368a498a51cfe2ad47cd1d9867c7d5a607981c58
   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 void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 335                                                      struct string_list *entries)
 336{
 337        /* If there are D/F conflicts, and the paths currently exist
 338         * in the working copy as a file, we want to remove them to
 339         * make room for the corresponding directory.  Such paths will
 340         * later be processed in process_df_entry() at the end.  If
 341         * the corresponding directory ends up being removed by the
 342         * merge, then the file will be reinstated at that time;
 343         * otherwise, if the file is not supposed to be removed by the
 344         * merge, the contents of the file will be placed in another
 345         * unique filename.
 346         *
 347         * NOTE: This function relies on the fact that entries for a
 348         * D/F conflict will appear adjacent in the index, with the
 349         * entries for the file appearing before entries for paths
 350         * below the corresponding directory.
 351         */
 352        const char *last_file = NULL;
 353        int last_len = 0;
 354        int i;
 355
 356        for (i = 0; i < entries->nr; i++) {
 357                const char *path = entries->items[i].string;
 358                int len = strlen(path);
 359                struct stage_data *e = entries->items[i].util;
 360
 361                /*
 362                 * Check if last_file & path correspond to a D/F conflict;
 363                 * i.e. whether path is last_file+'/'+<something>.
 364                 * If so, remove last_file to make room for path and friends.
 365                 */
 366                if (last_file &&
 367                    len > last_len &&
 368                    memcmp(path, last_file, last_len) == 0 &&
 369                    path[last_len] == '/') {
 370                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 371                        unlink(last_file);
 372                }
 373
 374                /*
 375                 * Determine whether path could exist as a file in the
 376                 * working directory as a possible D/F conflict.  This
 377                 * will only occur when it exists in stage 2 as a
 378                 * file.
 379                 */
 380                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 381                        last_file = path;
 382                        last_len = len;
 383                } else {
 384                        last_file = NULL;
 385                }
 386        }
 387}
 388
 389struct rename {
 390        struct diff_filepair *pair;
 391        struct stage_data *src_entry;
 392        struct stage_data *dst_entry;
 393        unsigned processed:1;
 394};
 395
 396/*
 397 * Get information of all renames which occurred between 'o_tree' and
 398 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 399 * 'b_tree') to be able to associate the correct cache entries with
 400 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 401 */
 402static struct string_list *get_renames(struct merge_options *o,
 403                                       struct tree *tree,
 404                                       struct tree *o_tree,
 405                                       struct tree *a_tree,
 406                                       struct tree *b_tree,
 407                                       struct string_list *entries)
 408{
 409        int i;
 410        struct string_list *renames;
 411        struct diff_options opts;
 412
 413        renames = xcalloc(1, sizeof(struct string_list));
 414        diff_setup(&opts);
 415        DIFF_OPT_SET(&opts, RECURSIVE);
 416        opts.detect_rename = DIFF_DETECT_RENAME;
 417        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 418                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 419                            1000;
 420        opts.rename_score = o->rename_score;
 421        opts.show_rename_progress = o->show_rename_progress;
 422        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 423        if (diff_setup_done(&opts) < 0)
 424                die("diff setup failed");
 425        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 426        diffcore_std(&opts);
 427        if (opts.needed_rename_limit > o->needed_rename_limit)
 428                o->needed_rename_limit = opts.needed_rename_limit;
 429        for (i = 0; i < diff_queued_diff.nr; ++i) {
 430                struct string_list_item *item;
 431                struct rename *re;
 432                struct diff_filepair *pair = diff_queued_diff.queue[i];
 433                if (pair->status != 'R') {
 434                        diff_free_filepair(pair);
 435                        continue;
 436                }
 437                re = xmalloc(sizeof(*re));
 438                re->processed = 0;
 439                re->pair = pair;
 440                item = string_list_lookup(entries, re->pair->one->path);
 441                if (!item)
 442                        re->src_entry = insert_stage_data(re->pair->one->path,
 443                                        o_tree, a_tree, b_tree, entries);
 444                else
 445                        re->src_entry = item->util;
 446
 447                item = string_list_lookup(entries, re->pair->two->path);
 448                if (!item)
 449                        re->dst_entry = insert_stage_data(re->pair->two->path,
 450                                        o_tree, a_tree, b_tree, entries);
 451                else
 452                        re->dst_entry = item->util;
 453                item = string_list_insert(renames, pair->one->path);
 454                item->util = re;
 455        }
 456        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 457        diff_queued_diff.nr = 0;
 458        diff_flush(&opts);
 459        return renames;
 460}
 461
 462static int update_stages(const char *path, const struct diff_filespec *o,
 463                         const struct diff_filespec *a,
 464                         const struct diff_filespec *b)
 465{
 466        int clear = 1;
 467        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 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_and_entry(const char *path,
 484                                   struct stage_data *entry,
 485                                   struct diff_filespec *o,
 486                                   struct diff_filespec *a,
 487                                   struct diff_filespec *b,
 488                                   int clear)
 489{
 490        int options;
 491
 492        entry->processed = 0;
 493        entry->stages[1].mode = o->mode;
 494        entry->stages[2].mode = a->mode;
 495        entry->stages[3].mode = b->mode;
 496        hashcpy(entry->stages[1].sha, o->sha1);
 497        hashcpy(entry->stages[2].sha, a->sha1);
 498        hashcpy(entry->stages[3].sha, b->sha1);
 499        return update_stages(path, o, a, b);
 500}
 501
 502static int remove_file(struct merge_options *o, int clean,
 503                       const char *path, int no_wd)
 504{
 505        int update_cache = o->call_depth || clean;
 506        int update_working_directory = !o->call_depth && !no_wd;
 507
 508        if (update_cache) {
 509                if (remove_file_from_cache(path))
 510                        return -1;
 511        }
 512        if (update_working_directory) {
 513                if (remove_path(path))
 514                        return -1;
 515        }
 516        return 0;
 517}
 518
 519static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 520{
 521        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 522        int suffix = 0;
 523        struct stat st;
 524        char *p = newpath + strlen(path);
 525        strcpy(newpath, path);
 526        *(p++) = '~';
 527        strcpy(p, branch);
 528        for (; *p; ++p)
 529                if ('/' == *p)
 530                        *p = '_';
 531        while (string_list_has_string(&o->current_file_set, newpath) ||
 532               string_list_has_string(&o->current_directory_set, newpath) ||
 533               lstat(newpath, &st) == 0)
 534                sprintf(p, "_%d", suffix++);
 535
 536        string_list_insert(&o->current_file_set, newpath);
 537        return newpath;
 538}
 539
 540static void flush_buffer(int fd, const char *buf, unsigned long size)
 541{
 542        while (size > 0) {
 543                long ret = write_in_full(fd, buf, size);
 544                if (ret < 0) {
 545                        /* Ignore epipe */
 546                        if (errno == EPIPE)
 547                                break;
 548                        die_errno("merge-recursive");
 549                } else if (!ret) {
 550                        die("merge-recursive: disk full?");
 551                }
 552                size -= ret;
 553                buf += ret;
 554        }
 555}
 556
 557static int would_lose_untracked(const char *path)
 558{
 559        int pos = cache_name_pos(path, strlen(path));
 560
 561        if (pos < 0)
 562                pos = -1 - pos;
 563        while (pos < active_nr &&
 564               !strcmp(path, active_cache[pos]->name)) {
 565                /*
 566                 * If stage #0, it is definitely tracked.
