99c963558b08ae59bff629e5980329a124bf099f
   1/*
   2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
   3 * Fredrik Kuivinen.
   4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
   5 */
   6#include "cache.h"
   7#include "advice.h"
   8#include "lockfile.h"
   9#include "cache-tree.h"
  10#include "commit.h"
  11#include "blob.h"
  12#include "builtin.h"
  13#include "tree-walk.h"
  14#include "diff.h"
  15#include "diffcore.h"
  16#include "tag.h"
  17#include "unpack-trees.h"
  18#include "string-list.h"
  19#include "xdiff-interface.h"
  20#include "ll-merge.h"
  21#include "attr.h"
  22#include "merge-recursive.h"
  23#include "dir.h"
  24#include "submodule.h"
  25
  26static void flush_output(struct merge_options *o)
  27{
  28        if (o->obuf.len) {
  29                fputs(o->obuf.buf, stdout);
  30                strbuf_reset(&o->obuf);
  31        }
  32}
  33
  34static int err(struct merge_options *o, const char *err, ...)
  35{
  36        va_list params;
  37
  38        flush_output(o);
  39        va_start(params, err);
  40        strbuf_vaddf(&o->obuf, err, params);
  41        va_end(params);
  42        error("%s", o->obuf.buf);
  43        strbuf_reset(&o->obuf);
  44
  45        return -1;
  46}
  47
  48static struct tree *shift_tree_object(struct tree *one, struct tree *two,
  49                                      const char *subtree_shift)
  50{
  51        struct object_id shifted;
  52
  53        if (!*subtree_shift) {
  54                shift_tree(&one->object.oid, &two->object.oid, &shifted, 0);
  55        } else {
  56                shift_tree_by(&one->object.oid, &two->object.oid, &shifted,
  57                              subtree_shift);
  58        }
  59        if (!oidcmp(&two->object.oid, &shifted))
  60                return two;
  61        return lookup_tree(shifted.hash);
  62}
  63
  64static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  65{
  66        struct commit *commit = alloc_commit_node();
  67        struct merge_remote_desc *desc = xmalloc(sizeof(*desc));
  68
  69        desc->name = comment;
  70        desc->obj = (struct object *)commit;
  71        commit->tree = tree;
  72        commit->util = desc;
  73        commit->object.parsed = 1;
  74        return commit;
  75}
  76
  77/*
  78 * Since we use get_tree_entry(), which does not put the read object into
  79 * the object pool, we cannot rely on a == b.
  80 */
  81static int oid_eq(const struct object_id *a, const struct object_id *b)
  82{
  83        if (!a && !b)
  84                return 2;
  85        return a && b && oidcmp(a, b) == 0;
  86}
  87
  88enum rename_type {
  89        RENAME_NORMAL = 0,
  90        RENAME_DELETE,
  91        RENAME_ONE_FILE_TO_ONE,
  92        RENAME_ONE_FILE_TO_TWO,
  93        RENAME_TWO_FILES_TO_ONE
  94};
  95
  96struct rename_conflict_info {
  97        enum rename_type rename_type;
  98        struct diff_filepair *pair1;
  99        struct diff_filepair *pair2;
 100        const char *branch1;
 101        const char *branch2;
 102        struct stage_data *dst_entry1;
 103        struct stage_data *dst_entry2;
 104        struct diff_filespec ren1_other;
 105        struct diff_filespec ren2_other;
 106};
 107
 108/*
 109 * Since we want to write the index eventually, we cannot reuse the index
 110 * for these (temporary) data.
 111 */
 112struct stage_data {
 113        struct {
 114                unsigned mode;
 115                struct object_id oid;
 116        } stages[4];
 117        struct rename_conflict_info *rename_conflict_info;
 118        unsigned processed:1;
 119};
 120
 121static inline void setup_rename_conflict_info(enum rename_type rename_type,
 122                                              struct diff_filepair *pair1,
 123                                              struct diff_filepair *pair2,
 124                                              const char *branch1,
 125                                              const char *branch2,
 126                                              struct stage_data *dst_entry1,
 127                                              struct stage_data *dst_entry2,
 128                                              struct merge_options *o,
 129                                              struct stage_data *src_entry1,
 130                                              struct stage_data *src_entry2)
 131{
 132        struct rename_conflict_info *ci = xcalloc(1, sizeof(struct rename_conflict_info));
 133        ci->rename_type = rename_type;
 134        ci->pair1 = pair1;
 135        ci->branch1 = branch1;
 136        ci->branch2 = branch2;
 137
 138        ci->dst_entry1 = dst_entry1;
 139        dst_entry1->rename_conflict_info = ci;
 140        dst_entry1->processed = 0;
 141
 142        assert(!pair2 == !dst_entry2);
 143        if (dst_entry2) {
 144                ci->dst_entry2 = dst_entry2;
 145                ci->pair2 = pair2;
 146                dst_entry2->rename_conflict_info = ci;
 147        }
 148
 149        if (rename_type == RENAME_TWO_FILES_TO_ONE) {
 150                /*
 151                 * For each rename, there could have been
 152                 * modifications on the side of history where that
 153                 * file was not renamed.
 154                 */
 155                int ostage1 = o->branch1 == branch1 ? 3 : 2;
 156                int ostage2 = ostage1 ^ 1;
 157
 158                ci->ren1_other.path = pair1->one->path;
 159                oidcpy(&ci->ren1_other.oid, &src_entry1->stages[ostage1].oid);
 160                ci->ren1_other.mode = src_entry1->stages[ostage1].mode;
 161
 162                ci->ren2_other.path = pair2->one->path;
 163                oidcpy(&ci->ren2_other.oid, &src_entry2->stages[ostage2].oid);
 164                ci->ren2_other.mode = src_entry2->stages[ostage2].mode;
 165        }
 166}
 167
 168static int show(struct merge_options *o, int v)
 169{
 170        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 171}
 172
 173__attribute__((format (printf, 3, 4)))
 174static void output(struct merge_options *o, int v, const char *fmt, ...)
 175{
 176        va_list ap;
 177
 178        if (!show(o, v))
 179                return;
 180
 181        strbuf_addchars(&o->obuf, ' ', o->call_depth * 2);
 182
 183        va_start(ap, fmt);
 184        strbuf_vaddf(&o->obuf, fmt, ap);
 185        va_end(ap);
 186
 187        strbuf_addch(&o->obuf, '\n');
 188        if (!o->buffer_output)
 189                flush_output(o);
 190}
 191
 192static void output_commit_title(struct merge_options *o, struct commit *commit)
 193{
 194        strbuf_addchars(&o->obuf, ' ', o->call_depth * 2);
 195        if (commit->util)
 196                strbuf_addf(&o->obuf, "virtual %s\n",
 197                        merge_remote_util(commit)->name);
 198        else {
 199                strbuf_addf(&o->obuf, "%s ",
 200                        find_unique_abbrev(commit->object.oid.hash,
 201                                DEFAULT_ABBREV));
 202                if (parse_commit(commit) != 0)
 203                        strbuf_addf(&o->obuf, _("(bad commit)\n"));
 204                else {
 205                        const char *title;
 206                        const char *msg = get_commit_buffer(commit, NULL);
 207                        int len = find_commit_subject(msg, &title);
 208                        if (len)
 209                                strbuf_addf(&o->obuf, "%.*s\n", len, title);
 210                        unuse_commit_buffer(commit, msg);
 211                }
 212        }
 213        flush_output(o);
 214}
 215
 216static int add_cacheinfo(struct merge_options *o,
 217                unsigned int mode, const struct object_id *oid,
 218                const char *path, int stage, int refresh, int options)
 219{
 220        struct cache_entry *ce;
 221        int ret;
 222
 223        ce = make_cache_entry(mode, oid ? oid->hash : null_sha1, path, stage, 0);
 224        if (!ce)
 225                return err(o, _("addinfo_cache failed for path '%s'"), path);
 226
 227        ret = add_cache_entry(ce, options);
 228        if (refresh) {
 229                struct cache_entry *nce;
 230
 231                nce = refresh_cache_entry(ce, CE_MATCH_REFRESH | CE_MATCH_IGNORE_MISSING);
 232                if (nce != ce)
 233                        ret = add_cache_entry(nce, options);
 234        }
 235        return ret;
 236}
 237
 238static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 239{
 240        parse_tree(tree);
 241        init_tree_desc(desc, tree->buffer, tree->size);
 242}
 243
 244static int git_merge_trees(int index_only,
 245                           struct tree *common,
 246                           struct tree *head,
 247                           struct tree *merge)
 248{
 249        int rc;
 250        struct tree_desc t[3];
 251        struct unpack_trees_options opts;
 252
 253        memset(&opts, 0, sizeof(opts));
 254        if (index_only)
 255                opts.index_only = 1;
 256        else
 257                opts.update = 1;
 258        opts.merge = 1;
 259        opts.head_idx = 2;
 260        opts.fn = threeway_merge;
 261        opts.src_index = &the_index;
 262        opts.dst_index = &the_index;
 263        setup_unpack_trees_porcelain(&opts, "merge");
 264
 265        init_tree_desc_from_tree(t+0, common);
 266        init_tree_desc_from_tree(t+1, head);
 267        init_tree_desc_from_tree(t+2, merge);
 268
 269        rc = unpack_trees(3, t, &opts);
 270        cache_tree_free(&active_cache_tree);
 271        return rc;
 272}
 273
 274struct tree *write_tree_from_memory(struct merge_options *o)
 275{
 276        struct tree *result = NULL;
 277
 278        if (unmerged_cache()) {
 279                int i;
 280                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 281                for (i = 0; i < active_nr; i++) {
 282                        const struct cache_entry *ce = active_cache[i];
 283                        if (ce_stage(ce))
 284                                fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
 285                                        (int)ce_namelen(ce), ce->name);
 286                }
 287                die("BUG: unmerged index entries in merge-recursive.c");
 288        }
 289
 290        if (!active_cache_tree)
 291                active_cache_tree = cache_tree();
 292
 293        if (!cache_tree_fully_valid(active_cache_tree) &&
 294            cache_tree_update(&the_index, 0) < 0) {
 295                err(o, _("error building trees"));
 296                return NULL;
 297        }
 298
 299        result = lookup_tree(active_cache_tree->sha1);
 300
 301        return result;
 302}
 303
 304static int save_files_dirs(const unsigned char *sha1,
 305                struct strbuf *base, const char *path,
 306                unsigned int mode, int stage, void *context)
 307{
 308        int baselen = base->len;
 309        struct merge_options *o = context;
 310
 311        strbuf_addstr(base, path);
 312
 313        if (S_ISDIR(mode))
 314                string_list_insert(&o->current_directory_set, base->buf);
 315        else
 316                string_list_insert(&o->current_file_set, base->buf);
 317
 318        strbuf_setlen(base, baselen);
 319        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 320}
 321
 322static int get_files_dirs(struct merge_options *o, struct tree *tree)
 323{
 324        int n;
 325        struct pathspec match_all;
 326        memset(&match_all, 0, sizeof(match_all));
 327        if (read_tree_recursive(tree, "", 0, 0, &match_all, save_files_dirs, o))
 328                return 0;
 329        n = o->current_file_set.nr + o->current_directory_set.nr;
 330        return n;
 331}
 332
 333/*
 334 * Returns an index_entry instance which doesn't have to correspond to
 335 * a real cache entry in Git's index.
