name);
 260                }
 261                die("Bug in merge-recursive.c");
 262        }
 263
 264        if (!active_cache_tree)
 265                active_cache_tree = cache_tree();
 266
 267        if (!cache_tree_fully_valid(active_cache_tree) &&
 268            cache_tree_update(&the_index, 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        memset(&match_all, 0, sizeof(match_all));
 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                const 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 tree, 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        DIFF_OPT_CLR(&opts, RENAME_EMPTY);
 490        opts.detect_rename = DIFF_DETECT_RENAME;
 491        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 492                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 493                            1000;
 494        opts.rename_score = o->rename_score;
 495        opts.show_rename_progress = o->show_rename_progress;
 496        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 497        diff_setup_done(&opts);
 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 (ignore_case) {
 591                        struct cache_entry *ce;
 592                        ce = cache_file_exists(path, strlen(path), ignore_case);
 593                        if (ce && ce_stage(ce) == 0)
 594                                return 0;
 595                }
 596                if (remove_path(path))
 597                        return -1;
 598        }
 599        return 0;
 600}
 601
 602/* add a string to a strbuf, but converting "/" to "_" */
 603static void add_flattened_path(struct strbuf *out, const char *s)
 604{
 605        size_t i = out->len;
 606        strbuf_addstr(out, s);
 607        for (; i < out->len; i++)
 608                if (out->buf[i] == '/')
 609                        out->buf[i] = '_';
 610}
 611
 612static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 613{
 614        struct strbuf newpath = STRBUF_INIT;
 615        int suffix = 0;
 616        struct stat st;
 617        size_t base_len;
 618
 619        strbuf_addf(&newpath, "%s~", path);
 620        add_flattened_path(&newpath, branch);
 621
 622        base_len = newpath.len;
 623        while (string_list_has_string(&o->current_file_set, newpath.buf) ||
 624               string_list_has_string(&o->current_directory_set, newpath.buf) ||
 625               lstat(newpath.buf, &st) == 0) {
 626                strbuf_setlen(&newpath, base_len);
 627                strbuf_addf(&newpath, "_%d", suffix++);
 628        }
 629
 630        string_list_insert(&o->current_file_set, newpath.buf);
 631        return strbuf_detach(&newpath, NULL);
 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 == SCLD_EXISTS) {
 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                        write_in_full(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                        mkpathdup("%s:%s", o->ancestor, one->path);
 866                name1 = mkpathdup("%s:%s", branch1, a->path);
 867                name2 = mkpathdup("%s:%s", branch2, b->path);
 868        } else {
 869                base_name = o->ancestor == NULL ? NULL :
 870                        mkpathdup("%s", o->ancestor);
 871                name1 = mkpathdup("%s", branch1);
 872                name2 = mkpathdup("%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(base_name);
 883        free(name1);
 884        free(name2);
 885        free(orig.ptr);
 886        free(src1.ptr);
 887        free(src2.ptr);
 888        return merge_status;
 889}
 890
 891static struct merge_file_info merge_file_1(struct merge_options *o,
 892                                           const struct diff_filespec *one,
 893                                           const struct diff_filespec *a,
 894                                           const struct diff_filespec *b,
 895                                           const char *branch1,
 896                                           const char *branch2)
 897{
 898        struct merge_file_info result;
 899        result.merge = 0;
 900        result.clean = 1;
 901
 902        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 903                result.clean = 0;
 904                if (S_ISREG(a->mode)) {
 905                        result.mode = a->mode;
 906                        hashcpy(result.sha, a->sha1);
 907                } else {
 908                        result.mode = b->mode;
 909                        hashcpy(result.sha, b->sha1);
 910                }
 911        } else {
 912                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 913                        result.merge = 1;
 914
 915                /*
 916                 * Merge modes
 917                 */
 918                if (a->mode == b->mode || a->mode == one->mode)
 919                        result.mode = b->mode;
 920                else {
 921                        result.mode = a->mode;
 922                        if (b->mode != one->mode) {
 923                                result.clean = 0;
 924                                result.merge = 1;
 925                        }
 926                }
 927
 928                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 929                        hashcpy(result.sha, b->sha1);
 930                else if (sha_eq(b->sha1, one->sha1))
 931                        hashcpy(result.sha, a->sha1);
 932                else if (S_ISREG(a->mode)) {
 933                        mmbuffer_t result_buf;
 934                        int merge_status;
 935
 936                        merge_status = merge_3way(o, &result_buf, one, a, b,
 937                                                  branch1, branch2);
 938
 939                        if ((merge_status < 0) || !result_buf.ptr)
 940                                die(_("Failed to execute internal merge"));
 941
 942                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 943                                            blob_type, result.sha))
 944                                die(_("Unable to add %s to database"),
 945                                    a->path);
 946
 947                        free(result_buf.ptr);
 948                        result.clean = (merge_status == 0);
 949                } else if (S_ISGITLINK(a->mode)) {
 950                        result.clean = merge_submodule(result.sha,
 951                                                       one->path, one->sha1,
 952                                                       a->sha1, b->sha1,
 953                                                       !o->call_depth);
 954                } else if (S_ISLNK(a->mode)) {
 955                        hashcpy(result.sha, a->sha1);
 956
 957                        if (!sha_eq(a->sha1, b->sha1))
 958                                result.clean = 0;
