231e5cbd7f87c95f909709cc649bfb202a4ece87
   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        int len;
 141        va_list ap;
 142
 143        if (!show(o, v))
 144                return;
 145
 146        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 147        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 148        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 149
 150        va_start(ap, fmt);
 151        len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 152        va_end(ap);
 153
 154        if (len < 0)
 155                len = 0;
 156        if (len >= strbuf_avail(&o->obuf)) {
 157                strbuf_grow(&o->obuf, len + 2);
 158                va_start(ap, fmt);
 159                len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 160                va_end(ap);
 161                if (len >= strbuf_avail(&o->obuf)) {
 162                        die("this should not happen, your snprintf is broken");
 163                }
 164        }
 165        strbuf_setlen(&o->obuf, o->obuf.len + len);
 166        strbuf_add(&o->obuf, "\n", 1);
 167        if (!o->buffer_output)
 168                flush_output(o);
 169}
 170
 171static void output_commit_title(struct merge_options *o, struct commit *commit)
 172{
 173        int i;
 174        flush_output(o);
 175        for (i = o->call_depth; i--;)
 176                fputs("  ", stdout);
 177        if (commit->util)
 178                printf("virtual %s\n", (char *)commit->util);
 179        else {
 180                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 181                if (parse_commit(commit) != 0)
 182                        printf("(bad commit)\n");
 183                else {
 184                        const char *title;
 185                        int len = find_commit_subject(commit->buffer, &title);
 186                        if (len)
 187                                printf("%.*s\n", len, title);
 188                }
 189        }
 190}
 191
 192static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 193                const char *path, int stage, int refresh, int options)
 194{
 195        struct cache_entry *ce;
 196        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 197        if (!ce)
 198                return error("addinfo_cache failed for path '%s'", path);
 199        return add_cache_entry(ce, options);
 200}
 201
 202static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 203{
 204        parse_tree(tree);
 205        init_tree_desc(desc, tree->buffer, tree->size);
 206}
 207
 208static int git_merge_trees(int index_only,
 209                           struct tree *common,
 210                           struct tree *head,
 211                           struct tree *merge)
 212{
 213        int rc;
 214        struct tree_desc t[3];
 215        struct unpack_trees_options opts;
 216
 217        memset(&opts, 0, sizeof(opts));
 218        if (index_only)
 219                opts.index_only = 1;
 220        else
 221                opts.update = 1;
 222        opts.merge = 1;
 223        opts.head_idx = 2;
 224        opts.fn = threeway_merge;
 225        opts.src_index = &the_index;
 226        opts.dst_index = &the_index;
 227        setup_unpack_trees_porcelain(&opts, "merge");
 228
 229        init_tree_desc_from_tree(t+0, common);
 230        init_tree_desc_from_tree(t+1, head);
 231        init_tree_desc_from_tree(t+2, merge);
 232
 233        rc = unpack_trees(3, t, &opts);
 234        cache_tree_free(&active_cache_tree);
 235        return rc;
 236}
 237
 238struct tree *write_tree_from_memory(struct merge_options *o)
 239{
 240        struct tree *result = NULL;
 241
 242        if (unmerged_cache()) {
 243                int i;
 244                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 245                for (i = 0; i < active_nr; i++) {
 246                        struct cache_entry *ce = active_cache[i];
 247                        if (ce_stage(ce))
 248                                fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
 249                                        (int)ce_namelen(ce), ce->name);
 250                }
 251                die("Bug in merge-recursive.c");
 252        }
 253
 254        if (!active_cache_tree)
 255                active_cache_tree = cache_tree();
 256
 257        if (!cache_tree_fully_valid(active_cache_tree) &&
 258            cache_tree_update(active_cache_tree,
 259                              active_cache, active_nr, 0, 0) < 0)
 260                die("error building trees");
 261
 262        result = lookup_tree(active_cache_tree->sha1);
 263
 264        return result;
 265}
 266
 267static int save_files_dirs(const unsigned char *sha1,
 268                const char *base, int baselen, const char *path,
 269                unsigned int mode, int stage, void *context)
 270{
 271        int len = strlen(path);
 272        char *newpath = xmalloc(baselen + len + 1);
 273        struct merge_options *o = context;
 274
 275        memcpy(newpath, base, baselen);
 276        memcpy(newpath + baselen, path, len);
 277        newpath[baselen + len] = '\0';
 278
 279        if (S_ISDIR(mode))
 280                string_list_insert(&o->current_directory_set, newpath);
 281        else
 282                string_list_insert(&o->current_file_set, newpath);
 283        free(newpath);
 284
 285        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 286}
 287
 288static int get_files_dirs(struct merge_options *o, struct tree *tree)
 289{
 290        int n;
 291        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 292                return 0;
 293        n = o->current_file_set.nr + o->current_directory_set.nr;
 294        return n;
 295}
 296
 297/*
 298 * Returns an index_entry instance which doesn't have to correspond to
 299 * a real cache entry in Git's index.
 300 */
 301static struct stage_data *insert_stage_data(const char *path,
 302                struct tree *o, struct tree *a, struct tree *b,
 303                struct string_list *entries)
 304{
 305        struct string_list_item *item;
 306        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 307        get_tree_entry(o->object.sha1, path,
 308                        e->stages[1].sha, &e->stages[1].mode);
 309        get_tree_entry(a->object.sha1, path,
 310                        e->stages[2].sha, &e->stages[2].mode);
 311        get_tree_entry(b->object.sha1, path,
 312                        e->stages[3].sha, &e->stages[3].mode);
 313        item = string_list_insert(entries, path);
 314        item->util = e;
 315        return e;
 316}
 317
 318/*
 319 * Create a dictionary mapping file names to stage_data objects. The
 320 * dictionary contains one entry for every path with a non-zero stage entry.
