merge-recursive.con commit Merge branch 'jk/strbuf-vaddf' (d0ef5a7)
   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{
  88        struct
  89        {
  90                unsigned mode;
  91                unsigned char sha[20];
  92        } stages[4];
  93        struct rename_df_conflict_info *rename_df_conflict_info;
  94        unsigned processed:1;
  95};
  96
  97static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
  98                                                 struct diff_filepair *pair1,
  99                                                 struct diff_filepair *pair2,
 100                                                 const char *branch1,
 101                                                 const char *branch2,
 102                                                 struct stage_data *dst_entry1,
 103                                                 struct stage_data *dst_entry2)
 104{
 105        struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
 106        ci->rename_type = rename_type;
 107        ci->pair1 = pair1;
 108        ci->branch1 = branch1;
 109        ci->branch2 = branch2;
 110
 111        ci->dst_entry1 = dst_entry1;
 112        dst_entry1->rename_df_conflict_info = ci;
 113        dst_entry1->processed = 0;
 114
 115        assert(!pair2 == !dst_entry2);
 116        if (dst_entry2) {
 117                ci->dst_entry2 = dst_entry2;
 118                ci->pair2 = pair2;
 119                dst_entry2->rename_df_conflict_info = ci;
 120                dst_entry2->processed = 0;
 121        }
 122}
 123
 124static int show(struct merge_options *o, int v)
 125{
 126        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 127}
 128
 129static void flush_output(struct merge_options *o)
 130{
 131        if (o->obuf.len) {
 132                fputs(o->obuf.buf, stdout);
 133                strbuf_reset(&o->obuf);
 134        }
 135}
 136
 137__attribute__((format (printf, 3, 4)))
 138static void output(struct merge_options *o, int v, const char *fmt, ...)
 139{
 140        va_list ap;
 141
 142        if (!show(o, v))
 143                return;
 144
 145        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 146        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 147        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 148
 149        va_start(ap, fmt);
 150        strbuf_vaddf(&o->obuf, fmt, ap);
 151        va_end(ap);
 152
 153        strbuf_add(&o->obuf, "\n", 1);
 154        if (!o->buffer_output)
 155                flush_output(o);
 156}
 157
 158static void output_commit_title(struct merge_options *o, struct commit *commit)
 159{
 160        int i;
 161        flush_output(o);
 162        for (i = o->call_depth; i--;)
 163                fputs("  ", stdout);
 164        if (commit->util)
 165                printf("virtual %s\n", (char *)commit->util);
 166        else {
 167                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 168                if (parse_commit(commit) != 0)
 169                        printf("(bad commit)\n");
 170                else {
 171                        const char *title;
 172                        int len = find_commit_subject(commit->buffer, &title);
 173                        if (len)
 174                                printf("%.*s\n", len, title);
 175                }
 176        }
 177}
 178
 179static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 180                const char *path, int stage, int refresh, int options)
 181{
 182        struct cache_entry *ce;
 183        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 184        if (!ce)
 185                return error("addinfo_cache failed for path '%s'", path);
 186        return add_cache_entry(ce, options);
 187}
 188
 189static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 190{
 191        parse_tree(tree);
 192        init_tree_desc(desc, tree->buffer, tree->size);
 193}
 194
 195static int git_merge_trees(int index_only,
 196                           struct tree *common,
 197                           struct tree *head,
 198                           struct tree *merge)
 199{
 200        int rc;
 201        struct tree_desc t[3];
 202        struct unpack_trees_options opts;
 203
 204        memset(&opts, 0, sizeof(opts));
 205        if (index_only)
 206                opts.index_only = 1;
 207        else
 208                opts.update = 1;
 209        opts.merge = 1;
 210        opts.head_idx = 2;
 211        opts.fn = threeway_merge;
 212        opts.src_index = &the_index;
 213        opts.dst_index = &the_index;
 214        setup_unpack_trees_porcelain(&opts, "merge");
 215
 216        init_tree_desc_from_tree(t+0, common);
 217        init_tree_desc_from_tree(t+1, head);
 218        init_tree_desc_from_tree(t+2, merge);
 219
 220        rc = unpack_trees(3, t, &opts);
 221        cache_tree_free(&active_cache_tree);
 222        return rc;
 223}
 224
 225struct tree *write_tree_from_memory(struct merge_options *o)
 226{
 227        struct tree *result = NULL;
 228
 229        if (unmerged_cache()) {
 230                int i;
 231                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 232                for (i = 0; i < active_nr; i++) {
 233                        struct cache_entry *ce = active_cache[i];
 234                        if (ce_stage(ce))
 235                                fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
 236                                        (int)ce_namelen(ce), ce->name);
 237                }
 238                die("Bug in merge-recursive.c");
 239        }
 240
 241        if (!active_cache_tree)
 242                active_cache_tree = cache_tree();
 243
 244        if (!cache_tree_fully_valid(active_cache_tree) &&
 245            cache_tree_update(active_cache_tree,
 246                              active_cache, active_nr, 0, 0) < 0)
 247                die("error building trees");
 248
 249        result = lookup_tree(active_cache_tree->sha1);
 250
 251        return result;
 252}
 253
 254static int save_files_dirs(const unsigned char *sha1,
 255                const char *base, int baselen, const char *path,
 256                unsigned int mode, int stage, void *context)
 257{
 258        int len = strlen(path);
 259        char *newpath = xmalloc(baselen + len + 1);
 260        struct merge_options *o = context;
 261
 262        memcpy(newpath, base, baselen);
 263        memcpy(newpath + baselen, path, len);
 264        newpath[baselen + len] = '\0';
 265
 266        if (S_ISDIR(mode))
 267                string_list_insert(&o->current_directory_set, newpath);
 268        else
 269                string_list_insert(&o->current_file_set, newpath);
 270        free(newpath);
 271
 272        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 273}
 274
 275static int get_files_dirs(struct merge_options *o, struct tree *tree)
 276{
 277        int n;
 278        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 279                return 0;
 280        n = o->current_file_set.nr + o->current_directory_set.nr;
 281        return n;
 282}
 283
 284/*
 285 * Returns an index_entry instance which doesn't have to correspond to
 286 * a real cache entry in Git's index.
 287 */
 288static struct stage_data *insert_stage_data(const char *path,
 289                struct tree *o, struct tree *a, struct tree *b,
 290                struct string_list *entries)
 291{
 292        struct string_list_item *item;
 293        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 294        get_tree_entry(o->object.sha1, path,
 295                        e->stages[1].sha, &e->stages[1].mode);
 296        get_tree_entry(a->object.sha1, path,
 297                        e->stages[2].sha, &e->stages[2].mode);
 298        get_tree_entry(b->object.sha1, path,
 299                        e->stages[3].sha, &e->stages[3].mode);
 300        item = string_list_insert(entries, path);
 301        item->util = e;
 302        return e;
 303}
 304
 305/*
 306 * Create a dictionary mapping file names to stage_data objects. The
 307 * dictionary contains one entry for every path with a non-zero stage entry.
