merge-recursive.con commit Merge branch 'im/hashcmp-optim' (efa67bf)
   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         * (albeit with a different timestamp!); otherwise, if the
 346         * file is not supposed to be removed by the merge, the
 347         * contents of the file will be placed in another unique
 348         * filename.
 349         *
 350         * NOTE: This function relies on the fact that entries for a
 351         * D/F conflict will appear adjacent in the index, with the
 352         * entries for the file appearing before entries for paths
 353         * below the corresponding directory.
 354         */
 355        const char *last_file = NULL;
 356        int last_len = 0;
 357        int i;
 358
 359        /*
 360         * Do not do any of this crazyness during the recursive; we don't
 361         * even write anything to the working tree!
 362         */
 363        if (o->call_depth)
 364                return;
 365
 366        for (i = 0; i < entries->nr; i++) {
 367                const char *path = entries->items[i].string;
 368                int len = strlen(path);
 369                struct stage_data *e = entries->items[i].util;
 370
 371                /*
 372                 * Check if last_file & path correspond to a D/F conflict;
 373                 * i.e. whether path is last_file+'/'+<something>.
 374                 * If so, remove last_file to make room for path and friends.
 375                 */
 376                if (last_file &&
 377                    len > last_len &&
 378                    memcmp(path, last_file, last_len) == 0 &&
 379                    path[last_len] == '/') {
 380                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 381                        unlink(last_file);
 382                }
 383
 384                /*
 385                 * Determine whether path could exist as a file in the
 386                 * working directory as a possible D/F conflict.  This
 387                 * will only occur when it exists in stage 2 as a
 388                 * file.
 389                 */
 390                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 391                        last_file = path;
 392                        last_len = len;
 393                } else {
 394                        last_file = NULL;
 395                }
 396        }
 397}
 398
 399struct rename {
 400        struct diff_filepair *pair;
 401        struct stage_data *src_entry;
 402        struct stage_data *dst_entry;
 403        unsigned processed:1;
 404};
 405
 406/*
 407 * Get information of all renames which occurred between 'o_tree' and
 408 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 409 * 'b_tree') to be able to associate the correct cache entries with
 410 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 411 */
 412static struct string_list *get_renames(struct merge_options *o,
 413                                       struct tree *tree,
 414                                       struct tree *o_tree,
 415                                       struct tree *a_tree,
 416                                       struct tree *b_tree,
 417                                       struct string_list *entries)
 418{
 419        int i;
 420        struct string_list *renames;
 421        struct diff_options opts;
 422
 423        renames = xcalloc(1, sizeof(struct string_list));
 424        diff_setup(&opts);
 425        DIFF_OPT_SET(&opts, RECURSIVE);
 426        opts.detect_rename = DIFF_DETECT_RENAME;
 427        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 428                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 429                            1000;
 430        opts.rename_score = o->rename_score;
 431        opts.show_rename_progress = o->show_rename_progress;
 432        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 433        if (diff_setup_done(&opts) < 0)
 434                die("diff setup failed");
 435        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 436        diffcore_std(&opts);
 437        if (opts.needed_rename_limit > o->needed_rename_limit)
 438                o->needed_rename_limit = opts.needed_rename_limit;
 439        for (i = 0; i < diff_queued_diff.nr; ++i) {
 440                struct string_list_item *item;
 441                struct rename *re;
 442                struct diff_filepair *pair = diff_queued_diff.queue[i];
 443                if (pair->status != 'R') {
 444                        diff_free_filepair(pair);
 445                        continue;
 446                }
 447                re = xmalloc(sizeof(*re));
 448                re->processed = 0;
 449                re->pair = pair;
 450                item = string_list_lookup(entries, re->pair->one->path);
 451                if (!item)
 452                        re->src_entry = insert_stage_data(re->pair->one->path,
 453                                        o_tree, a_tree, b_tree, entries);
 454                else
 455                        re->src_entry = item->util;
 456
 457                item = string_list_lookup(entries, re->pair->two->path);
 458                if (!item)
 459                        re->dst_entry = insert_stage_data(re->pair->two->path,
 460                                        o_tree, a_tree, b_tree, entries);
 461                else
 462                        re->dst_entry = item->util;
 463                item = string_list_insert(renames, pair->one->path);
 464                item->util = re;
 465        }
 466        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 467        diff_queued_diff.nr = 0;
 468        diff_flush(&opts);
 469        return renames;
 470}
 471
 472static int update_stages_options(const char *path, struct diff_filespec *o,
 473                         struct diff_filespec *a, struct diff_filespec *b,
 474                         int clear, int options)
 475{
 476        if (clear)
 477                if (remove_file_from_cache(path))
 478                        return -1;
 479        if (o)
 480                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 481                        return -1;
 482        if (a)
 483                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 484                        return -1;
 485        if (b)
 486                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 487                        return -1;
 488        return 0;
 489}
 490
 491static int update_stages(const char *path, struct diff_filespec *o,
 492                         struct diff_filespec *a, struct diff_filespec *b,
 493                         int clear)
 494{
 495        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 496        return update_stages_options(path, o, a, b, clear, options);
 497}
 498
 499static int update_stages_and_entry(const char *path,
 500                                   struct stage_data *entry,
 501                                   struct diff_filespec *o,
 502                                   struct diff_filespec *a,
 503                                   struct diff_filespec *b,
 504                                   int clear)
 505{
 506        int options;
 507
 508        entry->processed = 0;
 509        entry->stages[1].mode = o->mode;
 510        entry->stages[2].mode = a->mode;
 511        entry->stages[3].mode = b->mode;
 512        hashcpy(entry->stages[1].sha, o->sha1);
 513        hashcpy(entry->stages[2].sha, a->sha1);
 514        hashcpy(entry->stages[3].sha, b->sha1);
 515        options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 516        return update_stages_options(path, o, a, b, clear, options);