 321 */
 322static struct string_list *get_unmerged(void)
 323{
 324        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 325        int i;
 326
 327        unmerged->strdup_strings = 1;
 328
 329        for (i = 0; i < active_nr; i++) {
 330                struct string_list_item *item;
 331                struct stage_data *e;
 332                struct cache_entry *ce = active_cache[i];
 333                if (!ce_stage(ce))
 334                        continue;
 335
 336                item = string_list_lookup(unmerged, ce->name);
 337                if (!item) {
 338                        item = string_list_insert(unmerged, ce->name);
 339                        item->util = xcalloc(1, sizeof(struct stage_data));
 340                }
 341                e = item->util;
 342                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 343                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 344        }
 345
 346        return unmerged;
 347}
 348
 349static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 350                                                      struct string_list *entries)
 351{
 352        /* If there are D/F conflicts, and the paths currently exist
 353         * in the working copy as a file, we want to remove them to
 354         * make room for the corresponding directory.  Such paths will
 355         * later be processed in process_df_entry() at the end.  If
 356         * the corresponding directory ends up being removed by the
 357         * merge, then the file will be reinstated at that time;
 358         * otherwise, if the file is not supposed to be removed by the
 359         * merge, the contents of the file will be placed in another
 360         * unique filename.
 361         *
 362         * NOTE: This function relies on the fact that entries for a
 363         * D/F conflict will appear adjacent in the index, with the
 364         * entries for the file appearing before entries for paths
 365         * below the corresponding directory.
 366         */
 367        const char *last_file = NULL;
 368        int last_len = 0;
 369        struct stage_data *last_e;
 370        int i;
 371
 372        for (i = 0; i < entries->nr; i++) {
 373                const char *path = entries->items[i].string;
 374                int len = strlen(path);
 375                struct stage_data *e = entries->items[i].util;
 376
 377                /*
 378                 * Check if last_file & path correspond to a D/F conflict;
 379                 * i.e. whether path is last_file+'/'+<something>.
 380                 * If so, remove last_file to make room for path and friends.
 381                 */
 382                if (last_file &&
 383                    len > last_len &&
 384                    memcmp(path, last_file, last_len) == 0 &&
 385                    path[last_len] == '/') {
 386                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 387                        unlink(last_file);
 388                }
 389
 390                /*
 391                 * Determine whether path could exist as a file in the
 392                 * working directory as a possible D/F conflict.  This
 393                 * will only occur when it exists in stage 2 as a
 394                 * file.
 395                 */
 396                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 397                        last_file = path;
 398                        last_len = len;
 399                        last_e = e;
 400                } else {
 401                        last_file = NULL;
 402                }
 403        }
 404}
 405
 406struct rename
 407{
 408        struct diff_filepair *pair;
 409        struct stage_data *src_entry;
 410        struct stage_data *dst_entry;
 411        unsigned processed:1;
 412};
 413
 414/*
 415 * Get information of all renames which occurred between 'o_tree' and
 416 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 417 * 'b_tree') to be able to associate the correct cache entries with
 418 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 419 */
 420static struct string_list *get_renames(struct merge_options *o,
 421                                       struct tree *tree,
 422                                       struct tree *o_tree,
 423                                       struct tree *a_tree,
 424                                       struct tree *b_tree,
 425                                       struct string_list *entries)
 426{
 427        int i;
 428        struct string_list *renames;
 429        struct diff_options opts;
 430
 431        renames = xcalloc(1, sizeof(struct string_list));
 432        diff_setup(&opts);
 433        DIFF_OPT_SET(&opts, RECURSIVE);
 434        opts.detect_rename = DIFF_DETECT_RENAME;
 435        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 436                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 437                            500;
 438        opts.warn_on_too_large_rename = 1;
 439        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 440        if (diff_setup_done(&opts) < 0)
 441                die("diff setup failed");
 442        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 443        diffcore_std(&opts);
 444        for (i = 0; i < diff_queued_diff.nr; ++i) {
 445                struct string_list_item *item;
 446                struct rename *re;
 447                struct diff_filepair *pair = diff_queued_diff.queue[i];
 448                if (pair->status != 'R') {
 449                        diff_free_filepair(pair);
 450                        continue;
 451                }
 452                re = xmalloc(sizeof(*re));
 453                re->processed = 0;
 454                re->pair = pair;
 455                item = string_list_lookup(entries, re->pair->one->path);
 456                if (!item)
 457                        re->src_entry = insert_stage_data(re->pair->one->path,
 458                                        o_tree, a_tree, b_tree, entries);
 459                else
 460                        re->src_entry = item->util;
 461
 462                item = string_list_lookup(entries, re->pair->two->path);
 463                if (!item)
 464                        re->dst_entry = insert_stage_data(re->pair->two->path,
 465                                        o_tree, a_tree, b_tree, entries);
 466                else
 467                        re->dst_entry = item->util;
 468                item = string_list_insert(renames, pair->one->path);
 469                item->util = re;
 470        }
 471        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 472        diff_queued_diff.nr = 0;
 473        diff_flush(&opts);
 474        return renames;
 475}
 476
 477static int update_stages_options(const char *path, struct diff_filespec *o,
 478                         struct diff_filespec *a, struct diff_filespec *b,
 479                         int clear, int options)
 480{
 481        if (clear)
 482                if (remove_file_from_cache(path))
 483                        return -1;
 484        if (o)
 485                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 486                        return -1;
 487        if (a)
 488                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 489                        return -1;
 490        if (b)
 491                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 492                        return -1;
 493        return 0;
 494}
 495
 496static int update_stages(const char *path, struct diff_filespec *o,
 497                         struct diff_filespec *a, struct diff_filespec *b,
 498                         int clear)
 499{
 500        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 501        return update_stages_options(path, o, a, b, clear, options);
 502}
 503
 504static int update_stages_and_entry(const char *path,
 505                                   struct stage_data *entry,
 506                                   struct diff_filespec *o,
 507                                   struct diff_filespec *a,
 508                                   struct diff_filespec *b,
 509                                   int clear)
 510{
 511        int options;
 512
 513        entry->processed = 0;
 514        entry->stages[1].mode = o->mode;
 515        entry->stages[2].mode = a->mode;
 516        entry->stages[3].mode = b->mode;
 517        hashcpy(entry->stages[1].sha, o->sha1);
 518        hashcpy(entry->stages[2].sha, a->sha1);
 519        hashcpy(entry->stages[3].sha, b->sha1);
 520        options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 521        return update_stages_options(path, o, a, b, clear, options);
 522}
 523
 524static int remove_file(struct merge_options *o, int clean,
 525                       const char *path, int no_wd)
 526{
 527        int update_cache = o->call_depth || clean;
 528        int update_working_directory = !o->call_depth && !no_wd;
 529
 530        if (update_cache) {
 531                if (remove_file_from_cache(path))
 532                        return -1;
 533        }
 534        if (update_working_directory) {
 535                if (remove_path(path))
 536                        return -1;
 537        }
 538        return 0;
 539}
 540
 541static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 542{
 543        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 544        int suffix = 0;
 545        struct stat st;
 546        char *p = newpath + strlen(path);
 547        strcpy(newpath, path);
 548        *(p++) = '~';
 549        strcpy(p, branch);
 550        for (; *p; ++p)
 551                if ('/' == *p)
 552                        *p = '_';
 553        while (string_list_has_string(&o->current_file_set, newpath) ||
 554               string_list_has_string(&o->current_directory_set, newpath) ||
 555               lstat(newpath, &st) == 0)
 556                sprintf(p, "_%d", suffix++);
 557
 558        string_list_insert(&o->current_file_set, newpath);
 559        return newpath;
 560}
 561
 562static void flush_buffer(int fd, const char *buf, unsigned long size)
 563{
 564        while (size > 0) {
 565                long ret = write_in_full(fd, buf, size);
 566                if (ret < 0) {
 567                        /* Ignore epipe */
 568                        if (errno == EPIPE)
 569                                break;
 570                        die_errno("merge-recursive");
 571                } else if (!ret) {
 572                        die("merge-recursive: disk full?");
 573                }
 574                size -= ret;
 575                buf += ret;
 576        }
 577}
 578
 579static int would_lose_untracked(const char *path)
 580{
 581        int pos = cache_name_pos(path, strlen(path));
 582
 583        if (pos < 0)
 584                pos = -1 - pos;
 585        while (pos < active_nr &&
 586               !strcmp(path, active_cache[pos]->name)) {
 587                /*
 588                 * If stage #0, it is definitely tracked.