 308 */
 309static struct string_list *get_unmerged(void)
 310{
 311        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 312        int i;
 313
 314        unmerged->strdup_strings = 1;
 315
 316        for (i = 0; i < active_nr; i++) {
 317                struct string_list_item *item;
 318                struct stage_data *e;
 319                struct cache_entry *ce = active_cache[i];
 320                if (!ce_stage(ce))
 321                        continue;
 322
 323                item = string_list_lookup(unmerged, ce->name);
 324                if (!item) {
 325                        item = string_list_insert(unmerged, ce->name);
 326                        item->util = xcalloc(1, sizeof(struct stage_data));
 327                }
 328                e = item->util;
 329                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 330                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 331        }
 332
 333        return unmerged;
 334}
 335
 336static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 337                                                      struct string_list *entries)
 338{
 339        /* If there are D/F conflicts, and the paths currently exist
 340         * in the working copy as a file, we want to remove them to
 341         * make room for the corresponding directory.  Such paths will
 342         * later be processed in process_df_entry() at the end.  If
 343         * the corresponding directory ends up being removed by the
 344         * merge, then the file will be reinstated at that time;
 345         * otherwise, if the file is not supposed to be removed by the
 346         * merge, the contents of the file will be placed in another
 347         * unique filename.
 348         *
 349         * NOTE: This function relies on the fact that entries for a
 350         * D/F conflict will appear adjacent in the index, with the
 351         * entries for the file appearing before entries for paths
 352         * below the corresponding directory.
 353         */
 354        const char *last_file = NULL;
 355        int last_len = 0;
 356        struct stage_data *last_e;
 357        int i;
 358
 359        for (i = 0; i < entries->nr; i++) {
 360                const char *path = entries->items[i].string;
 361                int len = strlen(path);
 362                struct stage_data *e = entries->items[i].util;
 363
 364                /*
 365                 * Check if last_file & path correspond to a D/F conflict;
 366                 * i.e. whether path is last_file+'/'+<something>.
 367                 * If so, remove last_file to make room for path and friends.
 368                 */
 369                if (last_file &&
 370                    len > last_len &&
 371                    memcmp(path, last_file, last_len) == 0 &&
 372                    path[last_len] == '/') {
 373                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 374                        unlink(last_file);
 375                }
 376
 377                /*
 378                 * Determine whether path could exist as a file in the
 379                 * working directory as a possible D/F conflict.  This
 380                 * will only occur when it exists in stage 2 as a
 381                 * file.
 382                 */
 383                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 384                        last_file = path;
 385                        last_len = len;
 386                        last_e = e;
 387                } else {
 388                        last_file = NULL;
 389                }
 390        }
 391}
 392
 393struct rename
 394{
 395        struct diff_filepair *pair;
 396        struct stage_data *src_entry;
 397        struct stage_data *dst_entry;
 398        unsigned processed:1;
 399};
 400
 401/*
 402 * Get information of all renames which occurred between 'o_tree' and
 403 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 404 * 'b_tree') to be able to associate the correct cache entries with
 405 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 406 */
 407static struct string_list *get_renames(struct merge_options *o,
 408                                       struct tree *tree,
 409                                       struct tree *o_tree,
 410                                       struct tree *a_tree,
 411                                       struct tree *b_tree,
 412                                       struct string_list *entries)
 413{
 414        int i;
 415        struct string_list *renames;
 416        struct diff_options opts;
 417
 418        renames = xcalloc(1, sizeof(struct string_list));
 419        diff_setup(&opts);
 420        DIFF_OPT_SET(&opts, RECURSIVE);
 421        opts.detect_rename = DIFF_DETECT_RENAME;
 422        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 423                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 424                            500;
 425        opts.rename_score = o->rename_score;
 426        opts.warn_on_too_large_rename = 1;
 427        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 428        if (diff_setup_done(&opts) < 0)
 429                die("diff setup failed");
 430        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 431        diffcore_std(&opts);
 432        for (i = 0; i < diff_queued_diff.nr; ++i) {
 433                struct string_list_item *item;
 434                struct rename *re;
 435                struct diff_filepair *pair = diff_queued_diff.queue[i];
 436                if (pair->status != 'R') {
 437                        diff_free_filepair(pair);
 438                        continue;
 439                }
 440                re = xmalloc(sizeof(*re));
 441                re->processed = 0;
 442                re->pair = pair;
 443                item = string_list_lookup(entries, re->pair->one->path);
 444                if (!item)
 445                        re->src_entry = insert_stage_data(re->pair->one->path,
 446                                        o_tree, a_tree, b_tree, entries);
 447                else
 448                        re->src_entry = item->util;
 449
 450                item = string_list_lookup(entries, re->pair->two->path);
 451                if (!item)
 452                        re->dst_entry = insert_stage_data(re->pair->two->path,
 453                                        o_tree, a_tree, b_tree, entries);
 454                else
 455                        re->dst_entry = item->util;
 456                item = string_list_insert(renames, pair->one->path);
 457                item->util = re;
 458        }
 459        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 460        diff_queued_diff.nr = 0;
 461        diff_flush(&opts);
 462        return renames;
 463}
 464
 465static int update_stages_options(const char *path, struct diff_filespec *o,
 466                         struct diff_filespec *a, struct diff_filespec *b,
 467                         int clear, int options)
 468{
 469        if (clear)
 470                if (remove_file_from_cache(path))
 471                        return -1;
 472        if (o)
 473                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 474                        return -1;
 475        if (a)
 476                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 477                        return -1;
 478        if (b)
 479                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 480                        return -1;
 481        return 0;
 482}
 483
 484static int update_stages(const char *path, struct diff_filespec *o,
 485                         struct diff_filespec *a, struct diff_filespec *b,
 486                         int clear)
 487{
 488        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 489        return update_stages_options(path, o, a, b, clear, options);
 490}
 491
 492static int update_stages_and_entry(const char *path,
 493                                   struct stage_data *entry,
 494                                   struct diff_filespec *o,
 495                                   struct diff_filespec *a,
 496                                   struct diff_filespec *b,
 497                                   int clear)
 498{
 499        int options;
 500
 501        entry->processed = 0;
 502        entry->stages[1].mode = o->mode;
 503        entry->stages[2].mode = a->mode;
 504        entry->stages[3].mode = b->mode;
 505        hashcpy(entry->stages[1].sha, o->sha1);
 506        hashcpy(entry->stages[2].sha, a->sha1);
 507        hashcpy(entry->stages[3].sha, b->sha1);
 508        options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 509        return update_stages_options(path, o, a, b, clear, options);
 510}
 511
 512static int remove_file(struct merge_options *o, int clean,
 513                       const char *path, int no_wd)
 514{
 515        int update_cache = o->call_depth || clean;
 516        int update_working_directory = !o->call_depth && !no_wd;
 517
 518        if (update_cache) {
 519                if (remove_file_from_cache(path))
 520                        return -1;
 521        }
 522        if (update_working_directory) {
 523                if (remove_path(path))
 524                        return -1;
 525        }
 526        return 0;
 527}
 528
 529static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 530{
 531        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 532        int suffix = 0;
 533        struct stat st;
 534        char *p = newpath + strlen(path);
 535        strcpy(newpath, path);
 536        *(p++) = '~';
 537        strcpy(p, branch);
 538        for (; *p; ++p)
 539                if ('/' == *p)
 540                        *p = '_';
 541        while (string_list_has_string(&o->current_file_set, newpath) ||
 542               string_list_has_string(&o->current_directory_set, newpath) ||
 543               lstat(newpath, &st) == 0)
 544                sprintf(p, "_%d", suffix++);
 545
 546        string_list_insert(&o->current_file_set, newpath);
 547        return newpath;
 548}
 549
 550static void flush_buffer(int fd, const char *buf, unsigned long size)
 551{
 552        while (size > 0) {
 553                long ret = write_in_full(fd, buf, size);
 554                if (ret < 0) {
 555                        /* Ignore epipe */
 556                        if (errno == EPIPE)
 557                                break;
 558                        die_errno("merge-recursive");
 559                } else if (!ret) {
 560                        die("merge-recursive: disk full?");
 561                }
 562                size -= ret;
 563                buf += ret;
 564        }
 565}
 566
 567static int would_lose_untracked(const char *path)
 568{
 569        int pos = cache_name_pos(path, strlen(path));
 570
 571        if (pos < 0)
 572                pos = -1 - pos;
 573        while (pos < active_nr &&
 574               !strcmp(path, active_cache[pos]->name)) {
 575                /*
 576                 * If stage #0, it is definitely tracked.