 959                } else {
 960                        die(_("unsupported object type in the tree"));
 961                }
 962        }
 963
 964        return result;
 965}
 966
 967static struct merge_file_info
 968merge_file_special_markers(struct merge_options *o,
 969                           const struct diff_filespec *one,
 970                           const struct diff_filespec *a,
 971                           const struct diff_filespec *b,
 972                           const char *branch1,
 973                           const char *filename1,
 974                           const char *branch2,
 975                           const char *filename2)
 976{
 977        char *side1 = NULL;
 978        char *side2 = NULL;
 979        struct merge_file_info mfi;
 980
 981        if (filename1)
 982                side1 = xstrfmt("%s:%s", branch1, filename1);
 983        if (filename2)
 984                side2 = xstrfmt("%s:%s", branch2, filename2);
 985
 986        mfi = merge_file_1(o, one, a, b,
 987                           side1 ? side1 : branch1, side2 ? side2 : branch2);
 988        free(side1);
 989        free(side2);
 990        return mfi;
 991}
 992
 993static struct merge_file_info merge_file_one(struct merge_options *o,
 994                                         const char *path,
 995                                         const unsigned char *o_sha, int o_mode,
 996                                         const unsigned char *a_sha, int a_mode,
 997                                         const unsigned char *b_sha, int b_mode,
 998                                         const char *branch1,
 999                                         const char *branch2)
1000{
1001        struct diff_filespec one, a, b;
1002
1003        one.path = a.path = b.path = (char *)path;
1004        hashcpy(one.sha1, o_sha);
1005        one.mode = o_mode;
1006        hashcpy(a.sha1, a_sha);
1007        a.mode = a_mode;
1008        hashcpy(b.sha1, b_sha);
1009        b.mode = b_mode;
1010        return merge_file_1(o, &one, &a, &b, branch1, branch2);
1011}
1012
1013static void handle_change_delete(struct merge_options *o,
1014                                 const char *path,
1015                                 const unsigned char *o_sha, int o_mode,
1016                                 const unsigned char *a_sha, int a_mode,
1017                                 const unsigned char *b_sha, int b_mode,
1018                                 const char *change, const char *change_past)
1019{
1020        char *renamed = NULL;
1021        if (dir_in_way(path, !o->call_depth)) {
1022                renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1023        }
1024
1025        if (o->call_depth) {
1026                /*
1027                 * We cannot arbitrarily accept either a_sha or b_sha as
1028                 * correct; since there is no true "middle point" between
1029                 * them, simply reuse the base version for virtual merge base.
1030                 */
1031                remove_file_from_cache(path);
1032                update_file(o, 0, o_sha, o_mode, renamed ? renamed : path);
1033        } else if (!a_sha) {
1034                if (!renamed) {
1035                        output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1036                               "and %s in %s. Version %s of %s left in tree."),
1037                               change, path, o->branch1, change_past,
1038                               o->branch2, o->branch2, path);
1039                        update_file(o, 0, b_sha, b_mode, path);
1040                } else {
1041                        output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1042                               "and %s in %s. Version %s of %s left in tree at %s."),
1043                               change, path, o->branch1, change_past,
1044                               o->branch2, o->branch2, path, renamed);
1045                        update_file(o, 0, b_sha, b_mode, renamed);
1046                }
1047        } else {
1048                if (!renamed) {
1049                        output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1050                               "and %s in %s. Version %s of %s left in tree."),
1051                               change, path, o->branch2, change_past,
1052                               o->branch1, o->branch1, path);
1053                } else {
1054                        output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1055                               "and %s in %s. Version %s of %s left in tree at %s."),
1056                               change, path, o->branch2, change_past,
1057                               o->branch1, o->branch1, path, renamed);
1058                        update_file(o, 0, a_sha, a_mode, renamed);
1059                }
1060                /*
1061                 * No need to call update_file() on path when !renamed, since
1062                 * that would needlessly touch path.  We could call
1063                 * update_file_flags() with update_cache=0 and update_wd=0,
1064                 * but that's a no-op.
1065                 */
1066        }
1067        free(renamed);
1068}
1069
1070static void conflict_rename_delete(struct merge_options *o,
1071                                   struct diff_filepair *pair,
1072                                   const char *rename_branch,
1073                                   const char *other_branch)
1074{
1075        const struct diff_filespec *orig = pair->one;
1076        const struct diff_filespec *dest = pair->two;
1077        const unsigned char *a_sha = NULL;
1078        const unsigned char *b_sha = NULL;
1079        int a_mode = 0;
1080        int b_mode = 0;
1081
1082        if (rename_branch == o->branch1) {
1083                a_sha = dest->sha1;
1084                a_mode = dest->mode;
1085        } else {
1086                b_sha = dest->sha1;
1087                b_mode = dest->mode;
1088        }
1089
1090        handle_change_delete(o,
1091                             o->call_depth ? orig->path : dest->path,
1092                             orig->sha1, orig->mode,
1093                             a_sha, a_mode,
1094                             b_sha, b_mode,
1095                             _("rename"), _("renamed"));
1096
1097        if (o->call_depth) {
1098                remove_file_from_cache(dest->path);
1099        } else {
1100                update_stages(dest->path, NULL,
1101                              rename_branch == o->branch1 ? dest : NULL,
1102                              rename_branch == o->branch1 ? NULL : dest);
1103        }
1104
1105}
1106
1107static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
1108                                                 struct stage_data *entry,
1109                                                 int stage)