 517}
 518
 519static int remove_file(struct merge_options *o, int clean,
 520                       const char *path, int no_wd)
 521{
 522        int update_cache = o->call_depth || clean;
 523        int update_working_directory = !o->call_depth && !no_wd;
 524
 525        if (update_cache) {
 526                if (remove_file_from_cache(path))
 527                        return -1;
 528        }
 529        if (update_working_directory) {
 530                if (remove_path(path))
 531                        return -1;
 532        }
 533        return 0;
 534}
 535
 536static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 537{
 538        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 539        int suffix = 0;
 540        struct stat st;
 541        char *p = newpath + strlen(path);
 542        strcpy(newpath, path);
 543        *(p++) = '~';
 544        strcpy(p, branch);
 545        for (; *p; ++p)
 546                if ('/' == *p)
 547                        *p = '_';
 548        while (string_list_has_string(&o->current_file_set, newpath) ||
 549               string_list_has_string(&o->current_directory_set, newpath) ||
 550               lstat(newpath, &st) == 0)
 551                sprintf(p, "_%d", suffix++);
 552
 553        string_list_insert(&o->current_file_set, newpath);
 554        return newpath;
 555}
 556
 557static void flush_buffer(int fd, const char *buf, unsigned long size)
 558{
 559        while (size > 0) {
 560                long ret = write_in_full(fd, buf, size);
 561                if (ret < 0) {
 562                        /* Ignore epipe */
 563                        if (errno == EPIPE)
 564                                break;
 565                        die_errno("merge-recursive");
 566                } else if (!ret) {
 567                        die("merge-recursive: disk full?");
 568                }
 569                size -= ret;
 570                buf += ret;
 571        }
 572}
 573
 574static int would_lose_untracked(const char *path)
 575{
 576        int pos = cache_name_pos(path, strlen(path));
 577
 578        if (pos < 0)
 579                pos = -1 - pos;
 580        while (pos < active_nr &&
 581               !strcmp(path, active_cache[pos]->name)) {
 582                /*
 583                 * If stage #0, it is definitely tracked.
 584                 * If it has stage #2 then it was tracked
 585                 * before this merge started.  All other
 586                 * cases the path was not tracked.
 587                 */
 588                switch (ce_stage(active_cache[pos])) {
 589                case 0:
 590                case 2:
 591                        return 0;
 592                }
 593                pos++;
 594        }
 595        return file_exists(path);
 596}
 597
 598static int make_room_for_path(const char *path)
 599{
 600        int status;
 601        const char *msg = "failed to create path '%s'%s";
 602
 603        status = safe_create_leading_directories_const(path);
 604        if (status) {
 605                if (status == -3) {
 606                        /* something else exists */
 607                        error(msg, path, ": perhaps a D/F conflict?");
 608                        return -1;
 609                }
 610                die(msg, path, "");
 611        }
 612
 613        /*
 614         * Do not unlink a file in the work tree if we are not
 615         * tracking it.
 616         */
 617        if (would_lose_untracked(path))
 618                return error("refusing to lose untracked file at '%s'",
 619                             path);
 620
 621        /* Successful unlink is good.. */
 622        if (!unlink(path))
 623                return 0;
 624        /* .. and so is no existing file */
 625        if (errno == ENOENT)
 626                return 0;
 627        /* .. but not some other error (who really cares what?) */
 628        return error(msg, path, ": perhaps a D/F conflict?");
 629}
 630
 631static void update_file_flags(struct merge_options *o,
 632                              const unsigned char *sha,
 633                              unsigned mode,
 634                              const char *path,
 635                              int update_cache,
 636                              int update_wd)
 637{
 638        if (o->call_depth)
 639                update_wd = 0;
 640
 641        if (update_wd) {
 642                enum object_type type;
 643                void *buf;
 644                unsigned long size;
 645
 646                if (S_ISGITLINK(mode)) {
 647                        /*
 648                         * We may later decide to recursively descend into
 649                         * the submodule directory and update its index
 650                         * and/or work tree, but we do not do that now.
 651                         */
 652                        update_wd = 0;
 653                        goto update_index;
 654                }
 655
 656                buf = read_sha1_file(sha, &type, &size);
 657                if (!buf)
 658                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 659                if (type != OBJ_BLOB)
 660                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 661                if (S_ISREG(mode)) {
 662                        struct strbuf strbuf = STRBUF_INIT;
 663                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 664                                free(buf);
 665                                size = strbuf.len;
 666                                buf = strbuf_detach(&strbuf, NULL);
 667                        }
 668                }
 669
 670                if (make_room_for_path(path) < 0) {
 671                        update_wd = 0;
 672                        free(buf);
 673                        goto update_index;
 674                }
 675                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 676                        int fd;
 677                        if (mode & 0100)
 678                                mode = 0777;
 679                        else
 680                                mode = 0666;
 681                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 682                        if (fd < 0)
 683                                die_errno("failed to open '%s'", path);
 684                        flush_buffer(fd, buf, size);
 685                        close(fd);
 686                } else if (S_ISLNK(mode)) {
 687                        char *lnk = xmemdupz(buf, size);
 688                        safe_create_leading_directories_const(path);
 689                        unlink(path);
 690                        if (symlink(lnk, path))
 691                                die_errno("failed to symlink '%s'", path);
 692                        free(lnk);
 693                } else
 694                        die("do not know what to do with %06o %s '%s'",
 695                            mode, sha1_to_hex(sha), path);
 696                free(buf);
 697        }
 698 update_index:
 699        if (update_cache)
 700                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 701}
 702
 703static void update_file(struct merge_options *o,
 704                        int clean,
 705                        const unsigned char *sha,
 706                        unsigned mode,
 707                        const char *path)
 708{
 709        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 710}
 711
 712/* Low level file merging, update and removal */
 713
 714struct merge_file_info {
 715        unsigned char sha[20];
 716        unsigned mode;
