merge-recursive.con commit merge-recursive: Fix code checking for D/F conflicts still being present (f2507b4)
   1/*
   2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
   3 * Fredrik Kuivinen.
   4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
   5 */
   6#include "advice.h"
   7#include "cache.h"
   8#include "cache-tree.h"
   9#include "commit.h"
  10#include "blob.h"
  11#include "builtin.h"
  12#include "tree-walk.h"
  13#include "diff.h"
  14#include "diffcore.h"
  15#include "tag.h"
  16#include "unpack-trees.h"
  17#include "string-list.h"
  18#include "xdiff-interface.h"
  19#include "ll-merge.h"
  20#include "attr.h"
  21#include "merge-recursive.h"
  22#include "dir.h"
  23#include "submodule.h"
  24
  25static struct tree *shift_tree_object(struct tree *one, struct tree *two,
  26                                      const char *subtree_shift)
  27{
  28        unsigned char shifted[20];
  29
  30        if (!*subtree_shift) {
  31                shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
  32        } else {
  33                shift_tree_by(one->object.sha1, two->object.sha1, shifted,
  34                              subtree_shift);
  35        }
  36        if (!hashcmp(two->object.sha1, shifted))
  37                return two;
  38        return lookup_tree(shifted);
  39}
  40
  41/*
  42 * A virtual commit has (const char *)commit->util set to the name.
  43 */
  44
  45static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  46{
  47        struct commit *commit = xcalloc(1, sizeof(struct commit));
  48        commit->tree = tree;
  49        commit->util = (void*)comment;
  50        /* avoid warnings */
  51        commit->object.parsed = 1;
  52        return commit;
  53}
  54
  55/*
  56 * Since we use get_tree_entry(), which does not put the read object into
  57 * the object pool, we cannot rely on a == b.
  58 */
  59static int sha_eq(const unsigned char *a, const unsigned char *b)
  60{
  61        if (!a && !b)
  62                return 2;
  63        return a && b && hashcmp(a, b) == 0;
  64}
  65
  66enum rename_type {
  67        RENAME_NORMAL = 0,
  68        RENAME_DELETE,
  69        RENAME_ONE_FILE_TO_TWO
  70};
  71
  72struct rename_df_conflict_info {
  73        enum rename_type rename_type;
  74        struct diff_filepair *pair1;
  75        struct diff_filepair *pair2;
  76        const char *branch1;
  77        const char *branch2;
  78        struct stage_data *dst_entry1;
  79        struct stage_data *dst_entry2;
  80};
  81
  82/*
  83 * Since we want to write the index eventually, we cannot reuse the index
  84 * for these (temporary) data.
  85 */
  86struct stage_data {
  87        struct {
  88                unsigned mode;
  89                unsigned char sha[20];
  90        } stages[4];
  91        struct rename_df_conflict_info *rename_df_conflict_info;
  92        unsigned processed:1;
  93};
  94
  95static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
  96                                                 struct diff_filepair *pair1,
  97                                                 struct diff_filepair *pair2,
  98                                                 const char *branch1,
  99                                                 const char *branch2,
 100                                                 struct stage_data *dst_entry1,
 101                                                 struct stage_data *dst_entry2)
 102{
 103        struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
 104        ci->rename_type = rename_type;
 105        ci->pair1 = pair1;
 106        ci->branch1 = branch1;
 107        ci->branch2 = branch2;
 108
 109        ci->dst_entry1 = dst_entry1;
 110        dst_entry1->rename_df_conflict_info = ci;
 111        dst_entry1->processed = 0;
 112
 113        assert(!pair2 == !dst_entry2);
 114        if (dst_entry2) {
 115                ci->dst_entry2 = dst_entry2;
 116                ci->pair2 = pair2;
 117                dst_entry2->rename_df_conflict_info = ci;
 118                dst_entry2->processed = 0;
 119        }
 120}
 121
 122static int show(struct merge_options *o, int v)
 123{
 124        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 125}
 126
 127static void flush_output(struct merge_options *o)
 128{
 129        if (o->obuf.len) {
 130                fputs(o->obuf.buf, stdout);
 131                strbuf_reset(&o->obuf);
 132        }
 133}
 134
 135__attribute__((format (printf, 3, 4)))
 136static void output(struct merge_options *o, int v, const char *fmt, ...)
 137{
 138        va_list ap;
 139
 140        if (!show(o, v))
 141                return;
 142
 143        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 144        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 145        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 146
 147        va_start(ap, fmt);
 148        strbuf_vaddf(&o->obuf, fmt, ap);
 149        va_end(ap);
 150
 151        strbuf_add(&o->obuf, "\n", 1);
 152        if (!o->buffer_output)
 153                flush_output(o);
 154}
 155
 156static void output_commit_title(struct merge_options *o, struct commit *commit)
 157{
 158        int i;
 159        flush_output(o);
 160        for (i = o->call_depth; i--;)
 161                fputs("  ", stdout);
 162        if (commit->util)
 163                printf("virtual %s\n", (char *)commit->util);
 164        else {
 165                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 166                if (parse_commit(commit) != 0)
 167                        printf("(bad commit)\n");
 168                else {
 169                        const char *title;
 170                        int len = find_commit_subject(commit->buffer, &title);
 171                        if (len)
 172                                printf("%.*s\n", len, title);
 173                }
 174        }
 175}
 176
 177static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 178                const char *path, int stage, int refresh, int options)
 179{
 180        struct cache_entry *ce;
 181        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 182        if (!ce)
 183                return error("addinfo_cache failed for path '%s'", path);
 184        return add_cache_entry(ce, options);
 185}
 186
 187static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 188{
 189        parse_tree(tree);
 190        init_tree_desc(desc, tree->buffer, tree->size);
 191}
 192
 193static int git_merge_trees(int index_only,
 194                           struct tree *common,
 195                           struct tree *head,
 196                           struct tree *merge)
 197{
 198        int rc;
 199        struct tree_desc t[3];
 200        struct unpack_trees_options opts;
 201
 202        memset(&opts, 0, sizeof(opts));
 203        if (index_only)
 204                opts.index_only = 1;
 205        else
 206                opts.update = 1;
 207        opts.merge = 1;
 208        opts.head_idx = 2;
 209        opts.fn = threeway_merge;
 210        opts.src_index = &the_index;
 211        opts.dst_index = &the_index;
 212        setup_unpack_trees_porcelain(&opts, "merge");
 213
 214        init_tree_desc_from_tree(t+0, common);
 215        init_tree_desc_from_tree(t+1, head);
 216        init_tree_desc_from_tree(t+2, merge);
 217
 218        rc = unpack_trees(3, t, &opts);
 219        cache_tree_free(&active_cache_tree);
 220        return rc;
 221}
 222
 223struct tree *write_tree_from_memory(struct merge_options *o)
 224{
 225        struct tree *result = NULL;
 226
 227        if (unmerged_cache()) {
 228                int i;
 229                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 230                for (i = 0; i < active_nr; i++) {
 231                        struct cache_entry *ce = active_cache[i];
 232                        if (ce_stage(ce))
 233                                fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
 234                                        (int)ce_namelen(ce), ce->name);
 235                }
 236                die("Bug in merge-recursive.c");
 237        }
 238
 239        if (!active_cache_tree)
 240                active_cache_tree = cache_tree();
 241
 242        if (!cache_tree_fully_valid(active_cache_tree) &&
 243            cache_tree_update(active_cache_tree,
 244                              active_cache, active_nr, 0, 0) < 0)
 245                die("error building trees");
 246
 247        result = lookup_tree(active_cache_tree->sha1);
 248
 249        return result;
 250}
 251
 252static int save_files_dirs(const unsigned char *sha1,
 253                const char *base, int baselen, const char *path,
 254                unsigned int mode, int stage, void *context)
 255{
 256        int len = strlen(path);
 257        char *newpath = xmalloc(baselen + len + 1);
 258        struct merge_options *o = context;
 259
 260        memcpy(newpath, base, baselen);
 261        memcpy(newpath + baselen, path, len);
 262        newpath[baselen + len] = '\0';
 263
 264        if (S_ISDIR(mode))
 265                string_list_insert(&o->current_directory_set, newpath);
 266        else
 267                string_list_insert(&o->current_file_set, newpath);
 268        free(newpath);
 269
 270        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 271}
 272
 273static int get_files_dirs(struct merge_options *o, struct tree *tree)
 274{
 275        int n;
 276        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 277                return 0;
 278        n = o->current_file_set.nr + o->current_directory_set.nr;
 279        return n;
 280}
 281
 282/*
 283 * Returns an index_entry instance which doesn't have to correspond to
 284 * a real cache entry in Git's index.