 336 */
 337static struct stage_data *insert_stage_data(const char *path,
 338                struct tree *o, struct tree *a, struct tree *b,
 339                struct string_list *entries)
 340{
 341        struct string_list_item *item;
 342        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 343        get_tree_entry(o->object.oid.hash, path,
 344                        e->stages[1].oid.hash, &e->stages[1].mode);
 345        get_tree_entry(a->object.oid.hash, path,
 346                        e->stages[2].oid.hash, &e->stages[2].mode);
 347        get_tree_entry(b->object.oid.hash, path,
 348                        e->stages[3].oid.hash, &e->stages[3].mode);
 349        item = string_list_insert(entries, path);
 350        item->util = e;
 351        return e;
 352}
 353
 354/*
 355 * Create a dictionary mapping file names to stage_data objects. The
 356 * dictionary contains one entry for every path with a non-zero stage entry.
 357 */
 358static struct string_list *get_unmerged(void)
 359{
 360        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 361        int i;
 362
 363        unmerged->strdup_strings = 1;
 364
 365        for (i = 0; i < active_nr; i++) {
 366                struct string_list_item *item;
 367                struct stage_data *e;
 368                const struct cache_entry *ce = active_cache[i];
 369                if (!ce_stage(ce))
 370                        continue;
 371
 372                item = string_list_lookup(unmerged, ce->name);
 373                if (!item) {
 374                        item = string_list_insert(unmerged, ce->name);
 375                        item->util = xcalloc(1, sizeof(struct stage_data));
 376                }
 377                e = item->util;
 378                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 379                hashcpy(e->stages[ce_stage(ce)].oid.hash, ce->sha1);
 380        }
 381
 382        return unmerged;
 383}
 384
 385static int string_list_df_name_compare(const void *a, const void *b)
 386{
 387        const struct string_list_item *one = a;
 388        const struct string_list_item *two = b;
 389        int onelen = strlen(one->string);
 390        int twolen = strlen(two->string);
 391        /*
 392         * Here we only care that entries for D/F conflicts are
 393         * adjacent, in particular with the file of the D/F conflict
 394         * appearing before files below the corresponding directory.
 395         * The order of the rest of the list is irrelevant for us.
 396         *
 397         * To achieve this, we sort with df_name_compare and provide
 398         * the mode S_IFDIR so that D/F conflicts will sort correctly.
 399         * We use the mode S_IFDIR for everything else for simplicity,
 400         * since in other cases any changes in their order due to
 401         * sorting cause no problems for us.
 402         */
 403        int cmp = df_name_compare(one->string, onelen, S_IFDIR,
 404                                  two->string, twolen, S_IFDIR);
 405        /*
 406         * Now that 'foo' and 'foo/bar' compare equal, we have to make sure
 407         * that 'foo' comes before 'foo/bar'.
 408         */
 409        if (cmp)
 410                return cmp;
 411        return onelen - twolen;
 412}
 413
 414static void record_df_conflict_files(struct merge_options *o,
 415                                     struct string_list *entries)
 416{
 417        /* If there is a D/F conflict and the file for such a conflict
 418         * currently exist in the working tree, we want to allow it to be
 419         * removed to make room for the corresponding directory if needed.
 420         * The files underneath the directories of such D/F conflicts will
 421         * be processed before the corresponding file involved in the D/F
 422         * conflict.  If the D/F directory ends up being removed by the
 423         * merge, then we won't have to touch the D/F file.  If the D/F
 424         * directory needs to be written to the working copy, then the D/F
 425         * file will simply be removed (in make_room_for_path()) to make
 426         * room for the necessary paths.  Note that if both the directory
 427         * and the file need to be present, then the D/F file will be
 428         * reinstated with a new unique name at the time it is processed.
 429         */
 430        struct string_list df_sorted_entries;
 431        const char *last_file = NULL;
 432        int last_len = 0;
 433        int i;
 434
 435        /*
 436         * If we're merging merge-bases, we don't want to bother with
 437         * any working directory changes.
 438         */
 439        if (o->call_depth)
 440                return;
 441
 442        /* Ensure D/F conflicts are adjacent in the entries list. */
 443        memset(&df_sorted_entries, 0, sizeof(struct string_list));
 444        for (i = 0; i < entries->nr; i++) {
 445                struct string_list_item *next = &entries->items[i];
 446                string_list_append(&df_sorted_entries, next->string)->util =
 447                                   next->util;
 448        }
 449        qsort(df_sorted_entries.items, entries->nr, sizeof(*entries->items),
 450              string_list_df_name_compare);
 451
 452        string_list_clear(&o->df_conflict_file_set, 1);
 453        for (i = 0; i < df_sorted_entries.nr; i++) {
 454                const char *path = df_sorted_entries.items[i].string;
 455                int len = strlen(path);
 456                struct stage_data *e = df_sorted_entries.items[i].util;
 457
 458                /*
 459                 * Check if last_file & path correspond to a D/F conflict;
 460                 * i.e. whether path is last_file+'/'+<something>.
 461                 * If so, record that it's okay to remove last_file to make
 462                 * room for path and friends if needed.
 463                 */
 464                if (last_file &&
 465                    len > last_len &&
 466                    memcmp(path, last_file, last_len) == 0 &&
 467                    path[last_len] == '/') {
 468                        string_list_insert(&o->df_conflict_file_set, last_file);
 469                }
 470
 471                /*
 472                 * Determine whether path could exist as a file in the
 473                 * working directory as a possible D/F conflict.  This
 474                 * will only occur when it exists in stage 2 as a
 475                 * file.
 476                 */
 477                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 478                        last_file = path;
 479                        last_len = len;
 480                } else {
 481                        last_file = NULL;
 482                }
 483        }
 484        string_list_clear(&df_sorted_entries, 0);
 485}
 486
 487struct rename {
 488        struct diff_filepair *pair;
 489        struct stage_data *src_entry;
 490        struct stage_data *dst_entry;
 491        unsigned processed:1;
 492};
 493
 494/*
 495 * Get information of all renames which occurred between 'o_tree' and
 496 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 497 * 'b_tree') to be able to associate the correct cache entries with
 498 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 499 */
 500static struct string_list *get_renames(struct merge_options *o,
 501                                       struct tree *tree,
 502                                       struct tree *o_tree,
 503                                       struct tree *a_tree,
 504                                       struct tree *b_tree,
 505                                       struct string_list *entries)
 506{
 507        int i;
 508        struct string_list *renames;
 509        struct diff_options opts;
 510
 511        renames = xcalloc(1, sizeof(struct string_list));
 512        if (!o->detect_rename)
 513                return renames;
 514
 515        diff_setup(&opts);
 516        DIFF_OPT_SET(&opts, RECURSIVE);
 517        DIFF_OPT_CLR(&opts, RENAME_EMPTY);
 518        opts.detect_rename = DIFF_DETECT_RENAME;
 519        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 520                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 521                            1000;
 522        opts.rename_score = o->rename_score;
 523        opts.show_rename_progress = o->show_rename_progress;
 524        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 525        diff_setup_done(&opts);
 526        diff_tree_sha1(o_tree->object.oid.hash, tree->object.oid.hash, "", &opts);
 527        diffcore_std(&opts);
 528        if (opts.needed_rename_limit > o->needed_rename_limit)
 529                o->needed_rename_limit = opts.needed_rename_limit;
 530        for (i = 0; i < diff_queued_diff.nr; ++i) {
 531                struct string_list_item *item;
 532                struct rename *re;
 533                struct diff_filepair *pair = diff_queued_diff.queue[i];
 534                if (pair->status != 'R') {
 535                        diff_free_filepair(pair);
 536                        continue;
 537                }
 538                re = xmalloc(sizeof(*re));
 539                re->processed = 0;
 540                re->pair = pair;
 541                item = string_list_lookup(entries, re->pair->one->path);
 542                if (!item)
 543                        re->src_entry = insert_stage_data(re->pair->one->path,
 544                                        o_tree, a_tree, b_tree, entries);
 545                else
 546                        re->src_entry = item->util;
 547
 548                item = string_list_lookup(entries, re->pair->two->path);
 549                if (!item)
 550                        re->dst_entry = insert_stage_data(re->pair->two->path,
 551                                        o_tree, a_tree, b_tree, entries);
 552                else
 553                        re->dst_entry = item->util;
 554                item = string_list_insert(renames, pair->one->path);
 555                item->util = re;
 556        }
 557        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 558        diff_queued_diff.nr = 0;
 559        diff_flush(&opts);
 560        return renames;
 561}
 562
 563static int update_stages(struct merge_options *opt, const char *path,
 564                         const struct diff_filespec *o,
 565                         const struct diff_filespec *a,
 566                         const struct diff_filespec *b)
 567{
 568
 569        /*
 570         * NOTE: It is usually a bad idea to call update_stages on a path
 571         * before calling update_file on that same path, since it can
 572         * sometimes lead to spurious "refusing to lose untracked file..."
 573         * messages from update_file (via make_room_for path via
 574         * would_lose_untracked).  Instead, reverse the order of the calls
 575         * (executing update_file first and then update_stages).