 589                 * If it has stage #2 then it was tracked
 590                 * before this merge started.  All other
 591                 * cases the path was not tracked.
 592                 */
 593                switch (ce_stage(active_cache[pos])) {
 594                case 0:
 595                case 2:
 596                        return 0;
 597                }
 598                pos++;
 599        }
 600        return file_exists(path);
 601}
 602
 603static int make_room_for_path(const char *path)
 604{
 605        int status;
 606        const char *msg = "failed to create path '%s'%s";
 607
 608        status = safe_create_leading_directories_const(path);
 609        if (status) {
 610                if (status == -3) {
 611                        /* something else exists */
 612                        error(msg, path, ": perhaps a D/F conflict?");
 613                        return -1;
 614                }
 615                die(msg, path, "");
 616        }
 617
 618        /*
 619         * Do not unlink a file in the work tree if we are not
 620         * tracking it.
 621         */
 622        if (would_lose_untracked(path))
 623                return error("refusing to lose untracked file at '%s'",
 624                             path);
 625
 626        /* Successful unlink is good.. */
 627        if (!unlink(path))
 628                return 0;
 629        /* .. and so is no existing file */
 630        if (errno == ENOENT)
 631                return 0;
 632        /* .. but not some other error (who really cares what?) */
 633        return error(msg, path, ": perhaps a D/F conflict?");
 634}
 635
 636static void update_file_flags(struct merge_options *o,
 637                              const unsigned char *sha,
 638                              unsigned mode,
 639                              const char *path,
 640                              int update_cache,
 641                              int update_wd)
 642{
 643        if (o->call_depth)
 644                update_wd = 0;
 645
 646        if (update_wd) {
 647                enum object_type type;
 648                void *buf;
 649                unsigned long size;
 650
 651                if (S_ISGITLINK(mode)) {
 652                        /*
 653                         * We may later decide to recursively descend into
 654                         * the submodule directory and update its index
 655                         * and/or work tree, but we do not do that now.
 656                         */
 657                        update_wd = 0;
 658                        goto update_index;
 659                }
 660
 661                buf = read_sha1_file(sha, &type, &size);
 662                if (!buf)
 663                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 664                if (type != OBJ_BLOB)
 665                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 666                if (S_ISREG(mode)) {
 667                        struct strbuf strbuf = STRBUF_INIT;
 668                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 669                                free(buf);
 670                                size = strbuf.len;
 671                                buf = strbuf_detach(&strbuf, NULL);
 672                        }
 673                }
 674
 675                if (make_room_for_path(path) < 0) {
 676                        update_wd = 0;
 677                        free(buf);
 678                        goto update_index;
 679                }
 680                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 681                        int fd;
 682                        if (mode & 0100)
 683                                mode = 0777;
 684                        else
 685                                mode = 0666;
 686                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 687                        if (fd < 0)
 688                                die_errno("failed to open '%s'", path);
 689                        flush_buffer(fd, buf, size);
 690                        close(fd);
 691                } else if (S_ISLNK(mode)) {
 692                        char *lnk = xmemdupz(buf, size);
 693                        safe_create_leading_directories_const(path);
 694                        unlink(path);
 695                        if (symlink(lnk, path))
 696                                die_errno("failed to symlink '%s'", path);
 697                        free(lnk);
 698                } else
 699                        die("do not know what to do with %06o %s '%s'",
 700                            mode, sha1_to_hex(sha), path);
 701                free(buf);
 702        }
 703 update_index:
 704        if (update_cache)
 705                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 706}
 707
 708static void update_file(struct merge_options *o,
 709                        int clean,
 710                        const unsigned char *sha,
 711                        unsigned mode,
 712                        const char *path)
 713{
 714        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 715}
 716
 717/* Low level file merging, update and removal */
 718
 719struct merge_file_info
 720{
 721        unsigned char sha[20];
 722        unsigned mode;
 723        unsigned clean:1,
 724                 merge:1;
 725};
 726
 727static int merge_3way(struct merge_options *o,
 728                      mmbuffer_t *result_buf,
 729                      struct diff_filespec *one,
 730                      struct diff_filespec *a,
 731                      struct diff_filespec *b,
 732                      const char *branch1,
 733                      const char *branch2)
 734{
 735        mmfile_t orig, src1, src2;
 736        char *base_name, *name1, *name2;
 737        int merge_status;
 738        int favor;
 739
 740        if (o->call_depth)
 741                favor = 0;
 742        else {
 743                switch (o->recursive_variant) {
 744                case MERGE_RECURSIVE_OURS:
 745                        favor = XDL_MERGE_FAVOR_OURS;
 746                        break;
 747                case MERGE_RECURSIVE_THEIRS:
 748                        favor = XDL_MERGE_FAVOR_THEIRS;
 749                        break;
 750                default:
 751                        favor = 0;
 752                        break;
 753                }
 754        }
 755
 756        if (strcmp(a->path, b->path) ||
 757            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 758                base_name = o->ancestor == NULL ? NULL :
 759                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 760                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 761                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 762        } else {
 763                base_name = o->ancestor == NULL ? NULL :