1110{
1111        unsigned char *sha = entry->stages[stage].sha;
1112        unsigned mode = entry->stages[stage].mode;
1113        if (mode == 0 || is_null_sha1(sha))
1114                return NULL;
1115        hashcpy(target->sha1, sha);
1116        target->mode = mode;
1117        return target;
1118}
1119
1120static void handle_file(struct merge_options *o,
1121                        struct diff_filespec *rename,
1122                        int stage,
1123                        struct rename_conflict_info *ci)
1124{
1125        char *dst_name = rename->path;
1126        struct stage_data *dst_entry;
1127        const char *cur_branch, *other_branch;
1128        struct diff_filespec other;
1129        struct diff_filespec *add;
1130
1131        if (stage == 2) {
1132                dst_entry = ci->dst_entry1;
1133                cur_branch = ci->branch1;
1134                other_branch = ci->branch2;
1135        } else {
1136                dst_entry = ci->dst_entry2;
1137                cur_branch = ci->branch2;
1138                other_branch = ci->branch1;
1139        }
1140
1141        add = filespec_from_entry(&other, dst_entry, stage ^ 1);
1142        if (add) {
1143                char *add_name = unique_path(o, rename->path, other_branch);
1144                update_file(o, 0, add->sha1, add->mode, add_name);
1145
1146                remove_file(o, 0, rename->path, 0);
1147                dst_name = unique_path(o, rename->path, cur_branch);
1148        } else {
1149                if (dir_in_way(rename->path, !o->call_depth)) {
1150                        dst_name = unique_path(o, rename->path, cur_branch);
1151                        output(o, 1, _("%s is a directory in %s adding as %s instead"),
1152                               rename->path, other_branch, dst_name);
1153                }
1154        }
1155        update_file(o, 0, rename->sha1, rename->mode, dst_name);
1156        if (stage == 2)
1157                update_stages(rename->path, NULL, rename, add);
1158        else
1159                update_stages(rename->path, NULL, add, rename);
1160
1161        if (dst_name != rename->path)
1162                free(dst_name);
1163}
1164
1165static void conflict_rename_rename_1to2(struct merge_options *o,
1166                                        struct rename_conflict_info *ci)
1167{
1168        /* One file was renamed in both branches, but to different names. */
1169        struct diff_filespec *one = ci->pair1->one;
1170        struct diff_filespec *a = ci->pair1->two;
1171        struct diff_filespec *b = ci->pair2->two;
1172
1173        output(o, 1, _("CONFLICT (rename/rename): "
1174               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1175               "rename \"%s\"->\"%s\" in \"%s\"%s"),
1176               one->path, a->path, ci->branch1,
1177               one->path, b->path, ci->branch2,
1178               o->call_depth ? _(" (left unresolved)") : "");
1179        if (o->call_depth) {
1180                struct merge_file_info mfi;
1181                struct diff_filespec other;
1182                struct diff_filespec *add;
1183                mfi = merge_file_one(o, one->path,
1184                                 one->sha1, one->mode,
1185                                 a->sha1, a->mode,
1186                                 b->sha1, b->mode,
1187                                 ci->branch1, ci->branch2);
1188                /*
1189                 * FIXME: For rename/add-source conflicts (if we could detect
1190                 * such), this is wrong.  We should instead find a unique
1191                 * pathname and then either rename the add-source file to that
1192                 * unique path, or use that unique path instead of src here.
1193                 */
1194                update_file(o, 0, mfi.sha, mfi.mode, one->path);
1195
1196                /*
1197                 * Above, we put the merged content at the merge-base's
1198                 * path.  Now we usually need to delete both a->path and
1199                 * b->path.  However, the rename on each side of the merge
1200                 * could also be involved in a rename/add conflict.  In
1201                 * such cases, we should keep the added file around,
1202                 * resolving the conflict at that path in its favor.
1203                 */
1204                add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
1205                if (add)
1206                        update_file(o, 0, add->sha1, add->mode, a->path);
1207                else
1208                        remove_file_from_cache(a->path);
1209                add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
1210                if (add)
1211                        update_file(o, 0, add->sha1, add->mode, b->path);
1212                else
1213                        remove_file_from_cache(b->path);
1214        } else {
1215                handle_file(o, a, 2, ci);
1216                handle_file(o, b, 3, ci);
1217        }
1218}
1219
1220static void conflict_rename_rename_2to1(struct merge_options *o,
1221                                        struct rename_conflict_info *ci)
1222{
1223        /* Two files, a & b, were renamed to the same thing, c. */
1224        struct diff_filespec *a = ci->pair1->one;
1225        struct diff_filespec *b = ci->pair2->one;
1226        struct diff_filespec *c1 = ci->pair1->two;
1227        struct diff_filespec *c2 = ci->pair2->two;
1228        char *path = c1->path; /* == c2->path */
1229        struct merge_file_info mfi_c1;
1230        struct merge_file_info mfi_c2;
1231
1232        output(o, 1, _("CONFLICT (rename/rename): "
1233               "Rename %s->%s in %s. "
1234               "Rename %s->%s in %s"),
1235               a->path, c1->path, ci->branch1,
1236               b->path, c2->path, ci->branch2);
1237
1238        remove_file(o, 1, a->path, would_lose_untracked(a->path));
1239        remove_file(o, 1, b->path, would_lose_untracked(b->path));
1240
1241        mfi_c1 = merge_file_special_markers(o, a, c1, &ci->ren1_other,
1242                                            o->branch1, c1->path,
1243                                            o->branch2, ci->ren1_other.path);
1244        mfi_c2 = merge_file_special_markers(o, b, &ci->ren2_other, c2,
1245                                            o->branch1, ci->ren2_other.path,
1246                                            o->branch2, c2->path);
1247
1248        if (o->call_depth) {
1249                /*
1250                 * If mfi_c1.clean && mfi_c2.clean, then it might make
1251                 * sense to do a two-way merge of those results.  But, I
1252                 * think in all cases, it makes sense to have the virtual
1253                 * merge base just undo the renames; they can be detected
1254                 * again later for the non-recursive merge.