 577                 * If it has stage #2 then it was tracked
 578                 * before this merge started.  All other
 579                 * cases the path was not tracked.
 580                 */
 581                switch (ce_stage(active_cache[pos])) {
 582                case 0:
 583                case 2:
 584                        return 0;
 585                }
 586                pos++;
 587        }
 588        return file_exists(path);
 589}
 590
 591static int make_room_for_path(const char *path)
 592{
 593        int status;
 594        const char *msg = "failed to create path '%s'%s";
 595
 596        status = safe_create_leading_directories_const(path);
 597        if (status) {
 598                if (status == -3) {
 599                        /* something else exists */
 600                        error(msg, path, ": perhaps a D/F conflict?");
 601                        return -1;
 602                }
 603                die(msg, path, "");
 604        }
 605
 606        /*
 607         * Do not unlink a file in the work tree if we are not
 608         * tracking it.
 609         */
 610        if (would_lose_untracked(path))
 611                return error("refusing to lose untracked file at '%s'",
 612                             path);
 613
 614        /* Successful unlink is good.. */
 615        if (!unlink(path))
 616                return 0;
 617        /* .. and so is no existing file */
 618        if (errno == ENOENT)
 619                return 0;
 620        /* .. but not some other error (who really cares what?) */
 621        return error(msg, path, ": perhaps a D/F conflict?");
 622}
 623
 624static void update_file_flags(struct merge_options *o,
 625                              const unsigned char *sha,
 626                              unsigned mode,
 627                              const char *path,
 628                              int update_cache,
 629                              int update_wd)
 630{
 631        if (o->call_depth)
 632                update_wd = 0;
 633
 634        if (update_wd) {
 635                enum object_type type;
 636                void *buf;
 637                unsigned long size;
 638
 639                if (S_ISGITLINK(mode)) {
 640                        /*
 641                         * We may later decide to recursively descend into
 642                         * the submodule directory and update its index
 643                         * and/or work tree, but we do not do that now.
 644                         */
 645                        update_wd = 0;
 646                        goto update_index;
 647                }
 648
 649                buf = read_sha1_file(sha, &type, &size);
 650                if (!buf)
 651                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 652                if (type != OBJ_BLOB)
 653                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 654                if (S_ISREG(mode)) {
 655                        struct strbuf strbuf = STRBUF_INIT;
 656                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 657                                free(buf);
 658                                size = strbuf.len;
 659                                buf = strbuf_detach(&strbuf, NULL);
 660                        }
 661                }
 662
 663                if (make_room_for_path(path) < 0) {
 664                        update_wd = 0;
 665                        free(buf);
 666                        goto update_index;
 667                }
 668                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 669                        int fd;
 670                        if (mode & 0100)
 671                                mode = 0777;
 672                        else
 673                                mode = 0666;
 674                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 675                        if (fd < 0)
 676                                die_errno("failed to open '%s'", path);
 677                        flush_buffer(fd, buf, size);
 678                        close(fd);
 679                } else if (S_ISLNK(mode)) {
 680                        char *lnk = xmemdupz(buf, size);
 681                        safe_create_leading_directories_const(path);
 682                        unlink(path);
 683                        if (symlink(lnk, path))
 684                                die_errno("failed to symlink '%s'", path);
 685                        free(lnk);
 686                } else
 687                        die("do not know what to do with %06o %s '%s'",
 688                            mode, sha1_to_hex(sha), path);
 689                free(buf);
 690        }
 691 update_index:
 692        if (update_cache)
 693                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 694}
 695
 696static void update_file(struct merge_options *o,
 697                        int clean,
 698                        const unsigned char *sha,
 699                        unsigned mode,
 700                        const char *path)
 701{
 702        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 703}
 704
 705/* Low level file merging, update and removal */
 706
 707struct merge_file_info
 708{
 709        unsigned char sha[20];
 710        unsigned mode;
 711        unsigned clean:1,
 712                 merge:1;
 713};
 714
 715static int merge_3way(struct merge_options *o,
 716                      mmbuffer_t *result_buf,
 717                      struct diff_filespec *one,
 718                      struct diff_filespec *a,
 719                      struct diff_filespec *b,
 720                      const char *branch1,
 721                      const char *branch2)
 722{
 723        mmfile_t orig, src1, src2;
 724        struct ll_merge_options ll_opts = {0};
 725        char *base_name, *name1, *name2;
 726        int merge_status;
 727
 728        ll_opts.renormalize = o->renormalize;
 729        ll_opts.xdl_opts = o->xdl_opts;
 730
 731        if (o->call_depth) {
 732                ll_opts.virtual_ancestor = 1;
 733                ll_opts.variant = 0;
 734        } else {
 735                switch (o->recursive_variant) {
 736                case MERGE_RECURSIVE_OURS:
 737                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 738                        break;
 739                case MERGE_RECURSIVE_THEIRS:
 740                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 741                        break;
 742                default:
 743                        ll_opts.variant = 0;
 744                        break;
 745                }
 746        }
 747
 748        if (strcmp(a->path, b->path) ||
 749            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 750                base_name = o->ancestor == NULL ? NULL :
 751                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 752                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 753                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 754        } else {
 755                base_name = o->ancestor == NULL ? NULL :
 756                        xstrdup(mkpath("%s", o->ancestor));
 757                name1 = xstrdup(mkpath("%s", branch1));
 758                name2 = xstrdup(mkpath("%s", branch2));
 759        }
 760
 761        read_mmblob(&orig, one->sha1);
 762        read_mmblob(&src1, a->sha1);
 763        read_mmblob(&src2, b->sha1);
 764
 765        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 766                                &src1, name1, &src2, name2, &ll_opts);
 767
 768        free(name1);
 769        free(name2);
 770        free(orig.ptr);
 771        free(src1.ptr);
 772        free(src2.ptr);
 773        return merge_status;
 774}
 775
 776static struct merge_file_info merge_file(struct merge_options *o,
 777                                         struct diff_filespec *one,
 778                                         struct diff_filespec *a,
 779                                         struct diff_filespec *b,
 780                                         const char *branch1,
 781                                         const char *branch2)
 782{
 783        struct merge_file_info result;
 784        result.merge = 0;
 785        result.clean = 1;
 786
 787        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 788                result.clean = 0;
 789                if (S_ISREG(a->mode)) {
 790                        result.mode = a->mode;
 791                        hashcpy(result.sha, a->sha1);
 792                } else {
 793                        result.mode = b->mode;
 794                        hashcpy(result.sha, b->sha1);
 795                }
 796        } else {
 797                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 798                        result.merge = 1;
 799
 800                /*
 801                 * Merge modes
 802                 */
 803                if (a->mode == b->mode || a->mode == one->mode)
 804                        result.mode = b->mode;
 805                else {
 806                        result.mode = a->mode;
 807                        if (b->mode != one->mode) {
 808                                result.clean = 0;
 809                                result.merge = 1;
 810                        }
 811                }
 812
 813                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 814                        hashcpy(result.sha, b->sha1);
 815                else if (sha_eq(b->sha1, one->sha1))
 816                        hashcpy(result.sha, a->sha1);