 717        unsigned clean:1,
 718                 merge:1;
 719};
 720
 721static int merge_3way(struct merge_options *o,
 722                      mmbuffer_t *result_buf,
 723                      struct diff_filespec *one,
 724                      struct diff_filespec *a,
 725                      struct diff_filespec *b,
 726                      const char *branch1,
 727                      const char *branch2)
 728{
 729        mmfile_t orig, src1, src2;
 730        struct ll_merge_options ll_opts = {0};
 731        char *base_name, *name1, *name2;
 732        int merge_status;
 733
 734        ll_opts.renormalize = o->renormalize;
 735        ll_opts.xdl_opts = o->xdl_opts;
 736
 737        if (o->call_depth) {
 738                ll_opts.virtual_ancestor = 1;
 739                ll_opts.variant = 0;
 740        } else {
 741                switch (o->recursive_variant) {
 742                case MERGE_RECURSIVE_OURS:
 743                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 744                        break;
 745                case MERGE_RECURSIVE_THEIRS:
 746                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 747                        break;
 748                default:
 749                        ll_opts.variant = 0;
 750                        break;
 751                }
 752        }
 753
 754        if (strcmp(a->path, b->path) ||
 755            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 756                base_name = o->ancestor == NULL ? NULL :
 757                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 758                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 759                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 760        } else {
 761                base_name = o->ancestor == NULL ? NULL :
 762                        xstrdup(mkpath("%s", o->ancestor));
 763                name1 = xstrdup(mkpath("%s", branch1));
 764                name2 = xstrdup(mkpath("%s", branch2));
 765        }
 766
 767        read_mmblob(&orig, one->sha1);
 768        read_mmblob(&src1, a->sha1);
 769        read_mmblob(&src2, b->sha1);
 770
 771        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 772                                &src1, name1, &src2, name2, &ll_opts);
 773
 774        free(name1);
 775        free(name2);
 776        free(orig.ptr);
 777        free(src1.ptr);
 778        free(src2.ptr);
 779        return merge_status;
 780}
 781
 782static struct merge_file_info merge_file(struct merge_options *o,
 783                                         struct diff_filespec *one,
 784                                         struct diff_filespec *a,
 785                                         struct diff_filespec *b,
 786                                         const char *branch1,
 787                                         const char *branch2)
 788{
 789        struct merge_file_info result;
 790        result.merge = 0;
 791        result.clean = 1;
 792
 793        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 794                result.clean = 0;
 795                if (S_ISREG(a->mode)) {
 796                        result.mode = a->mode;
 797                        hashcpy(result.sha, a->sha1);
 798                } else {
 799                        result.mode = b->mode;
 800                        hashcpy(result.sha, b->sha1);
 801                }
 802        } else {
 803                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 804                        result.merge = 1;
 805
 806                /*
 807                 * Merge modes
 808                 */
 809                if (a->mode == b->mode || a->mode == one->mode)
 810                        result.mode = b->mode;
 811                else {
 812                        result.mode = a->mode;
 813                        if (b->mode != one->mode) {
 814                                result.clean = 0;
 815                                result.merge = 1;
 816                        }
 817                }
 818
 819                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 820                        hashcpy(result.sha, b->sha1);
 821                else if (sha_eq(b->sha1, one->sha1))
 822                        hashcpy(result.sha, a->sha1);
 823                else if (S_ISREG(a->mode)) {
 824                        mmbuffer_t result_buf;
 825                        int merge_status;
 826
 827                        merge_status = merge_3way(o, &result_buf, one, a, b,
 828                                                  branch1, branch2);
 829
 830                        if ((merge_status < 0) || !result_buf.ptr)
 831                                die("Failed to execute internal merge");
 832
 833                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 834                                            blob_type, result.sha))
 835                                die("Unable to add %s to database",
 836                                    a->path);
 837
 838                        free(result_buf.ptr);
 839                        result.clean = (merge_status == 0);
 840                } else if (S_ISGITLINK(a->mode)) {
 841                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 842                                                       a->sha1, b->sha1);
 843                } else if (S_ISLNK(a->mode)) {
 844                        hashcpy(result.sha, a->sha1);
 845
 846                        if (!sha_eq(a->sha1, b->sha1))
 847                                result.clean = 0;
 848                } else {
 849                        die("unsupported object type in the tree");
 850                }
 851        }
 852
 853        return result;
 854}
 855
 856static void conflict_rename_delete(struct merge_options *o,
 857                                   struct diff_filepair *pair,
 858                                   const char *rename_branch,
 859                                   const char *other_branch)
 860{
 861        char *dest_name = pair->two->path;
 862        int df_conflict = 0;
 863        struct stat st;
 864
 865        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 866               "and deleted in %s",
 867               pair->one->path, pair->two->path, rename_branch,
 868               other_branch);
 869        if (!o->call_depth)
 870                update_stages(dest_name, NULL,
 871                              rename_branch == o->branch1 ? pair->two : NULL,
 872                              rename_branch == o->branch1 ? NULL : pair->two,
 873                              1);
 874        if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 875                dest_name = unique_path(o, dest_name, rename_branch);
 876                df_conflict = 1;
 877        }
 878        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 879        if (df_conflict)
 880                free(dest_name);
 881}
 882
 883static void conflict_rename_rename_1to2(struct merge_options *o,
 884                                        struct diff_filepair *pair1,
 885                                        const char *branch1,
 886                                        struct diff_filepair *pair2,
 887                                        const char *branch2)
 888{
 889        /* One file was renamed in both branches, but to different names. */
 890        char *del[2];
 891        int delp = 0;
 892        const char *ren1_dst = pair1->two->path;
 893        const char *ren2_dst = pair2->two->path;
 894        const char *dst_name1 = ren1_dst;
 895        const char *dst_name2 = ren2_dst;
 896        struct stat st;
