merge-recursive.con commit fast-import: prevent producing bad delta (8fb3ad7)
   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", 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        struct pathspec match_all;
 277        init_pathspec(&match_all, NULL);
 278        if (read_tree_recursive(tree, "", 0, 0, &match_all, save_files_dirs, o))
 279                return 0;
 280        n = o->current_file_set.nr + o->current_directory_set.nr;
 281        return n;
 282}
 283
 284/*
 285 * Returns an index_entry instance which doesn't have to correspond to
 286 * a real cache entry in Git's index.
 287 */
 288static struct stage_data *insert_stage_data(const char *path,
 289                struct tree *o, struct tree *a, struct tree *b,
 290                struct string_list *entries)
 291{
 292        struct string_list_item *item;
 293        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 294        get_tree_entry(o->object.sha1, path,
 295                        e->stages[1].sha, &e->stages[1].mode);
 296        get_tree_entry(a->object.sha1, path,
 297                        e->stages[2].sha, &e->stages[2].mode);
 298        get_tree_entry(b->object.sha1, path,
 299                        e->stages[3].sha, &e->stages[3].mode);
 300        item = string_list_insert(entries, path);
 301        item->util = e;
 302        return e;
 303}
 304
 305/*
 306 * Create a dictionary mapping file names to stage_data objects. The
 307 * dictionary contains one entry for every path with a non-zero stage entry.
 308 */
 309static struct string_list *get_unmerged(void)
 310{
 311        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 312        int i;
 313
 314        unmerged->strdup_strings = 1;
 315
 316        for (i = 0; i < active_nr; i++) {
 317                struct string_list_item *item;
 318                struct stage_data *e;
 319                struct cache_entry *ce = active_cache[i];
 320                if (!ce_stage(ce))
 321                        continue;
 322
 323                item = string_list_lookup(unmerged, ce->name);
 324                if (!item) {
 325                        item = string_list_insert(unmerged, ce->name);
 326                        item->util = xcalloc(1, sizeof(struct stage_data));
 327                }
 328                e = item->util;
 329                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 330                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 331        }
 332
 333        return unmerged;
 334}
 335
 336static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 337                                                      struct string_list *entries)
 338{
 339        /* If there are D/F conflicts, and the paths currently exist
 340         * in the working copy as a file, we want to remove them to
 341         * make room for the corresponding directory.  Such paths will
 342         * later be processed in process_df_entry() at the end.  If
 343         * the corresponding directory ends up being removed by the
 344         * merge, then the file will be reinstated at that time;
 345         * otherwise, if the file is not supposed to be removed by the
 346         * merge, the contents of the file will be placed in another
 347         * unique filename.
 348         *
 349         * NOTE: This function relies on the fact that entries for a
 350         * D/F conflict will appear adjacent in the index, with the
 351         * entries for the file appearing before entries for paths
 352         * below the corresponding directory.
 353         */
 354        const char *last_file = NULL;
 355        int last_len = 0;
 356        int i;
 357
 358        for (i = 0; i < entries->nr; i++) {
 359                const char *path = entries->items[i].string;
 360                int len = strlen(path);
 361                struct stage_data *e = entries->items[i].util;
 362
 363                /*
 364                 * Check if last_file & path correspond to a D/F conflict;
 365                 * i.e. whether path is last_file+'/'+<something>.
 366                 * If so, remove last_file to make room for path and friends.
 367                 */
 368                if (last_file &&
 369                    len > last_len &&
 370                    memcmp(path, last_file, last_len) == 0 &&
 371                    path[last_len] == '/') {
 372                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 373                        unlink(last_file);
 374                }
 375
 376                /*
 377                 * Determine whether path could exist as a file in the
 378                 * working directory as a possible D/F conflict.  This
 379                 * will only occur when it exists in stage 2 as a
 380                 * file.
 381                 */
 382                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 383                        last_file = path;
 384                        last_len = len;
 385                } else {
 386                        last_file = NULL;
 387                }
 388        }
 389}
 390
 391struct rename {
 392        struct diff_filepair *pair;
 393        struct stage_data *src_entry;
 394        struct stage_data *dst_entry;
 395        unsigned processed:1;
 396};
 397
 398/*
 399 * Get information of all renames which occurred between 'o_tree' and
 400 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 401 * 'b_tree') to be able to associate the correct cache entries with
 402 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 403 */
 404static struct string_list *get_renames(struct merge_options *o,
 405                                       struct tree *tree,
 406                                       struct tree *o_tree,
 407                                       struct tree *a_tree,
 408                                       struct tree *b_tree,
 409                                       struct string_list *entries)
 410{
 411        int i;
 412        struct string_list *renames;
 413        struct diff_options opts;
 414
 415        renames = xcalloc(1, sizeof(struct string_list));
 416        diff_setup(&opts);
 417        DIFF_OPT_SET(&opts, RECURSIVE);
 418        opts.detect_rename = DIFF_DETECT_RENAME;
 419        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 420                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 421                            1000;
 422        opts.rename_score = o->rename_score;
 423        opts.show_rename_progress = o->show_rename_progress;
 424        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 425        if (diff_setup_done(&opts) < 0)
 426                die("diff setup failed");
 427        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 428        diffcore_std(&opts);
 429        if (opts.needed_rename_limit > o->needed_rename_limit)
 430                o->needed_rename_limit = opts.needed_rename_limit;
 431        for (i = 0; i < diff_queued_diff.nr; ++i) {
 432                struct string_list_item *item;
 433                struct rename *re;
 434                struct diff_filepair *pair = diff_queued_diff.queue[i];
 435                if (pair->status != 'R') {
 436                        diff_free_filepair(pair);
 437                        continue;
 438                }
 439                re = xmalloc(sizeof(*re));
 440                re->processed = 0;
 441                re->pair = pair;
 442                item = string_list_lookup(entries, re->pair->one->path);
 443                if (!item)
 444                        re->src_entry = insert_stage_data(re->pair->one->path,