 817                else if (S_ISREG(a->mode)) {
 818                        mmbuffer_t result_buf;
 819                        int merge_status;
 820
 821                        merge_status = merge_3way(o, &result_buf, one, a, b,
 822                                                  branch1, branch2);
 823
 824                        if ((merge_status < 0) || !result_buf.ptr)
 825                                die("Failed to execute internal merge");
 826
 827                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 828                                            blob_type, result.sha))
 829                                die("Unable to add %s to database",
 830                                    a->path);
 831
 832                        free(result_buf.ptr);
 833                        result.clean = (merge_status == 0);
 834                } else if (S_ISGITLINK(a->mode)) {
 835                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 836                                                       a->sha1, b->sha1);
 837                } else if (S_ISLNK(a->mode)) {
 838                        hashcpy(result.sha, a->sha1);
 839
 840                        if (!sha_eq(a->sha1, b->sha1))
 841                                result.clean = 0;
 842                } else {
 843                        die("unsupported object type in the tree");
 844                }
 845        }
 846
 847        return result;
 848}
 849
 850static void conflict_rename_delete(struct merge_options *o,
 851                                   struct diff_filepair *pair,
 852                                   const char *rename_branch,
 853                                   const char *other_branch)
 854{
 855        char *dest_name = pair->two->path;
 856        int df_conflict = 0;
 857        struct stat st;
 858
 859        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 860               "and deleted in %s",
 861               pair->one->path, pair->two->path, rename_branch,
 862               other_branch);
 863        if (!o->call_depth)
 864                update_stages(dest_name, NULL,
 865                              rename_branch == o->branch1 ? pair->two : NULL,
 866                              rename_branch == o->branch1 ? NULL : pair->two,
 867                              1);
 868        if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 869                dest_name = unique_path(o, dest_name, rename_branch);
 870                df_conflict = 1;
 871        }
 872        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 873        if (df_conflict)
 874                free(dest_name);
 875}
 876
 877static void conflict_rename_rename_1to2(struct merge_options *o,
 878                                        struct diff_filepair *pair1,
 879                                        const char *branch1,
 880                                        struct diff_filepair *pair2,
 881                                        const char *branch2)
 882{
 883        /* One file was renamed in both branches, but to different names. */
 884        char *del[2];
 885        int delp = 0;
 886        const char *ren1_dst = pair1->two->path;
 887        const char *ren2_dst = pair2->two->path;
 888        const char *dst_name1 = ren1_dst;
 889        const char *dst_name2 = ren2_dst;
 890        struct stat st;
 891        if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 892                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 893                output(o, 1, "%s is a directory in %s adding as %s instead",
 894                       ren1_dst, branch2, dst_name1);
 895        }
 896        if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 897                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 898                output(o, 1, "%s is a directory in %s adding as %s instead",
 899                       ren2_dst, branch1, dst_name2);
 900        }
 901        if (o->call_depth) {
 902                remove_file_from_cache(dst_name1);
 903                remove_file_from_cache(dst_name2);
 904                /*
 905                 * Uncomment to leave the conflicting names in the resulting tree
 906                 *
 907                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 908                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 909                 */
 910        } else {
 911                update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 912                update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 913
 914                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 915                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 916        }
 917        while (delp--)
 918                free(del[delp]);
 919}
 920
 921static void conflict_rename_rename_2to1(struct merge_options *o,
 922                                        struct rename *ren1,
 923                                        const char *branch1,
 924                                        struct rename *ren2,
 925                                        const char *branch2)
 926{
 927        /* Two files were renamed to the same thing. */
 928        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 929        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 930        output(o, 1, "Renaming %s to %s and %s to %s instead",
 931               ren1->pair->one->path, new_path1,
 932               ren2->pair->one->path, new_path2);
 933        remove_file(o, 0, ren1->pair->two->path, 0);
 934        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 935        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 936        free(new_path2);
 937        free(new_path1);
 938}
 939
 940static int process_renames(struct merge_options *o,
 941                           struct string_list *a_renames,
 942                           struct string_list *b_renames)
 943{
 944        int clean_merge = 1, i, j;
 945        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 946        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 947        const struct rename *sre;
 948
 949        for (i = 0; i < a_renames->nr; i++) {
 950                sre = a_renames->items[i].util;
 951                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 952                        = sre->dst_entry;
 953        }
 954        for (i = 0; i < b_renames->nr; i++) {
 955                sre = b_renames->items[i].util;
 956                string_list_insert(&b_by_dst, sre->pair->two->path)->util
 957                        = sre->dst_entry;
 958        }
 959
 960        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 961                char *src;
 962                struct string_list *renames1, *renames2Dst;
 963                struct rename *ren1 = NULL, *ren2 = NULL;
 964                const char *branch1, *branch2;
 965                const char *ren1_src, *ren1_dst;
 966
 967                if (i >= a_renames->nr) {
 968                        ren2 = b_renames->items[j++].util;
 969                } else if (j >= b_renames->nr) {
 970                        ren1 = a_renames->items[i++].util;
 971                } else {
 972                        int compare = strcmp(a_renames->items[i].string,
 973                                             b_renames->items[j].string);
 974                        if (compare <= 0)
 975                                ren1 = a_renames->items[i++].util;
 976                        if (compare >= 0)
 977                                ren2 = b_renames->items[j++].util;
 978                }
 979
 980                /* TODO: refactor, so that 1/2 are not needed */
 981                if (ren1) {
 982                        renames1 = a_renames;
 983                        renames2Dst = &b_by_dst;
 984                        branch1 = o->branch1;
 985                        branch2 = o->branch2;
 986                } else {
 987                        struct rename *tmp;
 988                        renames1 = b_renames;
 989                        renames2Dst = &a_by_dst;
 990                        branch1 = o->branch2;
 991                        branch2 = o->branch1;
 992                        tmp = ren2;
 993                        ren2 = ren1;
 994                        ren1 = tmp;
 995                }
 996                src = ren1->pair->one->path;
 997
 998                ren1->dst_entry->processed = 1;
 999                ren1->src_entry->processed = 1;
1000
1001                if (ren1->processed)
1002                        continue;
1003                ren1->processed = 1;
1004
1005                ren1_src = ren1->pair->one->path;
1006                ren1_dst = ren1->pair->two->path;
1007
1008                if (ren2) {
1009                        const char *ren2_src = ren2->pair->one->path;
1010                        const char *ren2_dst = ren2->pair->two->path;
1011                        /* Renamed in 1 and renamed in 2 */
1012                        if (strcmp(ren1_src, ren2_src) != 0)
1013                                die("ren1.src != ren2.src");
1014                        ren2->dst_entry->processed = 1;
1015                        ren2->processed = 1;
1016                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1017                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1018                                                              ren1->pair,
1019                                                              ren2->pair,
1020                                                              branch1,
1021                                                              branch2,