 576         */
 577        int clear = 1;
 578        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 579        if (clear)
 580                if (remove_file_from_cache(path))
 581                        return -1;
 582        if (o)
 583                if (add_cacheinfo(opt, o->mode, &o->oid, path, 1, 0, options))
 584                        return -1;
 585        if (a)
 586                if (add_cacheinfo(opt, a->mode, &a->oid, path, 2, 0, options))
 587                        return -1;
 588        if (b)
 589                if (add_cacheinfo(opt, b->mode, &b->oid, path, 3, 0, options))
 590                        return -1;
 591        return 0;
 592}
 593
 594static void update_entry(struct stage_data *entry,
 595                         struct diff_filespec *o,
 596                         struct diff_filespec *a,
 597                         struct diff_filespec *b)
 598{
 599        entry->processed = 0;
 600        entry->stages[1].mode = o->mode;
 601        entry->stages[2].mode = a->mode;
 602        entry->stages[3].mode = b->mode;
 603        oidcpy(&entry->stages[1].oid, &o->oid);
 604        oidcpy(&entry->stages[2].oid, &a->oid);
 605        oidcpy(&entry->stages[3].oid, &b->oid);
 606}
 607
 608static int remove_file(struct merge_options *o, int clean,
 609                       const char *path, int no_wd)
 610{
 611        int update_cache = o->call_depth || clean;
 612        int update_working_directory = !o->call_depth && !no_wd;
 613
 614        if (update_cache) {
 615                if (remove_file_from_cache(path))
 616                        return -1;
 617        }
 618        if (update_working_directory) {
 619                if (ignore_case) {
 620                        struct cache_entry *ce;
 621                        ce = cache_file_exists(path, strlen(path), ignore_case);
 622                        if (ce && ce_stage(ce) == 0)
 623                                return 0;
 624                }
 625                if (remove_path(path))
 626                        return -1;
 627        }
 628        return 0;
 629}
 630
 631/* add a string to a strbuf, but converting "/" to "_" */
 632static void add_flattened_path(struct strbuf *out, const char *s)
 633{
 634        size_t i = out->len;
 635        strbuf_addstr(out, s);
 636        for (; i < out->len; i++)
 637                if (out->buf[i] == '/')
 638                        out->buf[i] = '_';
 639}
 640
 641static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 642{
 643        struct strbuf newpath = STRBUF_INIT;
 644        int suffix = 0;
 645        size_t base_len;
 646
 647        strbuf_addf(&newpath, "%s~", path);
 648        add_flattened_path(&newpath, branch);
 649
 650        base_len = newpath.len;
 651        while (string_list_has_string(&o->current_file_set, newpath.buf) ||
 652               string_list_has_string(&o->current_directory_set, newpath.buf) ||
 653               (!o->call_depth && file_exists(newpath.buf))) {
 654                strbuf_setlen(&newpath, base_len);
 655                strbuf_addf(&newpath, "_%d", suffix++);
 656        }
 657
 658        string_list_insert(&o->current_file_set, newpath.buf);
 659        return strbuf_detach(&newpath, NULL);
 660}
 661
 662static int dir_in_way(const char *path, int check_working_copy)
 663{
 664        int pos;
 665        struct strbuf dirpath = STRBUF_INIT;
 666        struct stat st;
 667
 668        strbuf_addstr(&dirpath, path);
 669        strbuf_addch(&dirpath, '/');
 670
 671        pos = cache_name_pos(dirpath.buf, dirpath.len);
 672
 673        if (pos < 0)
 674                pos = -1 - pos;
 675        if (pos < active_nr &&
 676            !strncmp(dirpath.buf, active_cache[pos]->name, dirpath.len)) {
 677                strbuf_release(&dirpath);
 678                return 1;
 679        }
 680
 681        strbuf_release(&dirpath);
 682        return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode);
 683}
 684
 685static int was_tracked(const char *path)
 686{
 687        int pos = cache_name_pos(path, strlen(path));
 688
 689        if (0 <= pos)
 690                /* we have been tracking this path */
 691                return 1;
 692
 693        /*
 694         * Look for an unmerged entry for the path,
 695         * specifically stage #2, which would indicate
 696         * that "our" side before the merge started
 697         * had the path tracked (and resulted in a conflict).
 698         */
 699        for (pos = -1 - pos;
 700             pos < active_nr && !strcmp(path, active_cache[pos]->name);
 701             pos++)
 702                if (ce_stage(active_cache[pos]) == 2)
 703                        return 1;
 704        return 0;
 705}
 706
 707static int would_lose_untracked(const char *path)
 708{
 709        return !was_tracked(path) && file_exists(path);
 710}
 711
 712static int make_room_for_path(struct merge_options *o, const char *path)
 713{
 714        int status, i;
 715        const char *msg = _("failed to create path '%s'%s");
 716
 717        /* Unlink any D/F conflict files that are in the way */
 718        for (i = 0; i < o->df_conflict_file_set.nr; i++) {
 719                const char *df_path = o->df_conflict_file_set.items[i].string;
 720                size_t pathlen = strlen(path);
 721                size_t df_pathlen = strlen(df_path);
 722                if (df_pathlen < pathlen &&
 723                    path[df_pathlen] == '/' &&
 724                    strncmp(path, df_path, df_pathlen) == 0) {
 725                        output(o, 3,
 726                               _("Removing %s to make room for subdirectory\n"),
 727                               df_path);
 728                        unlink(df_path);
 729                        unsorted_string_list_delete_item(&o->df_conflict_file_set,
 730                                                         i, 0);
 731                        break;
 732                }
 733        }
 734
 735        /* Make sure leading directories are created */
 736        status = safe_create_leading_directories_const(path);
 737        if (status) {
 738                if (status == SCLD_EXISTS)
 739                        /* something else exists */
 740                        return err(o, msg, path, _(": perhaps a D/F conflict?"));
 741                return err(o, msg, path, "");
 742        }
 743
 744        /*
 745         * Do not unlink a file in the work tree if we are not
 746         * tracking it.
 747         */
 748        if (would_lose_untracked(path))
 749                return err(o, _("refusing to lose untracked file at '%s'"),
 750                             path);
 751
 752        /* Successful unlink is good.. */
 753        if (!unlink(path))
 754                return 0;
 755        /* .. and so is no existing file */
 756        if (errno == ENOENT)
 757                return 0;
 758        /* .. but not some other error (who really cares what?) */
 759        return err(o, msg, path, _(": perhaps a D/F conflict?"));
 760}
 761
 762static int update_file_flags(struct merge_options *o,
 763                             const struct object_id *oid,
 764                             unsigned mode,
 765                             const char *path,
 766                             int update_cache,
 767                             int update_wd)
 768{
 769        int ret = 0;
 770
 771        if (o->call_depth)
 772                update_wd = 0;
 773
 774        if (update_wd) {
 775                enum object_type type;
 776                void *buf;
 777                unsigned long size;
 778
 779                if (S_ISGITLINK(mode)) {
 780                        /*
 781                         * We may later decide to recursively descend into
 782                         * the submodule directory and update its index
 783                         * and/or work tree, but we do not do that now.