 445                                        o_tree, a_tree, b_tree, entries);
 446                else
 447                        re->src_entry = item->util;
 448
 449                item = string_list_lookup(entries, re->pair->two->path);
 450                if (!item)
 451                        re->dst_entry = insert_stage_data(re->pair->two->path,
 452                                        o_tree, a_tree, b_tree, entries);
 453                else
 454                        re->dst_entry = item->util;
 455                item = string_list_insert(renames, pair->one->path);
 456                item->util = re;
 457        }
 458        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 459        diff_queued_diff.nr = 0;
 460        diff_flush(&opts);
 461        return renames;
 462}
 463
 464static int update_stages_options(const char *path, struct diff_filespec *o,
 465                         struct diff_filespec *a, struct diff_filespec *b,
 466                         int clear, int options)
 467{
 468        if (clear)
 469                if (remove_file_from_cache(path))
 470                        return -1;
 471        if (o)
 472                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 473                        return -1;
 474        if (a)
 475                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 476                        return -1;
 477        if (b)
 478                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 479                        return -1;
 480        return 0;
 481}
 482
 483static int update_stages(const char *path, struct diff_filespec *o,
 484                         struct diff_filespec *a, struct diff_filespec *b,
 485                         int clear)
 486{
 487        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 488        return update_stages_options(path, o, a, b, clear, options);
 489}
 490
 491static int update_stages_and_entry(const char *path,
 492                                   struct stage_data *entry,
 493                                   struct diff_filespec *o,
 494                                   struct diff_filespec *a,
 495                                   struct diff_filespec *b,
 496                                   int clear)
 497{
 498        int options;
 499
 500        entry->processed = 0;
 501        entry->stages[1].mode = o->mode;
 502        entry->stages[2].mode = a->mode;
 503        entry->stages[3].mode = b->mode;
 504        hashcpy(entry->stages[1].sha, o->sha1);
 505        hashcpy(entry->stages[2].sha, a->sha1);
 506        hashcpy(entry->stages[3].sha, b->sha1);
 507        options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 508        return update_stages_options(path, o, a, b, clear, options);
 509}
 510
 511static int remove_file(struct merge_options *o, int clean,
 512                       const char *path, int no_wd)
 513{
 514        int update_cache = o->call_depth || clean;
 515        int update_working_directory = !o->call_depth && !no_wd;
 516
 517        if (update_cache) {
 518                if (remove_file_from_cache(path))
 519                        return -1;
 520        }
 521        if (update_working_directory) {
 522                if (remove_path(path))
 523                        return -1;
 524        }
 525        return 0;
 526}
 527
 528static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 529{
 530        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 531        int suffix = 0;
 532        struct stat st;
 533        char *p = newpath + strlen(path);
 534        strcpy(newpath, path);
 535        *(p++) = '~';
 536        strcpy(p, branch);
 537        for (; *p; ++p)
 538                if ('/' == *p)
 539                        *p = '_';
 540        while (string_list_has_string(&o->current_file_set, newpath) ||
 541               string_list_has_string(&o->current_directory_set, newpath) ||
 542               lstat(newpath, &st) == 0)
 543                sprintf(p, "_%d", suffix++);
 544
 545        string_list_insert(&o->current_file_set, newpath);
 546        return newpath;
 547}
 548
 549static void flush_buffer(int fd, const char *buf, unsigned long size)
 550{
 551        while (size > 0) {
 552                long ret = write_in_full(fd, buf, size);
 553                if (ret < 0) {
 554                        /* Ignore epipe */
 555                        if (errno == EPIPE)
 556                                break;
 557                        die_errno("merge-recursive");
 558                } else if (!ret) {
 559                        die("merge-recursive: disk full?");
 560                }
 561                size -= ret;
 562                buf += ret;
 563        }
 564}
 565
 566static int would_lose_untracked(const char *path)
 567{
 568        int pos = cache_name_pos(path, strlen(path));
 569
 570        if (pos < 0)
 571                pos = -1 - pos;
 572        while (pos < active_nr &&
 573               !strcmp(path, active_cache[pos]->name)) {
 574                /*
 575                 * If stage #0, it is definitely tracked.
 576                 * If it has stage #2 then it was tracked
 577                 * before this merge started.  All other
 578                 * cases the path was not tracked.
 579                 */
 580                switch (ce_stage(active_cache[pos])) {
 581                case 0:
 582                case 2:
 583                        return 0;
 584                }
 585                pos++;
 586        }
 587        return file_exists(path);
 588}
 589
 590static int make_room_for_path(const char *path)
 591{
 592        int status;
 593        const char *msg = "failed to create path '%s'%s";
 594
 595        status = safe_create_leading_directories_const(path);
 596        if (status) {
 597                if (status == -3) {
 598                        /* something else exists */
 599                        error(msg, path, ": perhaps a D/F conflict?");
 600                        return -1;
 601                }
 602                die(msg, path, "");
 603        }
 604
 605        /*
 606         * Do not unlink a file in the work tree if we are not
 607         * tracking it.
 608         */
 609        if (would_lose_untracked(path))
 610                return error("refusing to lose untracked file at '%s'",
 611                             path);
 612
 613        /* Successful unlink is good.. */
 614        if (!unlink(path))
 615                return 0;
 616        /* .. and so is no existing file */
 617        if (errno == ENOENT)
 618                return 0;
 619        /* .. but not some other error (who really cares what?) */
 620        return error(msg, path, ": perhaps a D/F conflict?");
 621}
 622
 623static void update_file_flags(struct merge_options *o,
 624                              const unsigned char *sha,
 625                              unsigned mode,
 626                              const char *path,
 627                              int update_cache,
 628                              int update_wd)
 629{
 630        if (o->call_depth)
 631                update_wd = 0;
 632
 633        if (update_wd) {
 634                enum object_type type;
 635                void *buf;
 636                unsigned long size;
 637
 638                if (S_ISGITLINK(mode)) {
 639                        /*
 640                         * We may later decide to recursively descend into
 641                         * the submodule directory and update its index
 642                         * and/or work tree, but we do not do that now.