1022                                                              ren1->dst_entry,
1023                                                              ren2->dst_entry);
1024                        } else {
1025                                remove_file(o, 1, ren1_src, 1);
1026                                update_stages_and_entry(ren1_dst,
1027                                                        ren1->dst_entry,
1028                                                        ren1->pair->one,
1029                                                        ren1->pair->two,
1030                                                        ren2->pair->two,
1031                                                        1 /* clear */);
1032                        }
1033                } else {
1034                        /* Renamed in 1, maybe changed in 2 */
1035                        struct string_list_item *item;
1036                        /* we only use sha1 and mode of these */
1037                        struct diff_filespec src_other, dst_other;
1038                        int try_merge;
1039
1040                        /*
1041                         * unpack_trees loads entries from common-commit
1042                         * into stage 1, from head-commit into stage 2, and
1043                         * from merge-commit into stage 3.  We keep track
1044                         * of which side corresponds to the rename.
1045                         */
1046                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1047                        int other_stage =   a_renames == renames1 ? 3 : 2;
1048
1049                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1050
1051                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1052                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1053                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1054                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1055                        try_merge = 0;
1056
1057                        if (sha_eq(src_other.sha1, null_sha1)) {
1058                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1059                                        ren1->dst_entry->processed = 0;
1060                                        setup_rename_df_conflict_info(RENAME_DELETE,
1061                                                                      ren1->pair,
1062                                                                      NULL,
1063                                                                      branch1,
1064                                                                      branch2,
1065                                                                      ren1->dst_entry,
1066                                                                      NULL);
1067                                } else {
1068                                        clean_merge = 0;
1069                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1070                                }
1071                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1072                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1073                                /* Added file on the other side
1074                                   identical to the file being
1075                                   renamed: clean merge */
1076                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1077                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1078                                const char *new_path;
1079                                clean_merge = 0;
1080                                try_merge = 1;
1081                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1082                                       "%s added in %s",
1083                                       ren1_src, ren1_dst, branch1,
1084                                       ren1_dst, branch2);
1085                                if (o->call_depth) {
1086                                        struct merge_file_info mfi;
1087                                        struct diff_filespec one, a, b;
1088
1089                                        one.path = a.path = b.path =
1090                                                (char *)ren1_dst;
1091                                        hashcpy(one.sha1, null_sha1);
1092                                        one.mode = 0;
1093                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1094                                        a.mode = ren1->pair->two->mode;
1095                                        hashcpy(b.sha1, dst_other.sha1);
1096                                        b.mode = dst_other.mode;
1097                                        mfi = merge_file(o, &one, &a, &b,
1098                                                         branch1,
1099                                                         branch2);
1100                                        output(o, 1, "Adding merged %s", ren1_dst);
1101                                        update_file(o, 0,
1102                                                    mfi.sha,
1103                                                    mfi.mode,
1104                                                    ren1_dst);
1105                                        try_merge = 0;
1106                                } else {
1107                                        new_path = unique_path(o, ren1_dst, branch2);
1108                                        output(o, 1, "Adding as %s instead", new_path);
1109                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1110                                }
1111                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1112                                ren2 = item->util;
1113                                clean_merge = 0;
1114                                ren2->processed = 1;
1115                                output(o, 1, "CONFLICT (rename/rename): "
1116                                       "Rename %s->%s in %s. "
1117                                       "Rename %s->%s in %s",
1118                                       ren1_src, ren1_dst, branch1,
1119                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1120                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1121                        } else
1122                                try_merge = 1;
1123
1124                        if (try_merge) {
1125                                struct diff_filespec *one, *a, *b;
1126                                src_other.path = (char *)ren1_src;
1127
1128                                one = ren1->pair->one;
1129                                if (a_renames == renames1) {
1130                                        a = ren1->pair->two;
1131                                        b = &src_other;
1132                                } else {
1133                                        b = ren1->pair->two;
1134                                        a = &src_other;
1135                                }
1136                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1137                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1138                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1139                                                                      ren1->pair,
1140                                                                      NULL,
1141                                                                      branch1,
1142                                                                      NULL,
1143                                                                      ren1->dst_entry,
1144                                                                      NULL);
1145                                }
1146                        }
1147                }
1148        }
1149        string_list_clear(&a_by_dst, 0);
1150        string_list_clear(&b_by_dst, 0);
1151
1152        return clean_merge;
1153}
1154
1155static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1156{
1157        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1158}
1159
1160static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1161{
1162        void *buf;
1163        enum object_type type;
1164        unsigned long size;
1165        buf = read_sha1_file(sha1, &type, &size);
1166        if (!buf)
1167                return error("cannot read object %s", sha1_to_hex(sha1));
1168        if (type != OBJ_BLOB) {
1169                free(buf);
1170                return error("object %s is not a blob", sha1_to_hex(sha1));
1171        }
1172        strbuf_attach(dst, buf, size, size + 1);
1173        return 0;
1174}
1175
1176static int blob_unchanged(const unsigned char *o_sha,
1177                          const unsigned char *a_sha,
1178                          int renormalize, const char *path)
1179{
1180        struct strbuf o = STRBUF_INIT;
1181        struct strbuf a = STRBUF_INIT;
1182        int ret = 0; /* assume changed for safety */
1183
1184        if (sha_eq(o_sha, a_sha))
1185                return 1;
1186        if (!renormalize)
1187                return 0;
1188
1189        assert(o_sha && a_sha);
1190        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1191                goto error_return;
1192        /*
1193         * Note: binary | is used so that both renormalizations are
1194         * performed.  Comparison can be skipped if both files are
1195         * unchanged since their sha1s have already been compared.