 784                         */
 785                        update_wd = 0;
 786                        goto update_index;
 787                }
 788
 789                buf = read_sha1_file(oid->hash, &type, &size);
 790                if (!buf)
 791                        return err(o, _("cannot read object %s '%s'"), oid_to_hex(oid), path);
 792                if (type != OBJ_BLOB) {
 793                        ret = err(o, _("blob expected for %s '%s'"), oid_to_hex(oid), path);
 794                        goto free_buf;
 795                }
 796                if (S_ISREG(mode)) {
 797                        struct strbuf strbuf = STRBUF_INIT;
 798                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 799                                free(buf);
 800                                size = strbuf.len;
 801                                buf = strbuf_detach(&strbuf, NULL);
 802                        }
 803                }
 804
 805                if (make_room_for_path(o, path) < 0) {
 806                        update_wd = 0;
 807                        goto free_buf;
 808                }
 809                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 810                        int fd;
 811                        if (mode & 0100)
 812                                mode = 0777;
 813                        else
 814                                mode = 0666;
 815                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 816                        if (fd < 0) {
 817                                ret = err(o, _("failed to open '%s': %s"),
 818                                          path, strerror(errno));
 819                                goto free_buf;
 820                        }
 821                        write_in_full(fd, buf, size);
 822                        close(fd);
 823                } else if (S_ISLNK(mode)) {
 824                        char *lnk = xmemdupz(buf, size);
 825                        safe_create_leading_directories_const(path);
 826                        unlink(path);
 827                        if (symlink(lnk, path))
 828                                ret = err(o, _("failed to symlink '%s': %s"),
 829                                        path, strerror(errno));
 830                        free(lnk);
 831                } else
 832                        ret = err(o,
 833                                  _("do not know what to do with %06o %s '%s'"),
 834                                  mode, oid_to_hex(oid), path);
 835 free_buf:
 836                free(buf);
 837        }
 838 update_index:
 839        if (!ret && update_cache)
 840                add_cacheinfo(o, mode, oid, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 841        return ret;
 842}
 843
 844static int update_file(struct merge_options *o,
 845                       int clean,
 846                       const struct object_id *oid,
 847                       unsigned mode,
 848                       const char *path)
 849{
 850        return update_file_flags(o, oid, mode, path, o->call_depth || clean, !o->call_depth);
 851}
 852
 853/* Low level file merging, update and removal */
 854
 855struct merge_file_info {
 856        struct object_id oid;
 857        unsigned mode;
 858        unsigned clean:1,
 859                 merge:1;
 860};
 861
 862static int merge_3way(struct merge_options *o,
 863                      mmbuffer_t *result_buf,
 864                      const struct diff_filespec *one,
 865                      const struct diff_filespec *a,
 866                      const struct diff_filespec *b,
 867                      const char *branch1,
 868                      const char *branch2)
 869{
 870        mmfile_t orig, src1, src2;
 871        struct ll_merge_options ll_opts = {0};
 872        char *base_name, *name1, *name2;
 873        int merge_status;
 874
 875        ll_opts.renormalize = o->renormalize;
 876        ll_opts.xdl_opts = o->xdl_opts;
 877
 878        if (o->call_depth) {
 879                ll_opts.virtual_ancestor = 1;
 880                ll_opts.variant = 0;
 881        } else {
 882                switch (o->recursive_variant) {
 883                case MERGE_RECURSIVE_OURS:
 884                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 885                        break;
 886                case MERGE_RECURSIVE_THEIRS:
 887                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 888                        break;
 889                default:
 890                        ll_opts.variant = 0;
 891                        break;
 892                }
 893        }
 894
 895        if (strcmp(a->path, b->path) ||
 896            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 897                base_name = o->ancestor == NULL ? NULL :
 898                        mkpathdup("%s:%s", o->ancestor, one->path);
 899                name1 = mkpathdup("%s:%s", branch1, a->path);
 900                name2 = mkpathdup("%s:%s", branch2, b->path);
 901        } else {
 902                base_name = o->ancestor == NULL ? NULL :
 903                        mkpathdup("%s", o->ancestor);
 904                name1 = mkpathdup("%s", branch1);
 905                name2 = mkpathdup("%s", branch2);
 906        }
 907
 908        read_mmblob(&orig, one->oid.hash);
 909        read_mmblob(&src1, a->oid.hash);
 910        read_mmblob(&src2, b->oid.hash);
 911
 912        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 913                                &src1, name1, &src2, name2, &ll_opts);
 914
 915        free(base_name);
 916        free(name1);
 917        free(name2);
 918        free(orig.ptr);
 919        free(src1.ptr);
 920        free(src2.ptr);
 921        return merge_status;
 922}
 923
 924static int merge_file_1(struct merge_options *o,
 925                                           const struct diff_filespec *one,
 926                                           const struct diff_filespec *a,
 927                                           const struct diff_filespec *b,
 928                                           const char *branch1,
 929                                           const char *branch2,
 930                                           struct merge_file_info *result)
 931{
 932        result->merge = 0;
 933        result->clean = 1;
 934
 935        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 936                result->clean = 0;
 937                if (S_ISREG(a->mode)) {
 938                        result->mode = a->mode;
 939                        oidcpy(&result->oid, &a->oid);
 940                } else {
 941                        result->mode = b->mode;
 942                        oidcpy(&result->oid, &b->oid);
 943                }
 944        } else {
 945                if (!oid_eq(&a->oid, &one->oid) && !oid_eq(&b->oid, &one->oid))
 946                        result->merge = 1;
 947
 948                /*
 949                 * Merge modes
 950                 */
 951                if (a->mode == b->mode || a->mode == one->mode)
 952                        result->mode = b->mode;
 953                else {
 954                        result->mode = a->mode;
 955                        if (b->mode != one->mode) {
 956                                result->clean = 0;
 957                                result->merge = 1;
 958                        }
 959                }
 960
 961                if (oid_eq(&a->oid, &b->oid) || oid_eq(&a->oid, &one->oid))
 962                        oidcpy(&result->oid, &b->oid);
 963                else if (oid_eq(&b->oid, &one->oid))
 964                        oidcpy(&result->oid, &a->oid);
 965                else if (S_ISREG(a->mode)) {
 966                        mmbuffer_t result_buf;
 967                        int ret = 0, merge_status;
 968
 969                        merge_status = merge_3way(o, &result_buf, one, a, b,
 970                                                  branch1, branch2);
 971
 972                        if ((merge_status < 0) || !result_buf.ptr)
 973                                ret = err(o, _("Failed to execute internal merge"));
 974
 975                        if (!ret && write_sha1_file(result_buf.ptr, result_buf.size,
 976                                                    blob_type, result->oid.hash))
 977                                ret = err(o, _("Unable to add %s to database"),
 978                                          a->path);
 979
 980                        free(result_buf.ptr);
 981                        if (ret)
 982                                return ret;
 983                        result->clean = (merge_status == 0);
 984                } else if (S_ISGITLINK(a->mode)) {
 985                        result->clean = merge_submodule(result->oid.hash,
 986                                                       one->path,
 987                                                       one->oid.hash,
 988                                                       a->oid.hash,
 989                                                       b->oid.hash,
 990                                                       !o->call_depth);
 991                } else if (S_ISLNK(a->mode)) {
 992                        oidcpy(&result->oid, &a->oid);
 993
 994                        if (!oid_eq(&a->oid, &b->oid))
 995                                result->clean = 0;
 996                } else
 997                        die("BUG: unsupported object type in the tree");
 998        }
 999
1000        return 0;
1001}
1002
1003static int merge_file_special_markers(struct merge_options *o,
1004                           const struct diff_filespec *one,
1005                           const struct diff_filespec *a,
1006                           const struct diff_filespec *b,
1007                           const char *branch1,
1008                           const char *filename1,
1009                           const char *branch2,
1010                           const char *filename2,
1011                           struct merge_file_info *mfi)
1012{
1013        char *side1 = NULL;
1014        char *side2 = NULL;
1015        int ret;
1016
1017        if (filename1)
1018                side1 = xstrfmt("%s:%s", branch1, filename1);
1019        if (filename2)
1020                side2 = xstrfmt("%s:%s", branch2, filename2);
1021
1022        ret = merge_file_1(o, one, a, b,
1023                           side1 ? side1 : branch1,
1024                           side2 ? side2 : branch2, mfi);
1025        free(side1);
1026        free(side2);
1027        return ret;
1028}
1029
1030static int merge_file_one(struct merge_options *o,
1031                                         const char *path,
1032                                         const struct object_id *o_oid, int o_mode,
1033                                         const struct object_id *a_oid, int a_mode,
1034                                         const struct object_id *b_oid, int b_mode,
1035                                         const char *branch1,
1036                                         const char *branch2,
1037                                         struct merge_file_info *mfi)
1038{
1039        struct diff_filespec one, a, b;
1040
1041        one.path = a.path = b.path = (char *)path;
1042        oidcpy(&one.oid, o_oid);
1043        one.mode = o_mode;
1044        oidcpy(&a.oid, a_oid);
1045        a.mode = a_mode;
1046        oidcpy(&b.oid, b_oid);
1047        b.mode = b_mode;
1048        return merge_file_1(o, &one, &a, &b, branch1, branch2, mfi);
1049}
1050
1051static int handle_change_delete(struct merge_options *o,
1052                                 const char *path,
1053                                 const struct object_id *o_oid, int o_mode,
1054                                 const struct object_id *a_oid, int a_mode,
1055                                 const struct object_id *b_oid, int b_mode,
1056                                 const char *change, const char *change_past)
1057{
1058        char *renamed = NULL;
1059        int ret = 0;
1060        if (dir_in_way(path, !o->call_depth)) {
1061                renamed = unique_path(o, path, a_oid ? o->branch1 : o->branch2);
1062        }
1063
1064        if (o->call_depth) {
1065                /*
1066                 * We cannot arbitrarily accept either a_sha or b_sha as
1067                 * correct; since there is no true "middle point" between
1068                 * them, simply reuse the base version for virtual merge base.
1069                 */
1070                ret = remove_file_from_cache(path);
1071                if (!ret)
1072                        ret = update_file(o, 0, o_oid, o_mode,
1073                                          renamed ? renamed : path);
1074        } else if (!a_oid) {
1075                if (!renamed) {
1076                        output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1077                               "and %s in %s. Version %s of %s left in tree."),
1078                               change, path, o->branch1, change_past,
1079                               o->branch2, o->branch2, path);
1080                        ret = update_file(o, 0, b_oid, b_mode, path);
1081                } else {
1082                        output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1083                               "and %s in %s. Version %s of %s left in tree at %s."),
1084                               change, path, o->branch1, change_past,
1085                               o->branch2, o->branch2, path, renamed);
1086                        ret = update_file(o, 0, b_oid, b_mode, renamed);
1087                }
1088        } else {
1089                if (!renamed) {
1090                        output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1091                               "and %s in %s. Version %s of %s left in tree."),
1092                               change, path, o->branch2, change_past,
1093                               o->branch1, o->branch1, path);
1094                } else {
1095                        output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1096                               "and %s in %s. Version %s of %s left in tree at %s."),
1097                               change, path, o->branch2, change_past,
1098                               o->branch1, o->branch1, path, renamed);
1099                        ret = update_file(o, 0, a_oid, a_mode, renamed);
1100                }
1101                /*
1102                 * No need to call update_file() on path when !renamed, since
1103                 * that would needlessly touch path.  We could call
1104                 * update_file_flags() with update_cache=0 and update_wd=0,
1105                 * but that's a no-op.