 567                 * If it has stage #2 then it was tracked
 568                 * before this merge started.  All other
 569                 * cases the path was not tracked.
 570                 */
 571                switch (ce_stage(active_cache[pos])) {
 572                case 0:
 573                case 2:
 574                        return 0;
 575                }
 576                pos++;
 577        }
 578        return file_exists(path);
 579}
 580
 581static int make_room_for_path(const char *path)
 582{
 583        int status;
 584        const char *msg = "failed to create path '%s'%s";
 585
 586        status = safe_create_leading_directories_const(path);
 587        if (status) {
 588                if (status == -3) {
 589                        /* something else exists */
 590                        error(msg, path, ": perhaps a D/F conflict?");
 591                        return -1;
 592                }
 593                die(msg, path, "");
 594        }
 595
 596        /*
 597         * Do not unlink a file in the work tree if we are not
 598         * tracking it.
 599         */
 600        if (would_lose_untracked(path))
 601                return error("refusing to lose untracked file at '%s'",
 602                             path);
 603
 604        /* Successful unlink is good.. */
 605        if (!unlink(path))
 606                return 0;
 607        /* .. and so is no existing file */
 608        if (errno == ENOENT)
 609                return 0;
 610        /* .. but not some other error (who really cares what?) */
 611        return error(msg, path, ": perhaps a D/F conflict?");
 612}
 613
 614static void update_file_flags(struct merge_options *o,
 615                              const unsigned char *sha,
 616                              unsigned mode,
 617                              const char *path,
 618                              int update_cache,
 619                              int update_wd)
 620{
 621        if (o->call_depth)
 622                update_wd = 0;
 623
 624        if (update_wd) {
 625                enum object_type type;
 626                void *buf;
 627                unsigned long size;
 628
 629                if (S_ISGITLINK(mode)) {
 630                        /*
 631                         * We may later decide to recursively descend into
 632                         * the submodule directory and update its index
 633                         * and/or work tree, but we do not do that now.
 634                         */
 635                        update_wd = 0;
 636                        goto update_index;
 637                }
 638
 639                buf = read_sha1_file(sha, &type, &size);
 640                if (!buf)
 641                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 642                if (type != OBJ_BLOB)
 643                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 644                if (S_ISREG(mode)) {
 645                        struct strbuf strbuf = STRBUF_INIT;
 646                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 647                                free(buf);
 648                                size = strbuf.len;
 649                                buf = strbuf_detach(&strbuf, NULL);
 650                        }
 651                }
 652
 653                if (make_room_for_path(path) < 0) {
 654                        update_wd = 0;
 655                        free(buf);
 656                        goto update_index;
 657                }
 658                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 659                        int fd;
 660                        if (mode & 0100)
 661                                mode = 0777;
 662                        else
 663                                mode = 0666;
 664                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 665                        if (fd < 0)
 666                                die_errno("failed to open '%s'", path);
 667                        flush_buffer(fd, buf, size);
 668                        close(fd);
 669                } else if (S_ISLNK(mode)) {
 670                        char *lnk = xmemdupz(buf, size);
 671                        safe_create_leading_directories_const(path);
 672                        unlink(path);
 673                        if (symlink(lnk, path))
 674                                die_errno("failed to symlink '%s'", path);
 675                        free(lnk);
 676                } else
 677                        die("do not know what to do with %06o %s '%s'",
 678                            mode, sha1_to_hex(sha), path);
 679                free(buf);
 680        }
 681 update_index:
 682        if (update_cache)
 683                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 684}
 685
 686static void update_file(struct merge_options *o,
 687                        int clean,
 688                        const unsigned char *sha,
 689                        unsigned mode,
 690                        const char *path)
 691{
 692        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 693}
 694
 695/* Low level file merging, update and removal */
 696
 697struct merge_file_info {
 698        unsigned char sha[20];
 699        unsigned mode;
 700        unsigned clean:1,
 701                 merge:1;
 702};
 703
 704static int merge_3way(struct merge_options *o,
 705                      mmbuffer_t *result_buf,
 706                      const struct diff_filespec *one,
 707                      const struct diff_filespec *a,
 708                      const struct diff_filespec *b,
 709                      const char *branch1,
 710                      const char *branch2)
 711{
 712        mmfile_t orig, src1, src2;
 713        struct ll_merge_options ll_opts = {0};
 714        char *base_name, *name1, *name2;
 715        int merge_status;
 716
 717        ll_opts.renormalize = o->renormalize;
 718        ll_opts.xdl_opts = o->xdl_opts;
 719
 720        if (o->call_depth) {
 721                ll_opts.virtual_ancestor = 1;
 722                ll_opts.variant = 0;
 723        } else {
 724                switch (o->recursive_variant) {
 725                case MERGE_RECURSIVE_OURS:
 726                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 727                        break;
 728                case MERGE_RECURSIVE_THEIRS:
 729                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 730                        break;
 731                default:
 732                        ll_opts.variant = 0;
 733                        break;
 734                }
 735        }
 736
 737        if (strcmp(a->path, b->path) ||
 738            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 739                base_name = o->ancestor == NULL ? NULL :