 285 */
 286static struct stage_data *insert_stage_data(const char *path,
 287                struct tree *o, struct tree *a, struct tree *b,
 288                struct string_list *entries)
 289{
 290        struct string_list_item *item;
 291        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 292        get_tree_entry(o->object.sha1, path,
 293                        e->stages[1].sha, &e->stages[1].mode);
 294        get_tree_entry(a->object.sha1, path,
 295                        e->stages[2].sha, &e->stages[2].mode);
 296        get_tree_entry(b->object.sha1, path,
 297                        e->stages[3].sha, &e->stages[3].mode);
 298        item = string_list_insert(entries, path);
 299        item->util = e;
 300        return e;
 301}
 302
 303/*
 304 * Create a dictionary mapping file names to stage_data objects. The
 305 * dictionary contains one entry for every path with a non-zero stage entry.
 306 */
 307static struct string_list *get_unmerged(void)
 308{
 309        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 310        int i;
 311
 312        unmerged->strdup_strings = 1;
 313
 314        for (i = 0; i < active_nr; i++) {
 315                struct string_list_item *item;
 316                struct stage_data *e;
 317                struct cache_entry *ce = active_cache[i];
 318                if (!ce_stage(ce))
 319                        continue;
 320
 321                item = string_list_lookup(unmerged, ce->name);
 322                if (!item) {
 323                        item = string_list_insert(unmerged, ce->name);
 324                        item->util = xcalloc(1, sizeof(struct stage_data));
 325                }
 326                e = item->util;
 327                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 328                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 329        }
 330
 331        return unmerged;
 332}
 333
 334static int string_list_df_name_compare(const void *a, const void *b)
 335{
 336        const struct string_list_item *one = a;
 337        const struct string_list_item *two = b;
 338        int onelen = strlen(one->string);
 339        int twolen = strlen(two->string);
 340        /*
 341         * Here we only care that entries for D/F conflicts are
 342         * adjacent, in particular with the file of the D/F conflict
 343         * appearing before files below the corresponding directory.
 344         * The order of the rest of the list is irrelevant for us.
 345         *
 346         * To achieve this, we sort with df_name_compare and provide
 347         * the mode S_IFDIR so that D/F conflicts will sort correctly.
 348         * We use the mode S_IFDIR for everything else for simplicity,
 349         * since in other cases any changes in their order due to
 350         * sorting cause no problems for us.
 351         */
 352        int cmp = df_name_compare(one->string, onelen, S_IFDIR,
 353                                  two->string, twolen, S_IFDIR);
 354        /*
 355         * Now that 'foo' and 'foo/bar' compare equal, we have to make sure
 356         * that 'foo' comes before 'foo/bar'.
 357         */
 358        if (cmp)
 359                return cmp;
 360        return onelen - twolen;
 361}
 362
 363
 364
 365static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 366                                                      struct string_list *entries)
 367{
 368        /* If there are D/F conflicts, and the paths currently exist
 369         * in the working copy as a file, we want to remove them to
 370         * make room for the corresponding directory.  Such paths will
 371         * later be processed in process_df_entry() at the end.  If
 372         * the corresponding directory ends up being removed by the
 373         * merge, then the file will be reinstated at that time;
 374         * otherwise, if the file is not supposed to be removed by the
 375         * merge, the contents of the file will be placed in another
 376         * unique filename.
 377         */
 378        const char *last_file = NULL;
 379        int last_len = 0;
 380        int i;
 381
 382        /*
 383         * If we're merging merge-bases, we don't want to bother with
 384         * any working directory changes.
 385         */
 386        if (o->call_depth)
 387                return;
 388
 389        /* Ensure D/F conflicts are adjacent in the entries list. */
 390        qsort(entries->items, entries->nr, sizeof(*entries->items),
 391              string_list_df_name_compare);
 392
 393        for (i = 0; i < entries->nr; i++) {
 394                const char *path = entries->items[i].string;
 395                int len = strlen(path);
 396                struct stage_data *e = entries->items[i].util;
 397
 398                /*
 399                 * Check if last_file & path correspond to a D/F conflict;
 400                 * i.e. whether path is last_file+'/'+<something>.
 401                 * If so, remove last_file to make room for path and friends.
 402                 */
 403                if (last_file &&
 404                    len > last_len &&
 405                    memcmp(path, last_file, last_len) == 0 &&
 406                    path[last_len] == '/') {
 407                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 408                        unlink(last_file);
 409                }
 410
 411                /*
 412                 * Determine whether path could exist as a file in the
 413                 * working directory as a possible D/F conflict.  This
 414                 * will only occur when it exists in stage 2 as a
 415                 * file.