1106                 */
1107        }
1108        free(renamed);
1109
1110        return ret;
1111}
1112
1113static int conflict_rename_delete(struct merge_options *o,
1114                                   struct diff_filepair *pair,
1115                                   const char *rename_branch,
1116                                   const char *other_branch)
1117{
1118        const struct diff_filespec *orig = pair->one;
1119        const struct diff_filespec *dest = pair->two;
1120        const struct object_id *a_oid = NULL;
1121        const struct object_id *b_oid = NULL;
1122        int a_mode = 0;
1123        int b_mode = 0;
1124
1125        if (rename_branch == o->branch1) {
1126                a_oid = &dest->oid;
1127                a_mode = dest->mode;
1128        } else {
1129                b_oid = &dest->oid;
1130                b_mode = dest->mode;
1131        }
1132
1133        if (handle_change_delete(o,
1134                                 o->call_depth ? orig->path : dest->path,
1135                                 &orig->oid, orig->mode,
1136                                 a_oid, a_mode,
1137                                 b_oid, b_mode,
1138                                 _("rename"), _("renamed")))
1139                return -1;
1140
1141        if (o->call_depth)
1142                return remove_file_from_cache(dest->path);
1143        else
1144                return update_stages(o, dest->path, NULL,
1145                                     rename_branch == o->branch1 ? dest : NULL,
1146                                     rename_branch == o->branch1 ? NULL : dest);
1147}
1148
1149static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
1150                                                 struct stage_data *entry,
1151                                                 int stage)
1152{
1153        struct object_id *oid = &entry->stages[stage].oid;
1154        unsigned mode = entry->stages[stage].mode;
1155        if (mode == 0 || is_null_oid(oid))
1156                return NULL;
1157        oidcpy(&target->oid, oid);
1158        target->mode = mode;
1159        return target;
1160}
1161
1162static int handle_file(struct merge_options *o,
1163                        struct diff_filespec *rename,
1164                        int stage,
1165                        struct rename_conflict_info *ci)
1166{
1167        char *dst_name = rename->path;
1168        struct stage_data *dst_entry;
1169        const char *cur_branch, *other_branch;
1170        struct diff_filespec other;
1171        struct diff_filespec *add;
1172        int ret;
1173
1174        if (stage == 2) {
1175                dst_entry = ci->dst_entry1;
1176                cur_branch = ci->branch1;
1177                other_branch = ci->branch2;
1178        } else {
1179                dst_entry = ci->dst_entry2;
1180                cur_branch = ci->branch2;
1181                other_branch = ci->branch1;
1182        }
1183
1184        add = filespec_from_entry(&other, dst_entry, stage ^ 1);
1185        if (add) {
1186                char *add_name = unique_path(o, rename->path, other_branch);
1187                if (update_file(o, 0, &add->oid, add->mode, add_name))
1188                        return -1;
1189
1190                remove_file(o, 0, rename->path, 0);
1191                dst_name = unique_path(o, rename->path, cur_branch);
1192        } else {
1193                if (dir_in_way(rename->path, !o->call_depth)) {
1194                        dst_name = unique_path(o, rename->path, cur_branch);
1195                        output(o, 1, _("%s is a directory in %s adding as %s instead"),
1196                               rename->path, other_branch, dst_name);
1197                }
1198        }
1199        if ((ret = update_file(o, 0, &rename->oid, rename->mode, dst_name)))
1200                ; /* fall through, do allow dst_name to be released */
1201        else if (stage == 2)
1202                ret = update_stages(o, rename->path, NULL, rename, add);
1203        else
1204                ret = update_stages(o, rename->path, NULL, add, rename);
1205
1206        if (dst_name != rename->path)
1207                free(dst_name);
1208
1209        return ret;
1210}
1211
1212static int conflict_rename_rename_1to2(struct merge_options *o,
1213                                        struct rename_conflict_info *ci)
1214{
1215        /* One file was renamed in both branches, but to different names. */
1216        struct diff_filespec *one = ci->pair1->one;
1217        struct diff_filespec *a = ci->pair1->two;
1218        struct diff_filespec *b = ci->pair2->two;
1219
1220        output(o, 1, _("CONFLICT (rename/rename): "
1221               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1222               "rename \"%s\"->\"%s\" in \"%s\"%s"),
1223               one->path, a->path, ci->branch1,
1224               one->path, b->path, ci->branch2,
1225               o->call_depth ? _(" (left unresolved)") : "");
1226        if (o->call_depth) {
1227                struct merge_file_info mfi;
1228                struct diff_filespec other;
1229                struct diff_filespec *add;
1230                if (merge_file_one(o, one->path,
1231                                 &one->oid, one->mode,
1232                                 &a->oid, a->mode,
1233                                 &b->oid, b->mode,
1234                                 ci->branch1, ci->branch2, &mfi))
1235                        return -1;
1236
1237                /*
1238                 * FIXME: For rename/add-source conflicts (if we could detect
1239                 * such), this is wrong.  We should instead find a unique
1240                 * pathname and then either rename the add-source file to that
1241                 * unique path, or use that unique path instead of src here.
1242                 */
1243                if (update_file(o, 0, &mfi.oid, mfi.mode, one->path))
1244                        return -1;
1245
1246                /*
1247                 * Above, we put the merged content at the merge-base's
1248                 * path.  Now we usually need to delete both a->path and
1249                 * b->path.  However, the rename on each side of the merge
1250                 * could also be involved in a rename/add conflict.  In
1251                 * such cases, we should keep the added file around,
1252                 * resolving the conflict at that path in its favor.
1253                 */
1254                add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
1255                if (add) {
1256                        if (update_file(o, 0, &add->oid, add->mode, a->path))
1257                                return -1;
1258                }
1259                else
1260                        remove_file_from_cache(a->path);
1261                add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
1262                if (add) {
1263                        if (update_file(o, 0, &add->oid, add->mode, b->path))
1264                                return -1;
1265                }
1266                else
1267                        remove_file_from_cache(b->path);
1268        } else if (handle_file(o, a, 2, ci) || handle_file(o, b, 3, ci))
1269                return -1;
1270
1271        return 0;
1272}
1273
1274static int conflict_rename_rename_2to1(struct merge_options *o,
1275                                        struct rename_conflict_info *ci)
1276{
1277        /* Two files, a & b, were renamed to the same thing, c. */
1278        struct diff_filespec *a = ci->pair1->one;
1279        struct diff_filespec *b = ci->pair2->one;
1280        struct diff_filespec *c1 = ci->pair1->two;
1281        struct diff_filespec *c2 = ci->pair2->two;
1282        char *path = c1->path; /* == c2->path */
1283        struct merge_file_info mfi_c1;
1284        struct merge_file_info mfi_c2;
1285        int ret;
1286
1287        output(o, 1, _("CONFLICT (rename/rename): "
1288               "Rename %s->%s in %s. "
1289               "Rename %s->%s in %s"),
1290               a->path, c1->path, ci->branch1,
1291               b->path, c2->path, ci->branch2);
1292
1293        remove_file(o, 1, a->path, o->call_depth || would_lose_untracked(a->path));
1294        remove_file(o, 1, b->path, o->call_depth || would_lose_untracked(b->path));
1295
1296        if (merge_file_special_markers(o, a, c1, &ci->ren1_other,
1297                                       o->branch1, c1->path,
1298                                       o->branch2, ci->ren1_other.path, &mfi_c1) ||
1299            merge_file_special_markers(o, b, &ci->ren2_other, c2,
1300                                       o->branch1, ci->ren2_other.path,
1301                                       o->branch2, c2->path, &mfi_c2))
1302                return -1;
1303
1304        if (o->call_depth) {
1305                /*
1306                 * If mfi_c1.clean && mfi_c2.clean, then it might make
1307                 * sense to do a two-way merge of those results.  But, I
1308                 * think in all cases, it makes sense to have the virtual
1309                 * merge base just undo the renames; they can be detected
1310                 * again later for the non-recursive merge.
1311                 */
1312                remove_file(o, 0, path, 0);
1313                ret = update_file(o, 0, &mfi_c1.oid, mfi_c1.mode, a->path);
1314                if (!ret)
1315                        ret = update_file(o, 0, &mfi_c2.oid, mfi_c2.mode,
1316                                          b->path);
1317        } else {
1318                char *new_path1 = unique_path(o, path, ci->branch1);
1319                char *new_path2 = unique_path(o, path, ci->branch2);
1320                output(o, 1, _("Renaming %s to %s and %s to %s instead"),
1321                       a->path, new_path1, b->path, new_path2);
1322                remove_file(o, 0, path, 0);
1323                ret = update_file(o, 0, &mfi_c1.oid, mfi_c1.mode, new_path1);
1324                if (!ret)
1325                        ret = update_file(o, 0, &mfi_c2.oid, mfi_c2.mode,
1326                                          new_path2);
1327                free(new_path2);
1328                free(new_path1);
1329        }
1330
1331        return ret;
1332}
1333
1334static int process_renames(struct merge_options *o,
1335                           struct string_list *a_renames,
1336                           struct string_list *b_renames)
1337{
1338        int clean_merge = 1, i, j;
1339        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
1340        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
1341        const struct rename *sre;
1342
1343        for (i = 0; i < a_renames->nr; i++) {
1344                sre = a_renames->items[i].util;
1345                string_list_insert(&a_by_dst, sre->pair->two->path)->util
1346                        = (void *)sre;
1347        }
1348        for (i = 0; i < b_renames->nr; i++) {
1349                sre = b_renames->items[i].util;
1350                string_list_insert(&b_by_dst, sre->pair->two->path)->util
1351                        = (void *)sre;
1352        }
1353
1354        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1355                struct string_list *renames1, *renames2Dst;
1356                struct rename *ren1 = NULL, *ren2 = NULL;
1357                const char *branch1, *branch2;
1358                const char *ren1_src, *ren1_dst;
1359                struct string_list_item *lookup;
1360
1361                if (i >= a_renames->nr) {
1362                        ren2 = b_renames->items[j++].util;
1363                } else if (j >= b_renames->nr) {
1364                        ren1 = a_renames->items[i++].util;
1365                } else {
1366                        int compare = strcmp(a_renames->items[i].string,
1367                                             b_renames->items[j].string);
1368                        if (compare <= 0)
1369                                ren1 = a_renames->items[i++].util;
1370                        if (compare >= 0)
1371                                ren2 = b_renames->items[j++].util;
1372                }
1373
1374                /* TODO: refactor, so that 1/2 are not needed */
1375                if (ren1) {
1376                        renames1 = a_renames;
1377                        renames2Dst = &b_by_dst;
1378                        branch1 = o->branch1;
1379                        branch2 = o->branch2;
1380                } else {
1381                        struct rename *tmp;
1382                        renames1 = b_renames;
1383                        renames2Dst = &a_by_dst;
1384                        branch1 = o->branch2;
1385                        branch2 = o->branch1;
1386                        tmp = ren2;
1387                        ren2 = ren1;
1388                        ren1 = tmp;
1389                }
1390
1391                if (ren1->processed)
1392                        continue;
1393                ren1->processed = 1;
1394                ren1->dst_entry->processed = 1;
1395                /* BUG: We should only mark src_entry as processed if we
1396                 * are not dealing with a rename + add-source case.
1397                 */
1398                ren1->src_entry->processed = 1;
1399
1400                ren1_src = ren1->pair->one->path;
1401                ren1_dst = ren1->pair->two->path;
1402
1403                if (ren2) {
1404                        /* One file renamed on both sides */
1405                        const char *ren2_src = ren2->pair->one->path;
1406                        const char *ren2_dst = ren2->pair->two->path;
1407                        enum rename_type rename_type;
1408                        if (strcmp(ren1_src, ren2_src) != 0)
1409                                die("BUG: ren1_src != ren2_src");
1410                        ren2->dst_entry->processed = 1;
1411                        ren2->processed = 1;
1412                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1413                                rename_type = RENAME_ONE_FILE_TO_TWO;
1414                                clean_merge = 0;
1415                        } else {
1416                                rename_type = RENAME_ONE_FILE_TO_ONE;
1417                                /* BUG: We should only remove ren1_src in
1418                                 * the base stage (think of rename +
1419                                 * add-source cases).