1196         */
1197        if (renormalize_buffer(path, o.buf, o.len, &o) |
1198            renormalize_buffer(path, a.buf, o.len, &a))
1199                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1200
1201error_return:
1202        strbuf_release(&o);
1203        strbuf_release(&a);
1204        return ret;
1205}
1206
1207static void handle_delete_modify(struct merge_options *o,
1208                                 const char *path,
1209                                 const char *new_path,
1210                                 unsigned char *a_sha, int a_mode,
1211                                 unsigned char *b_sha, int b_mode)
1212{
1213        if (!a_sha) {
1214                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1215                       "and modified in %s. Version %s of %s left in tree%s%s.",
1216                       path, o->branch1,
1217                       o->branch2, o->branch2, path,
1218                       path == new_path ? "" : " at ",
1219                       path == new_path ? "" : new_path);
1220                update_file(o, 0, b_sha, b_mode, new_path);
1221        } else {
1222                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1223                       "and modified in %s. Version %s of %s left in tree%s%s.",
1224                       path, o->branch2,
1225                       o->branch1, o->branch1, path,
1226                       path == new_path ? "" : " at ",
1227                       path == new_path ? "" : new_path);
1228                update_file(o, 0, a_sha, a_mode, new_path);
1229        }
1230}
1231
1232static int merge_content(struct merge_options *o,
1233                         const char *path,
1234                         unsigned char *o_sha, int o_mode,
1235                         unsigned char *a_sha, int a_mode,
1236                         unsigned char *b_sha, int b_mode,
1237                         const char *df_rename_conflict_branch)
1238{
1239        const char *reason = "content";
1240        struct merge_file_info mfi;
1241        struct diff_filespec one, a, b;
1242        struct stat st;
1243        unsigned df_conflict_remains = 0;
1244
1245        if (!o_sha) {
1246                reason = "add/add";
1247                o_sha = (unsigned char *)null_sha1;
1248        }
1249        one.path = a.path = b.path = (char *)path;
1250        hashcpy(one.sha1, o_sha);
1251        one.mode = o_mode;
1252        hashcpy(a.sha1, a_sha);
1253        a.mode = a_mode;
1254        hashcpy(b.sha1, b_sha);
1255        b.mode = b_mode;
1256
1257        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1258        if (df_rename_conflict_branch &&
1259            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1260                df_conflict_remains = 1;
1261        }
1262
1263        if (mfi.clean && !df_conflict_remains &&
1264            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1265                output(o, 3, "Skipped %s (merged same as existing)", path);
1266        else
1267                output(o, 2, "Auto-merging %s", path);
1268
1269        if (!mfi.clean) {
1270                if (S_ISGITLINK(mfi.mode))
1271                        reason = "submodule";
1272                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1273                                reason, path);
1274        }
1275
1276        if (df_conflict_remains) {
1277                const char *new_path;
1278                update_file_flags(o, mfi.sha, mfi.mode, path,
1279                                  o->call_depth || mfi.clean, 0);
1280                new_path = unique_path(o, path, df_rename_conflict_branch);
1281                mfi.clean = 0;
1282                output(o, 1, "Adding as %s instead", new_path);
1283                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1284        } else {
1285                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1286        }
1287        return mfi.clean;
1288
1289}
1290
1291/* Per entry merge function */
1292static int process_entry(struct merge_options *o,
1293                         const char *path, struct stage_data *entry)
1294{
1295        /*
1296        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1297        print_index_entry("\tpath: ", entry);
1298        */
1299        int clean_merge = 1;
1300        int normalize = o->renormalize;
1301        unsigned o_mode = entry->stages[1].mode;
1302        unsigned a_mode = entry->stages[2].mode;
1303        unsigned b_mode = entry->stages[3].mode;
1304        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1305        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1306        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1307
1308        if (entry->rename_df_conflict_info)
1309                return 1; /* Such cases are handled elsewhere. */
1310
1311        entry->processed = 1;
1312        if (o_sha && (!a_sha || !b_sha)) {
1313                /* Case A: Deleted in one */
1314                if ((!a_sha && !b_sha) ||
1315                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1316                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1317                        /* Deleted in both or deleted in one and
1318                         * unchanged in the other */
1319                        if (a_sha)
1320                                output(o, 2, "Removing %s", path);
1321                        /* do not touch working file if it did not exist */
1322                        remove_file(o, 1, path, !a_sha);
1323                } else if (string_list_has_string(&o->current_directory_set,
1324                                                  path)) {
1325                        entry->processed = 0;
1326                        return 1; /* Assume clean until processed */
1327                } else {
1328                        /* Deleted in one and changed in the other */
1329                        clean_merge = 0;
1330                        handle_delete_modify(o, path, path,
1331                                             a_sha, a_mode, b_sha, b_mode);
1332                }
1333
1334        } else if ((!o_sha && a_sha && !b_sha) ||
1335                   (!o_sha && !a_sha && b_sha)) {
1336                /* Case B: Added in one. */
1337                unsigned mode;
1338                const unsigned char *sha;
1339
1340                if (a_sha) {
1341                        mode = a_mode;
1342                        sha = a_sha;
1343                } else {
1344                        mode = b_mode;
1345                        sha = b_sha;
1346                }
1347                if (string_list_has_string(&o->current_directory_set, path)) {
1348                        /* Handle D->F conflicts after all subfiles */
1349                        entry->processed = 0;
1350                        return 1; /* Assume clean until processed */
1351                } else {
1352                        output(o, 2, "Adding %s", path);
1353                        update_file(o, 1, sha, mode, path);
1354                }
1355        } else if (a_sha && b_sha) {
1356                /* Case C: Added in both (check for same permissions) and */
1357                /* case D: Modified in both, but differently. */
1358                clean_merge = merge_content(o, path,
1359                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1360                                            NULL);
1361        } else if (!o_sha && !a_sha && !b_sha) {
1362                /*
1363                 * this entry was deleted altogether. a_mode == 0 means
1364                 * we had that path and want to actively remove it.
1365                 */
1366                remove_file(o, 1, path, !a_mode);
1367        } else
1368                die("Fatal merge failure, shouldn't happen.");
1369
1370        return clean_merge;
1371}
1372
1373/*
1374 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1375 * cases we can cleanly resolve D/F conflicts, process_entry() can
1376 * clean out all the files below the directory for us.  All D/F
1377 * conflict cases must be handled here at the end to make sure any
1378 * directories that can be cleaned out, are.