 740                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 741                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 742                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 743        } else {
 744                base_name = o->ancestor == NULL ? NULL :
 745                        xstrdup(mkpath("%s", o->ancestor));
 746                name1 = xstrdup(mkpath("%s", branch1));
 747                name2 = xstrdup(mkpath("%s", branch2));
 748        }
 749
 750        read_mmblob(&orig, one->sha1);
 751        read_mmblob(&src1, a->sha1);
 752        read_mmblob(&src2, b->sha1);
 753
 754        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 755                                &src1, name1, &src2, name2, &ll_opts);
 756
 757        free(name1);
 758        free(name2);
 759        free(orig.ptr);
 760        free(src1.ptr);
 761        free(src2.ptr);
 762        return merge_status;
 763}
 764
 765static struct merge_file_info merge_file(struct merge_options *o,
 766                                         const struct diff_filespec *one,
 767                                         const struct diff_filespec *a,
 768                                         const struct diff_filespec *b,
 769                                         const char *branch1,
 770                                         const char *branch2)
 771{
 772        struct merge_file_info result;
 773        result.merge = 0;
 774        result.clean = 1;
 775
 776        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 777                result.clean = 0;
 778                if (S_ISREG(a->mode)) {
 779                        result.mode = a->mode;
 780                        hashcpy(result.sha, a->sha1);
 781                } else {
 782                        result.mode = b->mode;
 783                        hashcpy(result.sha, b->sha1);
 784                }
 785        } else {
 786                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 787                        result.merge = 1;
 788
 789                /*
 790                 * Merge modes
 791                 */
 792                if (a->mode == b->mode || a->mode == one->mode)
 793                        result.mode = b->mode;
 794                else {
 795                        result.mode = a->mode;
 796                        if (b->mode != one->mode) {
 797                                result.clean = 0;
 798                                result.merge = 1;
 799                        }
 800                }
 801
 802                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 803                        hashcpy(result.sha, b->sha1);
 804                else if (sha_eq(b->sha1, one->sha1))
 805                        hashcpy(result.sha, a->sha1);
 806                else if (S_ISREG(a->mode)) {
 807                        mmbuffer_t result_buf;
 808                        int merge_status;
 809
 810                        merge_status = merge_3way(o, &result_buf, one, a, b,
 811                                                  branch1, branch2);
 812
 813                        if ((merge_status < 0) || !result_buf.ptr)
 814                                die("Failed to execute internal merge");
 815
 816                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 817                                            blob_type, result.sha))
 818                                die("Unable to add %s to database",
 819                                    a->path);
 820
 821                        free(result_buf.ptr);
 822                        result.clean = (merge_status == 0);
 823                } else if (S_ISGITLINK(a->mode)) {
 824                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 825                                                       a->sha1, b->sha1);
 826                } else if (S_ISLNK(a->mode)) {
 827                        hashcpy(result.sha, a->sha1);
 828
 829                        if (!sha_eq(a->sha1, b->sha1))
 830                                result.clean = 0;
 831                } else {
 832                        die("unsupported object type in the tree");
 833                }
 834        }
 835
 836        return result;
 837}
 838
 839static void conflict_rename_delete(struct merge_options *o,
 840                                   struct diff_filepair *pair,
 841                                   const char *rename_branch,
 842                                   const char *other_branch)
 843{
 844        char *dest_name = pair->two->path;
 845        int df_conflict = 0;
 846        struct stat st;
 847
 848        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 849               "and deleted in %s",
 850               pair->one->path, pair->two->path, rename_branch,
 851               other_branch);
 852        if (!o->call_depth)
 853                update_stages(dest_name, NULL,
 854                              rename_branch == o->branch1 ? pair->two : NULL,
 855                              rename_branch == o->branch1 ? NULL : pair->two);
 856        if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 857                dest_name = unique_path(o, dest_name, rename_branch);
 858                df_conflict = 1;
 859        }
 860        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 861        if (df_conflict)
 862                free(dest_name);
 863}
 864
 865static void conflict_rename_rename_1to2(struct merge_options *o,
 866                                        struct diff_filepair *pair1,
 867                                        const char *branch1,
 868                                        struct diff_filepair *pair2,
 869                                        const char *branch2)
 870{
 871        /* One file was renamed in both branches, but to different names. */
 872        char *del[2];
 873        int delp = 0;
 874        const char *ren1_dst = pair1->two->path;
 875        const char *ren2_dst = pair2->two->path;
 876        const char *dst_name1 = ren1_dst;
 877        const char *dst_name2 = ren2_dst;
 878        struct stat st;
 879        if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 880                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 881                output(o, 1, "%s is a directory in %s adding as %s instead",
 882                       ren1_dst, branch2, dst_name1);
 883        }
 884        if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 885                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 886                output(o, 1, "%s is a directory in %s adding as %s instead",
 887                       ren2_dst, branch1, dst_name2);
 888        }
 889        if (o->call_depth) {
 890                remove_file_from_cache(dst_name1);
 891                remove_file_from_cache(dst_name2);
 892                /*