 897        if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 898                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 899                output(o, 1, "%s is a directory in %s adding as %s instead",
 900                       ren1_dst, branch2, dst_name1);
 901        }
 902        if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 903                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 904                output(o, 1, "%s is a directory in %s adding as %s instead",
 905                       ren2_dst, branch1, dst_name2);
 906        }
 907        if (o->call_depth) {
 908                remove_file_from_cache(dst_name1);
 909                remove_file_from_cache(dst_name2);
 910                /*
 911                 * Uncomment to leave the conflicting names in the resulting tree
 912                 *
 913                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 914                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 915                 */
 916        } else {
 917                update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 918                update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 919
 920                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 921                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 922        }
 923        while (delp--)
 924                free(del[delp]);
 925}
 926
 927static void conflict_rename_rename_2to1(struct merge_options *o,
 928                                        struct rename *ren1,
 929                                        const char *branch1,
 930                                        struct rename *ren2,
 931                                        const char *branch2)
 932{
 933        /* Two files were renamed to the same thing. */
 934        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 935        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 936        output(o, 1, "Renaming %s to %s and %s to %s instead",
 937               ren1->pair->one->path, new_path1,
 938               ren2->pair->one->path, new_path2);
 939        remove_file(o, 0, ren1->pair->two->path, 0);
 940        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 941        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 942        free(new_path2);
 943        free(new_path1);
 944}
 945
 946static int process_renames(struct merge_options *o,
 947                           struct string_list *a_renames,
 948                           struct string_list *b_renames)
 949{
 950        int clean_merge = 1, i, j;
 951        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 952        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 953        const struct rename *sre;
 954
 955        for (i = 0; i < a_renames->nr; i++) {
 956                sre = a_renames->items[i].util;
 957                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 958                        = sre->dst_entry;
 959        }
 960        for (i = 0; i < b_renames->nr; i++) {
 961                sre = b_renames->items[i].util;
 962                string_list_insert(&b_by_dst, sre->pair->two->path)->util
 963                        = sre->dst_entry;
 964        }
 965
 966        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 967                struct string_list *renames1, *renames2Dst;
 968                struct rename *ren1 = NULL, *ren2 = NULL;
 969                const char *branch1, *branch2;
 970                const char *ren1_src, *ren1_dst;
 971
 972                if (i >= a_renames->nr) {
 973                        ren2 = b_renames->items[j++].util;
 974                } else if (j >= b_renames->nr) {
 975                        ren1 = a_renames->items[i++].util;
 976                } else {
 977                        int compare = strcmp(a_renames->items[i].string,
 978                                             b_renames->items[j].string);
 979                        if (compare <= 0)
 980                                ren1 = a_renames->items[i++].util;
 981                        if (compare >= 0)
 982                                ren2 = b_renames->items[j++].util;
 983                }
 984
 985                /* TODO: refactor, so that 1/2 are not needed */
 986                if (ren1) {
 987                        renames1 = a_renames;
 988                        renames2Dst = &b_by_dst;
 989                        branch1 = o->branch1;
 990                        branch2 = o->branch2;
 991                } else {
 992                        struct rename *tmp;
 993                        renames1 = b_renames;
 994                        renames2Dst = &a_by_dst;
 995                        branch1 = o->branch2;
 996                        branch2 = o->branch1;
 997                        tmp = ren2;
 998                        ren2 = ren1;
 999                        ren1 = tmp;
1000                }
1001
1002                ren1->dst_entry->processed = 1;
1003                ren1->src_entry->processed = 1;
1004
1005                if (ren1->processed)
1006                        continue;
1007                ren1->processed = 1;
1008
1009                ren1_src = ren1->pair->one->path;
1010                ren1_dst = ren1->pair->two->path;
1011
1012                if (ren2) {
1013                        const char *ren2_src = ren2->pair->one->path;
1014                        const char *ren2_dst = ren2->pair->two->path;
1015                        /* Renamed in 1 and renamed in 2 */
1016                        if (strcmp(ren1_src, ren2_src) != 0)
1017                                die("ren1.src != ren2.src");
1018                        ren2->dst_entry->processed = 1;
1019                        ren2->processed = 1;
1020                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1021                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1022                                                              ren1->pair,
1023                                                              ren2->pair,
1024                                                              branch1,
1025                                                              branch2,
1026                                                              ren1->dst_entry,
1027                                                              ren2->dst_entry);
1028                        } else {
1029                                remove_file(o, 1, ren1_src, 1);
1030                                update_stages_and_entry(ren1_dst,
1031                                                        ren1->dst_entry,
1032                                                        ren1->pair->one,
1033                                                        ren1->pair->two,
1034                                                        ren2->pair->two,
1035                                                        1 /* clear */);
1036                        }
1037                } else {
1038                        /* Renamed in 1, maybe changed in 2 */
1039                        struct string_list_item *item;
1040                        /* we only use sha1 and mode of these */
1041                        struct diff_filespec src_other, dst_other;
1042                        int try_merge;
1043
1044                        /*
1045                         * unpack_trees loads entries from common-commit
1046                         * into stage 1, from head-commit into stage 2, and
1047                         * from merge-commit into stage 3.  We keep track
1048                         * of which side corresponds to the rename.