 764                        xstrdup(mkpath("%s", o->ancestor));
 765                name1 = xstrdup(mkpath("%s", branch1));
 766                name2 = xstrdup(mkpath("%s", branch2));
 767        }
 768
 769        read_mmblob(&orig, one->sha1);
 770        read_mmblob(&src1, a->sha1);
 771        read_mmblob(&src2, b->sha1);
 772
 773        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 774                                &src1, name1, &src2, name2,
 775                                ((o->call_depth ? LL_OPT_VIRTUAL_ANCESTOR : 0) |
 776                                 (o->renormalize ? LL_OPT_RENORMALIZE : 0) |
 777                                 create_ll_flag(favor)));
 778
 779        free(name1);
 780        free(name2);
 781        free(orig.ptr);
 782        free(src1.ptr);
 783        free(src2.ptr);
 784        return merge_status;
 785}
 786
 787static struct merge_file_info merge_file(struct merge_options *o,
 788                                         struct diff_filespec *one,
 789                                         struct diff_filespec *a,
 790                                         struct diff_filespec *b,
 791                                         const char *branch1,
 792                                         const char *branch2)
 793{
 794        struct merge_file_info result;
 795        result.merge = 0;
 796        result.clean = 1;
 797
 798        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 799                result.clean = 0;
 800                if (S_ISREG(a->mode)) {
 801                        result.mode = a->mode;
 802                        hashcpy(result.sha, a->sha1);
 803                } else {
 804                        result.mode = b->mode;
 805                        hashcpy(result.sha, b->sha1);
 806                }
 807        } else {
 808                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 809                        result.merge = 1;
 810
 811                /*
 812                 * Merge modes
 813                 */
 814                if (a->mode == b->mode || a->mode == one->mode)
 815                        result.mode = b->mode;
 816                else {
 817                        result.mode = a->mode;
 818                        if (b->mode != one->mode) {
 819                                result.clean = 0;
 820                                result.merge = 1;
 821                        }
 822                }
 823
 824                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 825                        hashcpy(result.sha, b->sha1);
 826                else if (sha_eq(b->sha1, one->sha1))
 827                        hashcpy(result.sha, a->sha1);
 828                else if (S_ISREG(a->mode)) {
 829                        mmbuffer_t result_buf;
 830                        int merge_status;
 831
 832                        merge_status = merge_3way(o, &result_buf, one, a, b,
 833                                                  branch1, branch2);
 834
 835                        if ((merge_status < 0) || !result_buf.ptr)
 836                                die("Failed to execute internal merge");
 837
 838                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 839                                            blob_type, result.sha))
 840                                die("Unable to add %s to database",
 841                                    a->path);
 842
 843                        free(result_buf.ptr);
 844                        result.clean = (merge_status == 0);
 845                } else if (S_ISGITLINK(a->mode)) {
 846                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 847                                                       a->sha1, b->sha1);
 848                } else if (S_ISLNK(a->mode)) {
 849                        hashcpy(result.sha, a->sha1);
 850
 851                        if (!sha_eq(a->sha1, b->sha1))
 852                                result.clean = 0;
 853                } else {
 854                        die("unsupported object type in the tree");
 855                }
 856        }
 857
 858        return result;
 859}
 860
 861static void conflict_rename_delete(struct merge_options *o,
 862                                   struct diff_filepair *pair,
 863                                   const char *rename_branch,
 864                                   const char *other_branch)
 865{
 866        char *dest_name = pair->two->path;
 867        int df_conflict = 0;
 868        struct stat st;
 869
 870        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 871               "and deleted in %s",
 872               pair->one->path, pair->two->path, rename_branch,
 873               other_branch);
 874        if (!o->call_depth)
 875                update_stages(dest_name, NULL,
 876                              rename_branch == o->branch1 ? pair->two : NULL,
 877                              rename_branch == o->branch1 ? NULL : pair->two,
 878                              1);
 879        if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 880                dest_name = unique_path(o, dest_name, rename_branch);
 881                df_conflict = 1;
 882        }
 883        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 884        if (df_conflict)
 885                free(dest_name);
 886}
 887
 888static void conflict_rename_rename_1to2(struct merge_options *o,
 889                                        struct diff_filepair *pair1,
 890                                        const char *branch1,
 891                                        struct diff_filepair *pair2,
 892                                        const char *branch2)
 893{
 894        /* One file was renamed in both branches, but to different names. */
 895        char *del[2];
 896        int delp = 0;
 897        const char *ren1_dst = pair1->two->path;
 898        const char *ren2_dst = pair2->two->path;
 899        const char *dst_name1 = ren1_dst;
 900        const char *dst_name2 = ren2_dst;
 901        struct stat st;
 902        if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 903                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 904                output(o, 1, "%s is a directory in %s adding as %s instead",
 905                       ren1_dst, branch2, dst_name1);
 906        }
 907        if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 908                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 909                output(o, 1, "%s is a directory in %s adding as %s instead",
 910                       ren2_dst, branch1, dst_name2);
 911        }
 912        if (o->call_depth) {
 913                remove_file_from_cache(dst_name1);
 914                remove_file_from_cache(dst_name2);
 915                /*
 916                 * Uncomment to leave the conflicting names in the resulting tree