1379 *
1380 * Some rename conflicts may also be handled here that don't necessarily
1381 * involve D/F conflicts, since the code to handle them is generic enough
1382 * to handle those rename conflicts with or without D/F conflicts also
1383 * being involved.
1384 */
1385static int process_df_entry(struct merge_options *o,
1386                            const char *path, struct stage_data *entry)
1387{
1388        int clean_merge = 1;
1389        unsigned o_mode = entry->stages[1].mode;
1390        unsigned a_mode = entry->stages[2].mode;
1391        unsigned b_mode = entry->stages[3].mode;
1392        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1393        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1394        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1395        struct stat st;
1396
1397        entry->processed = 1;
1398        if (entry->rename_df_conflict_info) {
1399                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1400                char *src;
1401                switch (conflict_info->rename_type) {
1402                case RENAME_NORMAL:
1403                        clean_merge = merge_content(o, path,
1404                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1405                                                    conflict_info->branch1);
1406                        break;
1407                case RENAME_DELETE:
1408                        clean_merge = 0;
1409                        conflict_rename_delete(o, conflict_info->pair1,
1410                                               conflict_info->branch1,
1411                                               conflict_info->branch2);
1412                        break;
1413                case RENAME_ONE_FILE_TO_TWO:
1414                        src = conflict_info->pair1->one->path;
1415                        clean_merge = 0;
1416                        output(o, 1, "CONFLICT (rename/rename): "
1417                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1418                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1419                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1420                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1421                               o->call_depth ? " (left unresolved)" : "");
1422                        if (o->call_depth) {
1423                                remove_file_from_cache(src);
1424                                update_file(o, 0, conflict_info->pair1->one->sha1,
1425                                            conflict_info->pair1->one->mode, src);
1426                        }
1427                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1428                                                    conflict_info->branch1,
1429                                                    conflict_info->pair2,
1430                                                    conflict_info->branch2);
1431                        conflict_info->dst_entry2->processed = 1;
1432                        break;
1433                default:
1434                        entry->processed = 0;
1435                        break;
1436                }
1437        } else if (o_sha && (!a_sha || !b_sha)) {
1438                /* Modify/delete; deleted side may have put a directory in the way */
1439                const char *new_path = path;
1440                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1441                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1442                clean_merge = 0;
1443                handle_delete_modify(o, path, new_path,
1444                                     a_sha, a_mode, b_sha, b_mode);
1445        } else if (!o_sha && !!a_sha != !!b_sha) {
1446                /* directory -> (directory, file) */
1447                const char *add_branch;
1448                const char *other_branch;
1449                unsigned mode;
1450                const unsigned char *sha;
1451                const char *conf;
1452
1453                if (a_sha) {
1454                        add_branch = o->branch1;
1455                        other_branch = o->branch2;
1456                        mode = a_mode;
1457                        sha = a_sha;
1458                        conf = "file/directory";
1459                } else {
1460                        add_branch = o->branch2;
1461                        other_branch = o->branch1;
1462                        mode = b_mode;
1463                        sha = b_sha;
1464                        conf = "directory/file";
1465                }
1466                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1467                        const char *new_path = unique_path(o, path, add_branch);
1468                        clean_merge = 0;
1469                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1470                               "Adding %s as %s",
1471                               conf, path, other_branch, path, new_path);
1472                        update_file(o, 0, sha, mode, new_path);
1473                } else {
1474                        output(o, 2, "Adding %s", path);
1475                        update_file(o, 1, sha, mode, path);
1476                }
1477        } else {
1478                entry->processed = 0;
1479                return 1; /* not handled; assume clean until processed */
1480        }
1481
1482        return clean_merge;
1483}
1484
1485int merge_trees(struct merge_options *o,
1486                struct tree *head,
1487                struct tree *merge,
1488                struct tree *common,
1489                struct tree **result)
1490{
1491        int code, clean;
1492
1493        if (o->subtree_shift) {
1494                merge = shift_tree_object(head, merge, o->subtree_shift);
1495                common = shift_tree_object(head, common, o->subtree_shift);
1496        }
1497
1498        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1499                output(o, 0, "Already up-to-date!");
1500                *result = head;
1501                return 1;
1502        }
1503
1504        code = git_merge_trees(o->call_depth, common, head, merge);
1505
1506        if (code != 0) {
1507                if (show(o, 4) || o->call_depth)
1508                        die("merging of trees %s and %s failed",
1509                            sha1_to_hex(head->object.sha1),
1510                            sha1_to_hex(merge->object.sha1));
1511                else
1512                        exit(128);
1513        }
1514
1515        if (unmerged_cache()) {
1516                struct string_list *entries, *re_head, *re_merge;
1517                int i;
1518                string_list_clear(&o->current_file_set, 1);
1519                string_list_clear(&o->current_directory_set, 1);
1520                get_files_dirs(o, head);
1521                get_files_dirs(o, merge);
1522
1523                entries = get_unmerged();
1524                make_room_for_directories_of_df_conflicts(o, entries);
1525                re_head  = get_renames(o, head, common, head, merge, entries);
1526                re_merge = get_renames(o, merge, common, head, merge, entries);
1527                clean = process_renames(o, re_head, re_merge);
1528                for (i = 0; i < entries->nr; i++) {
1529                        const char *path = entries->items[i].string;
1530                        struct stage_data *e = entries->items[i].util;
1531                        if (!e->processed
1532                                && !process_entry(o, path, e))
1533                                clean = 0;
1534                }
1535                for (i = 0; i < entries->nr; i++) {
1536                        const char *path = entries->items[i].string;
1537                        struct stage_data *e = entries->items[i].util;
1538                        if (!e->processed
1539                                && !process_df_entry(o, path, e))
1540                                clean = 0;
1541                }
1542                for (i = 0; i < entries->nr; i++) {
1543                        struct stage_data *e = entries->items[i].util;
1544                        if (!e->processed)
1545                                die("Unprocessed path??? %s",
1546                                    entries->items[i].string);
1547                }
1548
1549                string_list_clear(re_merge, 0);
1550                string_list_clear(re_head, 0);
1551                string_list_clear(entries, 1);
1552
1553        }
1554        else
1555                clean = 1;
1556
1557        if (o->call_depth)
1558                *result = write_tree_from_memory(o);
1559
1560        return clean;
1561}
1562
1563static struct commit_list *reverse_commit_list(struct commit_list *list)
1564{
1565        struct commit_list *next = NULL, *current, *backup;
1566        for (current = list; current; current = backup) {
1567                backup = current->next;
1568                current->next = next;
1569                next = current;
1570        }
1571        return next;
1572}
1573
1574/*
1575 * Merge the commits h1 and h2, return the resulting virtual
1576 * commit object and a flag indicating the cleanness of the merge.