 643                         */
 644                        update_wd = 0;
 645                        goto update_index;
 646                }
 647
 648                buf = read_sha1_file(sha, &type, &size);
 649                if (!buf)
 650                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 651                if (type != OBJ_BLOB)
 652                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 653                if (S_ISREG(mode)) {
 654                        struct strbuf strbuf = STRBUF_INIT;
 655                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 656                                free(buf);
 657                                size = strbuf.len;
 658                                buf = strbuf_detach(&strbuf, NULL);
 659                        }
 660                }
 661
 662                if (make_room_for_path(path) < 0) {
 663                        update_wd = 0;
 664                        free(buf);
 665                        goto update_index;
 666                }
 667                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 668                        int fd;
 669                        if (mode & 0100)
 670                                mode = 0777;
 671                        else
 672                                mode = 0666;
 673                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 674                        if (fd < 0)
 675                                die_errno("failed to open '%s'", path);
 676                        flush_buffer(fd, buf, size);
 677                        close(fd);
 678                } else if (S_ISLNK(mode)) {
 679                        char *lnk = xmemdupz(buf, size);
 680                        safe_create_leading_directories_const(path);
 681                        unlink(path);
 682                        if (symlink(lnk, path))
 683                                die_errno("failed to symlink '%s'", path);
 684                        free(lnk);
 685                } else
 686                        die("do not know what to do with %06o %s '%s'",
 687                            mode, sha1_to_hex(sha), path);
 688                free(buf);
 689        }
 690 update_index:
 691        if (update_cache)
 692                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 693}
 694
 695static void update_file(struct merge_options *o,
 696                        int clean,
 697                        const unsigned char *sha,
 698                        unsigned mode,
 699                        const char *path)
 700{
 701        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 702}
 703
 704/* Low level file merging, update and removal */
 705
 706struct merge_file_info {
 707        unsigned char sha[20];
 708        unsigned mode;
 709        unsigned clean:1,
 710                 merge:1;
 711};
 712
 713static int merge_3way(struct merge_options *o,
 714                      mmbuffer_t *result_buf,
 715                      struct diff_filespec *one,
 716                      struct diff_filespec *a,
 717                      struct diff_filespec *b,
 718                      const char *branch1,
 719                      const char *branch2)
 720{
 721        mmfile_t orig, src1, src2;
 722        struct ll_merge_options ll_opts = {0};
 723        char *base_name, *name1, *name2;
 724        int merge_status;
 725
 726        ll_opts.renormalize = o->renormalize;
 727        ll_opts.xdl_opts = o->xdl_opts;
 728
 729        if (o->call_depth) {
 730                ll_opts.virtual_ancestor = 1;
 731                ll_opts.variant = 0;
 732        } else {
 733                switch (o->recursive_variant) {
 734                case MERGE_RECURSIVE_OURS:
 735                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 736                        break;
 737                case MERGE_RECURSIVE_THEIRS:
 738                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 739                        break;
 740                default:
 741                        ll_opts.variant = 0;
 742                        break;
 743                }
 744        }
 745
 746        if (strcmp(a->path, b->path) ||
 747            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 748                base_name = o->ancestor == NULL ? NULL :
 749                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 750                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 751                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 752        } else {
 753                base_name = o->ancestor == NULL ? NULL :
 754                        xstrdup(mkpath("%s", o->ancestor));
 755                name1 = xstrdup(mkpath("%s", branch1));
 756                name2 = xstrdup(mkpath("%s", branch2));
 757        }
 758
 759        read_mmblob(&orig, one->sha1);
 760        read_mmblob(&src1, a->sha1);
 761        read_mmblob(&src2, b->sha1);
 762
 763        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 764                                &src1, name1, &src2, name2, &ll_opts);
 765
 766        free(name1);
 767        free(name2);
 768        free(orig.ptr);
 769        free(src1.ptr);
 770        free(src2.ptr);
 771        return merge_status;
 772}
 773
 774static struct merge_file_info merge_file(struct merge_options *o,
 775                                         struct diff_filespec *one,
 776                                         struct diff_filespec *a,
 777                                         struct diff_filespec *b,
 778                                         const char *branch1,
 779                                         const char *branch2)
 780{
 781        struct merge_file_info result;
 782        result.merge = 0;
 783        result.clean = 1;
 784
 785        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 786                result.clean = 0;
 787                if (S_ISREG(a->mode)) {
 788                        result.mode = a->mode;
 789                        hashcpy(result.sha, a->sha1);
 790                } else {
 791                        result.mode = b->mode;
 792                        hashcpy(result.sha, b->sha1);
 793                }
 794        } else {
 795                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 796                        result.merge = 1;
 797
 798                /*
 799                 * Merge modes
 800                 */
 801                if (a->mode == b->mode || a->mode == one->mode)
 802                        result.mode = b->mode;
 803                else {
 804                        result.mode = a->mode;
 805                        if (b->mode != one->mode) {
 806                                result.clean = 0;
 807                                result.merge = 1;
 808                        }
 809                }
 810
 811                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 812                        hashcpy(result.sha, b->sha1);
 813                else if (sha_eq(b->sha1, one->sha1))
 814                        hashcpy(result.sha, a->sha1);
 815                else if (S_ISREG(a->mode)) {
 816                        mmbuffer_t result_buf;
 817                        int merge_status;
 818
 819                        merge_status = merge_3way(o, &result_buf, one, a, b,
 820                                                  branch1, branch2);
 821
 822                        if ((merge_status < 0) || !result_buf.ptr)
 823                                die("Failed to execute internal merge");
 824
 825                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 826                                            blob_type, result.sha))
 827                                die("Unable to add %s to database",
 828                                    a->path);
 829
 830                        free(result_buf.ptr);
 831                        result.clean = (merge_status == 0);
 832                } else if (S_ISGITLINK(a->mode)) {
 833                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 834                                                       a->sha1, b->sha1);
 835                } else if (S_ISLNK(a->mode)) {
 836                        hashcpy(result.sha, a->sha1);
 837
 838                        if (!sha_eq(a->sha1, b->sha1))
 839                                result.clean = 0;
 840                } else {
 841                        die("unsupported object type in the tree");
 842                }
 843        }
 844
 845        return result;
 846}
 847
 848static void conflict_rename_delete(struct merge_options *o,
 849                                   struct diff_filepair *pair,
 850                                   const char *rename_branch,
 851                                   const char *other_branch)
 852{
 853        char *dest_name = pair->two->path;
 854        int df_conflict = 0;
 855        struct stat st;
 856
 857        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 858               "and deleted in %s",