1255                 */
1256                remove_file(o, 0, path, 0);
1257                update_file(o, 0, mfi_c1.sha, mfi_c1.mode, a->path);
1258                update_file(o, 0, mfi_c2.sha, mfi_c2.mode, b->path);
1259        } else {
1260                char *new_path1 = unique_path(o, path, ci->branch1);
1261                char *new_path2 = unique_path(o, path, ci->branch2);
1262                output(o, 1, _("Renaming %s to %s and %s to %s instead"),
1263                       a->path, new_path1, b->path, new_path2);
1264                remove_file(o, 0, path, 0);
1265                update_file(o, 0, mfi_c1.sha, mfi_c1.mode, new_path1);
1266                update_file(o, 0, mfi_c2.sha, mfi_c2.mode, new_path2);
1267                free(new_path2);
1268                free(new_path1);
1269        }
1270}
1271
1272static int process_renames(struct merge_options *o,
1273                           struct string_list *a_renames,
1274                           struct string_list *b_renames)
1275{
1276        int clean_merge = 1, i, j;
1277        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
1278        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
1279        const struct rename *sre;
1280
1281        for (i = 0; i < a_renames->nr; i++) {
1282                sre = a_renames->items[i].util;
1283                string_list_insert(&a_by_dst, sre->pair->two->path)->util
1284                        = (void *)sre;
1285        }
1286        for (i = 0; i < b_renames->nr; i++) {
1287                sre = b_renames->items[i].util;
1288                string_list_insert(&b_by_dst, sre->pair->two->path)->util
1289                        = (void *)sre;
1290        }
1291
1292        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1293                struct string_list *renames1, *renames2Dst;
1294                struct rename *ren1 = NULL, *ren2 = NULL;
1295                const char *branch1, *branch2;
1296                const char *ren1_src, *ren1_dst;
1297                struct string_list_item *lookup;
1298
1299                if (i >= a_renames->nr) {
1300                        ren2 = b_renames->items[j++].util;
1301                } else if (j >= b_renames->nr) {
1302                        ren1 = a_renames->items[i++].util;
1303                } else {
1304                        int compare = strcmp(a_renames->items[i].string,
1305                                             b_renames->items[j].string);
1306                        if (compare <= 0)
1307                                ren1 = a_renames->items[i++].util;
1308                        if (compare >= 0)
1309                                ren2 = b_renames->items[j++].util;
1310                }
1311
1312                /* TODO: refactor, so that 1/2 are not needed */
1313                if (ren1) {
1314                        renames1 = a_renames;
1315                        renames2Dst = &b_by_dst;
1316                        branch1 = o->branch1;
1317                        branch2 = o->branch2;
1318                } else {
1319                        struct rename *tmp;
1320                        renames1 = b_renames;
1321                        renames2Dst = &a_by_dst;
1322                        branch1 = o->branch2;
1323                        branch2 = o->branch1;
1324                        tmp = ren2;
1325                        ren2 = ren1;
1326                        ren1 = tmp;
1327                }
1328
1329                if (ren1->processed)
1330                        continue;
1331                ren1->processed = 1;
1332                ren1->dst_entry->processed = 1;
1333                /* BUG: We should only mark src_entry as processed if we
1334                 * are not dealing with a rename + add-source case.
1335                 */
1336                ren1->src_entry->processed = 1;
1337
1338                ren1_src = ren1->pair->one->path;
1339                ren1_dst = ren1->pair->two->path;
1340
1341                if (ren2) {
1342                        /* One file renamed on both sides */
1343                        const char *ren2_src = ren2->pair->one->path;
1344                        const char *ren2_dst = ren2->pair->two->path;
1345                        enum rename_type rename_type;
1346                        if (strcmp(ren1_src, ren2_src) != 0)
1347                                die("ren1_src != ren2_src");
1348                        ren2->dst_entry->processed = 1;
1349                        ren2->processed = 1;
1350                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1351                                rename_type = RENAME_ONE_FILE_TO_TWO;
1352                                clean_merge = 0;
1353                        } else {
1354                                rename_type = RENAME_ONE_FILE_TO_ONE;
1355                                /* BUG: We should only remove ren1_src in
1356                                 * the base stage (think of rename +
1357                                 * add-source cases).
1358                                 */
1359                                remove_file(o, 1, ren1_src, 1);
1360                                update_entry(ren1->dst_entry,
1361                                             ren1->pair->one,
1362                                             ren1->pair->two,
1363                                             ren2->pair->two);
1364                        }
1365                        setup_rename_conflict_info(rename_type,
1366                                                   ren1->pair,
1367                                                   ren2->pair,
1368                                                   branch1,
1369                                                   branch2,
1370                                                   ren1->dst_entry,
1371                                                   ren2->dst_entry,
1372                                                   o,
1373                                                   NULL,
1374                                                   NULL);
1375                } else if ((lookup = string_list_lookup(renames2Dst, ren1_dst))) {
1376                        /* Two different files renamed to the same thing */
1377                        char *ren2_dst;
1378                        ren2 = lookup->util;
1379                        ren2_dst = ren2->pair->two->path;
1380                        if (strcmp(ren1_dst, ren2_dst) != 0)
1381                                die("ren1_dst != ren2_dst");
1382
1383                        clean_merge = 0;
1384                        ren2->processed = 1;
1385                        /*
1386                         * BUG: We should only mark src_entry as processed
1387                         * if we are not dealing with a rename + add-source
1388                         * case.
1389                         */
1390                        ren2->src_entry->processed = 1;
1391
1392                        setup_rename_conflict_info(RENAME_TWO_FILES_TO_ONE,
1393                                                   ren1->pair,
1394                                                   ren2->pair,
1395                                                   branch1,
1396                                                   branch2,
1397                                                   ren1->dst_entry,
1398                                                   ren2->dst_entry,
1399                                                   o,
1400                                                   ren1->src_entry,
1401                                                   ren2->src_entry);
1402
1403                } else {
1404                        /* Renamed in 1, maybe changed in 2 */
1405                        /* we only use sha1 and mode of these */
1406                        struct diff_filespec src_other, dst_other;
1407                        int try_merge;
1408
1409                        /*
1410                         * unpack_trees loads entries from common-commit
1411                         * into stage 1, from head-commit into stage 2, and
1412                         * from merge-commit into stage 3.  We keep track
1413                         * of which side corresponds to the rename.
1414                         */
1415                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1416                        int other_stage =   a_renames == renames1 ? 3 : 2;
1417
1418                        /* BUG: We should only remove ren1_src in the base
1419                         * stage and in other_stage (think of rename +
1420                         * add-source case).
1421                         */
1422                        remove_file(o, 1, ren1_src,
1423                                    renamed_stage == 2 || !was_tracked(ren1_src));
1424
1425                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1426                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1427                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1428                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1429                        try_merge = 0;
1430
1431                        if (sha_eq(src_other.sha1, null_sha1)) {
1432                                setup_rename_conflict_info(RENAME_DELETE,
1433                                                           ren1->pair,
1434                                                           NULL,
1435                                                           branch1,
1436                                                           branch2,
1437                                                           ren1->dst_entry,
1438                                                           NULL,
1439                                                           o,
1440                                                           NULL,
1441                                                           NULL);
1442                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1443                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1444                                /*
1445                                 * Added file on the other side identical to
1446                                 * the file being renamed: clean merge.