1049                         */
1050                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1051                        int other_stage =   a_renames == renames1 ? 3 : 2;
1052
1053                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1054
1055                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1056                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1057                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1058                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1059                        try_merge = 0;
1060
1061                        if (sha_eq(src_other.sha1, null_sha1)) {
1062                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1063                                        ren1->dst_entry->processed = 0;
1064                                        setup_rename_df_conflict_info(RENAME_DELETE,
1065                                                                      ren1->pair,
1066                                                                      NULL,
1067                                                                      branch1,
1068                                                                      branch2,
1069                                                                      ren1->dst_entry,
1070                                                                      NULL);
1071                                } else {
1072                                        clean_merge = 0;
1073                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1074                                }
1075                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1076                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1077                                /* Added file on the other side
1078                                   identical to the file being
1079                                   renamed: clean merge */
1080                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1081                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1082                                const char *new_path;
1083                                clean_merge = 0;
1084                                try_merge = 1;
1085                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1086                                       "%s added in %s",
1087                                       ren1_src, ren1_dst, branch1,
1088                                       ren1_dst, branch2);
1089                                if (o->call_depth) {
1090                                        struct merge_file_info mfi;
1091                                        struct diff_filespec one, a, b;
1092
1093                                        one.path = a.path = b.path =
1094                                                (char *)ren1_dst;
1095                                        hashcpy(one.sha1, null_sha1);
1096                                        one.mode = 0;
1097                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1098                                        a.mode = ren1->pair->two->mode;
1099                                        hashcpy(b.sha1, dst_other.sha1);
1100                                        b.mode = dst_other.mode;
1101                                        mfi = merge_file(o, &one, &a, &b,
1102                                                         branch1,
1103                                                         branch2);
1104                                        output(o, 1, "Adding merged %s", ren1_dst);
1105                                        update_file(o, 0,
1106                                                    mfi.sha,
1107                                                    mfi.mode,
1108                                                    ren1_dst);
1109                                        try_merge = 0;
1110                                } else {
1111                                        new_path = unique_path(o, ren1_dst, branch2);
1112                                        output(o, 1, "Adding as %s instead", new_path);
1113                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1114                                }
1115                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1116                                ren2 = item->util;
1117                                clean_merge = 0;
1118                                ren2->processed = 1;
1119                                output(o, 1, "CONFLICT (rename/rename): "
1120                                       "Rename %s->%s in %s. "
1121                                       "Rename %s->%s in %s",
1122                                       ren1_src, ren1_dst, branch1,
1123                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1124                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1125                        } else
1126                                try_merge = 1;
1127
1128                        if (try_merge) {
1129                                struct diff_filespec *one, *a, *b;
1130                                src_other.path = (char *)ren1_src;
1131
1132                                one = ren1->pair->one;
1133                                if (a_renames == renames1) {
1134                                        a = ren1->pair->two;
1135                                        b = &src_other;
1136                                } else {
1137                                        b = ren1->pair->two;
1138                                        a = &src_other;
1139                                }
1140                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1141                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1142                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1143                                                                      ren1->pair,
1144                                                                      NULL,
1145                                                                      branch1,
1146                                                                      NULL,
1147                                                                      ren1->dst_entry,
1148                                                                      NULL);
1149                                }
1150                        }
1151                }
1152        }
1153        string_list_clear(&a_by_dst, 0);
1154        string_list_clear(&b_by_dst, 0);
1155
1156        return clean_merge;
1157}
1158
1159static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1160{
1161        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1162}
1163
1164static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1165{
1166        void *buf;
1167        enum object_type type;
1168        unsigned long size;
1169        buf = read_sha1_file(sha1, &type, &size);
1170        if (!buf)
1171                return error("cannot read object %s", sha1_to_hex(sha1));
1172        if (type != OBJ_BLOB) {
1173                free(buf);
1174                return error("object %s is not a blob", sha1_to_hex(sha1));
1175        }
1176        strbuf_attach(dst, buf, size, size + 1);
1177        return 0;
1178}
1179
1180static int blob_unchanged(const unsigned char *o_sha,
1181                          const unsigned char *a_sha,
1182                          int renormalize, const char *path)
1183{
1184        struct strbuf o = STRBUF_INIT;
1185        struct strbuf a = STRBUF_INIT;
1186        int ret = 0; /* assume changed for safety */
1187
1188        if (sha_eq(o_sha, a_sha))
1189                return 1;
1190        if (!renormalize)
1191                return 0;
1192
1193        assert(o_sha && a_sha);
1194        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1195                goto error_return;
1196        /*
1197         * Note: binary | is used so that both renormalizations are
1198         * performed.  Comparison can be skipped if both files are
1199         * unchanged since their sha1s have already been compared.
1200         */
1201        if (renormalize_buffer(path, o.buf, o.len, &o) |
1202            renormalize_buffer(path, a.buf, o.len, &a))
1203                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1204
1205error_return:
1206        strbuf_release(&o);
1207        strbuf_release(&a);
1208        return ret;
1209}
1210
1211static void handle_delete_modify(struct merge_options *o,
1212                                 const char *path,
1213                                 const char *new_path,
1214                                 unsigned char *a_sha, int a_mode,
1215                                 unsigned char *b_sha, int b_mode)
1216{
1217        if (!a_sha) {
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->branch1,
1221                       o->branch2, o->branch2, path,
1222                       path == new_path ? "" : " at ",
1223                       path == new_path ? "" : new_path);
1224                update_file(o, 0, b_sha, b_mode, new_path);
1225        } else {