 859               pair->one->path, pair->two->path, rename_branch,
 860               other_branch);
 861        if (!o->call_depth)
 862                update_stages(dest_name, NULL,
 863                              rename_branch == o->branch1 ? pair->two : NULL,
 864                              rename_branch == o->branch1 ? NULL : pair->two,
 865                              1);
 866        if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 867                dest_name = unique_path(o, dest_name, rename_branch);
 868                df_conflict = 1;
 869        }
 870        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 871        if (df_conflict)
 872                free(dest_name);
 873}
 874
 875static void conflict_rename_rename_1to2(struct merge_options *o,
 876                                        struct diff_filepair *pair1,
 877                                        const char *branch1,
 878                                        struct diff_filepair *pair2,
 879                                        const char *branch2)
 880{
 881        /* One file was renamed in both branches, but to different names. */
 882        char *del[2];
 883        int delp = 0;
 884        const char *ren1_dst = pair1->two->path;
 885        const char *ren2_dst = pair2->two->path;
 886        const char *dst_name1 = ren1_dst;
 887        const char *dst_name2 = ren2_dst;
 888        struct stat st;
 889        if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 890                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 891                output(o, 1, "%s is a directory in %s adding as %s instead",
 892                       ren1_dst, branch2, dst_name1);
 893        }
 894        if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 895                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 896                output(o, 1, "%s is a directory in %s adding as %s instead",
 897                       ren2_dst, branch1, dst_name2);
 898        }
 899        if (o->call_depth) {
 900                remove_file_from_cache(dst_name1);
 901                remove_file_from_cache(dst_name2);
 902                /*
 903                 * Uncomment to leave the conflicting names in the resulting tree
 904                 *
 905                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 906                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 907                 */
 908        } else {
 909                update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 910                update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 911
 912                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 913                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 914        }
 915        while (delp--)
 916                free(del[delp]);
 917}
 918
 919static void conflict_rename_rename_2to1(struct merge_options *o,
 920                                        struct rename *ren1,
 921                                        const char *branch1,
 922                                        struct rename *ren2,
 923                                        const char *branch2)
 924{
 925        /* Two files were renamed to the same thing. */
 926        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 927        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 928        output(o, 1, "Renaming %s to %s and %s to %s instead",
 929               ren1->pair->one->path, new_path1,
 930               ren2->pair->one->path, new_path2);
 931        remove_file(o, 0, ren1->pair->two->path, 0);
 932        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 933        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 934        free(new_path2);
 935        free(new_path1);
 936}
 937
 938static int process_renames(struct merge_options *o,
 939                           struct string_list *a_renames,
 940                           struct string_list *b_renames)
 941{
 942        int clean_merge = 1, i, j;
 943        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 944        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 945        const struct rename *sre;
 946
 947        for (i = 0; i < a_renames->nr; i++) {
 948                sre = a_renames->items[i].util;
 949                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 950                        = sre->dst_entry;
 951        }
 952        for (i = 0; i < b_renames->nr; i++) {
 953                sre = b_renames->items[i].util;
 954                string_list_insert(&b_by_dst, sre->pair->two->path)->util
 955                        = sre->dst_entry;
 956        }
 957
 958        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 959                struct string_list *renames1, *renames2Dst;
 960                struct rename *ren1 = NULL, *ren2 = NULL;
 961                const char *branch1, *branch2;
 962                const char *ren1_src, *ren1_dst;
 963
 964                if (i >= a_renames->nr) {
 965                        ren2 = b_renames->items[j++].util;
 966                } else if (j >= b_renames->nr) {
 967                        ren1 = a_renames->items[i++].util;
 968                } else {
 969                        int compare = strcmp(a_renames->items[i].string,
 970                                             b_renames->items[j].string);
 971                        if (compare <= 0)
 972                                ren1 = a_renames->items[i++].util;
 973                        if (compare >= 0)
 974                                ren2 = b_renames->items[j++].util;
 975                }
 976
 977                /* TODO: refactor, so that 1/2 are not needed */
 978                if (ren1) {
 979                        renames1 = a_renames;
 980                        renames2Dst = &b_by_dst;
 981                        branch1 = o->branch1;
 982                        branch2 = o->branch2;
 983                } else {
 984                        struct rename *tmp;
 985                        renames1 = b_renames;
 986                        renames2Dst = &a_by_dst;
 987                        branch1 = o->branch2;
 988                        branch2 = o->branch1;
 989                        tmp = ren2;
 990                        ren2 = ren1;
 991                        ren1 = tmp;
 992                }
 993
 994                ren1->dst_entry->processed = 1;
 995                ren1->src_entry->processed = 1;
 996
 997                if (ren1->processed)
 998                        continue;
 999                ren1->processed = 1;
1000
1001                ren1_src = ren1->pair->one->path;
1002                ren1_dst = ren1->pair->two->path;
1003
1004                if (ren2) {
1005                        const char *ren2_src = ren2->pair->one->path;
1006                        const char *ren2_dst = ren2->pair->two->path;
1007                        /* Renamed in 1 and renamed in 2 */
1008                        if (strcmp(ren1_src, ren2_src) != 0)
1009                                die("ren1.src != ren2.src");
1010                        ren2->dst_entry->processed = 1;
1011                        ren2->processed = 1;
1012                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1013                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1014                                                              ren1->pair,
1015                                                              ren2->pair,
1016                                                              branch1,
1017                                                              branch2,
1018                                                              ren1->dst_entry,
1019                                                              ren2->dst_entry);
1020                        } else {
1021                                remove_file(o, 1, ren1_src, 1);
1022                                update_stages_and_entry(ren1_dst,
1023                                                        ren1->dst_entry,
1024                                                        ren1->pair->one,
1025                                                        ren1->pair->two,
1026                                                        ren2->pair->two,
1027                                                        1 /* clear */);
1028                        }
1029                } else {
1030                        /* Renamed in 1, maybe changed in 2 */
1031                        struct string_list_item *item;
1032                        /* we only use sha1 and mode of these */
1033                        struct diff_filespec src_other, dst_other;
1034                        int try_merge;
1035
1036                        /*
1037                         * unpack_trees loads entries from common-commit
1038                         * into stage 1, from head-commit into stage 2, and
1039                         * from merge-commit into stage 3.  We keep track
1040                         * of which side corresponds to the rename.