1447                                 * Also, there is no need to overwrite the
1448                                 * file already in the working copy, so call
1449                                 * update_file_flags() instead of
1450                                 * update_file().
1451                                 */
1452                                update_file_flags(o,
1453                                                  ren1->pair->two->sha1,
1454                                                  ren1->pair->two->mode,
1455                                                  ren1_dst,
1456                                                  1, /* update_cache */
1457                                                  0  /* update_wd    */);
1458                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1459                                clean_merge = 0;
1460                                try_merge = 1;
1461                                output(o, 1, _("CONFLICT (rename/add): Rename %s->%s in %s. "
1462                                       "%s added in %s"),
1463                                       ren1_src, ren1_dst, branch1,
1464                                       ren1_dst, branch2);
1465                                if (o->call_depth) {
1466                                        struct merge_file_info mfi;
1467                                        mfi = merge_file_one(o, ren1_dst, null_sha1, 0,
1468                                                         ren1->pair->two->sha1, ren1->pair->two->mode,
1469                                                         dst_other.sha1, dst_other.mode,
1470                                                         branch1, branch2);
1471                                        output(o, 1, _("Adding merged %s"), ren1_dst);
1472                                        update_file(o, 0, mfi.sha, mfi.mode, ren1_dst);
1473                                        try_merge = 0;
1474                                } else {
1475                                        char *new_path = unique_path(o, ren1_dst, branch2);
1476                                        output(o, 1, _("Adding as %s instead"), new_path);
1477                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1478                                        free(new_path);
1479                                }
1480                        } else
1481                                try_merge = 1;
1482
1483                        if (try_merge) {
1484                                struct diff_filespec *one, *a, *b;
1485                                src_other.path = (char *)ren1_src;
1486
1487                                one = ren1->pair->one;
1488                                if (a_renames == renames1) {
1489                                        a = ren1->pair->two;
1490                                        b = &src_other;
1491                                } else {
1492                                        b = ren1->pair->two;
1493                                        a = &src_other;
1494                                }
1495                                update_entry(ren1->dst_entry, one, a, b);
1496                                setup_rename_conflict_info(RENAME_NORMAL,
1497                                                           ren1->pair,
1498                                                           NULL,
1499                                                           branch1,
1500                                                           NULL,
1501                                                           ren1->dst_entry,
1502                                                           NULL,
1503                                                           o,
1504                                                           NULL,
1505                                                           NULL);
1506                        }
1507                }
1508        }
1509        string_list_clear(&a_by_dst, 0);
1510        string_list_clear(&b_by_dst, 0);
1511
1512        return clean_merge;
1513}
1514
1515static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1516{
1517        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1518}
1519
1520static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1521{
1522        void *buf;
1523        enum object_type type;
1524        unsigned long size;
1525        buf = read_sha1_file(sha1, &type, &size);
1526        if (!buf)
1527                return error(_("cannot read object %s"), sha1_to_hex(sha1));
1528        if (type != OBJ_BLOB) {
1529                free(buf);
1530                return error(_("object %s is not a blob"), sha1_to_hex(sha1));
1531        }
1532        strbuf_attach(dst, buf, size, size + 1);
1533        return 0;
1534}
1535
1536static int blob_unchanged(const unsigned char *o_sha,
1537                          const unsigned char *a_sha,
1538                          int renormalize, const char *path)
1539{
1540        struct strbuf o = STRBUF_INIT;
1541        struct strbuf a = STRBUF_INIT;
1542        int ret = 0; /* assume changed for safety */
1543
1544        if (sha_eq(o_sha, a_sha))
1545                return 1;
1546        if (!renormalize)
1547                return 0;
1548
1549        assert(o_sha && a_sha);
1550        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1551                goto error_return;
1552        /*
1553         * Note: binary | is used so that both renormalizations are
1554         * performed.  Comparison can be skipped if both files are
1555         * unchanged since their sha1s have already been compared.
1556         */
1557        if (renormalize_buffer(path, o.buf, o.len, &o) |
1558            renormalize_buffer(path, a.buf, a.len, &a))
1559                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1560
1561error_return:
1562        strbuf_release(&o);
1563        strbuf_release(&a);
1564        return ret;
1565}
1566
1567static void handle_modify_delete(struct merge_options *o,
1568                                 const char *path,
1569                                 unsigned char *o_sha, int o_mode,
1570                                 unsigned char *a_sha, int a_mode,
1571                                 unsigned char *b_sha, int b_mode)
1572{
1573        handle_change_delete(o,
1574                             path,
1575                             o_sha, o_mode,
1576                             a_sha, a_mode,
1577                             b_sha, b_mode,
1578                             _("modify"), _("modified"));
1579}
1580
1581static int merge_content(struct merge_options *o,
1582                         const char *path,
1583                         unsigned char *o_sha, int o_mode,
1584                         unsigned char *a_sha, int a_mode,
1585                         unsigned char *b_sha, int b_mode,
1586                         struct rename_conflict_info *rename_conflict_info)
1587{
1588        const char *reason = _("content");
1589        const char *path1 = NULL, *path2 = NULL;
1590        struct merge_file_info mfi;
1591        struct diff_filespec one, a, b;
1592        unsigned df_conflict_remains = 0;
1593
1594        if (!o_sha) {
1595                reason = _("add/add");
1596                o_sha = (unsigned char *)null_sha1;
1597        }
1598        one.path = a.path = b.path = (char *)path;
1599        hashcpy(one.sha1, o_sha);
1600        one.mode = o_mode;
1601        hashcpy(a.sha1, a_sha);
1602        a.mode = a_mode;
1603        hashcpy(b.sha1, b_sha);
1604        b.mode = b_mode;
1605
1606        if (rename_conflict_info) {
1607                struct diff_filepair *pair1 = rename_conflict_info->pair1;
1608
1609                path1 = (o->branch1 == rename_conflict_info->branch1) ?