 416                 */
 417                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 418                        last_file = path;
 419                        last_len = len;
 420                } else {
 421                        last_file = NULL;
 422                }
 423        }
 424}
 425
 426struct rename {
 427        struct diff_filepair *pair;
 428        struct stage_data *src_entry;
 429        struct stage_data *dst_entry;
 430        unsigned processed:1;
 431};
 432
 433/*
 434 * Get information of all renames which occurred between 'o_tree' and
 435 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 436 * 'b_tree') to be able to associate the correct cache entries with
 437 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 438 */
 439static struct string_list *get_renames(struct merge_options *o,
 440                                       struct tree *tree,
 441                                       struct tree *o_tree,
 442                                       struct tree *a_tree,
 443                                       struct tree *b_tree,
 444                                       struct string_list *entries)
 445{
 446        int i;
 447        struct string_list *renames;
 448        struct diff_options opts;
 449
 450        renames = xcalloc(1, sizeof(struct string_list));
 451        diff_setup(&opts);
 452        DIFF_OPT_SET(&opts, RECURSIVE);
 453        opts.detect_rename = DIFF_DETECT_RENAME;
 454        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 455                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 456                            1000;
 457        opts.rename_score = o->rename_score;
 458        opts.show_rename_progress = o->show_rename_progress;
 459        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 460        if (diff_setup_done(&opts) < 0)
 461                die("diff setup failed");
 462        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 463        diffcore_std(&opts);
 464        if (opts.needed_rename_limit > o->needed_rename_limit)
 465                o->needed_rename_limit = opts.needed_rename_limit;
 466        for (i = 0; i < diff_queued_diff.nr; ++i) {
 467                struct string_list_item *item;
 468                struct rename *re;
 469                struct diff_filepair *pair = diff_queued_diff.queue[i];
 470                if (pair->status != 'R') {
 471                        diff_free_filepair(pair);
 472                        continue;
 473                }
 474                re = xmalloc(sizeof(*re));
 475                re->processed = 0;
 476                re->pair = pair;
 477                item = string_list_lookup(entries, re->pair->one->path);
 478                if (!item)
 479                        re->src_entry = insert_stage_data(re->pair->one->path,
 480                                        o_tree, a_tree, b_tree, entries);
 481                else
 482                        re->src_entry = item->util;
 483
 484                item = string_list_lookup(entries, re->pair->two->path);
 485                if (!item)
 486                        re->dst_entry = insert_stage_data(re->pair->two->path,
 487                                        o_tree, a_tree, b_tree, entries);
 488                else
 489                        re->dst_entry = item->util;
 490                item = string_list_insert(renames, pair->one->path);
 491                item->util = re;
 492        }
 493        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 494        diff_queued_diff.nr = 0;
 495        diff_flush(&opts);
 496        return renames;
 497}
 498
 499static int update_stages(const char *path, const struct diff_filespec *o,
 500                         const struct diff_filespec *a,
 501                         const struct diff_filespec *b)
 502{
 503        int clear = 1;
 504        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 505        if (clear)
 506                if (remove_file_from_cache(path))
 507                        return -1;
 508        if (o)
 509                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 510                        return -1;
 511        if (a)
 512                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 513                        return -1;
 514        if (b)
 515                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 516                        return -1;
 517        return 0;
 518}
 519
 520static int update_stages_and_entry(const char *path,
 521                                   struct stage_data *entry,
 522                                   struct diff_filespec *o,
 523                                   struct diff_filespec *a,
 524                                   struct diff_filespec *b,
 525                                   int clear)
 526{
 527        int options;
 528
 529        entry->processed = 0;
 530        entry->stages[1].mode = o->mode;
 531        entry->stages[2].mode = a->mode;
 532        entry->stages[3].mode = b->mode;
 533        hashcpy(entry->stages[1].sha, o->sha1);
 534        hashcpy(entry->stages[2].sha, a->sha1);
 535        hashcpy(entry->stages[3].sha, b->sha1);
 536        return update_stages(path, o, a, b);
 537}
 538
 539static int remove_file(struct merge_options *o, int clean,
 540                       const char *path, int no_wd)
 541{
 542        int update_cache = o->call_depth || clean;
 543        int update_working_directory = !o->call_depth && !no_wd;
 544
 545        if (update_cache) {
 546                if (remove_file_from_cache(path))
 547                        return -1;
 548        }
 549        if (update_working_directory) {
 550                if (remove_path(path))
 551                        return -1;
 552        }
 553        return 0;
 554}
 555
 556static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 557{
 558        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 559        int suffix = 0;
 560        struct stat st;
 561        char *p = newpath + strlen(path);
 562        strcpy(newpath, path);
 563        *(p++) = '~';
 564        strcpy(p, branch);
 565        for (; *p; ++p)
 566                if ('/' == *p)
 567                        *p = '_';
 568        while (string_list_has_string(&o->current_file_set, newpath) ||
 569               string_list_has_string(&o->current_directory_set, newpath) ||
 570               lstat(newpath, &st) == 0)
 571                sprintf(p, "_%d", suffix++);
 572
 573        string_list_insert(&o->current_file_set, newpath);
 574        return newpath;
 575}
 576
 577static void flush_buffer(int fd, const char *buf, unsigned long size)
 578{
 579        while (size > 0) {
 580                long ret = write_in_full(fd, buf, size);
 581                if (ret < 0) {
 582                        /* Ignore epipe */
 583                        if (errno == EPIPE)
 584                                break;
 585                        die_errno("merge-recursive");
 586                } else if (!ret) {
 587                        die("merge-recursive: disk full?");
 588                }
 589                size -= ret;
 590                buf += ret;
 591        }
 592}
 593
 594static int dir_in_way(const char *path, int check_working_copy)
 595{
 596        int pos, pathlen = strlen(path);
 597        char *dirpath = xmalloc(pathlen + 2);
 598        struct stat st;
 599
 600        strcpy(dirpath, path);
 601        dirpath[pathlen] = '/';
 602        dirpath[pathlen+1] = '\0';
 603
 604        pos = cache_name_pos(dirpath, pathlen+1);
 605
 606        if (pos < 0)
 607                pos = -1 - pos;
 608        if (pos < active_nr &&
 609            !strncmp(dirpath, active_cache[pos]->name, pathlen+1)) {
 610                free(dirpath);
 611                return 1;
 612        }
 613
 614        free(dirpath);
 615        return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode);
 616}
 617
 618static int would_lose_untracked(const char *path)
 619{
 620        int pos = cache_name_pos(path, strlen(path));
 621
 622        if (pos < 0)
 623                pos = -1 - pos;
 624        while (pos < active_nr &&
 625               !strcmp(path, active_cache[pos]->name)) {
 626                /*
 627                 * If stage #0, it is definitely tracked.
 628                 * If it has stage #2 then it was tracked
 629                 * before this merge started.  All other
 630                 * cases the path was not tracked.
 631                 */
 632                switch (ce_stage(active_cache[pos])) {
 633                case 0:
 634                case 2:
 635                        return 0;
 636                }
 637                pos++;
 638        }
 639        return file_exists(path);
 640}
 641
 642static int make_room_for_path(const char *path)
 643{
 644        int status;
 645        const char *msg = "failed to create path '%s'%s";
 646
 647        status = safe_create_leading_directories_const(path);
 648        if (status) {
 649                if (status == -3) {
 650                        /* something else exists */
 651                        error(msg, path, ": perhaps a D/F conflict?");
 652                        return -1;
 653                }
 654                die(msg, path, "");
 655        }
 656
 657        /*
 658         * Do not unlink a file in the work tree if we are not
 659         * tracking it.
 660         */
 661        if (would_lose_untracked(path))
 662                return error("refusing to lose untracked file at '%s'",
 663                             path);
 664
 665        /* Successful unlink is good.. */
 666        if (!unlink(path))
 667                return 0;
 668        /* .. and so is no existing file */
 669        if (errno == ENOENT)
 670                return 0;
 671        /* .. but not some other error (who really cares what?) */
 672        return error(msg, path, ": perhaps a D/F conflict?");
 673}
 674
 675static void update_file_flags(struct merge_options *o,
 676                              const unsigned char *sha,
 677                              unsigned mode,
 678                              const char *path,
 679                              int update_cache,
 680                              int update_wd)
 681{
 682        if (o->call_depth)
 683                update_wd = 0;
 684
 685        if (update_wd) {
 686                enum object_type type;
 687                void *buf;
 688                unsigned long size;
 689
 690                if (S_ISGITLINK(mode)) {
 691                        /*
 692                         * We may later decide to recursively descend into
 693                         * the submodule directory and update its index
 694                         * and/or work tree, but we do not do that now.