1041                         */
1042                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1043                        int other_stage =   a_renames == renames1 ? 3 : 2;
1044
1045                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1046
1047                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1048                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1049                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1050                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1051                        try_merge = 0;
1052
1053                        if (sha_eq(src_other.sha1, null_sha1)) {
1054                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1055                                        ren1->dst_entry->processed = 0;
1056                                        setup_rename_df_conflict_info(RENAME_DELETE,
1057                                                                      ren1->pair,
1058                                                                      NULL,
1059                                                                      branch1,
1060                                                                      branch2,
1061                                                                      ren1->dst_entry,
1062                                                                      NULL);
1063                                } else {
1064                                        clean_merge = 0;
1065                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1066                                }
1067                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1068                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1069                                /* Added file on the other side
1070                                   identical to the file being
1071                                   renamed: clean merge */
1072                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1073                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1074                                const char *new_path;
1075                                clean_merge = 0;
1076                                try_merge = 1;
1077                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1078                                       "%s added in %s",
1079                                       ren1_src, ren1_dst, branch1,
1080                                       ren1_dst, branch2);
1081                                if (o->call_depth) {
1082                                        struct merge_file_info mfi;
1083                                        struct diff_filespec one, a, b;
1084
1085                                        one.path = a.path = b.path =
1086                                                (char *)ren1_dst;
1087                                        hashcpy(one.sha1, null_sha1);
1088                                        one.mode = 0;
1089                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1090                                        a.mode = ren1->pair->two->mode;
1091                                        hashcpy(b.sha1, dst_other.sha1);
1092                                        b.mode = dst_other.mode;
1093                                        mfi = merge_file(o, &one, &a, &b,
1094                                                         branch1,
1095                                                         branch2);
1096                                        output(o, 1, "Adding merged %s", ren1_dst);
1097                                        update_file(o, 0,
1098                                                    mfi.sha,
1099                                                    mfi.mode,
1100                                                    ren1_dst);
1101                                        try_merge = 0;
1102                                } else {
1103                                        new_path = unique_path(o, ren1_dst, branch2);
1104                                        output(o, 1, "Adding as %s instead", new_path);
1105                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1106                                }
1107                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1108                                ren2 = item->util;
1109                                clean_merge = 0;
1110                                ren2->processed = 1;
1111                                output(o, 1, "CONFLICT (rename/rename): "
1112                                       "Rename %s->%s in %s. "
1113                                       "Rename %s->%s in %s",
1114                                       ren1_src, ren1_dst, branch1,
1115                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1116                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1117                        } else
1118                                try_merge = 1;
1119
1120                        if (try_merge) {
1121                                struct diff_filespec *one, *a, *b;
1122                                src_other.path = (char *)ren1_src;
1123
1124                                one = ren1->pair->one;
1125                                if (a_renames == renames1) {
1126                                        a = ren1->pair->two;
1127                                        b = &src_other;
1128                                } else {
1129                                        b = ren1->pair->two;
1130                                        a = &src_other;
1131                                }
1132                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1133                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1134                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1135                                                                      ren1->pair,
1136                                                                      NULL,
1137                                                                      branch1,
1138                                                                      NULL,
1139                                                                      ren1->dst_entry,
1140                                                                      NULL);
1141                                }
1142                        }
1143                }
1144        }
1145        string_list_clear(&a_by_dst, 0);
1146        string_list_clear(&b_by_dst, 0);
1147
1148        return clean_merge;
1149}
1150
1151static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1152{
1153        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1154}
1155
1156static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1157{
1158        void *buf;
1159        enum object_type type;
1160        unsigned long size;
1161        buf = read_sha1_file(sha1, &type, &size);
1162        if (!buf)
1163                return error("cannot read object %s", sha1_to_hex(sha1));
1164        if (type != OBJ_BLOB) {
1165                free(buf);
1166                return error("object %s is not a blob", sha1_to_hex(sha1));
1167        }
1168        strbuf_attach(dst, buf, size, size + 1);
1169        return 0;
1170}
1171
1172static int blob_unchanged(const unsigned char *o_sha,
1173                          const unsigned char *a_sha,
1174                          int renormalize, const char *path)
1175{
1176        struct strbuf o = STRBUF_INIT;
1177        struct strbuf a = STRBUF_INIT;
1178        int ret = 0; /* assume changed for safety */
1179
1180        if (sha_eq(o_sha, a_sha))
1181                return 1;
1182        if (!renormalize)
1183                return 0;
1184
1185        assert(o_sha && a_sha);
1186        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1187                goto error_return;
1188        /*
1189         * Note: binary | is used so that both renormalizations are
1190         * performed.  Comparison can be skipped if both files are
1191         * unchanged since their sha1s have already been compared.