1610                        pair1->two->path : pair1->one->path;
1611                /* If rename_conflict_info->pair2 != NULL, we are in
1612                 * RENAME_ONE_FILE_TO_ONE case.  Otherwise, we have a
1613                 * normal rename.
1614                 */
1615                path2 = (rename_conflict_info->pair2 ||
1616                         o->branch2 == rename_conflict_info->branch1) ?
1617                        pair1->two->path : pair1->one->path;
1618
1619                if (dir_in_way(path, !o->call_depth))
1620                        df_conflict_remains = 1;
1621        }
1622        mfi = merge_file_special_markers(o, &one, &a, &b,
1623                                         o->branch1, path1,
1624                                         o->branch2, path2);
1625
1626        if (mfi.clean && !df_conflict_remains &&
1627            sha_eq(mfi.sha, a_sha) && mfi.mode == a_mode) {
1628                int path_renamed_outside_HEAD;
1629                output(o, 3, _("Skipped %s (merged same as existing)"), path);
1630                /*
1631                 * The content merge resulted in the same file contents we
1632                 * already had.  We can return early if those file contents
1633                 * are recorded at the correct path (which may not be true
1634                 * if the merge involves a rename).
1635                 */
1636                path_renamed_outside_HEAD = !path2 || !strcmp(path, path2);
1637                if (!path_renamed_outside_HEAD) {
1638                        add_cacheinfo(mfi.mode, mfi.sha, path,
1639                                      0, (!o->call_depth), 0);
1640                        return mfi.clean;
1641                }
1642        } else
1643                output(o, 2, _("Auto-merging %s"), path);
1644
1645        if (!mfi.clean) {
1646                if (S_ISGITLINK(mfi.mode))
1647                        reason = _("submodule");
1648                output(o, 1, _("CONFLICT (%s): Merge conflict in %s"),
1649                                reason, path);
1650                if (rename_conflict_info && !df_conflict_remains)
1651                        update_stages(path, &one, &a, &b);
1652        }
1653
1654        if (df_conflict_remains) {
1655                char *new_path;
1656                if (o->call_depth) {
1657                        remove_file_from_cache(path);
1658                } else {
1659                        if (!mfi.clean)
1660                                update_stages(path, &one, &a, &b);
1661                        else {
1662                                int file_from_stage2 = was_tracked(path);
1663                                struct diff_filespec merged;
1664                                hashcpy(merged.sha1, mfi.sha);
1665                                merged.mode = mfi.mode;
1666
1667                                update_stages(path, NULL,
1668                                              file_from_stage2 ? &merged : NULL,
1669                                              file_from_stage2 ? NULL : &merged);
1670                        }
1671
1672                }
1673                new_path = unique_path(o, path, rename_conflict_info->branch1);
1674                output(o, 1, _("Adding as %s instead"), new_path);
1675                update_file(o, 0, mfi.sha, mfi.mode, new_path);
1676                free(new_path);
1677                mfi.clean = 0;
1678        } else {
1679                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1680        }
1681        return mfi.clean;
1682
1683}
1684
1685/* Per entry merge function */
1686static int process_entry(struct merge_options *o,
1687                         const char *path, struct stage_data *entry)
1688{
1689        int clean_merge = 1;
1690        int normalize = o->renormalize;
1691        unsigned o_mode = entry->stages[1].mode;
1692        unsigned a_mode = entry->stages[2].mode;
1693        unsigned b_mode = entry->stages[3].mode;
1694        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1695        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1696        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1697
1698        entry->processed = 1;
1699        if (entry->rename_conflict_info) {
1700                struct rename_conflict_info *conflict_info = entry->rename_conflict_info;
1701                switch (conflict_info->rename_type) {
1702                case RENAME_NORMAL:
1703                case RENAME_ONE_FILE_TO_ONE:
1704                        clean_merge = merge_content(o, path,
1705                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1706                                                    conflict_info);
1707                        break;
1708                case RENAME_DELETE:
1709                        clean_merge = 0;
1710                        conflict_rename_delete(o, conflict_info->pair1,
1711                                               conflict_info->branch1,
1712                                               conflict_info->branch2);
1713                        break;
1714                case RENAME_ONE_FILE_TO_TWO:
1715                        clean_merge = 0;
1716                        conflict_rename_rename_1to2(o, conflict_info);
1717                        break;
1718                case RENAME_TWO_FILES_TO_ONE:
1719                        clean_merge = 0;
1720                        conflict_rename_rename_2to1(o, conflict_info);
1721                        break;
1722                default:
1723                        entry->processed = 0;
1724                        break;
1725                }
1726        } else if (o_sha && (!a_sha || !b_sha)) {
1727                /* Case A: Deleted in one */
1728                if ((!a_sha && !b_sha) ||
1729                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1730                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1731                        /* Deleted in both or deleted in one and
1732                         * unchanged in the other */
1733                        if (a_sha)
1734                                output(o, 2, _("Removing %s"), path);
1735                        /* do not touch working file if it did not exist */
1736                        remove_file(o, 1, path, !a_sha);
1737                } else {
1738                        /* Modify/delete; deleted side may have put a directory in the way */
1739                        clean_merge = 0;
1740                        handle_modify_delete(o, path, o_sha, o_mode,
1741                                             a_sha, a_mode, b_sha, b_mode);
1742                }
1743        } else if ((!o_sha && a_sha && !b_sha) ||
1744                   (!o_sha && !a_sha && b_sha)) {
1745                /* Case B: Added in one. */
1746                /* [nothing|directory] -> ([nothing|directory], file) */
1747
1748                const char *add_branch;
1749                const char *other_branch;
1750                unsigned mode;
1751                const unsigned char *sha;
1752                const char *conf;
1753
1754                if (a_sha) {
1755                        add_branch = o->branch1;
1756                        other_branch = o->branch2;
1757                        mode = a_mode;
1758                        sha = a_sha;
1759                        conf = _("file/directory");
1760                } else {
1761                        add_branch = o->branch2;
1762                        other_branch = o->branch1;
1763                        mode = b_mode;
1764                        sha = b_sha;
1765                        conf = _("directory/file");
1766                }
1767                if (dir_in_way(path, !o->call_depth)) {
1768                        char *new_path = unique_path(o, path, add_branch);
1769                        clean_merge = 0;
1770                        output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
1771                               "Adding %s as %s"),
1772                               conf, path, other_branch, path, new_path);
1773                        if (o->call_depth)
1774                                remove_file_from_cache(path);
1775                        update_file(o, 0, sha, mode, new_path);
1776                        if (o->call_depth)
1777                                remove_file_from_cache(path);
1778                        free(new_path);
1779                } else {
1780                        output(o, 2, _("Adding %s"), path);
1781                        /* do not overwrite file if already present */
1782                        update_file_flags(o, sha, mode, path, 1, !a_sha);
1783                }
1784        } else if (a_sha && b_sha) {
1785                /* Case C: Added in both (check for same permissions) and */
1786                /* case D: Modified in both, but differently. */
1787                clean_merge = merge_content(o, path,
1788                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1789                                            NULL);
1790        } else if (!o_sha && !a_sha && !b_sha) {
1791                /*
1792                 * this entry was deleted altogether. a_mode == 0 means
1793                 * we had that path and want to actively remove it.