 695                         */
 696                        update_wd = 0;
 697                        goto update_index;
 698                }
 699
 700                buf = read_sha1_file(sha, &type, &size);
 701                if (!buf)
 702                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 703                if (type != OBJ_BLOB)
 704                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 705                if (S_ISREG(mode)) {
 706                        struct strbuf strbuf = STRBUF_INIT;
 707                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 708                                free(buf);
 709                                size = strbuf.len;
 710                                buf = strbuf_detach(&strbuf, NULL);
 711                        }
 712                }
 713
 714                if (make_room_for_path(path) < 0) {
 715                        update_wd = 0;
 716                        free(buf);
 717                        goto update_index;
 718                }
 719                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 720                        int fd;
 721                        if (mode & 0100)
 722                                mode = 0777;
 723                        else
 724                                mode = 0666;
 725                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 726                        if (fd < 0)
 727                                die_errno("failed to open '%s'", path);
 728                        flush_buffer(fd, buf, size);
 729                        close(fd);
 730                } else if (S_ISLNK(mode)) {
 731                        char *lnk = xmemdupz(buf, size);
 732                        safe_create_leading_directories_const(path);
 733                        unlink(path);
 734                        if (symlink(lnk, path))
 735                                die_errno("failed to symlink '%s'", path);
 736                        free(lnk);
 737                } else
 738                        die("do not know what to do with %06o %s '%s'",
 739                            mode, sha1_to_hex(sha), path);
 740                free(buf);
 741        }
 742 update_index:
 743        if (update_cache)
 744                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 745}
 746
 747static void update_file(struct merge_options *o,
 748                        int clean,
 749                        const unsigned char *sha,
 750                        unsigned mode,
 751                        const char *path)
 752{
 753        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 754}
 755
 756/* Low level file merging, update and removal */
 757
 758struct merge_file_info {
 759        unsigned char sha[20];
 760        unsigned mode;
 761        unsigned clean:1,
 762                 merge:1;
 763};
 764
 765static int merge_3way(struct merge_options *o,
 766                      mmbuffer_t *result_buf,
 767                      const struct diff_filespec *one,
 768                      const struct diff_filespec *a,
 769                      const struct diff_filespec *b,
 770                      const char *branch1,
 771                      const char *branch2)
 772{
 773        mmfile_t orig, src1, src2;
 774        struct ll_merge_options ll_opts = {0};
 775        char *base_name, *name1, *name2;
 776        int merge_status;
 777
 778        ll_opts.renormalize = o->renormalize;
 779        ll_opts.xdl_opts = o->xdl_opts;
 780
 781        if (o->call_depth) {
 782                ll_opts.virtual_ancestor = 1;
 783                ll_opts.variant = 0;
 784        } else {
 785                switch (o->recursive_variant) {
 786                case MERGE_RECURSIVE_OURS:
 787                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 788                        break;
 789                case MERGE_RECURSIVE_THEIRS:
 790                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 791                        break;
 792                default:
 793                        ll_opts.variant = 0;
 794                        break;
 795                }
 796        }
 797
 798        if (strcmp(a->path, b->path) ||
 799            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 800                base_name = o->ancestor == NULL ? NULL :
 801                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 802                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 803                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 804        } else {
 805                base_name = o->ancestor == NULL ? NULL :
 806                        xstrdup(mkpath("%s", o->ancestor));
 807                name1 = xstrdup(mkpath("%s", branch1));
 808                name2 = xstrdup(mkpath("%s", branch2));
 809        }
 810
 811        read_mmblob(&orig, one->sha1);
 812        read_mmblob(&src1, a->sha1);
 813        read_mmblob(&src2, b->sha1);
 814
 815        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 816                                &src1, name1, &src2, name2, &ll_opts);
 817
 818        free(name1);
 819        free(name2);
 820        free(orig.ptr);
 821        free(src1.ptr);
 822        free(src2.ptr);
 823        return merge_status;
 824}
 825
 826static struct merge_file_info merge_file(struct merge_options *o,
 827                                         const struct diff_filespec *one,
 828                                         const struct diff_filespec *a,
 829                                         const struct diff_filespec *b,
 830                                         const char *branch1,
 831                                         const char *branch2)
 832{
 833        struct merge_file_info result;
 834        result.merge = 0;
 835        result.clean = 1;
 836
 837        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 838                result.clean = 0;
 839                if (S_ISREG(a->mode)) {
 840                        result.mode = a->mode;
 841                        hashcpy(result.sha, a->sha1);
 842                } else {
 843                        result.mode = b->mode;
 844                        hashcpy(result.sha, b->sha1);
 845                }
 846        } else {
 847                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 848                        result.merge = 1;
 849
 850                /*
 851                 * Merge modes
 852                 */
 853                if (a->mode == b->mode || a->mode == one->mode)
 854                        result.mode = b->mode;
 855                else {
 856                        result.mode = a->mode;
 857                        if (b->mode != one->mode) {
 858                                result.clean = 0;
 859                                result.merge = 1;
 860                        }
 861                }
 862
 863                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 864                        hashcpy(result.sha, b->sha1);
 865                else if (sha_eq(b->sha1, one->sha1))
 866                        hashcpy(result.sha, a->sha1);
 867                else if (S_ISREG(a->mode)) {
 868                        mmbuffer_t result_buf;
 869                        int merge_status;
 870
 871                        merge_status = merge_3way(o, &result_buf, one, a, b,
 872                                                  branch1, branch2);
 873
 874                        if ((merge_status < 0) || !result_buf.ptr)
 875                                die("Failed to execute internal merge");
 876
 877                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 878                                            blob_type, result.sha))
 879                                die("Unable to add %s to database",
 880                                    a->path);
 881
 882                        free(result_buf.ptr);
 883                        result.clean = (merge_status == 0);
 884                } else if (S_ISGITLINK(a->mode)) {
 885                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 886                                                       a->sha1, b->sha1);
 887                } else if (S_ISLNK(a->mode)) {
 888                        hashcpy(result.sha, a->sha1);
 889
 890                        if (!sha_eq(a->sha1, b->sha1))
 891                                result.clean = 0;
 892                } else {
 893                        die("unsupported object type in the tree");
 894                }
 895        }
 896
 897        return result;
 898}
 899
 900static void conflict_rename_delete(struct merge_options *o,
 901                                   struct diff_filepair *pair,
 902                                   const char *rename_branch,
 903                                   const char *other_branch)
 904{
 905        char *dest_name = pair->two->path;
 906        int df_conflict = 0;
 907
 908        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 909               "and deleted in %s",
 910               pair->one->path, pair->two->path, rename_branch,
 911               other_branch);
 912        if (!o->call_depth)
 913                update_stages(dest_name, NULL,
 914                              rename_branch == o->branch1 ? pair->two : NULL,
 915                              rename_branch == o->branch1 ? NULL : pair->two);
 916        if (dir_in_way(dest_name, !o->call_depth)) {
 917                dest_name = unique_path(o, dest_name, rename_branch);
 918                df_conflict = 1;
 919        }
 920        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 921        if (df_conflict)
 922                free(dest_name);
 923}
 924
 925static void conflict_rename_rename_1to2(struct merge_options *o,
 926                                        struct diff_filepair *pair1,
 927                                        const char *branch1,
 928                                        struct diff_filepair *pair2,
 929                                        const char *branch2)
 930{
 931        /* One file was renamed in both branches, but to different names. */
 932        char *del[2];
 933        int delp = 0;
 934        const char *ren1_dst = pair1->two->path;
 935        const char *ren2_dst = pair2->two->path;
 936        const char *dst_name1 = ren1_dst;
 937        const char *dst_name2 = ren2_dst;
 938        if (dir_in_way(ren1_dst, !o->call_depth)) {
 939                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 940                output(o, 1, "%s is a directory in %s adding as %s instead",
 941                       ren1_dst, branch2, dst_name1);
 942        }
 943        if (dir_in_way(ren2_dst, !o->call_depth)) {
 944                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 945                output(o, 1, "%s is a directory in %s adding as %s instead",
 946                       ren2_dst, branch1, dst_name2);
 947        }
 948        if (o->call_depth) {
 949                remove_file_from_cache(dst_name1);
 950                remove_file_from_cache(dst_name2);
 951                /*
 952                 * Uncomment to leave the conflicting names in the resulting tree
 953                 *
 954                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 955                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 956                 */
 957        } else {
 958                update_stages(ren1_dst, NULL, pair1->two, NULL);
 959                update_stages(ren2_dst, NULL, NULL, pair2->two);
 960
 961                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 962                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 963        }
 964        while (delp--)
 965                free(del[delp]);
 966}
 967
 968static void conflict_rename_rename_2to1(struct merge_options *o,
 969                                        struct rename *ren1,
 970                                        const char *branch1,
 971                                        struct rename *ren2,
 972                                        const char *branch2)
 973{
 974        /* Two files were renamed to the same thing. */
 975        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 976        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 977        output(o, 1, "Renaming %s to %s and %s to %s instead",
 978               ren1->pair->one->path, new_path1,
 979               ren2->pair->one->path, new_path2);
 980        remove_file(o, 0, ren1->pair->two->path, 0);
 981        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 982        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 983        free(new_path2);
 984        free(new_path1);
 985}
 986
 987static int process_renames(struct merge_options *o,
 988                           struct string_list *a_renames,
 989                           struct string_list *b_renames)
 990{
 991        int clean_merge = 1, i, j;
 992        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 993        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 994        const struct rename *sre;