1192         */
1193        if (renormalize_buffer(path, o.buf, o.len, &o) |
1194            renormalize_buffer(path, a.buf, o.len, &a))
1195                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1196
1197error_return:
1198        strbuf_release(&o);
1199        strbuf_release(&a);
1200        return ret;
1201}
1202
1203static void handle_delete_modify(struct merge_options *o,
1204                                 const char *path,
1205                                 const char *new_path,
1206                                 unsigned char *a_sha, int a_mode,
1207                                 unsigned char *b_sha, int b_mode)
1208{
1209        if (!a_sha) {
1210                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1211                       "and modified in %s. Version %s of %s left in tree%s%s.",
1212                       path, o->branch1,
1213                       o->branch2, o->branch2, path,
1214                       path == new_path ? "" : " at ",
1215                       path == new_path ? "" : new_path);
1216                update_file(o, 0, b_sha, b_mode, new_path);
1217        } else {
1218                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1219                       "and modified in %s. Version %s of %s left in tree%s%s.",
1220                       path, o->branch2,
1221                       o->branch1, o->branch1, path,
1222                       path == new_path ? "" : " at ",
1223                       path == new_path ? "" : new_path);
1224                update_file(o, 0, a_sha, a_mode, new_path);
1225        }
1226}
1227
1228static int merge_content(struct merge_options *o,
1229                         const char *path,
1230                         unsigned char *o_sha, int o_mode,
1231                         unsigned char *a_sha, int a_mode,
1232                         unsigned char *b_sha, int b_mode,
1233                         const char *df_rename_conflict_branch)
1234{
1235        const char *reason = "content";
1236        struct merge_file_info mfi;
1237        struct diff_filespec one, a, b;
1238        struct stat st;
1239        unsigned df_conflict_remains = 0;
1240
1241        if (!o_sha) {
1242                reason = "add/add";
1243                o_sha = (unsigned char *)null_sha1;
1244        }
1245        one.path = a.path = b.path = (char *)path;
1246        hashcpy(one.sha1, o_sha);
1247        one.mode = o_mode;
1248        hashcpy(a.sha1, a_sha);
1249        a.mode = a_mode;
1250        hashcpy(b.sha1, b_sha);
1251        b.mode = b_mode;
1252
1253        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1254        if (df_rename_conflict_branch &&
1255            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1256                df_conflict_remains = 1;
1257        }
1258
1259        if (mfi.clean && !df_conflict_remains &&
1260            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1261                output(o, 3, "Skipped %s (merged same as existing)", path);
1262        else
1263                output(o, 2, "Auto-merging %s", path);
1264
1265        if (!mfi.clean) {
1266                if (S_ISGITLINK(mfi.mode))
1267                        reason = "submodule";
1268                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1269                                reason, path);
1270        }
1271
1272        if (df_conflict_remains) {
1273                const char *new_path;
1274                update_file_flags(o, mfi.sha, mfi.mode, path,
1275                                  o->call_depth || mfi.clean, 0);
1276                new_path = unique_path(o, path, df_rename_conflict_branch);
1277                mfi.clean = 0;
1278                output(o, 1, "Adding as %s instead", new_path);
1279                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1280        } else {
1281                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1282        }
1283        return mfi.clean;
1284
1285}
1286
1287/* Per entry merge function */
1288static int process_entry(struct merge_options *o,
1289                         const char *path, struct stage_data *entry)
1290{
1291        /*
1292        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1293        print_index_entry("\tpath: ", entry);
1294        */
1295        int clean_merge = 1;
1296        int normalize = o->renormalize;
1297        unsigned o_mode = entry->stages[1].mode;
1298        unsigned a_mode = entry->stages[2].mode;
1299        unsigned b_mode = entry->stages[3].mode;
1300        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1301        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1302        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1303
1304        if (entry->rename_df_conflict_info)
1305                return 1; /* Such cases are handled elsewhere. */
1306
1307        entry->processed = 1;
1308        if (o_sha && (!a_sha || !b_sha)) {
1309                /* Case A: Deleted in one */
1310                if ((!a_sha && !b_sha) ||
1311                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1312                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1313                        /* Deleted in both or deleted in one and
1314                         * unchanged in the other */
1315                        if (a_sha)
1316                                output(o, 2, "Removing %s", path);
1317                        /* do not touch working file if it did not exist */
1318                        remove_file(o, 1, path, !a_sha);
1319                } else if (string_list_has_string(&o->current_directory_set,
1320                                                  path)) {
1321                        entry->processed = 0;
1322                        return 1; /* Assume clean until processed */
1323                } else {
1324                        /* Deleted in one and changed in the other */
1325                        clean_merge = 0;
1326                        handle_delete_modify(o, path, path,
1327                                             a_sha, a_mode, b_sha, b_mode);
1328                }
1329
1330        } else if ((!o_sha && a_sha && !b_sha) ||
1331                   (!o_sha && !a_sha && b_sha)) {
1332                /* Case B: Added in one. */
1333                unsigned mode;
1334                const unsigned char *sha;
1335
1336                if (a_sha) {
1337                        mode = a_mode;
1338                        sha = a_sha;
1339                } else {
1340                        mode = b_mode;
1341                        sha = b_sha;
1342                }
1343                if (string_list_has_string(&o->current_directory_set, path)) {
1344                        /* Handle D->F conflicts after all subfiles */
1345                        entry->processed = 0;
1346                        return 1; /* Assume clean until processed */
1347                } else {
1348                        output(o, 2, "Adding %s", path);
1349                        update_file(o, 1, sha, mode, path);
1350                }
1351        } else if (a_sha && b_sha) {
1352                /* Case C: Added in both (check for same permissions) and */
1353                /* case D: Modified in both, but differently. */
1354                clean_merge = merge_content(o, path,
1355                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1356                                            NULL);
1357        } else if (!o_sha && !a_sha && !b_sha) {
1358                /*
1359                 * this entry was deleted altogether. a_mode == 0 means
1360                 * we had that path and want to actively remove it.
1361                 */
1362                remove_file(o, 1, path, !a_mode);
1363        } else
1364                die("Fatal merge failure, shouldn't happen.");
1365
1366        return clean_merge;
1367}
1368
1369/*
1370 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1371 * cases we can cleanly resolve D/F conflicts, process_entry() can
1372 * clean out all the files below the directory for us.  All D/F
1373 * conflict cases must be handled here at the end to make sure any
1374 * directories that can be cleaned out, are.
1375 *
1376 * Some rename conflicts may also be handled here that don't necessarily
1377 * involve D/F conflicts, since the code to handle them is generic enough
1378 * to handle those rename conflicts with or without D/F conflicts also
1379 * being involved.