1794                 */
1795                remove_file(o, 1, path, !a_mode);
1796        } else
1797                die(_("Fatal merge failure, shouldn't happen."));
1798
1799        return clean_merge;
1800}
1801
1802int merge_trees(struct merge_options *o,
1803                struct tree *head,
1804                struct tree *merge,
1805                struct tree *common,
1806                struct tree **result)
1807{
1808        int code, clean;
1809
1810        if (o->subtree_shift) {
1811                merge = shift_tree_object(head, merge, o->subtree_shift);
1812                common = shift_tree_object(head, common, o->subtree_shift);
1813        }
1814
1815        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1816                output(o, 0, _("Already up-to-date!"));
1817                *result = head;
1818                return 1;
1819        }
1820
1821        code = git_merge_trees(o->call_depth, common, head, merge);
1822
1823        if (code != 0) {
1824                if (show(o, 4) || o->call_depth)
1825                        die(_("merging of trees %s and %s failed"),
1826                            sha1_to_hex(head->object.sha1),
1827                            sha1_to_hex(merge->object.sha1));
1828                else
1829                        exit(128);
1830        }
1831
1832        if (unmerged_cache()) {
1833                struct string_list *entries, *re_head, *re_merge;
1834                int i;
1835                string_list_clear(&o->current_file_set, 1);
1836                string_list_clear(&o->current_directory_set, 1);
1837                get_files_dirs(o, head);
1838                get_files_dirs(o, merge);
1839
1840                entries = get_unmerged();
1841                record_df_conflict_files(o, entries);
1842                re_head  = get_renames(o, head, common, head, merge, entries);
1843                re_merge = get_renames(o, merge, common, head, merge, entries);
1844                clean = process_renames(o, re_head, re_merge);
1845                for (i = entries->nr-1; 0 <= i; i--) {
1846                        const char *path = entries->items[i].string;
1847                        struct stage_data *e = entries->items[i].util;
1848                        if (!e->processed
1849                                && !process_entry(o, path, e))
1850                                clean = 0;
1851                }
1852                for (i = 0; i < entries->nr; i++) {
1853                        struct stage_data *e = entries->items[i].util;
1854                        if (!e->processed)
1855                                die(_("Unprocessed path??? %s"),
1856                                    entries->items[i].string);
1857                }
1858
1859                string_list_clear(re_merge, 0);
1860                string_list_clear(re_head, 0);
1861                string_list_clear(entries, 1);
1862
1863        }
1864        else
1865                clean = 1;
1866
1867        if (o->call_depth)
1868                *result = write_tree_from_memory(o);
1869
1870        return clean;
1871}
1872
1873static struct commit_list *reverse_commit_list(struct commit_list *list)
1874{
1875        struct commit_list *next = NULL, *current, *backup;
1876        for (current = list; current; current = backup) {
1877                backup = current->next;
1878                current->next = next;
1879                next = current;
1880        }
1881        return next;
1882}
1883
1884/*
1885 * Merge the commits h1 and h2, return the resulting virtual
1886 * commit object and a flag indicating the cleanness of the merge.
1887 */
1888int merge_recursive(struct merge_options *o,
1889                    struct commit *h1,
1890                    struct commit *h2,
1891                    struct commit_list *ca,
1892                    struct commit **result)
1893{
1894        struct commit_list *iter;
1895        struct commit *merged_common_ancestors;
1896        struct tree *mrtree = mrtree;
1897        int clean;
1898
1899        if (show(o, 4)) {
1900                output(o, 4, _("Merging:"));
1901                output_commit_title(o, h1);
1902                output_commit_title(o, h2);
1903        }
1904
1905        if (!ca) {
1906                ca = get_merge_bases(h1, h2, 1);
1907                ca = reverse_commit_list(ca);
1908        }
1909
1910        if (show(o, 5)) {
1911                unsigned cnt = commit_list_count(ca);
1912
1913                output(o, 5, Q_("found %u common ancestor:",
1914                                "found %u common ancestors:", cnt), cnt);
1915                for (iter = ca; iter; iter = iter->next)
1916                        output_commit_title(o, iter->item);
1917        }
1918
1919        merged_common_ancestors = pop_commit(&ca);
1920        if (merged_common_ancestors == NULL) {
1921                /* if there is no common ancestor, use an empty tree */
1922                struct tree *tree;
1923
1924                tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
1925                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1926        }
1927
1928        for (iter = ca; iter; iter = iter->next) {
1929                const char *saved_b1, *saved_b2;
1930                o->call_depth++;
1931                /*
1932                 * When the merge fails, the result contains files
1933                 * with conflict markers. The cleanness flag is
1934                 * ignored, it was never actually used, as result of
1935                 * merge_trees has always overwritten it: the committed
1936                 * "conflicts" were already resolved.