 995
 996        for (i = 0; i < a_renames->nr; i++) {
 997                sre = a_renames->items[i].util;
 998                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 999                        = sre->dst_entry;
1000        }
1001        for (i = 0; i < b_renames->nr; i++) {
1002                sre = b_renames->items[i].util;
1003                string_list_insert(&b_by_dst, sre->pair->two->path)->util
1004                        = sre->dst_entry;
1005        }
1006
1007        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1008                struct string_list *renames1, *renames2Dst;
1009                struct rename *ren1 = NULL, *ren2 = NULL;
1010                const char *branch1, *branch2;
1011                const char *ren1_src, *ren1_dst;
1012
1013                if (i >= a_renames->nr) {
1014                        ren2 = b_renames->items[j++].util;
1015                } else if (j >= b_renames->nr) {
1016                        ren1 = a_renames->items[i++].util;
1017                } else {
1018                        int compare = strcmp(a_renames->items[i].string,
1019                                             b_renames->items[j].string);
1020                        if (compare <= 0)
1021                                ren1 = a_renames->items[i++].util;
1022                        if (compare >= 0)
1023                                ren2 = b_renames->items[j++].util;
1024                }
1025
1026                /* TODO: refactor, so that 1/2 are not needed */
1027                if (ren1) {
1028                        renames1 = a_renames;
1029                        renames2Dst = &b_by_dst;
1030                        branch1 = o->branch1;
1031                        branch2 = o->branch2;
1032                } else {
1033                        struct rename *tmp;
1034                        renames1 = b_renames;
1035                        renames2Dst = &a_by_dst;
1036                        branch1 = o->branch2;
1037                        branch2 = o->branch1;
1038                        tmp = ren2;
1039                        ren2 = ren1;
1040                        ren1 = tmp;
1041                }
1042
1043                ren1->dst_entry->processed = 1;
1044                ren1->src_entry->processed = 1;
1045
1046                if (ren1->processed)
1047                        continue;
1048                ren1->processed = 1;
1049
1050                ren1_src = ren1->pair->one->path;
1051                ren1_dst = ren1->pair->two->path;
1052
1053                if (ren2) {
1054                        const char *ren2_src = ren2->pair->one->path;
1055                        const char *ren2_dst = ren2->pair->two->path;
1056                        /* Renamed in 1 and renamed in 2 */
1057                        if (strcmp(ren1_src, ren2_src) != 0)
1058                                die("ren1.src != ren2.src");
1059                        ren2->dst_entry->processed = 1;
1060                        ren2->processed = 1;
1061                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1062                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1063                                                              ren1->pair,
1064                                                              ren2->pair,
1065                                                              branch1,
1066                                                              branch2,
1067                                                              ren1->dst_entry,
1068                                                              ren2->dst_entry);
1069                        } else {
1070                                remove_file(o, 1, ren1_src, 1);
1071                                update_stages_and_entry(ren1_dst,
1072                                                        ren1->dst_entry,
1073                                                        ren1->pair->one,
1074                                                        ren1->pair->two,
1075                                                        ren2->pair->two,
1076                                                        1 /* clear */);
1077                        }
1078                } else {
1079                        /* Renamed in 1, maybe changed in 2 */
1080                        struct string_list_item *item;
1081                        /* we only use sha1 and mode of these */
1082                        struct diff_filespec src_other, dst_other;
1083                        int try_merge;
1084
1085                        /*
1086                         * unpack_trees loads entries from common-commit
1087                         * into stage 1, from head-commit into stage 2, and
1088                         * from merge-commit into stage 3.  We keep track
1089                         * of which side corresponds to the rename.
1090                         */
1091                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1092                        int other_stage =   a_renames == renames1 ? 3 : 2;
1093
1094                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1095
1096                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1097                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1098                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1099                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1100                        try_merge = 0;
1101
1102                        if (sha_eq(src_other.sha1, null_sha1)) {
1103                                if (dir_in_way(ren1_dst, 0 /*check_wc*/)) {
1104                                        ren1->dst_entry->processed = 0;
1105                                        setup_rename_df_conflict_info(RENAME_DELETE,
1106                                                                      ren1->pair,
1107                                                                      NULL,
1108                                                                      branch1,
1109                                                                      branch2,
1110                                                                      ren1->dst_entry,
1111                                                                      NULL);
1112                                } else {
1113                                        clean_merge = 0;
1114                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1115                                }
1116                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1117                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1118                                /* Added file on the other side
1119                                   identical to the file being
1120                                   renamed: clean merge */
1121                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1122                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1123                                clean_merge = 0;
1124                                try_merge = 1;
1125                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1126                                       "%s added in %s",
1127                                       ren1_src, ren1_dst, branch1,
1128                                       ren1_dst, branch2);
1129                                if (o->call_depth) {
1130                                        struct merge_file_info mfi;
1131                                        struct diff_filespec one, a, b;
1132
1133                                        one.path = a.path = b.path =
1134                                                (char *)ren1_dst;
1135                                        hashcpy(one.sha1, null_sha1);
1136                                        one.mode = 0;
1137                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1138                                        a.mode = ren1->pair->two->mode;
1139                                        hashcpy(b.sha1, dst_other.sha1);
1140                                        b.mode = dst_other.mode;
1141                                        mfi = merge_file(o, &one, &a, &b,
1142                                                         branch1,
1143                                                         branch2);
1144                                        output(o, 1, "Adding merged %s", ren1_dst);
1145                                        update_file(o, 0,
1146                                                    mfi.sha,
1147                                                    mfi.mode,
1148                                                    ren1_dst);
1149                                        try_merge = 0;
1150                                } else {
1151                                        char *new_path = unique_path(o, ren1_dst, branch2);
1152                                        output(o, 1, "Adding as %s instead", new_path);
1153                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1154                                        free(new_path);
1155                                }
1156                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1157                                ren2 = item->util;
1158                                clean_merge = 0;
1159                                ren2->processed = 1;
1160                                output(o, 1, "CONFLICT (rename/rename): "
1161                                       "Rename %s->%s in %s. "
1162                                       "Rename %s->%s in %s",
1163                                       ren1_src, ren1_dst, branch1,
1164                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1165                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1166                        } else
1167                                try_merge = 1;
1168
1169                        if (try_merge) {
1170                                struct diff_filespec *one, *a, *b;
1171                                src_other.path = (char *)ren1_src;
1172
1173                                one = ren1->pair->one;
1174                                if (a_renames == renames1) {
1175                                        a = ren1->pair->two;
1176                                        b = &src_other;
1177                                } else {
1178                                        b = ren1->pair->two;
1179                                        a = &src_other;
1180                                }
1181                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1182                                if (dir_in_way(ren1_dst, 0 /*check_wc*/)) {
1183                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1184                                                                      ren1->pair,
1185                                                                      NULL,
1186                                                                      branch1,
1187                                                                      NULL,
1188                                                                      ren1->dst_entry,
1189                                                                      NULL);
1190                                }
1191                        }
1192                }
1193        }
1194        string_list_clear(&a_by_dst, 0);
1195        string_list_clear(&b_by_dst, 0);
1196
1197        return clean_merge;
1198}
1199
1200static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1201{
1202        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1203}
1204
1205static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1206{
1207        void *buf;
1208        enum object_type type;
1209        unsigned long size;
1210        buf = read_sha1_file(sha1, &type, &size);
1211        if (!buf)
1212                return error("cannot read object %s", sha1_to_hex(sha1));
1213        if (type != OBJ_BLOB) {
1214                free(buf);
1215                return error("object %s is not a blob", sha1_to_hex(sha1));
1216        }
1217        strbuf_attach(dst, buf, size, size + 1);
1218        return 0;
1219}
1220
1221static int blob_unchanged(const unsigned char *o_sha,
1222                          const unsigned char *a_sha,
1223                          int renormalize, const char *path)
1224{
1225        struct strbuf o = STRBUF_INIT;
1226        struct strbuf a = STRBUF_INIT;
1227        int ret = 0; /* assume changed for safety */
1228
1229        if (sha_eq(o_sha, a_sha))
1230                return 1;
1231        if (!renormalize)
1232                return 0;
1233
1234        assert(o_sha && a_sha);
1235        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1236                goto error_return;
1237        /*
1238         * Note: binary | is used so that both renormalizations are
1239         * performed.  Comparison can be skipped if both files are
1240         * unchanged since their sha1s have already been compared.