 893                 * Uncomment to leave the conflicting names in the resulting tree
 894                 *
 895                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 896                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 897                 */
 898        } else {
 899                update_stages(ren1_dst, NULL, pair1->two, NULL);
 900                update_stages(ren2_dst, NULL, NULL, pair2->two);
 901
 902                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 903                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 904        }
 905        while (delp--)
 906                free(del[delp]);
 907}
 908
 909static void conflict_rename_rename_2to1(struct merge_options *o,
 910                                        struct rename *ren1,
 911                                        const char *branch1,
 912                                        struct rename *ren2,
 913                                        const char *branch2)
 914{
 915        /* Two files were renamed to the same thing. */
 916        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 917        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 918        output(o, 1, "Renaming %s to %s and %s to %s instead",
 919               ren1->pair->one->path, new_path1,
 920               ren2->pair->one->path, new_path2);
 921        remove_file(o, 0, ren1->pair->two->path, 0);
 922        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 923        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 924        free(new_path2);
 925        free(new_path1);
 926}
 927
 928static int process_renames(struct merge_options *o,
 929                           struct string_list *a_renames,
 930                           struct string_list *b_renames)
 931{
 932        int clean_merge = 1, i, j;
 933        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 934        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 935        const struct rename *sre;
 936
 937        for (i = 0; i < a_renames->nr; i++) {
 938                sre = a_renames->items[i].util;
 939                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 940                        = sre->dst_entry;
 941        }
 942        for (i = 0; i < b_renames->nr; i++) {
 943                sre = b_renames->items[i].util;
 944                string_list_insert(&b_by_dst, sre->pair->two->path)->util
 945                        = sre->dst_entry;
 946        }
 947
 948        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 949                struct string_list *renames1, *renames2Dst;
 950                struct rename *ren1 = NULL, *ren2 = NULL;
 951                const char *branch1, *branch2;
 952                const char *ren1_src, *ren1_dst;
 953
 954                if (i >= a_renames->nr) {
 955                        ren2 = b_renames->items[j++].util;
 956                } else if (j >= b_renames->nr) {
 957                        ren1 = a_renames->items[i++].util;
 958                } else {
 959                        int compare = strcmp(a_renames->items[i].string,
 960                                             b_renames->items[j].string);
 961                        if (compare <= 0)
 962                                ren1 = a_renames->items[i++].util;
 963                        if (compare >= 0)
 964                                ren2 = b_renames->items[j++].util;
 965                }
 966
 967                /* TODO: refactor, so that 1/2 are not needed */
 968                if (ren1) {
 969                        renames1 = a_renames;
 970                        renames2Dst = &b_by_dst;
 971                        branch1 = o->branch1;
 972                        branch2 = o->branch2;
 973                } else {
 974                        struct rename *tmp;
 975                        renames1 = b_renames;
 976                        renames2Dst = &a_by_dst;
 977                        branch1 = o->branch2;
 978                        branch2 = o->branch1;
 979                        tmp = ren2;
 980                        ren2 = ren1;
 981                        ren1 = tmp;
 982                }
 983
 984                ren1->dst_entry->processed = 1;
 985                ren1->src_entry->processed = 1;
 986
 987                if (ren1->processed)
 988                        continue;
 989                ren1->processed = 1;
 990
 991                ren1_src = ren1->pair->one->path;
 992                ren1_dst = ren1->pair->two->path;
 993
 994                if (ren2) {
 995                        const char *ren2_src = ren2->pair->one->path;
 996                        const char *ren2_dst = ren2->pair->two->path;
 997                        /* Renamed in 1 and renamed in 2 */
 998                        if (strcmp(ren1_src, ren2_src) != 0)
 999                                die("ren1.src != ren2.src");
1000                        ren2->dst_entry->processed = 1;
1001                        ren2->processed = 1;
1002                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1003                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1004                                                              ren1->pair,
1005                                                              ren2->pair,
1006                                                              branch1,
1007                                                              branch2,
1008                                                              ren1->dst_entry,
1009                                                              ren2->dst_entry);
1010                        } else {
1011                                remove_file(o, 1, ren1_src, 1);
1012                                update_stages_and_entry(ren1_dst,
1013                                                        ren1->dst_entry,
1014                                                        ren1->pair->one,
1015                                                        ren1->pair->two,
1016                                                        ren2->pair->two,
1017                                                        1 /* clear */);
1018                        }
1019                } else {
1020                        /* Renamed in 1, maybe changed in 2 */
1021                        struct string_list_item *item;
1022                        /* we only use sha1 and mode of these */
1023                        struct diff_filespec src_other, dst_other;
1024                        int try_merge;
1025
1026                        /*
1027                         * unpack_trees loads entries from common-commit
1028                         * into stage 1, from head-commit into stage 2, and
1029                         * from merge-commit into stage 3.  We keep track
1030                         * of which side corresponds to the rename.