1226                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1227                       "and modified in %s. Version %s of %s left in tree%s%s.",
1228                       path, o->branch2,
1229                       o->branch1, o->branch1, path,
1230                       path == new_path ? "" : " at ",
1231                       path == new_path ? "" : new_path);
1232                update_file(o, 0, a_sha, a_mode, new_path);
1233        }
1234}
1235
1236static int merge_content(struct merge_options *o,
1237                         const char *path,
1238                         unsigned char *o_sha, int o_mode,
1239                         unsigned char *a_sha, int a_mode,
1240                         unsigned char *b_sha, int b_mode,
1241                         const char *df_rename_conflict_branch)
1242{
1243        const char *reason = "content";
1244        struct merge_file_info mfi;
1245        struct diff_filespec one, a, b;
1246        struct stat st;
1247        unsigned df_conflict_remains = 0;
1248
1249        if (!o_sha) {
1250                reason = "add/add";
1251                o_sha = (unsigned char *)null_sha1;
1252        }
1253        one.path = a.path = b.path = (char *)path;
1254        hashcpy(one.sha1, o_sha);
1255        one.mode = o_mode;
1256        hashcpy(a.sha1, a_sha);
1257        a.mode = a_mode;
1258        hashcpy(b.sha1, b_sha);
1259        b.mode = b_mode;
1260
1261        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1262        if (df_rename_conflict_branch &&
1263            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1264                df_conflict_remains = 1;
1265        }
1266
1267        if (mfi.clean && !df_conflict_remains &&
1268            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode &&
1269            !o->call_depth && !lstat(path, &st)) {
1270                output(o, 3, "Skipped %s (merged same as existing)", path);
1271                add_cacheinfo(mfi.mode, mfi.sha, path,
1272                              0 /*stage*/, 1 /*refresh*/, 0 /*options*/);
1273                return mfi.clean;
1274        } else
1275                output(o, 2, "Auto-merging %s", path);
1276
1277        if (!mfi.clean) {
1278                if (S_ISGITLINK(mfi.mode))
1279                        reason = "submodule";
1280                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1281                                reason, path);
1282        }
1283
1284        if (df_conflict_remains) {
1285                const char *new_path;
1286                update_file_flags(o, mfi.sha, mfi.mode, path,
1287                                  o->call_depth || mfi.clean, 0);
1288                new_path = unique_path(o, path, df_rename_conflict_branch);
1289                mfi.clean = 0;
1290                output(o, 1, "Adding as %s instead", new_path);
1291                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1292        } else {
1293                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1294        }
1295        return mfi.clean;
1296
1297}
1298
1299/* Per entry merge function */
1300static int process_entry(struct merge_options *o,
1301                         const char *path, struct stage_data *entry)
1302{
1303        /*
1304        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1305        print_index_entry("\tpath: ", entry);
1306        */
1307        int clean_merge = 1;
1308        int normalize = o->renormalize;
1309        unsigned o_mode = entry->stages[1].mode;
1310        unsigned a_mode = entry->stages[2].mode;
1311        unsigned b_mode = entry->stages[3].mode;
1312        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1313        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1314        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1315
1316        if (entry->rename_df_conflict_info)
1317                return 1; /* Such cases are handled elsewhere. */
1318
1319        entry->processed = 1;
1320        if (o_sha && (!a_sha || !b_sha)) {
1321                /* Case A: Deleted in one */
1322                if ((!a_sha && !b_sha) ||
1323                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1324                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1325                        /* Deleted in both or deleted in one and
1326                         * unchanged in the other */
1327                        if (a_sha)
1328                                output(o, 2, "Removing %s", path);
1329                        /* do not touch working file if it did not exist */
1330                        remove_file(o, 1, path, !a_sha);
1331                } else if (string_list_has_string(&o->current_directory_set,
1332                                                  path)) {
1333                        entry->processed = 0;
1334                        return 1; /* Assume clean until processed */
1335                } else {
1336                        /* Deleted in one and changed in the other */
1337                        clean_merge = 0;
1338                        handle_delete_modify(o, path, path,
1339                                             a_sha, a_mode, b_sha, b_mode);
1340                }
1341
1342        } else if ((!o_sha && a_sha && !b_sha) ||
1343                   (!o_sha && !a_sha && b_sha)) {
1344                /* Case B: Added in one. */
1345                unsigned mode;
1346                const unsigned char *sha;
1347
1348                if (a_sha) {
1349                        mode = a_mode;
1350                        sha = a_sha;
1351                } else {
1352                        mode = b_mode;
1353                        sha = b_sha;
1354                }
1355                if (string_list_has_string(&o->current_directory_set, path)) {
1356                        /* Handle D->F conflicts after all subfiles */
1357                        entry->processed = 0;
1358                        return 1; /* Assume clean until processed */
1359                } else {
1360                        output(o, 2, "Adding %s", path);
1361                        update_file(o, 1, sha, mode, path);
1362                }
1363        } else if (a_sha && b_sha) {
1364                /* Case C: Added in both (check for same permissions) and */
1365                /* case D: Modified in both, but differently. */
1366                clean_merge = merge_content(o, path,
1367                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1368                                            NULL);
1369        } else if (!o_sha && !a_sha && !b_sha) {
1370                /*
1371                 * this entry was deleted altogether. a_mode == 0 means
1372                 * we had that path and want to actively remove it.
1373                 */
1374                remove_file(o, 1, path, !a_mode);
1375        } else
1376                die("Fatal merge failure, shouldn't happen.");
1377
1378        return clean_merge;
1379}
1380
1381/*
1382 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1383 * cases we can cleanly resolve D/F conflicts, process_entry() can
1384 * clean out all the files below the directory for us.  All D/F
1385 * conflict cases must be handled here at the end to make sure any
1386 * directories that can be cleaned out, are.
1387 *
1388 * Some rename conflicts may also be handled here that don't necessarily
1389 * involve D/F conflicts, since the code to handle them is generic enough
1390 * to handle those rename conflicts with or without D/F conflicts also
1391 * being involved.
1392 */
1393static int process_df_entry(struct merge_options *o,
1394                            const char *path, struct stage_data *entry)
1395{
1396        int clean_merge = 1;
1397        unsigned o_mode = entry->stages[1].mode;
1398        unsigned a_mode = entry->stages[2].mode;
1399        unsigned b_mode = entry->stages[3].mode;
1400        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1401        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1402        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1403        struct stat st;
1404
1405        entry->processed = 1;
1406        if (entry->rename_df_conflict_info) {
1407                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1408                char *src;
1409                switch (conflict_info->rename_type) {
1410                case RENAME_NORMAL:
1411                        clean_merge = merge_content(o, path,
1412                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1413                                                    conflict_info->branch1);
1414                        break;
1415                case RENAME_DELETE:
1416                        clean_merge = 0;
1417                        conflict_rename_delete(o, conflict_info->pair1,
1418                                               conflict_info->branch1,
1419                                               conflict_info->branch2);
1420                        break;
1421                case RENAME_ONE_FILE_TO_TWO:
1422                        src = conflict_info->pair1->one->path;
1423                        clean_merge = 0;
1424                        output(o, 1, "CONFLICT (rename/rename): "