1420                                 */
1421                                remove_file(o, 1, ren1_src, 1);
1422                                update_entry(ren1->dst_entry,
1423                                             ren1->pair->one,
1424                                             ren1->pair->two,
1425                                             ren2->pair->two);
1426                        }
1427                        setup_rename_conflict_info(rename_type,
1428                                                   ren1->pair,
1429                                                   ren2->pair,
1430                                                   branch1,
1431                                                   branch2,
1432                                                   ren1->dst_entry,
1433                                                   ren2->dst_entry,
1434                                                   o,
1435                                                   NULL,
1436                                                   NULL);
1437                } else if ((lookup = string_list_lookup(renames2Dst, ren1_dst))) {
1438                        /* Two different files renamed to the same thing */
1439                        char *ren2_dst;
1440                        ren2 = lookup->util;
1441                        ren2_dst = ren2->pair->two->path;
1442                        if (strcmp(ren1_dst, ren2_dst) != 0)
1443                                die("BUG: ren1_dst != ren2_dst");
1444
1445                        clean_merge = 0;
1446                        ren2->processed = 1;
1447                        /*
1448                         * BUG: We should only mark src_entry as processed
1449                         * if we are not dealing with a rename + add-source
1450                         * case.
1451                         */
1452                        ren2->src_entry->processed = 1;
1453
1454                        setup_rename_conflict_info(RENAME_TWO_FILES_TO_ONE,
1455                                                   ren1->pair,
1456                                                   ren2->pair,
1457                                                   branch1,
1458                                                   branch2,
1459                                                   ren1->dst_entry,
1460                                                   ren2->dst_entry,
1461                                                   o,
1462                                                   ren1->src_entry,
1463                                                   ren2->src_entry);
1464
1465                } else {
1466                        /* Renamed in 1, maybe changed in 2 */
1467                        /* we only use sha1 and mode of these */
1468                        struct diff_filespec src_other, dst_other;
1469                        int try_merge;
1470
1471                        /*
1472                         * unpack_trees loads entries from common-commit
1473                         * into stage 1, from head-commit into stage 2, and
1474                         * from merge-commit into stage 3.  We keep track
1475                         * of which side corresponds to the rename.
1476                         */
1477                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1478                        int other_stage =   a_renames == renames1 ? 3 : 2;
1479
1480                        /* BUG: We should only remove ren1_src in the base
1481                         * stage and in other_stage (think of rename +
1482                         * add-source case).
1483                         */
1484                        remove_file(o, 1, ren1_src,
1485                                    renamed_stage == 2 || !was_tracked(ren1_src));
1486
1487                        oidcpy(&src_other.oid,
1488                               &ren1->src_entry->stages[other_stage].oid);
1489                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1490                        oidcpy(&dst_other.oid,
1491                               &ren1->dst_entry->stages[other_stage].oid);
1492                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1493                        try_merge = 0;
1494
1495                        if (oid_eq(&src_other.oid, &null_oid)) {
1496                                setup_rename_conflict_info(RENAME_DELETE,
1497                                                           ren1->pair,
1498                                                           NULL,
1499                                                           branch1,
1500                                                           branch2,
1501                                                           ren1->dst_entry,
1502                                                           NULL,
1503                                                           o,
1504                                                           NULL,
1505                                                           NULL);
1506                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1507                                   oid_eq(&dst_other.oid, &ren1->pair->two->oid)) {
1508                                /*
1509                                 * Added file on the other side identical to
1510                                 * the file being renamed: clean merge.
1511                                 * Also, there is no need to overwrite the
1512                                 * file already in the working copy, so call
1513                                 * update_file_flags() instead of
1514                                 * update_file().
1515                                 */
1516                                if (update_file_flags(o,
1517                                                      &ren1->pair->two->oid,
1518                                                      ren1->pair->two->mode,
1519                                                      ren1_dst,
1520                                                      1, /* update_cache */
1521                                                      0  /* update_wd    */))
1522                                        clean_merge = -1;
1523                        } else if (!oid_eq(&dst_other.oid, &null_oid)) {
1524                                clean_merge = 0;
1525                                try_merge = 1;
1526                                output(o, 1, _("CONFLICT (rename/add): Rename %s->%s in %s. "
1527                                       "%s added in %s"),
1528                                       ren1_src, ren1_dst, branch1,
1529                                       ren1_dst, branch2);
1530                                if (o->call_depth) {
1531                                        struct merge_file_info mfi;
1532                                        if (merge_file_one(o, ren1_dst, &null_oid, 0,
1533                                                           &ren1->pair->two->oid,
1534                                                           ren1->pair->two->mode,
1535                                                           &dst_other.oid,
1536                                                           dst_other.mode,
1537                                                           branch1, branch2, &mfi)) {
1538                                                clean_merge = -1;
1539                                                goto cleanup_and_return;
1540                                        }
1541                                        output(o, 1, _("Adding merged %s"), ren1_dst);
1542                                        if (update_file(o, 0, &mfi.oid,
1543                                                        mfi.mode, ren1_dst))
1544                                                clean_merge = -1;
1545                                        try_merge = 0;
1546                                } else {
1547                                        char *new_path = unique_path(o, ren1_dst, branch2);
1548                                        output(o, 1, _("Adding as %s instead"), new_path);
1549                                        if (update_file(o, 0, &dst_other.oid,
1550                                                        dst_other.mode, new_path))
1551                                                clean_merge = -1;
1552                                        free(new_path);
1553                                }
1554                        } else
1555                                try_merge = 1;
1556
1557                        if (clean_merge < 0)
1558                                goto cleanup_and_return;
1559                        if (try_merge) {
1560                                struct diff_filespec *one, *a, *b;
1561                                src_other.path = (char *)ren1_src;
1562
1563                                one = ren1->pair->one;
1564                                if (a_renames == renames1) {
1565                                        a = ren1->pair->two;
1566                                        b = &src_other;
1567                                } else {
1568                                        b = ren1->pair->two;
1569                                        a = &src_other;
1570                                }
1571                                update_entry(ren1->dst_entry, one, a, b);
1572                                setup_rename_conflict_info(RENAME_NORMAL,
1573                                                           ren1->pair,
1574                                                           NULL,
1575                                                           branch1,
1576                                                           NULL,
1577                                                           ren1->dst_entry,
1578                                                           NULL,
1579                                                           o,
1580                                                           NULL,
1581                                                           NULL);
1582                        }
1583                }
1584        }
1585cleanup_and_return:
1586        string_list_clear(&a_by_dst, 0);
1587        string_list_clear(&b_by_dst, 0);
1588
1589        return clean_merge;
1590}
1591
1592static struct object_id *stage_oid(const struct object_id *oid, unsigned mode)
1593{
1594        return (is_null_oid(oid) || mode == 0) ? NULL: (struct object_id *)oid;
1595}
1596
1597static int read_oid_strbuf(struct merge_options *o,
1598        const struct object_id *oid, struct strbuf *dst)
1599{
1600        void *buf;
1601        enum object_type type;
1602        unsigned long size;
1603        buf = read_sha1_file(oid->hash, &type, &size);
1604        if (!buf)
1605                return err(o, _("cannot read object %s"), oid_to_hex(oid));
1606        if (type != OBJ_BLOB) {
1607                free(buf);
1608                return err(o, _("object %s is not a blob"), oid_to_hex(oid));
1609        }
1610        strbuf_attach(dst, buf, size, size + 1);
1611        return 0;
1612}
1613
1614static int blob_unchanged(struct merge_options *opt,
1615                          const struct object_id *o_oid,
1616                          unsigned o_mode,
1617                          const struct object_id *a_oid,
1618                          unsigned a_mode,
1619                          int renormalize, const char *path)
1620{
1621        struct strbuf o = STRBUF_INIT;
1622        struct strbuf a = STRBUF_INIT;
1623        int ret = 0; /* assume changed for safety */
1624
1625        if (a_mode != o_mode)
1626                return 0;
1627        if (oid_eq(o_oid, a_oid))
1628                return 1;
1629        if (!renormalize)
1630                return 0;
1631
1632        assert(o_oid && a_oid);
1633        if (read_oid_strbuf(opt, o_oid, &o) || read_oid_strbuf(opt, a_oid, &a))
1634                goto error_return;
1635        /*
1636         * Note: binary | is used so that both renormalizations are
1637         * performed.  Comparison can be skipped if both files are
1638         * unchanged since their sha1s have already been compared.
1639         */
1640        if (renormalize_buffer(path, o.buf, o.len, &o) |
1641            renormalize_buffer(path, a.buf, a.len, &a))
1642                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1643
1644error_return:
1645        strbuf_release(&o);
1646        strbuf_release(&a);
1647        return ret;
1648}
1649
1650static int handle_modify_delete(struct merge_options *o,
1651                                 const char *path,
1652                                 struct object_id *o_oid, int o_mode,
1653                                 struct object_id *a_oid, int a_mode,
1654                                 struct object_id *b_oid, int b_mode)
1655{
1656        return handle_change_delete(o,
1657                                    path,
1658                                    o_oid, o_mode,
1659                                    a_oid, a_mode,
1660                                    b_oid, b_mode,
1661                                    _("modify"), _("modified"));
1662}
1663
1664static int merge_content(struct merge_options *o,
1665                         const char *path,
1666                         struct object_id *o_oid, int o_mode,
1667                         struct object_id *a_oid, int a_mode,
1668                         struct object_id *b_oid, int b_mode,
1669                         struct rename_conflict_info *rename_conflict_info)
1670{
1671        const char *reason = _("content");
1672        const char *path1 = NULL, *path2 = NULL;
1673        struct merge_file_info mfi;
1674        struct diff_filespec one, a, b;
1675        unsigned df_conflict_remains = 0;
1676
1677        if (!o_oid) {
1678                reason = _("add/add");
1679                o_oid = (struct object_id *)&null_oid;
1680        }
1681        one.path = a.path = b.path = (char *)path;
1682        oidcpy(&one.oid, o_oid);
1683        one.mode = o_mode;
1684        oidcpy(&a.oid, a_oid);
1685        a.mode = a_mode;
1686        oidcpy(&b.oid, b_oid);
1687        b.mode = b_mode;
1688
1689        if (rename_conflict_info) {
1690                struct diff_filepair *pair1 = rename_conflict_info->pair1;
1691
1692                path1 = (o->branch1 == rename_conflict_info->branch1) ?