1031                         */
1032                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1033                        int other_stage =   a_renames == renames1 ? 3 : 2;
1034
1035                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1036
1037                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1038                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1039                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1040                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1041                        try_merge = 0;
1042
1043                        if (sha_eq(src_other.sha1, null_sha1)) {
1044                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1045                                        ren1->dst_entry->processed = 0;
1046                                        setup_rename_df_conflict_info(RENAME_DELETE,
1047                                                                      ren1->pair,
1048                                                                      NULL,
1049                                                                      branch1,
1050                                                                      branch2,
1051                                                                      ren1->dst_entry,
1052                                                                      NULL);
1053                                } else {
1054                                        clean_merge = 0;
1055                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1056                                }
1057                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1058                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1059                                /* Added file on the other side
1060                                   identical to the file being
1061                                   renamed: clean merge */
1062                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1063                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1064                                const char *new_path;
1065                                clean_merge = 0;
1066                                try_merge = 1;
1067                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1068                                       "%s added in %s",
1069                                       ren1_src, ren1_dst, branch1,
1070                                       ren1_dst, branch2);
1071                                if (o->call_depth) {
1072                                        struct merge_file_info mfi;
1073                                        struct diff_filespec one, a, b;
1074
1075                                        one.path = a.path = b.path =
1076                                                (char *)ren1_dst;
1077                                        hashcpy(one.sha1, null_sha1);
1078                                        one.mode = 0;
1079                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1080                                        a.mode = ren1->pair->two->mode;
1081                                        hashcpy(b.sha1, dst_other.sha1);
1082                                        b.mode = dst_other.mode;
1083                                        mfi = merge_file(o, &one, &a, &b,
1084                                                         branch1,
1085                                                         branch2);
1086                                        output(o, 1, "Adding merged %s", ren1_dst);
1087                                        update_file(o, 0,
1088                                                    mfi.sha,
1089                                                    mfi.mode,
1090                                                    ren1_dst);
1091                                        try_merge = 0;
1092                                } else {
1093                                        new_path = unique_path(o, ren1_dst, branch2);
1094                                        output(o, 1, "Adding as %s instead", new_path);
1095                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1096                                }
1097                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1098                                ren2 = item->util;
1099                                clean_merge = 0;
1100                                ren2->processed = 1;
1101                                output(o, 1, "CONFLICT (rename/rename): "
1102                                       "Rename %s->%s in %s. "
1103                                       "Rename %s->%s in %s",
1104                                       ren1_src, ren1_dst, branch1,
1105                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1106                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1107                        } else
1108                                try_merge = 1;
1109
1110                        if (try_merge) {
1111                                struct diff_filespec *one, *a, *b;
1112                                src_other.path = (char *)ren1_src;
1113
1114                                one = ren1->pair->one;
1115                                if (a_renames == renames1) {
1116                                        a = ren1->pair->two;
1117                                        b = &src_other;
1118                                } else {
1119                                        b = ren1->pair->two;
1120                                        a = &src_other;
1121                                }
1122                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1123                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1124                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1125                                                                      ren1->pair,
1126                                                                      NULL,
1127                                                                      branch1,
1128                                                                      NULL,
1129                                                                      ren1->dst_entry,
1130                                                                      NULL);
1131                                }
1132                        }
1133                }
1134        }
1135        string_list_clear(&a_by_dst, 0);
1136        string_list_clear(&b_by_dst, 0);
1137
1138        return clean_merge;
1139}
1140
1141static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1142{
1143        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1144}
1145
1146static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1147{
1148        void *buf;
1149        enum object_type type;
1150        unsigned long size;
1151        buf = read_sha1_file(sha1, &type, &size);
1152        if (!buf)
1153                return error("cannot read object %s", sha1_to_hex(sha1));
1154        if (type != OBJ_BLOB) {
1155                free(buf);
1156                return error("object %s is not a blob", sha1_to_hex(sha1));
1157        }
1158        strbuf_attach(dst, buf, size, size + 1);
1159        return 0;
1160}
1161
1162static int blob_unchanged(const unsigned char *o_sha,
1163                          const unsigned char *a_sha,
1164                          int renormalize, const char *path)
1165{
1166        struct strbuf o = STRBUF_INIT;
1167        struct strbuf a = STRBUF_INIT;
1168        int ret = 0; /* assume changed for safety */
1169
1170        if (sha_eq(o_sha, a_sha))
1171                return 1;
1172        if (!renormalize)
1173                return 0;
1174
1175        assert(o_sha && a_sha);
1176        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1177                goto error_return;
1178        /*
1179         * Note: binary | is used so that both renormalizations are
1180         * performed.  Comparison can be skipped if both files are
1181         * unchanged since their sha1s have already been compared.
1182         */
1183        if (renormalize_buffer(path, o.buf, o.len, &o) |
1184            renormalize_buffer(path, a.buf, o.len, &a))
1185                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1186
1187error_return:
1188        strbuf_release(&o);
1189        strbuf_release(&a);
1190        return ret;
1191}
1192
1193static void handle_delete_modify(struct merge_options *o,
1194                                 const char *path,
1195                                 const char *new_path,
1196                                 unsigned char *a_sha, int a_mode,
1197                                 unsigned char *b_sha, int b_mode)
1198{
1199        if (!a_sha) {
1200                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1201                       "and modified in %s. Version %s of %s left in tree%s%s.",
1202                       path, o->branch1,
1203                       o->branch2, o->branch2, path,
1204                       path == new_path ? "" : " at ",
1205                       path == new_path ? "" : new_path);