1380 */
1381static int process_df_entry(struct merge_options *o,
1382                            const char *path, struct stage_data *entry)
1383{
1384        int clean_merge = 1;
1385        unsigned o_mode = entry->stages[1].mode;
1386        unsigned a_mode = entry->stages[2].mode;
1387        unsigned b_mode = entry->stages[3].mode;
1388        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1389        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1390        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1391        struct stat st;
1392
1393        entry->processed = 1;
1394        if (entry->rename_df_conflict_info) {
1395                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1396                char *src;
1397                switch (conflict_info->rename_type) {
1398                case RENAME_NORMAL:
1399                        clean_merge = merge_content(o, path,
1400                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1401                                                    conflict_info->branch1);
1402                        break;
1403                case RENAME_DELETE:
1404                        clean_merge = 0;
1405                        conflict_rename_delete(o, conflict_info->pair1,
1406                                               conflict_info->branch1,
1407                                               conflict_info->branch2);
1408                        break;
1409                case RENAME_ONE_FILE_TO_TWO:
1410                        src = conflict_info->pair1->one->path;
1411                        clean_merge = 0;
1412                        output(o, 1, "CONFLICT (rename/rename): "
1413                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1414                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1415                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1416                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1417                               o->call_depth ? " (left unresolved)" : "");
1418                        if (o->call_depth) {
1419                                remove_file_from_cache(src);
1420                                update_file(o, 0, conflict_info->pair1->one->sha1,
1421                                            conflict_info->pair1->one->mode, src);
1422                        }
1423                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1424                                                    conflict_info->branch1,
1425                                                    conflict_info->pair2,
1426                                                    conflict_info->branch2);
1427                        conflict_info->dst_entry2->processed = 1;
1428                        break;
1429                default:
1430                        entry->processed = 0;
1431                        break;
1432                }
1433        } else if (o_sha && (!a_sha || !b_sha)) {
1434                /* Modify/delete; deleted side may have put a directory in the way */
1435                const char *new_path = path;
1436                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1437                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1438                clean_merge = 0;
1439                handle_delete_modify(o, path, new_path,
1440                                     a_sha, a_mode, b_sha, b_mode);
1441        } else if (!o_sha && !!a_sha != !!b_sha) {
1442                /* directory -> (directory, file) */
1443                const char *add_branch;
1444                const char *other_branch;
1445                unsigned mode;
1446                const unsigned char *sha;
1447                const char *conf;
1448
1449                if (a_sha) {
1450                        add_branch = o->branch1;
1451                        other_branch = o->branch2;
1452                        mode = a_mode;
1453                        sha = a_sha;
1454                        conf = "file/directory";
1455                } else {
1456                        add_branch = o->branch2;
1457                        other_branch = o->branch1;
1458                        mode = b_mode;
1459                        sha = b_sha;
1460                        conf = "directory/file";
1461                }
1462                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1463                        const char *new_path = unique_path(o, path, add_branch);
1464                        clean_merge = 0;
1465                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1466                               "Adding %s as %s",
1467                               conf, path, other_branch, path, new_path);
1468                        update_file(o, 0, sha, mode, new_path);
1469                } else {
1470                        output(o, 2, "Adding %s", path);
1471                        update_file(o, 1, sha, mode, path);
1472                }
1473        } else {
1474                entry->processed = 0;
1475                return 1; /* not handled; assume clean until processed */
1476        }
1477
1478        return clean_merge;
1479}
1480
1481int merge_trees(struct merge_options *o,
1482                struct tree *head,
1483                struct tree *merge,
1484                struct tree *common,
1485                struct tree **result)
1486{
1487        int code, clean;
1488
1489        if (o->subtree_shift) {
1490                merge = shift_tree_object(head, merge, o->subtree_shift);
1491                common = shift_tree_object(head, common, o->subtree_shift);
1492        }
1493
1494        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1495                output(o, 0, "Already up-to-date!");
1496                *result = head;
1497                return 1;
1498        }
1499
1500        code = git_merge_trees(o->call_depth, common, head, merge);
1501
1502        if (code != 0) {
1503                if (show(o, 4) || o->call_depth)
1504                        die("merging of trees %s and %s failed",
1505                            sha1_to_hex(head->object.sha1),
1506                            sha1_to_hex(merge->object.sha1));
1507                else
1508                        exit(128);
1509        }
1510
1511        if (unmerged_cache()) {
1512                struct string_list *entries, *re_head, *re_merge;
1513                int i;
1514                string_list_clear(&o->current_file_set, 1);
1515                string_list_clear(&o->current_directory_set, 1);
1516                get_files_dirs(o, head);
1517                get_files_dirs(o, merge);
1518
1519                entries = get_unmerged();
1520                make_room_for_directories_of_df_conflicts(o, entries);
1521                re_head  = get_renames(o, head, common, head, merge, entries);
1522                re_merge = get_renames(o, merge, common, head, merge, entries);
1523                clean = process_renames(o, re_head, re_merge);
1524                for (i = 0; i < entries->nr; i++) {
1525                        const char *path = entries->items[i].string;
1526                        struct stage_data *e = entries->items[i].util;
1527                        if (!e->processed
1528                                && !process_entry(o, path, e))
1529                                clean = 0;
1530                }
1531                for (i = 0; i < entries->nr; i++) {
1532                        const char *path = entries->items[i].string;
1533                        struct stage_data *e = entries->items[i].util;
1534                        if (!e->processed
1535                                && !process_df_entry(o, path, e))
1536                                clean = 0;
1537                }
1538                for (i = 0; i < entries->nr; i++) {
1539                        struct stage_data *e = entries->items[i].util;
1540                        if (!e->processed)
1541                                die("Unprocessed path??? %s",
1542                                    entries->items[i].string);
1543                }
1544
1545                string_list_clear(re_merge, 0);
1546                string_list_clear(re_head, 0);
1547                string_list_clear(entries, 1);
1548
1549        }
1550        else
1551                clean = 1;
1552
1553        if (o->call_depth)
1554                *result = write_tree_from_memory(o);
1555
1556        return clean;
1557}
1558
1559static struct commit_list *reverse_commit_list(struct commit_list *list)
1560{
1561        struct commit_list *next = NULL, *current, *backup;
1562        for (current = list; current; current = backup) {
1563                backup = current->next;
1564                current->next = next;
1565                next = current;
1566        }
1567        return next;
1568}
1569
1570/*
1571 * Merge the commits h1 and h2, return the resulting virtual
1572 * commit object and a flag indicating the cleanness of the merge.
1573 */
1574int merge_recursive(struct merge_options *o,
1575                    struct commit *h1,
1576                    struct commit *h2,
1577                    struct commit_list *ca,
1578                    struct commit **result)
1579{
1580        struct commit_list *iter;
1581        struct commit *merged_common_ancestors;
1582        struct tree *mrtree = mrtree;
1583        int clean;
1584
1585        if (show(o, 4)) {
1586                output(o, 4, "Merging:");
1587                output_commit_title(o, h1);
1588                output_commit_title(o, h2);
1589        }
1590
1591        if (!ca) {
1592                ca = get_merge_bases(h1, h2, 1);
1593                ca = reverse_commit_list(ca);
1594        }
1595
1596        if (show(o, 5)) {
1597                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1598                for (iter = ca; iter; iter = iter->next)
1599                        output_commit_title(o, iter->item);
1600        }
1601
1602        merged_common_ancestors = pop_commit(&ca);
1603        if (merged_common_ancestors == NULL) {
1604                /* if there is no common ancestor, make an empty tree */
1605                struct tree *tree = xcalloc(1, sizeof(struct tree));
1606
1607                tree->object.parsed = 1;
1608                tree->object.type = OBJ_TREE;
1609                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1610                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1611        }
1612
1613        for (iter = ca; iter; iter = iter->next) {
1614                const char *saved_b1, *saved_b2;
1615                o->call_depth++;
1616                /*
1617                 * When the merge fails, the result contains files
1618                 * with conflict markers. The cleanness flag is
1619                 * ignored, it was never actually used, as result of
1620                 * merge_trees has always overwritten it: the committed
1621                 * "conflicts" were already resolved.