 917                 *
 918                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 919                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 920                 */
 921        } else {
 922                update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 923                update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 924
 925                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 926                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 927        }
 928        while (delp--)
 929                free(del[delp]);
 930}
 931
 932static void conflict_rename_rename_2to1(struct merge_options *o,
 933                                        struct rename *ren1,
 934                                        const char *branch1,
 935                                        struct rename *ren2,
 936                                        const char *branch2)
 937{
 938        /* Two files were renamed to the same thing. */
 939        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 940        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 941        output(o, 1, "Renaming %s to %s and %s to %s instead",
 942               ren1->pair->one->path, new_path1,
 943               ren2->pair->one->path, new_path2);
 944        remove_file(o, 0, ren1->pair->two->path, 0);
 945        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 946        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 947        free(new_path2);
 948        free(new_path1);
 949}
 950
 951static int process_renames(struct merge_options *o,
 952                           struct string_list *a_renames,
 953                           struct string_list *b_renames)
 954{
 955        int clean_merge = 1, i, j;
 956        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 957        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 958        const struct rename *sre;
 959
 960        for (i = 0; i < a_renames->nr; i++) {
 961                sre = a_renames->items[i].util;
 962                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 963                        = sre->dst_entry;
 964        }
 965        for (i = 0; i < b_renames->nr; i++) {
 966                sre = b_renames->items[i].util;
 967                string_list_insert(&b_by_dst, sre->pair->two->path)->util
 968                        = sre->dst_entry;
 969        }
 970
 971        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 972                char *src;
 973                struct string_list *renames1, *renames2Dst;
 974                struct rename *ren1 = NULL, *ren2 = NULL;
 975                const char *branch1, *branch2;
 976                const char *ren1_src, *ren1_dst;
 977
 978                if (i >= a_renames->nr) {
 979                        ren2 = b_renames->items[j++].util;
 980                } else if (j >= b_renames->nr) {
 981                        ren1 = a_renames->items[i++].util;
 982                } else {
 983                        int compare = strcmp(a_renames->items[i].string,
 984                                             b_renames->items[j].string);
 985                        if (compare <= 0)
 986                                ren1 = a_renames->items[i++].util;
 987                        if (compare >= 0)
 988                                ren2 = b_renames->items[j++].util;
 989                }
 990
 991                /* TODO: refactor, so that 1/2 are not needed */
 992                if (ren1) {
 993                        renames1 = a_renames;
 994                        renames2Dst = &b_by_dst;
 995                        branch1 = o->branch1;
 996                        branch2 = o->branch2;
 997                } else {
 998                        struct rename *tmp;
 999                        renames1 = b_renames;
1000                        renames2Dst = &a_by_dst;
1001                        branch1 = o->branch2;
1002                        branch2 = o->branch1;
1003                        tmp = ren2;
1004                        ren2 = ren1;
1005                        ren1 = tmp;
1006                }
1007                src = ren1->pair->one->path;
1008
1009                ren1->dst_entry->processed = 1;
1010                ren1->src_entry->processed = 1;
1011
1012                if (ren1->processed)
1013                        continue;
1014                ren1->processed = 1;
1015
1016                ren1_src = ren1->pair->one->path;
1017                ren1_dst = ren1->pair->two->path;
1018
1019                if (ren2) {
1020                        const char *ren2_src = ren2->pair->one->path;
1021                        const char *ren2_dst = ren2->pair->two->path;
1022                        /* Renamed in 1 and renamed in 2 */
1023                        if (strcmp(ren1_src, ren2_src) != 0)
1024                                die("ren1.src != ren2.src");
1025                        ren2->dst_entry->processed = 1;
1026                        ren2->processed = 1;
1027                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1028                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1029                                                              ren1->pair,
1030                                                              ren2->pair,
1031                                                              branch1,
1032                                                              branch2,
1033                                                              ren1->dst_entry,
1034                                                              ren2->dst_entry);
1035                        } else {
1036                                remove_file(o, 1, ren1_src, 1);
1037                                update_stages_and_entry(ren1_dst,
1038                                                        ren1->dst_entry,
1039                                                        ren1->pair->one,
1040                                                        ren1->pair->two,
1041                                                        ren2->pair->two,
1042                                                        1 /* clear */);
1043                        }
1044                } else {
1045                        /* Renamed in 1, maybe changed in 2 */
1046                        struct string_list_item *item;
1047                        /* we only use sha1 and mode of these */
1048                        struct diff_filespec src_other, dst_other;
1049                        int try_merge;
1050
1051                        /*
1052                         * unpack_trees loads entries from common-commit
1053                         * into stage 1, from head-commit into stage 2, and
1054                         * from merge-commit into stage 3.  We keep track
1055                         * of which side corresponds to the rename.