1693                        pair1->two->path : pair1->one->path;
1694                /* If rename_conflict_info->pair2 != NULL, we are in
1695                 * RENAME_ONE_FILE_TO_ONE case.  Otherwise, we have a
1696                 * normal rename.
1697                 */
1698                path2 = (rename_conflict_info->pair2 ||
1699                         o->branch2 == rename_conflict_info->branch1) ?
1700                        pair1->two->path : pair1->one->path;
1701
1702                if (dir_in_way(path, !o->call_depth))
1703                        df_conflict_remains = 1;
1704        }
1705        if (merge_file_special_markers(o, &one, &a, &b,
1706                                       o->branch1, path1,
1707                                       o->branch2, path2, &mfi))
1708                return -1;
1709
1710        if (mfi.clean && !df_conflict_remains &&
1711            oid_eq(&mfi.oid, a_oid) && mfi.mode == a_mode) {
1712                int path_renamed_outside_HEAD;
1713                output(o, 3, _("Skipped %s (merged same as existing)"), path);
1714                /*
1715                 * The content merge resulted in the same file contents we
1716                 * already had.  We can return early if those file contents
1717                 * are recorded at the correct path (which may not be true
1718                 * if the merge involves a rename).
1719                 */
1720                path_renamed_outside_HEAD = !path2 || !strcmp(path, path2);
1721                if (!path_renamed_outside_HEAD) {
1722                        add_cacheinfo(o, mfi.mode, &mfi.oid, path,
1723                                      0, (!o->call_depth), 0);
1724                        return mfi.clean;
1725                }
1726        } else
1727                output(o, 2, _("Auto-merging %s"), path);
1728
1729        if (!mfi.clean) {
1730                if (S_ISGITLINK(mfi.mode))
1731                        reason = _("submodule");
1732                output(o, 1, _("CONFLICT (%s): Merge conflict in %s"),
1733                                reason, path);
1734                if (rename_conflict_info && !df_conflict_remains)
1735                        if (update_stages(o, path, &one, &a, &b))
1736                                return -1;
1737        }
1738
1739        if (df_conflict_remains) {
1740                char *new_path;
1741                if (o->call_depth) {
1742                        remove_file_from_cache(path);
1743                } else {
1744                        if (!mfi.clean) {
1745                                if (update_stages(o, path, &one, &a, &b))
1746                                        return -1;
1747                        } else {
1748                                int file_from_stage2 = was_tracked(path);
1749                                struct diff_filespec merged;
1750                                oidcpy(&merged.oid, &mfi.oid);
1751                                merged.mode = mfi.mode;
1752
1753                                if (update_stages(o, path, NULL,
1754                                                  file_from_stage2 ? &merged : NULL,
1755                                                  file_from_stage2 ? NULL : &merged))
1756                                        return -1;
1757                        }
1758
1759                }
1760                new_path = unique_path(o, path, rename_conflict_info->branch1);
1761                output(o, 1, _("Adding as %s instead"), new_path);
1762                if (update_file(o, 0, &mfi.oid, mfi.mode, new_path)) {
1763                        free(new_path);
1764                        return -1;
1765                }
1766                free(new_path);
1767                mfi.clean = 0;
1768        } else if (update_file(o, mfi.clean, &mfi.oid, mfi.mode, path))
1769                return -1;
1770        return mfi.clean;
1771}
1772
1773/* Per entry merge function */
1774static int process_entry(struct merge_options *o,
1775                         const char *path, struct stage_data *entry)
1776{
1777        int clean_merge = 1;
1778        int normalize = o->renormalize;
1779        unsigned o_mode = entry->stages[1].mode;
1780        unsigned a_mode = entry->stages[2].mode;
1781        unsigned b_mode = entry->stages[3].mode;
1782        struct object_id *o_oid = stage_oid(&entry->stages[1].oid, o_mode);
1783        struct object_id *a_oid = stage_oid(&entry->stages[2].oid, a_mode);
1784        struct object_id *b_oid = stage_oid(&entry->stages[3].oid, b_mode);
1785
1786        entry->processed = 1;
1787        if (entry->rename_conflict_info) {
1788                struct rename_conflict_info *conflict_info = entry->rename_conflict_info;
1789                switch (conflict_info->rename_type) {
1790                case RENAME_NORMAL:
1791                case RENAME_ONE_FILE_TO_ONE:
1792                        clean_merge = merge_content(o, path,
1793                                                    o_oid, o_mode, a_oid, a_mode, b_oid, b_mode,
1794                                                    conflict_info);
1795                        break;
1796                case RENAME_DELETE:
1797                        clean_merge = 0;
1798                        if (conflict_rename_delete(o,
1799                                                   conflict_info->pair1,
1800                                                   conflict_info->branch1,
1801                                                   conflict_info->branch2))
1802                                clean_merge = -1;
1803                        break;
1804                case RENAME_ONE_FILE_TO_TWO:
1805                        clean_merge = 0;
1806                        if (conflict_rename_rename_1to2(o, conflict_info))
1807                                clean_merge = -1;
1808                        break;
1809                case RENAME_TWO_FILES_TO_ONE:
1810                        clean_merge = 0;
1811                        if (conflict_rename_rename_2to1(o, conflict_info))
1812                                clean_merge = -1;
1813                        break;
1814                default:
1815                        entry->processed = 0;
1816                        break;
1817                }
1818        } else if (o_oid && (!a_oid || !b_oid)) {
1819                /* Case A: Deleted in one */
1820                if ((!a_oid && !b_oid) ||
1821                    (!b_oid && blob_unchanged(o, o_oid, o_mode, a_oid, a_mode, normalize, path)) ||
1822                    (!a_oid && blob_unchanged(o, o_oid, o_mode, b_oid, b_mode, normalize, path))) {
1823                        /* Deleted in both or deleted in one and
1824                         * unchanged in the other */
1825                        if (a_oid)
1826                                output(o, 2, _("Removing %s"), path);
1827                        /* do not touch working file if it did not exist */
1828                        remove_file(o, 1, path, !a_oid);
1829                } else {
1830                        /* Modify/delete; deleted side may have put a directory in the way */
1831                        clean_merge = 0;
1832                        if (handle_modify_delete(o, path, o_oid, o_mode,
1833                                                 a_oid, a_mode, b_oid, b_mode))
1834                                clean_merge = -1;
1835                }
1836        } else if ((!o_oid && a_oid && !b_oid) ||
1837                   (!o_oid && !a_oid && b_oid)) {
1838                /* Case B: Added in one. */
1839                /* [nothing|directory] -> ([nothing|directory], file) */
1840
1841                const char *add_branch;
1842                const char *other_branch;
1843                unsigned mode;
1844                const struct object_id *oid;
1845                const char *conf;
1846
1847                if (a_oid) {
1848                        add_branch = o->branch1;
1849                        other_branch = o->branch2;
1850                        mode = a_mode;
1851                        oid = a_oid;
1852                        conf = _("file/directory");
1853                } else {
1854                        add_branch = o->branch2;
1855                        other_branch = o->branch1;
1856                        mode = b_mode;
1857                        oid = b_oid;
1858                        conf = _("directory/file");
1859                }
1860                if (dir_in_way(path, !o->call_depth)) {
1861                        char *new_path = unique_path(o, path, add_branch);
1862                        clean_merge = 0;
1863                        output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
1864                               "Adding %s as %s"),
1865                               conf, path, other_branch, path, new_path);
1866                        if (update_file(o, 0, oid, mode, new_path))
1867                                clean_merge = -1;
1868                        else if (o->call_depth)
1869                                remove_file_from_cache(path);
1870                        free(new_path);
1871                } else {
1872                        output(o, 2, _("Adding %s"), path);
1873                        /* do not overwrite file if already present */
1874                        if (update_file_flags(o, oid, mode, path, 1, !a_oid))
1875                                clean_merge = -1;
1876                }
1877        } else if (a_oid && b_oid) {
1878                /* Case C: Added in both (check for same permissions) and */
1879                /* case D: Modified in both, but differently. */
1880                clean_merge = merge_content(o, path,
1881                                            o_oid, o_mode, a_oid, a_mode, b_oid, b_mode,
1882                                            NULL);
1883        } else if (!o_oid && !a_oid && !b_oid) {
1884                /*
1885                 * this entry was deleted altogether. a_mode == 0 means
1886                 * we had that path and want to actively remove it.