1241         */
1242        if (renormalize_buffer(path, o.buf, o.len, &o) |
1243            renormalize_buffer(path, a.buf, o.len, &a))
1244                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1245
1246error_return:
1247        strbuf_release(&o);
1248        strbuf_release(&a);
1249        return ret;
1250}
1251
1252static void handle_delete_modify(struct merge_options *o,
1253                                 const char *path,
1254                                 const char *new_path,
1255                                 unsigned char *a_sha, int a_mode,
1256                                 unsigned char *b_sha, int b_mode)
1257{
1258        if (!a_sha) {
1259                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1260                       "and modified in %s. Version %s of %s left in tree%s%s.",
1261                       path, o->branch1,
1262                       o->branch2, o->branch2, path,
1263                       path == new_path ? "" : " at ",
1264                       path == new_path ? "" : new_path);
1265                update_file(o, 0, b_sha, b_mode, new_path);
1266        } else {
1267                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1268                       "and modified in %s. Version %s of %s left in tree%s%s.",
1269                       path, o->branch2,
1270                       o->branch1, o->branch1, path,
1271                       path == new_path ? "" : " at ",
1272                       path == new_path ? "" : new_path);
1273                update_file(o, 0, a_sha, a_mode, new_path);
1274        }
1275}
1276
1277static int merge_content(struct merge_options *o,
1278                         const char *path,
1279                         unsigned char *o_sha, int o_mode,
1280                         unsigned char *a_sha, int a_mode,
1281                         unsigned char *b_sha, int b_mode,
1282                         const char *df_rename_conflict_branch)
1283{
1284        const char *reason = "content";
1285        struct merge_file_info mfi;
1286        struct diff_filespec one, a, b;
1287        unsigned df_conflict_remains = 0;
1288
1289        if (!o_sha) {
1290                reason = "add/add";
1291                o_sha = (unsigned char *)null_sha1;
1292        }
1293        one.path = a.path = b.path = (char *)path;
1294        hashcpy(one.sha1, o_sha);
1295        one.mode = o_mode;
1296        hashcpy(a.sha1, a_sha);
1297        a.mode = a_mode;
1298        hashcpy(b.sha1, b_sha);
1299        b.mode = b_mode;
1300
1301        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1302        if (df_rename_conflict_branch &&
1303            dir_in_way(path, !o->call_depth)) {
1304                df_conflict_remains = 1;
1305        }
1306
1307        if (mfi.clean && !df_conflict_remains &&
1308            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1309                output(o, 3, "Skipped %s (merged same as existing)", path);
1310        else
1311                output(o, 2, "Auto-merging %s", path);
1312
1313        if (!mfi.clean) {
1314                if (S_ISGITLINK(mfi.mode))
1315                        reason = "submodule";
1316                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1317                                reason, path);
1318        }
1319
1320        if (df_conflict_remains) {
1321                char *new_path;
1322                update_file_flags(o, mfi.sha, mfi.mode, path,
1323                                  o->call_depth || mfi.clean, 0);
1324                new_path = unique_path(o, path, df_rename_conflict_branch);
1325                mfi.clean = 0;
1326                output(o, 1, "Adding as %s instead", new_path);
1327                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1328                free(new_path);
1329        } else {
1330                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1331        }
1332        return mfi.clean;
1333
1334}
1335
1336/* Per entry merge function */
1337static int process_entry(struct merge_options *o,
1338                         const char *path, struct stage_data *entry)
1339{
1340        /*
1341        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1342        print_index_entry("\tpath: ", entry);
1343        */
1344        int clean_merge = 1;
1345        int normalize = o->renormalize;
1346        unsigned o_mode = entry->stages[1].mode;
1347        unsigned a_mode = entry->stages[2].mode;
1348        unsigned b_mode = entry->stages[3].mode;
1349        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1350        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1351        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1352
1353        if (entry->rename_df_conflict_info)
1354                return 1; /* Such cases are handled elsewhere. */
1355
1356        entry->processed = 1;
1357        if (o_sha && (!a_sha || !b_sha)) {
1358                /* Case A: Deleted in one */
1359                if ((!a_sha && !b_sha) ||
1360                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1361                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1362                        /* Deleted in both or deleted in one and
1363                         * unchanged in the other */
1364                        if (a_sha)
1365                                output(o, 2, "Removing %s", path);
1366                        /* do not touch working file if it did not exist */
1367                        remove_file(o, 1, path, !a_sha);
1368                } else if (dir_in_way(path, 0 /*check_wc*/)) {
1369                        entry->processed = 0;
1370                        return 1; /* Assume clean until processed */
1371                } else {
1372                        /* Deleted in one and changed in the other */
1373                        clean_merge = 0;
1374                        handle_delete_modify(o, path, path,
1375                                             a_sha, a_mode, b_sha, b_mode);
1376                }
1377
1378        } else if ((!o_sha && a_sha && !b_sha) ||
1379                   (!o_sha && !a_sha && b_sha)) {
1380                /* Case B: Added in one. */
1381                unsigned mode;
1382                const unsigned char *sha;
1383
1384                if (a_sha) {
1385                        mode = a_mode;
1386                        sha = a_sha;
1387                } else {
1388                        mode = b_mode;
1389                        sha = b_sha;
1390                }
1391                if (dir_in_way(path, 0 /*check_wc*/)) {
1392                        /* Handle D->F conflicts after all subfiles */
1393                        entry->processed = 0;
1394                        return 1; /* Assume clean until processed */
1395                } else {
1396                        output(o, 2, "Adding %s", path);
1397                        update_file(o, 1, sha, mode, path);
1398                }
1399        } else if (a_sha && b_sha) {
1400                /* Case C: Added in both (check for same permissions) and */
1401                /* case D: Modified in both, but differently. */
1402                clean_merge = merge_content(o, path,
1403                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1404                                            NULL);
1405        } else if (!o_sha && !a_sha && !b_sha) {
1406                /*
1407                 * this entry was deleted altogether. a_mode == 0 means
1408                 * we had that path and want to actively remove it.