1937                 */
1938                discard_cache();
1939                saved_b1 = o->branch1;
1940                saved_b2 = o->branch2;
1941                o->branch1 = "Temporary merge branch 1";
1942                o->branch2 = "Temporary merge branch 2";
1943                merge_recursive(o, merged_common_ancestors, iter->item,
1944                                NULL, &merged_common_ancestors);
1945                o->branch1 = saved_b1;
1946                o->branch2 = saved_b2;
1947                o->call_depth--;
1948
1949                if (!merged_common_ancestors)
1950                        die(_("merge returned no commit"));
1951        }
1952
1953        discard_cache();
1954        if (!o->call_depth)
1955                read_cache();
1956
1957        o->ancestor = "merged common ancestors";
1958        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1959                            &mrtree);
1960
1961        if (o->call_depth) {
1962                *result = make_virtual_commit(mrtree, "merged tree");
1963                commit_list_insert(h1, &(*result)->parents);
1964                commit_list_insert(h2, &(*result)->parents->next);
1965        }
1966        flush_output(o);
1967        if (show(o, 2))
1968                diff_warn_rename_limit("merge.renamelimit",
1969                                       o->needed_rename_limit, 0);
1970        return clean;
1971}
1972
1973static struct commit *get_ref(const unsigned char *sha1, const char *name)
1974{
1975        struct object *object;
1976
1977        object = deref_tag(parse_object(sha1), name, strlen(name));
1978        if (!object)
1979                return NULL;
1980        if (object->type == OBJ_TREE)
1981                return make_virtual_commit((struct tree*)object, name);
1982        if (object->type != OBJ_COMMIT)
1983                return NULL;
1984        if (parse_commit((struct commit *)object))
1985                return NULL;
1986        return (struct commit *)object;
1987}
1988
1989int merge_recursive_generic(struct merge_options *o,
1990                            const unsigned char *head,
1991                            const unsigned char *merge,
1992                            int num_base_list,
1993                            const unsigned char **base_list,
1994                            struct commit **result)
1995{
1996        int clean;
1997        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1998        struct commit *head_commit = get_ref(head, o->branch1);
1999        struct commit *next_commit = get_ref(merge, o->branch2);
2000        struct commit_list *ca = NULL;
2001
2002        if (base_list) {
2003                int i;
2004                for (i = 0; i < num_base_list; ++i) {
2005                        struct commit *base;
2006                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
2007                                return error(_("Could not parse object '%s'"),
2008                                        sha1_to_hex(base_list[i]));
2009                        commit_list_insert(base, &ca);
2010                }
2011        }
2012
2013        hold_locked_index(lock, 1);
2014        clean = merge_recursive(o, head_commit, next_commit, ca,
2015                        result);
2016        if (active_cache_changed &&
2017            write_locked_index(&the_index, lock, COMMIT_LOCK))
2018                return error(_("Unable to write index."));
2019
2020        return clean ? 0 : 1;
2021}
2022
2023static void merge_recursive_config(struct merge_options *o)
2024{
2025        git_config_get_int("merge.verbosity", &o->verbosity);
2026        git_config_get_int("diff.renamelimit", &o->diff_rename_limit);
2027        git_config_get_int("merge.renamelimit", &o->merge_rename_limit);
2028        git_config(git_xmerge_config, NULL);
2029}
2030
2031void init_merge_options(struct merge_options *o)
2032{
2033        memset(o, 0, sizeof(struct merge_options));
2034        o->verbosity = 2;
2035        o->buffer_output = 1;
2036        o->diff_rename_limit = -1;
2037        o->merge_rename_limit = -1;
2038        o->renormalize = 0;
2039        merge_recursive_config(o);
2040        if (getenv("GIT_MERGE_VERBOSITY"))
2041                o->verbosity =
2042                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
2043        if (o->verbosity >= 5)
2044                o->buffer_output = 0;
2045        strbuf_init(&o->obuf, 0);
2046        string_list_init(&o->current_file_set, 1);
2047        string_list_init(&o->current_directory_set, 1);
2048        string_list_init(&o->df_conflict_file_set, 1);
2049}
2050
2051int parse_merge_opt(struct merge_options *o, const char *s)
2052{
2053        const char *arg;
2054
2055        if (!s || !*s)
2056                return -1;
2057        if (!strcmp(s, "ours"))
2058                o->recursive_variant = MERGE_RECURSIVE_OURS;
2059        else if (!strcmp(s, "theirs"))
2060                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
2061        else if (!strcmp(s, "subtree"))
2062                o->subtree_shift = "";
2063        else if (skip_prefix(s, "subtree=", &arg))
2064                o->subtree_shift = arg;
2065        else if (!strcmp(s, "patience"))
2066                o->xdl_opts = DIFF_WITH_ALG(o, PATIENCE_DIFF);
2067        else if (!strcmp(s, "histogram"))
2068                o->xdl_opts = DIFF_WITH_ALG(o, HISTOGRAM_DIFF);
2069        else if (skip_prefix(s, "diff-algorithm=", &arg)) {
2070                long value = parse_algorithm_value(arg);
2071                if (value < 0)
2072                        return -1;
2073                /* clear out previous settings */
2074                DIFF_XDL_CLR(o, NEED_MINIMAL);
2075                o->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
2076                o->xdl_opts |= value;
2077        }
2078        else if (!strcmp(s, "ignore-space-change"))
2079                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2080        else if (!strcmp(s, "ignore-all-space"))
2081                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
2082        else if (!strcmp(s, "ignore-space-at-eol"))
2083                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2084        else if (!strcmp(s, "renormalize"))
2085                o->renormalize = 1;
2086        else if (!strcmp(s, "no-renormalize"))
2087                o->renormalize = 0;
2088        else if (skip_prefix(s, "rename-threshold=", &arg)) {
2089                if ((o->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0)
2090                        return -1;
2091        }
2092        else
2093                return -1;
2094        return 0;
2095}