1056                         */
1057                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1058                        int other_stage =   a_renames == renames1 ? 3 : 2;
1059
1060                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1061
1062                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1063                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1064                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1065                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1066                        try_merge = 0;
1067
1068                        if (sha_eq(src_other.sha1, null_sha1)) {
1069                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1070                                        ren1->dst_entry->processed = 0;
1071                                        setup_rename_df_conflict_info(RENAME_DELETE,
1072                                                                      ren1->pair,
1073                                                                      NULL,
1074                                                                      branch1,
1075                                                                      branch2,
1076                                                                      ren1->dst_entry,
1077                                                                      NULL);
1078                                } else {
1079                                        clean_merge = 0;
1080                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1081                                }
1082                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1083                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1084                                /* Added file on the other side
1085                                   identical to the file being
1086                                   renamed: clean merge */
1087                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1088                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1089                                const char *new_path;
1090                                clean_merge = 0;
1091                                try_merge = 1;
1092                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1093                                       "%s added in %s",
1094                                       ren1_src, ren1_dst, branch1,
1095                                       ren1_dst, branch2);
1096                                if (o->call_depth) {
1097                                        struct merge_file_info mfi;
1098                                        struct diff_filespec one, a, b;
1099
1100                                        one.path = a.path = b.path =
1101                                                (char *)ren1_dst;
1102                                        hashcpy(one.sha1, null_sha1);
1103                                        one.mode = 0;
1104                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1105                                        a.mode = ren1->pair->two->mode;
1106                                        hashcpy(b.sha1, dst_other.sha1);
1107                                        b.mode = dst_other.mode;
1108                                        mfi = merge_file(o, &one, &a, &b,
1109                                                         branch1,
1110                                                         branch2);
1111                                        output(o, 1, "Adding merged %s", ren1_dst);
1112                                        update_file(o, 0,
1113                                                    mfi.sha,
1114                                                    mfi.mode,
1115                                                    ren1_dst);
1116                                        try_merge = 0;
1117                                } else {
1118                                        new_path = unique_path(o, ren1_dst, branch2);
1119                                        output(o, 1, "Adding as %s instead", new_path);
1120                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1121                                }
1122                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1123                                ren2 = item->util;
1124                                clean_merge = 0;
1125                                ren2->processed = 1;
1126                                output(o, 1, "CONFLICT (rename/rename): "
1127                                       "Rename %s->%s in %s. "
1128                                       "Rename %s->%s in %s",
1129                                       ren1_src, ren1_dst, branch1,
1130                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1131                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1132                        } else
1133                                try_merge = 1;
1134
1135                        if (try_merge) {
1136                                struct diff_filespec *one, *a, *b;
1137                                src_other.path = (char *)ren1_src;
1138
1139                                one = ren1->pair->one;
1140                                if (a_renames == renames1) {
1141                                        a = ren1->pair->two;
1142                                        b = &src_other;
1143                                } else {
1144                                        b = ren1->pair->two;
1145                                        a = &src_other;
1146                                }
1147                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1148                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1149                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1150                                                                      ren1->pair,
1151                                                                      NULL,
1152                                                                      branch1,
1153                                                                      NULL,
1154                                                                      ren1->dst_entry,
1155                                                                      NULL);
1156                                }
1157                        }
1158                }
1159        }
1160        string_list_clear(&a_by_dst, 0);
1161        string_list_clear(&b_by_dst, 0);
1162
1163        return clean_merge;
1164}
1165
1166static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1167{
1168        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1169}
1170
1171static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1172{
1173        void *buf;
1174        enum object_type type;
1175        unsigned long size;
1176        buf = read_sha1_file(sha1, &type, &size);
1177        if (!buf)
1178                return error("cannot read object %s", sha1_to_hex(sha1));
1179        if (type != OBJ_BLOB) {
1180                free(buf);
1181                return error("object %s is not a blob", sha1_to_hex(sha1));
1182        }
1183        strbuf_attach(dst, buf, size, size + 1);
1184        return 0;
1185}
1186
1187static int blob_unchanged(const unsigned char *o_sha,
1188                          const unsigned char *a_sha,
1189                          int renormalize, const char *path)
1190{
1191        struct strbuf o = STRBUF_INIT;
1192        struct strbuf a = STRBUF_INIT;
1193        int ret = 0; /* assume changed for safety */
1194
1195        if (sha_eq(o_sha, a_sha))
1196                return 1;
1197        if (!renormalize)
1198                return 0;
1199
1200        assert(o_sha && a_sha);
1201        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1202                goto error_return;
1203        /*
1204         * Note: binary | is used so that both renormalizations are
1205         * performed.  Comparison can be skipped if both files are
1206         * unchanged since their sha1s have already been compared.
1207         */
1208        if (renormalize_buffer(path, o.buf, o.len, &o) |
1209            renormalize_buffer(path, a.buf, o.len, &a))
1210                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1211
1212error_return:
1213        strbuf_release(&o);
1214        strbuf_release(&a);
1215        return ret;
1216}
1217
1218static void handle_delete_modify(struct merge_options *o,
1219                                 const char *path,
1220                                 const char *new_path,
1221                                 unsigned char *a_sha, int a_mode,
1222                                 unsigned char *b_sha, int b_mode)
1223{
1224        if (!a_sha) {
1225                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1226                       "and modified in %s. Version %s of %s left in tree%s%s.",
1227                       path, o->branch1,
1228                       o->branch2, o->branch2, path,
1229                       path == new_path ? "" : " at ",
1230                       path == new_path ? "" : new_path);
1231                update_file(o, 0, b_sha, b_mode, new_path);
1232        } else {
1233                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1234                       "and modified in %s. Version %s of %s left in tree%s%s.",
1235                       path, o->branch2,
1236                       o->branch1, o->branch1, path,
1237                       path == new_path ? "" : " at ",