1409                 */
1410                remove_file(o, 1, path, !a_mode);
1411        } else
1412                die("Fatal merge failure, shouldn't happen.");
1413
1414        return clean_merge;
1415}
1416
1417/*
1418 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1419 * cases we can cleanly resolve D/F conflicts, process_entry() can
1420 * clean out all the files below the directory for us.  All D/F
1421 * conflict cases must be handled here at the end to make sure any
1422 * directories that can be cleaned out, are.
1423 *
1424 * Some rename conflicts may also be handled here that don't necessarily
1425 * involve D/F conflicts, since the code to handle them is generic enough
1426 * to handle those rename conflicts with or without D/F conflicts also
1427 * being involved.
1428 */
1429static int process_df_entry(struct merge_options *o,
1430                            const char *path, struct stage_data *entry)
1431{
1432        int clean_merge = 1;
1433        unsigned o_mode = entry->stages[1].mode;
1434        unsigned a_mode = entry->stages[2].mode;
1435        unsigned b_mode = entry->stages[3].mode;
1436        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1437        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1438        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1439
1440        entry->processed = 1;
1441        if (entry->rename_df_conflict_info) {
1442                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1443                char *src;
1444                switch (conflict_info->rename_type) {
1445                case RENAME_NORMAL:
1446                        clean_merge = merge_content(o, path,
1447                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1448                                                    conflict_info->branch1);
1449                        break;
1450                case RENAME_DELETE:
1451                        clean_merge = 0;
1452                        conflict_rename_delete(o, conflict_info->pair1,
1453                                               conflict_info->branch1,
1454                                               conflict_info->branch2);
1455                        break;
1456                case RENAME_ONE_FILE_TO_TWO:
1457                        src = conflict_info->pair1->one->path;
1458                        clean_merge = 0;
1459                        output(o, 1, "CONFLICT (rename/rename): "
1460                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1461                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1462                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1463                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1464                               o->call_depth ? " (left unresolved)" : "");
1465                        if (o->call_depth) {
1466                                remove_file_from_cache(src);
1467                                update_file(o, 0, conflict_info->pair1->one->sha1,
1468                                            conflict_info->pair1->one->mode, src);
1469                        }
1470                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1471                                                    conflict_info->branch1,
1472                                                    conflict_info->pair2,
1473                                                    conflict_info->branch2);
1474                        conflict_info->dst_entry2->processed = 1;
1475                        break;
1476                default:
1477                        entry->processed = 0;
1478                        break;
1479                }
1480        } else if (o_sha && (!a_sha || !b_sha)) {
1481                /* Modify/delete; deleted side may have put a directory in the way */
1482                char *renamed = NULL;
1483                if (dir_in_way(path, !o->call_depth)) {
1484                        renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1485                }
1486                clean_merge = 0;
1487                handle_delete_modify(o, path, renamed ? renamed : path,
1488                                     a_sha, a_mode, b_sha, b_mode);
1489                free(renamed);
1490        } else if (!o_sha && !!a_sha != !!b_sha) {
1491                /* directory -> (directory, file) or <nothing> -> (directory, file) */
1492                const char *add_branch;
1493                const char *other_branch;
1494                unsigned mode;
1495                const unsigned char *sha;
1496                const char *conf;
1497
1498                if (a_sha) {
1499                        add_branch = o->branch1;
1500                        other_branch = o->branch2;
1501                        mode = a_mode;
1502                        sha = a_sha;
1503                        conf = "file/directory";
1504                } else {
1505                        add_branch = o->branch2;
1506                        other_branch = o->branch1;
1507                        mode = b_mode;
1508                        sha = b_sha;
1509                        conf = "directory/file";
1510                }
1511                if (dir_in_way(path, !o->call_depth)) {
1512                        char *new_path = unique_path(o, path, add_branch);
1513                        clean_merge = 0;
1514                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1515                               "Adding %s as %s",
1516                               conf, path, other_branch, path, new_path);
1517                        update_file(o, 0, sha, mode, new_path);
1518                        if (o->call_depth)
1519                                remove_file_from_cache(path);
1520                        free(new_path);
1521                } else {
1522                        output(o, 2, "Adding %s", path);
1523                        update_file(o, 1, sha, mode, path);
1524                }
1525        } else {
1526                entry->processed = 0;
1527                return 1; /* not handled; assume clean until processed */
1528        }
1529
1530        return clean_merge;
1531}
1532
1533int merge_trees(struct merge_options *o,
1534                struct tree *head,
1535                struct tree *merge,
1536                struct tree *common,
1537                struct tree **result)
1538{
1539        int code, clean;
1540
1541        if (o->subtree_shift) {
1542                merge = shift_tree_object(head, merge, o->subtree_shift);
1543                common = shift_tree_object(head, common, o->subtree_shift);
1544        }
1545
1546        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1547                output(o, 0, "Already up-to-date!");
1548                *result = head;
1549                return 1;
1550        }
1551
1552        code = git_merge_trees(o->call_depth, common, head, merge);
1553
1554        if (code != 0) {
1555                if (show(o, 4) || o->call_depth)
1556                        die("merging of trees %s and %s failed",
1557                            sha1_to_hex(head->object.sha1),
1558                            sha1_to_hex(merge->object.sha1));
1559                else
1560                        exit(128);
1561        }
1562
1563        if (unmerged_cache()) {
1564                struct string_list *entries, *re_head, *re_merge;
1565                int i;
1566                string_list_clear(&o->current_file_set, 1);
1567                string_list_clear(&o->current_directory_set, 1);
1568                get_files_dirs(o, head);
1569                get_files_dirs(o, merge);
1570
1571                entries = get_unmerged();
1572                make_room_for_directories_of_df_conflicts(o, entries);
1573                re_head  = get_renames(o, head, common, head, merge, entries);
1574                re_merge = get_renames(o, merge, common, head, merge, entries);
1575                clean = process_renames(o, re_head, re_merge);
1576                for (i = 0; i < entries->nr; i++) {
1577                        const char *path = entries->items[i].string;
1578                        struct stage_data *e = entries->items[i].util;
1579                        if (!e->processed
1580                                && !process_entry(o, path, e))
1581                                clean = 0;
1582                }
1583                for (i = 0; i < entries->nr; i++) {
1584                        const char *path = entries->items[i].string;
1585                        struct stage_data *e = entries->items[i].util;
1586                        if (!e->processed
1587                                && !process_df_entry(o, path, e))
1588                                clean = 0;
1589                }
1590                for (i = 0; i < entries->nr; i++) {
1591                        struct stage_data *e = entries->items[i].util;
1592                        if (!e->processed)
1593                                die("Unprocessed path??? %s",
1594                                    entries->items[i].string);
1595                }
1596
1597                string_list_clear(re_merge, 0);
1598                string_list_clear(re_head, 0);
1599                string_list_clear(entries, 1);
1600
1601        }
1602        else
1603                clean = 1;
1604
1605        if (o->call_depth)
1606                *result = write_tree_from_memory(o);
1607
1608        return clean;
1609}
1610
1611static struct commit_list *reverse_commit_list(struct commit_list *list)
1612{
1613        struct commit_list *next = NULL, *current, *backup;
1614        for (current = list; current; current = backup) {
1615                backup = current->next;
1616                current->next = next;
1617                next = current;
1618        }
1619        return next;
1620}
1621
1622/*
1623 * Merge the commits h1 and h2, return the resulting virtual
1624 * commit object and a flag indicating the cleanness of the merge.