1622                 */
1623                discard_cache();
1624                saved_b1 = o->branch1;
1625                saved_b2 = o->branch2;
1626                o->branch1 = "Temporary merge branch 1";
1627                o->branch2 = "Temporary merge branch 2";
1628                merge_recursive(o, merged_common_ancestors, iter->item,
1629                                NULL, &merged_common_ancestors);
1630                o->branch1 = saved_b1;
1631                o->branch2 = saved_b2;
1632                o->call_depth--;
1633
1634                if (!merged_common_ancestors)
1635                        die("merge returned no commit");
1636        }
1637
1638        discard_cache();
1639        if (!o->call_depth)
1640                read_cache();
1641
1642        o->ancestor = "merged common ancestors";
1643        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1644                            &mrtree);
1645
1646        if (o->call_depth) {
1647                *result = make_virtual_commit(mrtree, "merged tree");
1648                commit_list_insert(h1, &(*result)->parents);
1649                commit_list_insert(h2, &(*result)->parents->next);
1650        }
1651        flush_output(o);
1652        if (show(o, 2))
1653                diff_warn_rename_limit("merge.renamelimit",
1654                                       o->needed_rename_limit, 0);
1655        return clean;
1656}
1657
1658static struct commit *get_ref(const unsigned char *sha1, const char *name)
1659{
1660        struct object *object;
1661
1662        object = deref_tag(parse_object(sha1), name, strlen(name));
1663        if (!object)
1664                return NULL;
1665        if (object->type == OBJ_TREE)
1666                return make_virtual_commit((struct tree*)object, name);
1667        if (object->type != OBJ_COMMIT)
1668                return NULL;
1669        if (parse_commit((struct commit *)object))
1670                return NULL;
1671        return (struct commit *)object;
1672}
1673
1674int merge_recursive_generic(struct merge_options *o,
1675                            const unsigned char *head,
1676                            const unsigned char *merge,
1677                            int num_base_list,
1678                            const unsigned char **base_list,
1679                            struct commit **result)
1680{
1681        int clean, index_fd;
1682        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1683        struct commit *head_commit = get_ref(head, o->branch1);
1684        struct commit *next_commit = get_ref(merge, o->branch2);
1685        struct commit_list *ca = NULL;
1686
1687        if (base_list) {
1688                int i;
1689                for (i = 0; i < num_base_list; ++i) {
1690                        struct commit *base;
1691                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1692                                return error("Could not parse object '%s'",
1693                                        sha1_to_hex(base_list[i]));
1694                        commit_list_insert(base, &ca);
1695                }
1696        }
1697
1698        index_fd = hold_locked_index(lock, 1);
1699        clean = merge_recursive(o, head_commit, next_commit, ca,
1700                        result);
1701        if (active_cache_changed &&
1702                        (write_cache(index_fd, active_cache, active_nr) ||
1703                         commit_locked_index(lock)))
1704                return error("Unable to write index.");
1705
1706        return clean ? 0 : 1;
1707}
1708
1709static int merge_recursive_config(const char *var, const char *value, void *cb)
1710{
1711        struct merge_options *o = cb;
1712        if (!strcmp(var, "merge.verbosity")) {
1713                o->verbosity = git_config_int(var, value);
1714                return 0;
1715        }
1716        if (!strcmp(var, "diff.renamelimit")) {
1717                o->diff_rename_limit = git_config_int(var, value);
1718                return 0;
1719        }
1720        if (!strcmp(var, "merge.renamelimit")) {
1721                o->merge_rename_limit = git_config_int(var, value);
1722                return 0;
1723        }
1724        return git_xmerge_config(var, value, cb);
1725}
1726
1727void init_merge_options(struct merge_options *o)
1728{
1729        memset(o, 0, sizeof(struct merge_options));
1730        o->verbosity = 2;
1731        o->buffer_output = 1;
1732        o->diff_rename_limit = -1;
1733        o->merge_rename_limit = -1;
1734        o->renormalize = 0;
1735        git_config(merge_recursive_config, o);
1736        if (getenv("GIT_MERGE_VERBOSITY"))
1737                o->verbosity =
1738                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1739        if (o->verbosity >= 5)
1740                o->buffer_output = 0;
1741        strbuf_init(&o->obuf, 0);
1742        memset(&o->current_file_set, 0, sizeof(struct string_list));
1743        o->current_file_set.strdup_strings = 1;
1744        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1745        o->current_directory_set.strdup_strings = 1;
1746}
1747
1748int parse_merge_opt(struct merge_options *o, const char *s)
1749{
1750        if (!s || !*s)
1751                return -1;
1752        if (!strcmp(s, "ours"))
1753                o->recursive_variant = MERGE_RECURSIVE_OURS;
1754        else if (!strcmp(s, "theirs"))
1755                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1756        else if (!strcmp(s, "subtree"))
1757                o->subtree_shift = "";
1758        else if (!prefixcmp(s, "subtree="))
1759                o->subtree_shift = s + strlen("subtree=");
1760        else if (!strcmp(s, "patience"))
1761                o->xdl_opts |= XDF_PATIENCE_DIFF;
1762        else if (!strcmp(s, "ignore-space-change"))
1763                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1764        else if (!strcmp(s, "ignore-all-space"))
1765                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1766        else if (!strcmp(s, "ignore-space-at-eol"))
1767                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1768        else if (!strcmp(s, "renormalize"))
1769                o->renormalize = 1;
1770        else if (!strcmp(s, "no-renormalize"))
1771                o->renormalize = 0;
1772        else if (!prefixcmp(s, "rename-threshold=")) {
1773                const char *score = s + strlen("rename-threshold=");
1774                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1775                        return -1;
1776        }
1777        else
1778                return -1;
1779        return 0;
1780}