1425                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1426                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1427                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1428                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1429                               o->call_depth ? " (left unresolved)" : "");
1430                        if (o->call_depth) {
1431                                remove_file_from_cache(src);
1432                                update_file(o, 0, conflict_info->pair1->one->sha1,
1433                                            conflict_info->pair1->one->mode, src);
1434                        }
1435                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1436                                                    conflict_info->branch1,
1437                                                    conflict_info->pair2,
1438                                                    conflict_info->branch2);
1439                        conflict_info->dst_entry2->processed = 1;
1440                        break;
1441                default:
1442                        entry->processed = 0;
1443                        break;
1444                }
1445        } else if (o_sha && (!a_sha || !b_sha)) {
1446                /* Modify/delete; deleted side may have put a directory in the way */
1447                const char *new_path = path;
1448                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1449                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1450                clean_merge = 0;
1451                handle_delete_modify(o, path, new_path,
1452                                     a_sha, a_mode, b_sha, b_mode);
1453        } else if (!o_sha && !!a_sha != !!b_sha) {
1454                /* directory -> (directory, file) */
1455                const char *add_branch;
1456                const char *other_branch;
1457                unsigned mode;
1458                const unsigned char *sha;
1459                const char *conf;
1460
1461                if (a_sha) {
1462                        add_branch = o->branch1;
1463                        other_branch = o->branch2;
1464                        mode = a_mode;
1465                        sha = a_sha;
1466                        conf = "file/directory";
1467                } else {
1468                        add_branch = o->branch2;
1469                        other_branch = o->branch1;
1470                        mode = b_mode;
1471                        sha = b_sha;
1472                        conf = "directory/file";
1473                }
1474                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1475                        const char *new_path = unique_path(o, path, add_branch);
1476                        clean_merge = 0;
1477                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1478                               "Adding %s as %s",
1479                               conf, path, other_branch, path, new_path);
1480                        update_file(o, 0, sha, mode, new_path);
1481                } else {
1482                        output(o, 2, "Adding %s", path);
1483                        update_file(o, 1, sha, mode, path);
1484                }
1485        } else {
1486                entry->processed = 0;
1487                return 1; /* not handled; assume clean until processed */
1488        }
1489
1490        return clean_merge;
1491}
1492
1493int merge_trees(struct merge_options *o,
1494                struct tree *head,
1495                struct tree *merge,
1496                struct tree *common,
1497                struct tree **result)
1498{
1499        int code, clean;
1500
1501        if (o->subtree_shift) {
1502                merge = shift_tree_object(head, merge, o->subtree_shift);
1503                common = shift_tree_object(head, common, o->subtree_shift);
1504        }
1505
1506        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1507                output(o, 0, "Already up-to-date!");
1508                *result = head;
1509                return 1;
1510        }
1511
1512        code = git_merge_trees(o->call_depth, common, head, merge);
1513
1514        if (code != 0) {
1515                if (show(o, 4) || o->call_depth)
1516                        die("merging of trees %s and %s failed",
1517                            sha1_to_hex(head->object.sha1),
1518                            sha1_to_hex(merge->object.sha1));
1519                else
1520                        exit(128);
1521        }
1522
1523        if (unmerged_cache()) {
1524                struct string_list *entries, *re_head, *re_merge;
1525                int i;
1526                string_list_clear(&o->current_file_set, 1);
1527                string_list_clear(&o->current_directory_set, 1);
1528                get_files_dirs(o, head);
1529                get_files_dirs(o, merge);
1530
1531                entries = get_unmerged();
1532                make_room_for_directories_of_df_conflicts(o, entries);
1533                re_head  = get_renames(o, head, common, head, merge, entries);
1534                re_merge = get_renames(o, merge, common, head, merge, entries);
1535                clean = process_renames(o, re_head, re_merge);
1536                for (i = 0; i < entries->nr; i++) {
1537                        const char *path = entries->items[i].string;
1538                        struct stage_data *e = entries->items[i].util;
1539                        if (!e->processed
1540                                && !process_entry(o, path, e))
1541                                clean = 0;
1542                }
1543                for (i = 0; i < entries->nr; i++) {
1544                        const char *path = entries->items[i].string;
1545                        struct stage_data *e = entries->items[i].util;
1546                        if (!e->processed
1547                                && !process_df_entry(o, path, e))
1548                                clean = 0;
1549                }
1550                for (i = 0; i < entries->nr; i++) {
1551                        struct stage_data *e = entries->items[i].util;
1552                        if (!e->processed)
1553                                die("Unprocessed path??? %s",
1554                                    entries->items[i].string);
1555                }
1556
1557                string_list_clear(re_merge, 0);
1558                string_list_clear(re_head, 0);
1559                string_list_clear(entries, 1);
1560
1561        }
1562        else
1563                clean = 1;
1564
1565        if (o->call_depth)
1566                *result = write_tree_from_memory(o);
1567
1568        return clean;
1569}
1570
1571static struct commit_list *reverse_commit_list(struct commit_list *list)
1572{
1573        struct commit_list *next = NULL, *current, *backup;
1574        for (current = list; current; current = backup) {
1575                backup = current->next;
1576                current->next = next;
1577                next = current;
1578        }
1579        return next;
1580}
1581
1582/*
1583 * Merge the commits h1 and h2, return the resulting virtual
1584 * commit object and a flag indicating the cleanness of the merge.
1585 */
1586int merge_recursive(struct merge_options *o,
1587                    struct commit *h1,
1588                    struct commit *h2,
1589                    struct commit_list *ca,
1590                    struct commit **result)
1591{
1592        struct commit_list *iter;
1593        struct commit *merged_common_ancestors;
1594        struct tree *mrtree = mrtree;
1595        int clean;
1596
1597        if (show(o, 4)) {
1598                output(o, 4, "Merging:");
1599                output_commit_title(o, h1);
1600                output_commit_title(o, h2);
1601        }
1602
1603        if (!ca) {
1604                ca = get_merge_bases(h1, h2, 1);
1605                ca = reverse_commit_list(ca);
1606        }
1607
1608        if (show(o, 5)) {
1609                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1610                for (iter = ca; iter; iter = iter->next)
1611                        output_commit_title(o, iter->item);
1612        }
1613
1614        merged_common_ancestors = pop_commit(&ca);
1615        if (merged_common_ancestors == NULL) {
1616                /* if there is no common ancestor, make an empty tree */
1617                struct tree *tree = xcalloc(1, sizeof(struct tree));
1618
1619                tree->object.parsed = 1;
1620                tree->object.type = OBJ_TREE;
1621                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1622                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1623        }
1624
1625        for (iter = ca; iter; iter = iter->next) {
1626                const char *saved_b1, *saved_b2;
1627                o->call_depth++;
1628                /*
1629                 * When the merge fails, the result contains files
1630                 * with conflict markers. The cleanness flag is
1631                 * ignored, it was never actually used, as result of
1632                 * merge_trees has always overwritten it: the committed
1633                 * "conflicts" were already resolved.