1887                 */
1888                remove_file(o, 1, path, !a_mode);
1889        } else
1890                die("BUG: fatal merge failure, shouldn't happen.");
1891
1892        return clean_merge;
1893}
1894
1895int merge_trees(struct merge_options *o,
1896                struct tree *head,
1897                struct tree *merge,
1898                struct tree *common,
1899                struct tree **result)
1900{
1901        int code, clean;
1902
1903        if (o->subtree_shift) {
1904                merge = shift_tree_object(head, merge, o->subtree_shift);
1905                common = shift_tree_object(head, common, o->subtree_shift);
1906        }
1907
1908        if (oid_eq(&common->object.oid, &merge->object.oid)) {
1909                output(o, 0, _("Already up-to-date!"));
1910                *result = head;
1911                return 1;
1912        }
1913
1914        code = git_merge_trees(o->call_depth, common, head, merge);
1915
1916        if (code != 0) {
1917                if (show(o, 4) || o->call_depth)
1918                        err(o, _("merging of trees %s and %s failed"),
1919                            oid_to_hex(&head->object.oid),
1920                            oid_to_hex(&merge->object.oid));
1921                return -1;
1922        }
1923
1924        if (unmerged_cache()) {
1925                struct string_list *entries, *re_head, *re_merge;
1926                int i;
1927                string_list_clear(&o->current_file_set, 1);
1928                string_list_clear(&o->current_directory_set, 1);
1929                get_files_dirs(o, head);
1930                get_files_dirs(o, merge);
1931
1932                entries = get_unmerged();
1933                record_df_conflict_files(o, entries);
1934                re_head  = get_renames(o, head, common, head, merge, entries);
1935                re_merge = get_renames(o, merge, common, head, merge, entries);
1936                clean = process_renames(o, re_head, re_merge);
1937                if (clean < 0)
1938                        return clean;
1939                for (i = entries->nr-1; 0 <= i; i--) {
1940                        const char *path = entries->items[i].string;
1941                        struct stage_data *e = entries->items[i].util;
1942                        if (!e->processed) {
1943                                int ret = process_entry(o, path, e);
1944                                if (!ret)
1945                                        clean = 0;
1946                                else if (ret < 0)
1947                                        return ret;
1948                        }
1949                }
1950                for (i = 0; i < entries->nr; i++) {
1951                        struct stage_data *e = entries->items[i].util;
1952                        if (!e->processed)
1953                                die("BUG: unprocessed path??? %s",
1954                                    entries->items[i].string);
1955                }
1956
1957                string_list_clear(re_merge, 0);
1958                string_list_clear(re_head, 0);
1959                string_list_clear(entries, 1);
1960
1961                free(re_merge);
1962                free(re_head);
1963                free(entries);
1964        }
1965        else
1966                clean = 1;
1967
1968        if (o->call_depth && !(*result = write_tree_from_memory(o)))
1969                return -1;
1970
1971        return clean;
1972}
1973
1974static struct commit_list *reverse_commit_list(struct commit_list *list)
1975{
1976        struct commit_list *next = NULL, *current, *backup;
1977        for (current = list; current; current = backup) {
1978                backup = current->next;
1979                current->next = next;
1980                next = current;
1981        }
1982        return next;
1983}
1984
1985/*
1986 * Merge the commits h1 and h2, return the resulting virtual
1987 * commit object and a flag indicating the cleanness of the merge.
1988 */
1989int merge_recursive(struct merge_options *o,
1990                    struct commit *h1,
1991                    struct commit *h2,
1992                    struct commit_list *ca,
1993                    struct commit **result)
1994{
1995        struct commit_list *iter;
1996        struct commit *merged_common_ancestors;
1997        struct tree *mrtree = mrtree;
1998        int clean;
1999
2000        if (show(o, 4)) {
2001                output(o, 4, _("Merging:"));
2002                output_commit_title(o, h1);
2003                output_commit_title(o, h2);
2004        }
2005
2006        if (!ca) {
2007                ca = get_merge_bases(h1, h2);
2008                ca = reverse_commit_list(ca);
2009        }
2010
2011        if (show(o, 5)) {
2012                unsigned cnt = commit_list_count(ca);
2013
2014                output(o, 5, Q_("found %u common ancestor:",
2015                                "found %u common ancestors:", cnt), cnt);
2016                for (iter = ca; iter; iter = iter->next)
2017                        output_commit_title(o, iter->item);
2018        }
2019
2020        merged_common_ancestors = pop_commit(&ca);
2021        if (merged_common_ancestors == NULL) {
2022                /* if there is no common ancestor, use an empty tree */
2023                struct tree *tree;
2024
2025                tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
2026                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
2027        }
2028
2029        for (iter = ca; iter; iter = iter->next) {
2030                const char *saved_b1, *saved_b2;
2031                o->call_depth++;
2032                /*
2033                 * When the merge fails, the result contains files
2034                 * with conflict markers. The cleanness flag is
2035                 * ignored (unless indicating an error), it was never
2036                 * actually used, as result of merge_trees has always
2037                 * overwritten it: the committed "conflicts" were
2038                 * already resolved.
2039                 */
2040                discard_cache();
2041                saved_b1 = o->branch1;
2042                saved_b2 = o->branch2;
2043                o->branch1 = "Temporary merge branch 1";
2044                o->branch2 = "Temporary merge branch 2";
2045                if (merge_recursive(o, merged_common_ancestors, iter->item,
2046                                    NULL, &merged_common_ancestors) < 0)
2047                        return -1;
2048                o->branch1 = saved_b1;
2049                o->branch2 = saved_b2;
2050                o->call_depth--;
2051
2052                if (!merged_common_ancestors)
2053                        return err(o, _("merge returned no commit"));
2054        }
2055
2056        discard_cache();
2057        if (!o->call_depth)
2058                read_cache();
2059
2060        o->ancestor = "merged common ancestors";
2061        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
2062                            &mrtree);
2063        if (clean < 0)
2064                return clean;
2065
2066        if (o->call_depth) {
2067                *result = make_virtual_commit(mrtree, "merged tree");
2068                commit_list_insert(h1, &(*result)->parents);
2069                commit_list_insert(h2, &(*result)->parents->next);
2070        }
2071        flush_output(o);
2072        if (show(o, 2))
2073                diff_warn_rename_limit("merge.renamelimit",
2074                                       o->needed_rename_limit, 0);
2075        return clean;
2076}
2077
2078static struct commit *get_ref(const struct object_id *oid, const char *name)
2079{
2080        struct object *object;
2081
2082        object = deref_tag(parse_object(oid->hash), name, strlen(name));
2083        if (!object)
2084                return NULL;
2085        if (object->type == OBJ_TREE)
2086                return make_virtual_commit((struct tree*)object, name);
2087        if (object->type != OBJ_COMMIT)
2088                return NULL;
2089        if (parse_commit((struct commit *)object))
2090                return NULL;
2091        return (struct commit *)object;
2092}
2093
2094int merge_recursive_generic(struct merge_options *o,
2095                            const struct object_id *head,
2096                            const struct object_id *merge,
2097                            int num_base_list,
2098                            const struct object_id **base_list,
2099                            struct commit **result)
2100{
2101        int clean;
2102        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
2103        struct commit *head_commit = get_ref(head, o->branch1);
2104        struct commit *next_commit = get_ref(merge, o->branch2);
2105        struct commit_list *ca = NULL;
2106
2107        if (base_list) {
2108                int i;
2109                for (i = 0; i < num_base_list; ++i) {
2110                        struct commit *base;
2111                        if (!(base = get_ref(base_list[i], oid_to_hex(base_list[i]))))
2112                                return err(o, _("Could not parse object '%s'"),
2113                                        oid_to_hex(base_list[i]));
2114                        commit_list_insert(base, &ca);
2115                }
2116        }
2117
2118        hold_locked_index(lock, 1);
2119        clean = merge_recursive(o, head_commit, next_commit, ca,
2120                        result);
2121        if (clean < 0)
2122                return clean;
2123
2124        if (active_cache_changed &&
2125            write_locked_index(&the_index, lock, COMMIT_LOCK))
2126                return err(o, _("Unable to write index."));
2127
2128        return clean ? 0 : 1;
2129}
2130
2131static void merge_recursive_config(struct merge_options *o)
2132{
2133        git_config_get_int("merge.verbosity", &o->verbosity);
2134        git_config_get_int("diff.renamelimit", &o->diff_rename_limit);
2135        git_config_get_int("merge.renamelimit", &o->merge_rename_limit);
2136        git_config(git_xmerge_config, NULL);
2137}
2138
2139void init_merge_options(struct merge_options *o)
2140{
2141        memset(o, 0, sizeof(struct merge_options));
2142        o->verbosity = 2;
2143        o->buffer_output = 1;
2144        o->diff_rename_limit = -1;
2145        o->merge_rename_limit = -1;
2146        o->renormalize = 0;
2147        o->detect_rename = 1;
2148        merge_recursive_config(o);
2149        if (getenv("GIT_MERGE_VERBOSITY"))
2150                o->verbosity =
2151                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
2152        if (o->verbosity >= 5)
2153                o->buffer_output = 0;
2154        strbuf_init(&o->obuf, 0);
2155        string_list_init(&o->current_file_set, 1);
2156        string_list_init(&o->current_directory_set, 1);
2157        string_list_init(&o->df_conflict_file_set, 1);
2158}
2159
2160int parse_merge_opt(struct merge_options *o, const char *s)
2161{
2162        const char *arg;
2163
2164        if (!s || !*s)
2165                return -1;
2166        if (!strcmp(s, "ours"))
2167                o->recursive_variant = MERGE_RECURSIVE_OURS;
2168        else if (!strcmp(s, "theirs"))
2169                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
2170        else if (!strcmp(s, "subtree"))
2171                o->subtree_shift = "";
2172        else if (skip_prefix(s, "subtree=", &arg))
2173                o->subtree_shift = arg;
2174        else if (!strcmp(s, "patience"))
2175                o->xdl_opts = DIFF_WITH_ALG(o, PATIENCE_DIFF);
2176        else if (!strcmp(s, "histogram"))
2177                o->xdl_opts = DIFF_WITH_ALG(o, HISTOGRAM_DIFF);
2178        else if (skip_prefix(s, "diff-algorithm=", &arg)) {
2179                long value = parse_algorithm_value(arg);
2180                if (value < 0)
2181                        return -1;
2182                /* clear out previous settings */
2183                DIFF_XDL_CLR(o, NEED_MINIMAL);
2184                o->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
2185                o->xdl_opts |= value;
2186        }
2187        else if (!strcmp(s, "ignore-space-change"))
2188                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2189        else if (!strcmp(s, "ignore-all-space"))
2190                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
2191        else if (!strcmp(s, "ignore-space-at-eol"))
2192                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2193        else if (!strcmp(s, "renormalize"))
2194                o->renormalize = 1;
2195        else if (!strcmp(s, "no-renormalize"))
2196                o->renormalize = 0;
2197        else if (!strcmp(s, "no-renames"))
2198                o->detect_rename = 0;
2199        else if (!strcmp(s, "find-renames")) {
2200                o->detect_rename = 1;
2201                o->rename_score = 0;
2202        }
2203        else if (skip_prefix(s, "find-renames=", &arg) ||
2204                 skip_prefix(s, "rename-threshold=", &arg)) {
2205                if ((o->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0)
2206                        return -1;
2207                o->detect_rename = 1;
2208        }
2209        else
2210                return -1;
2211        return 0;
2212}