1206                update_file(o, 0, b_sha, b_mode, new_path);
1207        } else {
1208                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1209                       "and modified in %s. Version %s of %s left in tree%s%s.",
1210                       path, o->branch2,
1211                       o->branch1, o->branch1, path,
1212                       path == new_path ? "" : " at ",
1213                       path == new_path ? "" : new_path);
1214                update_file(o, 0, a_sha, a_mode, new_path);
1215        }
1216}
1217
1218static int merge_content(struct merge_options *o,
1219                         const char *path,
1220                         unsigned char *o_sha, int o_mode,
1221                         unsigned char *a_sha, int a_mode,
1222                         unsigned char *b_sha, int b_mode,
1223                         const char *df_rename_conflict_branch)
1224{
1225        const char *reason = "content";
1226        struct merge_file_info mfi;
1227        struct diff_filespec one, a, b;
1228        struct stat st;
1229        unsigned df_conflict_remains = 0;
1230
1231        if (!o_sha) {
1232                reason = "add/add";
1233                o_sha = (unsigned char *)null_sha1;
1234        }
1235        one.path = a.path = b.path = (char *)path;
1236        hashcpy(one.sha1, o_sha);
1237        one.mode = o_mode;
1238        hashcpy(a.sha1, a_sha);
1239        a.mode = a_mode;
1240        hashcpy(b.sha1, b_sha);
1241        b.mode = b_mode;
1242
1243        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1244        if (df_rename_conflict_branch &&
1245            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1246                df_conflict_remains = 1;
1247        }
1248
1249        if (mfi.clean && !df_conflict_remains &&
1250            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1251                output(o, 3, "Skipped %s (merged same as existing)", path);
1252        else
1253                output(o, 2, "Auto-merging %s", path);
1254
1255        if (!mfi.clean) {
1256                if (S_ISGITLINK(mfi.mode))
1257                        reason = "submodule";
1258                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1259                                reason, path);
1260        }
1261
1262        if (df_conflict_remains) {
1263                const char *new_path;
1264                update_file_flags(o, mfi.sha, mfi.mode, path,
1265                                  o->call_depth || mfi.clean, 0);
1266                new_path = unique_path(o, path, df_rename_conflict_branch);
1267                mfi.clean = 0;
1268                output(o, 1, "Adding as %s instead", new_path);
1269                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1270        } else {
1271                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1272        }
1273        return mfi.clean;
1274
1275}
1276
1277/* Per entry merge function */
1278static int process_entry(struct merge_options *o,
1279                         const char *path, struct stage_data *entry)
1280{
1281        /*
1282        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1283        print_index_entry("\tpath: ", entry);
1284        */
1285        int clean_merge = 1;
1286        int normalize = o->renormalize;
1287        unsigned o_mode = entry->stages[1].mode;
1288        unsigned a_mode = entry->stages[2].mode;
1289        unsigned b_mode = entry->stages[3].mode;
1290        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1291        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1292        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1293
1294        if (entry->rename_df_conflict_info)
1295                return 1; /* Such cases are handled elsewhere. */
1296
1297        entry->processed = 1;
1298        if (o_sha && (!a_sha || !b_sha)) {
1299                /* Case A: Deleted in one */
1300                if ((!a_sha && !b_sha) ||
1301                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1302                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1303                        /* Deleted in both or deleted in one and
1304                         * unchanged in the other */
1305                        if (a_sha)
1306                                output(o, 2, "Removing %s", path);
1307                        /* do not touch working file if it did not exist */
1308                        remove_file(o, 1, path, !a_sha);
1309                } else if (string_list_has_string(&o->current_directory_set,
1310                                                  path)) {
1311                        entry->processed = 0;
1312                        return 1; /* Assume clean until processed */
1313                } else {
1314                        /* Deleted in one and changed in the other */
1315                        clean_merge = 0;
1316                        handle_delete_modify(o, path, path,
1317                                             a_sha, a_mode, b_sha, b_mode);
1318                }
1319
1320        } else if ((!o_sha && a_sha && !b_sha) ||
1321                   (!o_sha && !a_sha && b_sha)) {
1322                /* Case B: Added in one. */
1323                unsigned mode;
1324                const unsigned char *sha;
1325
1326                if (a_sha) {
1327                        mode = a_mode;
1328                        sha = a_sha;
1329                } else {
1330                        mode = b_mode;
1331                        sha = b_sha;
1332                }
1333                if (string_list_has_string(&o->current_directory_set, path)) {
1334                        /* Handle D->F conflicts after all subfiles */
1335                        entry->processed = 0;
1336                        return 1; /* Assume clean until processed */
1337                } else {
1338                        output(o, 2, "Adding %s", path);
1339                        update_file(o, 1, sha, mode, path);
1340                }
1341        } else if (a_sha && b_sha) {
1342                /* Case C: Added in both (check for same permissions) and */
1343                /* case D: Modified in both, but differently. */
1344                clean_merge = merge_content(o, path,
1345                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1346                                            NULL);
1347        } else if (!o_sha && !a_sha && !b_sha) {
1348                /*
1349                 * this entry was deleted altogether. a_mode == 0 means
1350                 * we had that path and want to actively remove it.
1351                 */
1352                remove_file(o, 1, path, !a_mode);
1353        } else
1354                die("Fatal merge failure, shouldn't happen.");
1355
1356        return clean_merge;
1357}
1358
1359/*
1360 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1361 * cases we can cleanly resolve D/F conflicts, process_entry() can
1362 * clean out all the files below the directory for us.  All D/F
1363 * conflict cases must be handled here at the end to make sure any
1364 * directories that can be cleaned out, are.
1365 *
1366 * Some rename conflicts may also be handled here that don't necessarily
1367 * involve D/F conflicts, since the code to handle them is generic enough
1368 * to handle those rename conflicts with or without D/F conflicts also
1369 * being involved.
1370 */
1371static int process_df_entry(struct merge_options *o,
1372                            const char *path, struct stage_data *entry)
1373{
1374        int clean_merge = 1;
1375        unsigned o_mode = entry->stages[1].mode;
1376        unsigned a_mode = entry->stages[2].mode;
1377        unsigned b_mode = entry->stages[3].mode;
1378        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1379        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1380        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1381        struct stat st;
1382
1383        entry->processed = 1;
1384        if (entry->rename_df_conflict_info) {
1385                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1386                char *src;
1387                switch (conflict_info->rename_type) {
1388                case RENAME_NORMAL:
1389                        clean_merge = merge_content(o, path,
1390                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1391                                                    conflict_info->branch1);
1392                        break;
1393                case RENAME_DELETE:
1394                        clean_merge = 0;
1395                        conflict_rename_delete(o, conflict_info->pair1,
1396                                               conflict_info->branch1,
1397                                               conflict_info->branch2);
1398                        break;
1399                case RENAME_ONE_FILE_TO_TWO:
1400                        src = conflict_info->pair1->one->path;
1401                        clean_merge = 0;
1402                        output(o, 1, "CONFLICT (rename/rename): "