1634                 */
1635                discard_cache();
1636                saved_b1 = o->branch1;
1637                saved_b2 = o->branch2;
1638                o->branch1 = "Temporary merge branch 1";
1639                o->branch2 = "Temporary merge branch 2";
1640                merge_recursive(o, merged_common_ancestors, iter->item,
1641                                NULL, &merged_common_ancestors);
1642                o->branch1 = saved_b1;
1643                o->branch2 = saved_b2;
1644                o->call_depth--;
1645
1646                if (!merged_common_ancestors)
1647                        die("merge returned no commit");
1648        }
1649
1650        discard_cache();
1651        if (!o->call_depth)
1652                read_cache();
1653
1654        o->ancestor = "merged common ancestors";
1655        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1656                            &mrtree);
1657
1658        if (o->call_depth) {
1659                *result = make_virtual_commit(mrtree, "merged tree");
1660                commit_list_insert(h1, &(*result)->parents);
1661                commit_list_insert(h2, &(*result)->parents->next);
1662        }
1663        flush_output(o);
1664        if (show(o, 2))
1665                diff_warn_rename_limit("merge.renamelimit",
1666                                       o->needed_rename_limit, 0);
1667        return clean;
1668}
1669
1670static struct commit *get_ref(const unsigned char *sha1, const char *name)
1671{
1672        struct object *object;
1673
1674        object = deref_tag(parse_object(sha1), name, strlen(name));
1675        if (!object)
1676                return NULL;
1677        if (object->type == OBJ_TREE)
1678                return make_virtual_commit((struct tree*)object, name);
1679        if (object->type != OBJ_COMMIT)
1680                return NULL;
1681        if (parse_commit((struct commit *)object))
1682                return NULL;
1683        return (struct commit *)object;
1684}
1685
1686int merge_recursive_generic(struct merge_options *o,
1687                            const unsigned char *head,
1688                            const unsigned char *merge,
1689                            int num_base_list,
1690                            const unsigned char **base_list,
1691                            struct commit **result)
1692{
1693        int clean, index_fd;
1694        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1695        struct commit *head_commit = get_ref(head, o->branch1);
1696        struct commit *next_commit = get_ref(merge, o->branch2);
1697        struct commit_list *ca = NULL;
1698
1699        if (base_list) {
1700                int i;
1701                for (i = 0; i < num_base_list; ++i) {
1702                        struct commit *base;
1703                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1704                                return error("Could not parse object '%s'",
1705                                        sha1_to_hex(base_list[i]));
1706                        commit_list_insert(base, &ca);
1707                }
1708        }
1709
1710        index_fd = hold_locked_index(lock, 1);
1711        clean = merge_recursive(o, head_commit, next_commit, ca,
1712                        result);
1713        if (active_cache_changed &&
1714                        (write_cache(index_fd, active_cache, active_nr) ||
1715                         commit_locked_index(lock)))
1716                return error("Unable to write index.");
1717
1718        return clean ? 0 : 1;
1719}
1720
1721static int merge_recursive_config(const char *var, const char *value, void *cb)
1722{
1723        struct merge_options *o = cb;
1724        if (!strcasecmp(var, "merge.verbosity")) {
1725                o->verbosity = git_config_int(var, value);
1726                return 0;
1727        }
1728        if (!strcasecmp(var, "diff.renamelimit")) {
1729                o->diff_rename_limit = git_config_int(var, value);
1730                return 0;
1731        }
1732        if (!strcasecmp(var, "merge.renamelimit")) {
1733                o->merge_rename_limit = git_config_int(var, value);
1734                return 0;
1735        }
1736        return git_xmerge_config(var, value, cb);
1737}
1738
1739void init_merge_options(struct merge_options *o)
1740{
1741        memset(o, 0, sizeof(struct merge_options));
1742        o->verbosity = 2;
1743        o->buffer_output = 1;
1744        o->diff_rename_limit = -1;
1745        o->merge_rename_limit = -1;
1746        o->renormalize = 0;
1747        git_config(merge_recursive_config, o);
1748        if (getenv("GIT_MERGE_VERBOSITY"))
1749                o->verbosity =
1750                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1751        if (o->verbosity >= 5)
1752                o->buffer_output = 0;
1753        strbuf_init(&o->obuf, 0);
1754        memset(&o->current_file_set, 0, sizeof(struct string_list));
1755        o->current_file_set.strdup_strings = 1;
1756        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1757        o->current_directory_set.strdup_strings = 1;
1758}
1759
1760int parse_merge_opt(struct merge_options *o, const char *s)
1761{
1762        if (!s || !*s)
1763                return -1;
1764        if (!strcmp(s, "ours"))
1765                o->recursive_variant = MERGE_RECURSIVE_OURS;
1766        else if (!strcmp(s, "theirs"))
1767                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1768        else if (!strcmp(s, "subtree"))
1769                o->subtree_shift = "";
1770        else if (!prefixcmp(s, "subtree="))
1771                o->subtree_shift = s + strlen("subtree=");
1772        else if (!strcmp(s, "patience"))
1773                o->xdl_opts |= XDF_PATIENCE_DIFF;
1774        else if (!strcmp(s, "ignore-space-change"))
1775                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1776        else if (!strcmp(s, "ignore-all-space"))
1777                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1778        else if (!strcmp(s, "ignore-space-at-eol"))
1779                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1780        else if (!strcmp(s, "renormalize"))
1781                o->renormalize = 1;
1782        else if (!strcmp(s, "no-renormalize"))
1783                o->renormalize = 0;
1784        else if (!prefixcmp(s, "rename-threshold=")) {
1785                const char *score = s + strlen("rename-threshold=");
1786                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1787                        return -1;
1788        }
1789        else
1790                return -1;
1791        return 0;
1792}