1577 */
1578int merge_recursive(struct merge_options *o,
1579                    struct commit *h1,
1580                    struct commit *h2,
1581                    struct commit_list *ca,
1582                    struct commit **result)
1583{
1584        struct commit_list *iter;
1585        struct commit *merged_common_ancestors;
1586        struct tree *mrtree = mrtree;
1587        int clean;
1588
1589        if (show(o, 4)) {
1590                output(o, 4, "Merging:");
1591                output_commit_title(o, h1);
1592                output_commit_title(o, h2);
1593        }
1594
1595        if (!ca) {
1596                ca = get_merge_bases(h1, h2, 1);
1597                ca = reverse_commit_list(ca);
1598        }
1599
1600        if (show(o, 5)) {
1601                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1602                for (iter = ca; iter; iter = iter->next)
1603                        output_commit_title(o, iter->item);
1604        }
1605
1606        merged_common_ancestors = pop_commit(&ca);
1607        if (merged_common_ancestors == NULL) {
1608                /* if there is no common ancestor, make an empty tree */
1609                struct tree *tree = xcalloc(1, sizeof(struct tree));
1610
1611                tree->object.parsed = 1;
1612                tree->object.type = OBJ_TREE;
1613                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1614                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1615        }
1616
1617        for (iter = ca; iter; iter = iter->next) {
1618                const char *saved_b1, *saved_b2;
1619                o->call_depth++;
1620                /*
1621                 * When the merge fails, the result contains files
1622                 * with conflict markers. The cleanness flag is
1623                 * ignored, it was never actually used, as result of
1624                 * merge_trees has always overwritten it: the committed
1625                 * "conflicts" were already resolved.
1626                 */
1627                discard_cache();
1628                saved_b1 = o->branch1;
1629                saved_b2 = o->branch2;
1630                o->branch1 = "Temporary merge branch 1";
1631                o->branch2 = "Temporary merge branch 2";
1632                merge_recursive(o, merged_common_ancestors, iter->item,
1633                                NULL, &merged_common_ancestors);
1634                o->branch1 = saved_b1;
1635                o->branch2 = saved_b2;
1636                o->call_depth--;
1637
1638                if (!merged_common_ancestors)
1639                        die("merge returned no commit");
1640        }
1641
1642        discard_cache();
1643        if (!o->call_depth)
1644                read_cache();
1645
1646        o->ancestor = "merged common ancestors";
1647        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1648                            &mrtree);
1649
1650        if (o->call_depth) {
1651                *result = make_virtual_commit(mrtree, "merged tree");
1652                commit_list_insert(h1, &(*result)->parents);
1653                commit_list_insert(h2, &(*result)->parents->next);
1654        }
1655        flush_output(o);
1656        return clean;
1657}
1658
1659static struct commit *get_ref(const unsigned char *sha1, const char *name)
1660{
1661        struct object *object;
1662
1663        object = deref_tag(parse_object(sha1), name, strlen(name));
1664        if (!object)
1665                return NULL;
1666        if (object->type == OBJ_TREE)
1667                return make_virtual_commit((struct tree*)object, name);
1668        if (object->type != OBJ_COMMIT)
1669                return NULL;
1670        if (parse_commit((struct commit *)object))
1671                return NULL;
1672        return (struct commit *)object;
1673}
1674
1675int merge_recursive_generic(struct merge_options *o,
1676                            const unsigned char *head,
1677                            const unsigned char *merge,
1678                            int num_base_list,
1679                            const unsigned char **base_list,
1680                            struct commit **result)
1681{
1682        int clean, index_fd;
1683        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1684        struct commit *head_commit = get_ref(head, o->branch1);
1685        struct commit *next_commit = get_ref(merge, o->branch2);
1686        struct commit_list *ca = NULL;
1687
1688        if (base_list) {
1689                int i;
1690                for (i = 0; i < num_base_list; ++i) {
1691                        struct commit *base;
1692                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1693                                return error("Could not parse object '%s'",
1694                                        sha1_to_hex(base_list[i]));
1695                        commit_list_insert(base, &ca);
1696                }
1697        }
1698
1699        index_fd = hold_locked_index(lock, 1);
1700        clean = merge_recursive(o, head_commit, next_commit, ca,
1701                        result);
1702        if (active_cache_changed &&
1703                        (write_cache(index_fd, active_cache, active_nr) ||
1704                         commit_locked_index(lock)))
1705                return error("Unable to write index.");
1706
1707        return clean ? 0 : 1;
1708}
1709
1710static int merge_recursive_config(const char *var, const char *value, void *cb)
1711{
1712        struct merge_options *o = cb;
1713        if (!strcasecmp(var, "merge.verbosity")) {
1714                o->verbosity = git_config_int(var, value);
1715                return 0;
1716        }
1717        if (!strcasecmp(var, "diff.renamelimit")) {
1718                o->diff_rename_limit = git_config_int(var, value);
1719                return 0;
1720        }
1721        if (!strcasecmp(var, "merge.renamelimit")) {
1722                o->merge_rename_limit = git_config_int(var, value);
1723                return 0;
1724        }
1725        return git_xmerge_config(var, value, cb);
1726}
1727
1728void init_merge_options(struct merge_options *o)
1729{
1730        memset(o, 0, sizeof(struct merge_options));
1731        o->verbosity = 2;
1732        o->buffer_output = 1;
1733        o->diff_rename_limit = -1;
1734        o->merge_rename_limit = -1;
1735        o->renormalize = 0;
1736        git_config(merge_recursive_config, o);
1737        if (getenv("GIT_MERGE_VERBOSITY"))
1738                o->verbosity =
1739                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1740        if (o->verbosity >= 5)
1741                o->buffer_output = 0;
1742        strbuf_init(&o->obuf, 0);
1743        memset(&o->current_file_set, 0, sizeof(struct string_list));
1744        o->current_file_set.strdup_strings = 1;
1745        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1746        o->current_directory_set.strdup_strings = 1;
1747}
1748
1749int parse_merge_opt(struct merge_options *o, const char *s)
1750{
1751        if (!s || !*s)
1752                return -1;
1753        if (!strcmp(s, "ours"))
1754                o->recursive_variant = MERGE_RECURSIVE_OURS;
1755        else if (!strcmp(s, "theirs"))
1756                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1757        else if (!strcmp(s, "subtree"))
1758                o->subtree_shift = "";
1759        else if (!prefixcmp(s, "subtree="))
1760                o->subtree_shift = s + strlen("subtree=");
1761        else if (!strcmp(s, "patience"))
1762                o->xdl_opts |= XDF_PATIENCE_DIFF;
1763        else if (!strcmp(s, "ignore-space-change"))
1764                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1765        else if (!strcmp(s, "ignore-all-space"))
1766                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1767        else if (!strcmp(s, "ignore-space-at-eol"))
1768                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1769        else if (!strcmp(s, "renormalize"))
1770                o->renormalize = 1;
1771        else if (!strcmp(s, "no-renormalize"))
1772                o->renormalize = 0;
1773        else if (!prefixcmp(s, "rename-threshold=")) {
1774                const char *score = s + strlen("rename-threshold=");
1775                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1776                        return -1;
1777        }
1778        else
1779                return -1;
1780        return 0;
1781}