1625 */
1626int merge_recursive(struct merge_options *o,
1627                    struct commit *h1,
1628                    struct commit *h2,
1629                    struct commit_list *ca,
1630                    struct commit **result)
1631{
1632        struct commit_list *iter;
1633        struct commit *merged_common_ancestors;
1634        struct tree *mrtree = mrtree;
1635        int clean;
1636
1637        if (show(o, 4)) {
1638                output(o, 4, "Merging:");
1639                output_commit_title(o, h1);
1640                output_commit_title(o, h2);
1641        }
1642
1643        if (!ca) {
1644                ca = get_merge_bases(h1, h2, 1);
1645                ca = reverse_commit_list(ca);
1646        }
1647
1648        if (show(o, 5)) {
1649                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1650                for (iter = ca; iter; iter = iter->next)
1651                        output_commit_title(o, iter->item);
1652        }
1653
1654        merged_common_ancestors = pop_commit(&ca);
1655        if (merged_common_ancestors == NULL) {
1656                /* if there is no common ancestor, make an empty tree */
1657                struct tree *tree = xcalloc(1, sizeof(struct tree));
1658
1659                tree->object.parsed = 1;
1660                tree->object.type = OBJ_TREE;
1661                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1662                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1663        }
1664
1665        for (iter = ca; iter; iter = iter->next) {
1666                const char *saved_b1, *saved_b2;
1667                o->call_depth++;
1668                /*
1669                 * When the merge fails, the result contains files
1670                 * with conflict markers. The cleanness flag is
1671                 * ignored, it was never actually used, as result of
1672                 * merge_trees has always overwritten it: the committed
1673                 * "conflicts" were already resolved.
1674                 */
1675                discard_cache();
1676                saved_b1 = o->branch1;
1677                saved_b2 = o->branch2;
1678                o->branch1 = "Temporary merge branch 1";
1679                o->branch2 = "Temporary merge branch 2";
1680                merge_recursive(o, merged_common_ancestors, iter->item,
1681                                NULL, &merged_common_ancestors);
1682                o->branch1 = saved_b1;
1683                o->branch2 = saved_b2;
1684                o->call_depth--;
1685
1686                if (!merged_common_ancestors)
1687                        die("merge returned no commit");
1688        }
1689
1690        discard_cache();
1691        if (!o->call_depth)
1692                read_cache();
1693
1694        o->ancestor = "merged common ancestors";
1695        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1696                            &mrtree);
1697
1698        if (o->call_depth) {
1699                *result = make_virtual_commit(mrtree, "merged tree");
1700                commit_list_insert(h1, &(*result)->parents);
1701                commit_list_insert(h2, &(*result)->parents->next);
1702        }
1703        flush_output(o);
1704        if (show(o, 2))
1705                diff_warn_rename_limit("merge.renamelimit",
1706                                       o->needed_rename_limit, 0);
1707        return clean;
1708}
1709
1710static struct commit *get_ref(const unsigned char *sha1, const char *name)
1711{
1712        struct object *object;
1713
1714        object = deref_tag(parse_object(sha1), name, strlen(name));
1715        if (!object)
1716                return NULL;
1717        if (object->type == OBJ_TREE)
1718                return make_virtual_commit((struct tree*)object, name);
1719        if (object->type != OBJ_COMMIT)
1720                return NULL;
1721        if (parse_commit((struct commit *)object))
1722                return NULL;
1723        return (struct commit *)object;
1724}
1725
1726int merge_recursive_generic(struct merge_options *o,
1727                            const unsigned char *head,
1728                            const unsigned char *merge,
1729                            int num_base_list,
1730                            const unsigned char **base_list,
1731                            struct commit **result)
1732{
1733        int clean, index_fd;
1734        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1735        struct commit *head_commit = get_ref(head, o->branch1);
1736        struct commit *next_commit = get_ref(merge, o->branch2);
1737        struct commit_list *ca = NULL;
1738
1739        if (base_list) {
1740                int i;
1741                for (i = 0; i < num_base_list; ++i) {
1742                        struct commit *base;
1743                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1744                                return error("Could not parse object '%s'",
1745                                        sha1_to_hex(base_list[i]));
1746                        commit_list_insert(base, &ca);
1747                }
1748        }
1749
1750        index_fd = hold_locked_index(lock, 1);
1751        clean = merge_recursive(o, head_commit, next_commit, ca,
1752                        result);
1753        if (active_cache_changed &&
1754                        (write_cache(index_fd, active_cache, active_nr) ||
1755                         commit_locked_index(lock)))
1756                return error("Unable to write index.");
1757
1758        return clean ? 0 : 1;
1759}
1760
1761static int merge_recursive_config(const char *var, const char *value, void *cb)
1762{
1763        struct merge_options *o = cb;
1764        if (!strcmp(var, "merge.verbosity")) {
1765                o->verbosity = git_config_int(var, value);
1766                return 0;
1767        }
1768        if (!strcmp(var, "diff.renamelimit")) {
1769                o->diff_rename_limit = git_config_int(var, value);
1770                return 0;
1771        }
1772        if (!strcmp(var, "merge.renamelimit")) {
1773                o->merge_rename_limit = git_config_int(var, value);
1774                return 0;
1775        }
1776        return git_xmerge_config(var, value, cb);
1777}
1778
1779void init_merge_options(struct merge_options *o)
1780{
1781        memset(o, 0, sizeof(struct merge_options));
1782        o->verbosity = 2;
1783        o->buffer_output = 1;
1784        o->diff_rename_limit = -1;
1785        o->merge_rename_limit = -1;
1786        o->renormalize = 0;
1787        git_config(merge_recursive_config, o);
1788        if (getenv("GIT_MERGE_VERBOSITY"))
1789                o->verbosity =
1790                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1791        if (o->verbosity >= 5)
1792                o->buffer_output = 0;
1793        strbuf_init(&o->obuf, 0);
1794        memset(&o->current_file_set, 0, sizeof(struct string_list));
1795        o->current_file_set.strdup_strings = 1;
1796        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1797        o->current_directory_set.strdup_strings = 1;
1798}
1799
1800int parse_merge_opt(struct merge_options *o, const char *s)
1801{
1802        if (!s || !*s)
1803                return -1;
1804        if (!strcmp(s, "ours"))
1805                o->recursive_variant = MERGE_RECURSIVE_OURS;
1806        else if (!strcmp(s, "theirs"))
1807                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1808        else if (!strcmp(s, "subtree"))
1809                o->subtree_shift = "";
1810        else if (!prefixcmp(s, "subtree="))
1811                o->subtree_shift = s + strlen("subtree=");
1812        else if (!strcmp(s, "patience"))
1813                o->xdl_opts |= XDF_PATIENCE_DIFF;
1814        else if (!strcmp(s, "ignore-space-change"))
1815                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1816        else if (!strcmp(s, "ignore-all-space"))
1817                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1818        else if (!strcmp(s, "ignore-space-at-eol"))
1819                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1820        else if (!strcmp(s, "renormalize"))
1821                o->renormalize = 1;
1822        else if (!strcmp(s, "no-renormalize"))
1823                o->renormalize = 0;
1824        else if (!prefixcmp(s, "rename-threshold=")) {
1825                const char *score = s + strlen("rename-threshold=");
1826                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1827                        return -1;
1828        }
1829        else
1830                return -1;
1831        return 0;
1832}