1238                       path == new_path ? "" : new_path);
1239                update_file(o, 0, a_sha, a_mode, new_path);
1240        }
1241}
1242
1243static int merge_content(struct merge_options *o,
1244                         const char *path,
1245                         unsigned char *o_sha, int o_mode,
1246                         unsigned char *a_sha, int a_mode,
1247                         unsigned char *b_sha, int b_mode,
1248                         const char *df_rename_conflict_branch)
1249{
1250        const char *reason = "content";
1251        struct merge_file_info mfi;
1252        struct diff_filespec one, a, b;
1253        struct stat st;
1254        unsigned df_conflict_remains = 0;
1255
1256        if (!o_sha) {
1257                reason = "add/add";
1258                o_sha = (unsigned char *)null_sha1;
1259        }
1260        one.path = a.path = b.path = (char *)path;
1261        hashcpy(one.sha1, o_sha);
1262        one.mode = o_mode;
1263        hashcpy(a.sha1, a_sha);
1264        a.mode = a_mode;
1265        hashcpy(b.sha1, b_sha);
1266        b.mode = b_mode;
1267
1268        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1269        if (df_rename_conflict_branch &&
1270            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1271                df_conflict_remains = 1;
1272        }
1273
1274        if (mfi.clean && !df_conflict_remains &&
1275            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1276                output(o, 3, "Skipped %s (merged same as existing)", path);
1277        else
1278                output(o, 2, "Auto-merging %s", path);
1279
1280        if (!mfi.clean) {
1281                if (S_ISGITLINK(mfi.mode))
1282                        reason = "submodule";
1283                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1284                                reason, path);
1285        }
1286
1287        if (df_conflict_remains) {
1288                const char *new_path;
1289                update_file_flags(o, mfi.sha, mfi.mode, path,
1290                                  o->call_depth || mfi.clean, 0);
1291                new_path = unique_path(o, path, df_rename_conflict_branch);
1292                mfi.clean = 0;
1293                output(o, 1, "Adding as %s instead", new_path);
1294                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1295        } else {
1296                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1297        }
1298        return mfi.clean;
1299
1300}
1301
1302/* Per entry merge function */
1303static int process_entry(struct merge_options *o,
1304                         const char *path, struct stage_data *entry)
1305{
1306        /*
1307        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1308        print_index_entry("\tpath: ", entry);
1309        */
1310        int clean_merge = 1;
1311        int normalize = o->renormalize;
1312        unsigned o_mode = entry->stages[1].mode;
1313        unsigned a_mode = entry->stages[2].mode;
1314        unsigned b_mode = entry->stages[3].mode;
1315        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1316        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1317        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1318
1319        if (entry->rename_df_conflict_info)
1320                return 1; /* Such cases are handled elsewhere. */
1321
1322        entry->processed = 1;
1323        if (o_sha && (!a_sha || !b_sha)) {
1324                /* Case A: Deleted in one */
1325                if ((!a_sha && !b_sha) ||
1326                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1327                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1328                        /* Deleted in both or deleted in one and
1329                         * unchanged in the other */
1330                        if (a_sha)
1331                                output(o, 2, "Removing %s", path);
1332                        /* do not touch working file if it did not exist */
1333                        remove_file(o, 1, path, !a_sha);
1334                } else if (string_list_has_string(&o->current_directory_set,
1335                                                  path)) {
1336                        entry->processed = 0;
1337                        return 1; /* Assume clean until processed */
1338                } else {
1339                        /* Deleted in one and changed in the other */
1340                        clean_merge = 0;
1341                        handle_delete_modify(o, path, path,
1342                                             a_sha, a_mode, b_sha, b_mode);
1343                }
1344
1345        } else if ((!o_sha && a_sha && !b_sha) ||
1346                   (!o_sha && !a_sha && b_sha)) {
1347                /* Case B: Added in one. */
1348                unsigned mode;
1349                const unsigned char *sha;
1350
1351                if (a_sha) {
1352                        mode = a_mode;
1353                        sha = a_sha;
1354                } else {
1355                        mode = b_mode;
1356                        sha = b_sha;
1357                }
1358                if (string_list_has_string(&o->current_directory_set, path)) {
1359                        /* Handle D->F conflicts after all subfiles */
1360                        entry->processed = 0;
1361                        return 1; /* Assume clean until processed */
1362                } else {
1363                        output(o, 2, "Adding %s", path);
1364                        update_file(o, 1, sha, mode, path);
1365                }
1366        } else if (a_sha && b_sha) {
1367                /* Case C: Added in both (check for same permissions) and */
1368                /* case D: Modified in both, but differently. */
1369                clean_merge = merge_content(o, path,
1370                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1371                                            NULL);
1372        } else if (!o_sha && !a_sha && !b_sha) {
1373                /*
1374                 * this entry was deleted altogether. a_mode == 0 means
1375                 * we had that path and want to actively remove it.
1376                 */
1377                remove_file(o, 1, path, !a_mode);
1378        } else
1379                die("Fatal merge failure, shouldn't happen.");
1380
1381        return clean_merge;
1382}
1383
1384/*
1385 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1386 * cases we can cleanly resolve D/F conflicts, process_entry() can
1387 * clean out all the files below the directory for us.  All D/F
1388 * conflict cases must be handled here at the end to make sure any
1389 * directories that can be cleaned out, are.
1390 *
1391 * Some rename conflicts may also be handled here that don't necessarily
1392 * involve D/F conflicts, since the code to handle them is generic enough
1393 * to handle those rename conflicts with or without D/F conflicts also
1394 * being involved.
1395 */
1396static int process_df_entry(struct merge_options *o,
1397                            const char *path, struct stage_data *entry)
1398{
1399        int clean_merge = 1;
1400        unsigned o_mode = entry->stages[1].mode;
1401        unsigned a_mode = entry->stages[2].mode;
1402        unsigned b_mode = entry->stages[3].mode;
1403        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1404        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1405        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1406        struct stat st;
1407
1408        entry->processed = 1;
1409        if (entry->rename_df_conflict_info) {
1410                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1411                char *src;
1412                switch (conflict_info->rename_type) {
1413                case RENAME_NORMAL:
1414                        clean_merge = merge_content(o, path,
1415                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1416                                                    conflict_info->branch1);
1417                        break;
1418                case RENAME_DELETE:
1419                        clean_merge = 0;
1420                        conflict_rename_delete(o, conflict_info->pair1,
1421                                               conflict_info->branch1,
1422                                               conflict_info->branch2);
1423                        break;
1424                case RENAME_ONE_FILE_TO_TWO:
1425                        src = conflict_info->pair1->one->path;
1426                        clean_merge = 0;
1427                        output(o, 1, "CONFLICT (rename/rename): "
1428                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1429                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1430                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1431                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1432                               o->call_depth ? " (left unresolved)" : "");
1433                        if (o->call_depth) {
1434                                remove_file_from_cache(src);
1435                                update_file(o, 0, conflict_info->pair1->one->sha1,
1436                                            conflict_info->pair1->one->mode, src);
1437                        }
1438                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1439                                                    conflict_info->branch1,
1440                                                    conflict_info->pair2,