1403                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1404                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1405                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1406                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1407                               o->call_depth ? " (left unresolved)" : "");
1408                        if (o->call_depth) {
1409                                remove_file_from_cache(src);
1410                                update_file(o, 0, conflict_info->pair1->one->sha1,
1411                                            conflict_info->pair1->one->mode, src);
1412                        }
1413                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1414                                                    conflict_info->branch1,
1415                                                    conflict_info->pair2,
1416                                                    conflict_info->branch2);
1417                        conflict_info->dst_entry2->processed = 1;
1418                        break;
1419                default:
1420                        entry->processed = 0;
1421                        break;
1422                }
1423        } else if (o_sha && (!a_sha || !b_sha)) {
1424                /* Modify/delete; deleted side may have put a directory in the way */
1425                const char *new_path = path;
1426                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1427                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1428                clean_merge = 0;
1429                handle_delete_modify(o, path, new_path,
1430                                     a_sha, a_mode, b_sha, b_mode);
1431        } else if (!o_sha && !!a_sha != !!b_sha) {
1432                /* directory -> (directory, file) or <nothing> -> (directory, file) */
1433                const char *add_branch;
1434                const char *other_branch;
1435                unsigned mode;
1436                const unsigned char *sha;
1437                const char *conf;
1438
1439                if (a_sha) {
1440                        add_branch = o->branch1;
1441                        other_branch = o->branch2;
1442                        mode = a_mode;
1443                        sha = a_sha;
1444                        conf = "file/directory";
1445                } else {
1446                        add_branch = o->branch2;
1447                        other_branch = o->branch1;
1448                        mode = b_mode;
1449                        sha = b_sha;
1450                        conf = "directory/file";
1451                }
1452                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1453                        const char *new_path = unique_path(o, path, add_branch);
1454                        clean_merge = 0;
1455                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1456                               "Adding %s as %s",
1457                               conf, path, other_branch, path, new_path);
1458                        update_file(o, 0, sha, mode, new_path);
1459                } else {
1460                        output(o, 2, "Adding %s", path);
1461                        update_file(o, 1, sha, mode, path);
1462                }
1463        } else {
1464                entry->processed = 0;
1465                return 1; /* not handled; assume clean until processed */
1466        }
1467
1468        return clean_merge;
1469}
1470
1471int merge_trees(struct merge_options *o,
1472                struct tree *head,
1473                struct tree *merge,
1474                struct tree *common,
1475                struct tree **result)
1476{
1477        int code, clean;
1478
1479        if (o->subtree_shift) {
1480                merge = shift_tree_object(head, merge, o->subtree_shift);
1481                common = shift_tree_object(head, common, o->subtree_shift);
1482        }
1483
1484        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1485                output(o, 0, "Already up-to-date!");
1486                *result = head;
1487                return 1;
1488        }
1489
1490        code = git_merge_trees(o->call_depth, common, head, merge);
1491
1492        if (code != 0) {
1493                if (show(o, 4) || o->call_depth)
1494                        die("merging of trees %s and %s failed",
1495                            sha1_to_hex(head->object.sha1),
1496                            sha1_to_hex(merge->object.sha1));
1497                else
1498                        exit(128);
1499        }
1500
1501        if (unmerged_cache()) {
1502                struct string_list *entries, *re_head, *re_merge;
1503                int i;
1504                string_list_clear(&o->current_file_set, 1);
1505                string_list_clear(&o->current_directory_set, 1);
1506                get_files_dirs(o, head);
1507                get_files_dirs(o, merge);
1508
1509                entries = get_unmerged();
1510                make_room_for_directories_of_df_conflicts(o, entries);
1511                re_head  = get_renames(o, head, common, head, merge, entries);
1512                re_merge = get_renames(o, merge, common, head, merge, entries);
1513                clean = process_renames(o, re_head, re_merge);
1514                for (i = 0; i < entries->nr; i++) {
1515                        const char *path = entries->items[i].string;
1516                        struct stage_data *e = entries->items[i].util;
1517                        if (!e->processed
1518                                && !process_entry(o, path, e))
1519                                clean = 0;
1520                }
1521                for (i = 0; i < entries->nr; i++) {
1522                        const char *path = entries->items[i].string;
1523                        struct stage_data *e = entries->items[i].util;
1524                        if (!e->processed
1525                                && !process_df_entry(o, path, e))
1526                                clean = 0;
1527                }
1528                for (i = 0; i < entries->nr; i++) {
1529                        struct stage_data *e = entries->items[i].util;
1530                        if (!e->processed)
1531                                die("Unprocessed path??? %s",
1532                                    entries->items[i].string);
1533                }
1534
1535                string_list_clear(re_merge, 0);
1536                string_list_clear(re_head, 0);
1537                string_list_clear(entries, 1);
1538
1539        }
1540        else
1541                clean = 1;
1542
1543        if (o->call_depth)
1544                *result = write_tree_from_memory(o);
1545
1546        return clean;
1547}
1548
1549static struct commit_list *reverse_commit_list(struct commit_list *list)
1550{
1551        struct commit_list *next = NULL, *current, *backup;
1552        for (current = list; current; current = backup) {
1553                backup = current->next;
1554                current->next = next;
1555                next = current;
1556        }
1557        return next;
1558}
1559
1560/*
1561 * Merge the commits h1 and h2, return the resulting virtual
1562 * commit object and a flag indicating the cleanness of the merge.
1563 */
1564int merge_recursive(struct merge_options *o,
1565                    struct commit *h1,
1566                    struct commit *h2,
1567                    struct commit_list *ca,
1568                    struct commit **result)
1569{
1570        struct commit_list *iter;
1571        struct commit *merged_common_ancestors;
1572        struct tree *mrtree = mrtree;
1573        int clean;
1574
1575        if (show(o, 4)) {
1576                output(o, 4, "Merging:");
1577                output_commit_title(o, h1);
1578                output_commit_title(o, h2);
1579        }
1580
1581        if (!ca) {
1582                ca = get_merge_bases(h1, h2, 1);
1583                ca = reverse_commit_list(ca);
1584        }
1585
1586        if (show(o, 5)) {
1587                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1588                for (iter = ca; iter; iter = iter->next)
1589                        output_commit_title(o, iter->item);
1590        }
1591
1592        merged_common_ancestors = pop_commit(&ca);
1593        if (merged_common_ancestors == NULL) {
1594                /* if there is no common ancestor, make an empty tree */
1595                struct tree *tree = xcalloc(1, sizeof(struct tree));
1596
1597                tree->object.parsed = 1;
1598                tree->object.type = OBJ_TREE;
1599                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1600                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1601        }
1602
1603        for (iter = ca; iter; iter = iter->next) {
1604                const char *saved_b1, *saved_b2;
1605                o->call_depth++;
1606                /*
1607                 * When the merge fails, the result contains files
1608                 * with conflict markers. The cleanness flag is
1609                 * ignored, it was never actually used, as result of
1610                 * merge_trees has always overwritten it: the committed
1611                 * "conflicts" were already resolved.