1441                                                    conflict_info->branch2);
1442                        conflict_info->dst_entry2->processed = 1;
1443                        break;
1444                default:
1445                        entry->processed = 0;
1446                        break;
1447                }
1448        } else if (o_sha && (!a_sha || !b_sha)) {
1449                /* Modify/delete; deleted side may have put a directory in the way */
1450                const char *new_path = path;
1451                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1452                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1453                clean_merge = 0;
1454                handle_delete_modify(o, path, new_path,
1455                                     a_sha, a_mode, b_sha, b_mode);
1456        } else if (!o_sha && !!a_sha != !!b_sha) {
1457                /* directory -> (directory, file) */
1458                const char *add_branch;
1459                const char *other_branch;
1460                unsigned mode;
1461                const unsigned char *sha;
1462                const char *conf;
1463
1464                if (a_sha) {
1465                        add_branch = o->branch1;
1466                        other_branch = o->branch2;
1467                        mode = a_mode;
1468                        sha = a_sha;
1469                        conf = "file/directory";
1470                } else {
1471                        add_branch = o->branch2;
1472                        other_branch = o->branch1;
1473                        mode = b_mode;
1474                        sha = b_sha;
1475                        conf = "directory/file";
1476                }
1477                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1478                        const char *new_path = unique_path(o, path, add_branch);
1479                        clean_merge = 0;
1480                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1481                               "Adding %s as %s",
1482                               conf, path, other_branch, path, new_path);
1483                        update_file(o, 0, sha, mode, new_path);
1484                } else {
1485                        output(o, 2, "Adding %s", path);
1486                        update_file(o, 1, sha, mode, path);
1487                }
1488        } else {
1489                entry->processed = 0;
1490                return 1; /* not handled; assume clean until processed */
1491        }
1492
1493        return clean_merge;
1494}
1495
1496int merge_trees(struct merge_options *o,
1497                struct tree *head,
1498                struct tree *merge,
1499                struct tree *common,
1500                struct tree **result)
1501{
1502        int code, clean;
1503
1504        if (o->subtree_shift) {
1505                merge = shift_tree_object(head, merge, o->subtree_shift);
1506                common = shift_tree_object(head, common, o->subtree_shift);
1507        }
1508
1509        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1510                output(o, 0, "Already up-to-date!");
1511                *result = head;
1512                return 1;
1513        }
1514
1515        code = git_merge_trees(o->call_depth, common, head, merge);
1516
1517        if (code != 0) {
1518                if (show(o, 4) || o->call_depth)
1519                        die("merging of trees %s and %s failed",
1520                            sha1_to_hex(head->object.sha1),
1521                            sha1_to_hex(merge->object.sha1));
1522                else
1523                        exit(128);
1524        }
1525
1526        if (unmerged_cache()) {
1527                struct string_list *entries, *re_head, *re_merge;
1528                int i;
1529                string_list_clear(&o->current_file_set, 1);
1530                string_list_clear(&o->current_directory_set, 1);
1531                get_files_dirs(o, head);
1532                get_files_dirs(o, merge);
1533
1534                entries = get_unmerged();
1535                make_room_for_directories_of_df_conflicts(o, entries);
1536                re_head  = get_renames(o, head, common, head, merge, entries);
1537                re_merge = get_renames(o, merge, common, head, merge, entries);
1538                clean = process_renames(o, re_head, re_merge);
1539                for (i = 0; i < entries->nr; i++) {
1540                        const char *path = entries->items[i].string;
1541                        struct stage_data *e = entries->items[i].util;
1542                        if (!e->processed
1543                                && !process_entry(o, path, e))
1544                                clean = 0;
1545                }
1546                for (i = 0; i < entries->nr; i++) {
1547                        const char *path = entries->items[i].string;
1548                        struct stage_data *e = entries->items[i].util;
1549                        if (!e->processed
1550                                && !process_df_entry(o, path, e))
1551                                clean = 0;
1552                }
1553                for (i = 0; i < entries->nr; i++) {
1554                        struct stage_data *e = entries->items[i].util;
1555                        if (!e->processed)
1556                                die("Unprocessed path??? %s",
1557                                    entries->items[i].string);
1558                }
1559
1560                string_list_clear(re_merge, 0);
1561                string_list_clear(re_head, 0);
1562                string_list_clear(entries, 1);
1563
1564        }
1565        else
1566                clean = 1;
1567
1568        if (o->call_depth)
1569                *result = write_tree_from_memory(o);
1570
1571        return clean;
1572}
1573
1574static struct commit_list *reverse_commit_list(struct commit_list *list)
1575{
1576        struct commit_list *next = NULL, *current, *backup;
1577        for (current = list; current; current = backup) {
1578                backup = current->next;
1579                current->next = next;
1580                next = current;
1581        }
1582        return next;
1583}
1584
1585/*
1586 * Merge the commits h1 and h2, return the resulting virtual
1587 * commit object and a flag indicating the cleanness of the merge.
1588 */
1589int merge_recursive(struct merge_options *o,
1590                    struct commit *h1,
1591                    struct commit *h2,
1592                    struct commit_list *ca,
1593                    struct commit **result)
1594{
1595        struct commit_list *iter;
1596        struct commit *merged_common_ancestors;
1597        struct tree *mrtree = mrtree;
1598        int clean;
1599
1600        if (show(o, 4)) {
1601                output(o, 4, "Merging:");
1602                output_commit_title(o, h1);
1603                output_commit_title(o, h2);
1604        }
1605
1606        if (!ca) {
1607                ca = get_merge_bases(h1, h2, 1);
1608                ca = reverse_commit_list(ca);
1609        }
1610
1611        if (show(o, 5)) {
1612                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1613                for (iter = ca; iter; iter = iter->next)
1614                        output_commit_title(o, iter->item);
1615        }
1616
1617        merged_common_ancestors = pop_commit(&ca);
1618        if (merged_common_ancestors == NULL) {
1619                /* if there is no common ancestor, make an empty tree */
1620                struct tree *tree = xcalloc(1, sizeof(struct tree));
1621
1622                tree->object.parsed = 1;
1623                tree->object.type = OBJ_TREE;
1624                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1625                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1626        }
1627
1628        for (iter = ca; iter; iter = iter->next) {
1629                const char *saved_b1, *saved_b2;
1630                o->call_depth++;
1631                /*
1632                 * When the merge fails, the result contains files
1633                 * with conflict markers. The cleanness flag is
1634                 * ignored, it was never actually used, as result of
1635                 * merge_trees has always overwritten it: the committed
1636                 * "conflicts" were already resolved.
1637                 */
1638                discard_cache();
1639                saved_b1 = o->branch1;
1640                saved_b2 = o->branch2;
1641                o->branch1 = "Temporary merge branch 1";
1642                o->branch2 = "Temporary merge branch 2";
1643                merge_recursive(o, merged_common_ancestors, iter->item,
1644                                NULL, &merged_common_ancestors);
1645                o->branch1 = saved_b1;
1646                o->branch2 = saved_b2;
1647                o->call_depth--;
1648
1649                if (!merged_common_ancestors)
1650                        die("merge returned no commit");
1651        }
1652
1653        discard_cache();
1654        if (!o->call_depth)
1655                read_cache();
1656
1657        o->ancestor = "merged common ancestors";
1658        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1659                            &mrtree);
1660
1661        if (o->call_depth) {
1662                *result = make_virtual_commit(mrtree, "merged tree");
1663                commit_list_insert(h1, &(*result)->parents);
1664                commit_list_insert(h2, &(*result)->parents->next);
1665        }
1666        flush_output(o);
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}