1612                 */
1613                discard_cache();
1614                saved_b1 = o->branch1;
1615                saved_b2 = o->branch2;
1616                o->branch1 = "Temporary merge branch 1";
1617                o->branch2 = "Temporary merge branch 2";
1618                merge_recursive(o, merged_common_ancestors, iter->item,
1619                                NULL, &merged_common_ancestors);
1620                o->branch1 = saved_b1;
1621                o->branch2 = saved_b2;
1622                o->call_depth--;
1623
1624                if (!merged_common_ancestors)
1625                        die("merge returned no commit");
1626        }
1627
1628        discard_cache();
1629        if (!o->call_depth)
1630                read_cache();
1631
1632        o->ancestor = "merged common ancestors";
1633        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1634                            &mrtree);
1635
1636        if (o->call_depth) {
1637                *result = make_virtual_commit(mrtree, "merged tree");
1638                commit_list_insert(h1, &(*result)->parents);
1639                commit_list_insert(h2, &(*result)->parents->next);
1640        }
1641        flush_output(o);
1642        if (show(o, 2))
1643                diff_warn_rename_limit("merge.renamelimit",
1644                                       o->needed_rename_limit, 0);
1645        return clean;
1646}
1647
1648static struct commit *get_ref(const unsigned char *sha1, const char *name)
1649{
1650        struct object *object;
1651
1652        object = deref_tag(parse_object(sha1), name, strlen(name));
1653        if (!object)
1654                return NULL;
1655        if (object->type == OBJ_TREE)
1656                return make_virtual_commit((struct tree*)object, name);
1657        if (object->type != OBJ_COMMIT)
1658                return NULL;
1659        if (parse_commit((struct commit *)object))
1660                return NULL;
1661        return (struct commit *)object;
1662}
1663
1664int merge_recursive_generic(struct merge_options *o,
1665                            const unsigned char *head,
1666                            const unsigned char *merge,
1667                            int num_base_list,
1668                            const unsigned char **base_list,
1669                            struct commit **result)
1670{
1671        int clean, index_fd;
1672        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1673        struct commit *head_commit = get_ref(head, o->branch1);
1674        struct commit *next_commit = get_ref(merge, o->branch2);
1675        struct commit_list *ca = NULL;
1676
1677        if (base_list) {
1678                int i;
1679                for (i = 0; i < num_base_list; ++i) {
1680                        struct commit *base;
1681                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1682                                return error("Could not parse object '%s'",
1683                                        sha1_to_hex(base_list[i]));
1684                        commit_list_insert(base, &ca);
1685                }
1686        }
1687
1688        index_fd = hold_locked_index(lock, 1);
1689        clean = merge_recursive(o, head_commit, next_commit, ca,
1690                        result);
1691        if (active_cache_changed &&
1692                        (write_cache(index_fd, active_cache, active_nr) ||
1693                         commit_locked_index(lock)))
1694                return error("Unable to write index.");
1695
1696        return clean ? 0 : 1;
1697}
1698
1699static int merge_recursive_config(const char *var, const char *value, void *cb)
1700{
1701        struct merge_options *o = cb;
1702        if (!strcmp(var, "merge.verbosity")) {
1703                o->verbosity = git_config_int(var, value);
1704                return 0;
1705        }
1706        if (!strcmp(var, "diff.renamelimit")) {
1707                o->diff_rename_limit = git_config_int(var, value);
1708                return 0;
1709        }
1710        if (!strcmp(var, "merge.renamelimit")) {
1711                o->merge_rename_limit = git_config_int(var, value);
1712                return 0;
1713        }
1714        return git_xmerge_config(var, value, cb);
1715}
1716
1717void init_merge_options(struct merge_options *o)
1718{
1719        memset(o, 0, sizeof(struct merge_options));
1720        o->verbosity = 2;
1721        o->buffer_output = 1;
1722        o->diff_rename_limit = -1;
1723        o->merge_rename_limit = -1;
1724        o->renormalize = 0;
1725        git_config(merge_recursive_config, o);
1726        if (getenv("GIT_MERGE_VERBOSITY"))
1727                o->verbosity =
1728                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1729        if (o->verbosity >= 5)
1730                o->buffer_output = 0;
1731        strbuf_init(&o->obuf, 0);
1732        memset(&o->current_file_set, 0, sizeof(struct string_list));
1733        o->current_file_set.strdup_strings = 1;
1734        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1735        o->current_directory_set.strdup_strings = 1;
1736}
1737
1738int parse_merge_opt(struct merge_options *o, const char *s)
1739{
1740        if (!s || !*s)
1741                return -1;
1742        if (!strcmp(s, "ours"))
1743                o->recursive_variant = MERGE_RECURSIVE_OURS;
1744        else if (!strcmp(s, "theirs"))
1745                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1746        else if (!strcmp(s, "subtree"))
1747                o->subtree_shift = "";
1748        else if (!prefixcmp(s, "subtree="))
1749                o->subtree_shift = s + strlen("subtree=");
1750        else if (!strcmp(s, "patience"))
1751                o->xdl_opts |= XDF_PATIENCE_DIFF;
1752        else if (!strcmp(s, "ignore-space-change"))
1753                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1754        else if (!strcmp(s, "ignore-all-space"))
1755                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1756        else if (!strcmp(s, "ignore-space-at-eol"))
1757                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1758        else if (!strcmp(s, "renormalize"))
1759                o->renormalize = 1;
1760        else if (!strcmp(s, "no-renormalize"))
1761                o->renormalize = 0;
1762        else if (!prefixcmp(s, "rename-threshold=")) {
1763                const char *score = s + strlen("rename-threshold=");
1764                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1765                        return -1;
1766        }
1767        else
1768                return -1;
1769        return 0;
1770}