merge-recursive.con commit cherry-pick: handle root commits with external strategies (1618073)
   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 const char rename_limit_advice[] =
  26"inexact rename detection was skipped because there were too many\n"
  27"  files. You may want to set your merge.renamelimit variable to at least\n"
  28"  %d and retry this merge.";
  29
  30static struct tree *shift_tree_object(struct tree *one, struct tree *two,
  31                                      const char *subtree_shift)
  32{
  33        unsigned char shifted[20];
  34
  35        if (!*subtree_shift) {
  36                shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
  37        } else {
  38                shift_tree_by(one->object.sha1, two->object.sha1, shifted,
  39                              subtree_shift);
  40        }
  41        if (!hashcmp(two->object.sha1, shifted))
  42                return two;
  43        return lookup_tree(shifted);
  44}
  45
  46/*
  47 * A virtual commit has (const char *)commit->util set to the name.
  48 */
  49
  50static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  51{
  52        struct commit *commit = xcalloc(1, sizeof(struct commit));
  53        commit->tree = tree;
  54        commit->util = (void*)comment;
  55        /* avoid warnings */
  56        commit->object.parsed = 1;
  57        return commit;
  58}
  59
  60/*
  61 * Since we use get_tree_entry(), which does not put the read object into
  62 * the object pool, we cannot rely on a == b.
  63 */
  64static int sha_eq(const unsigned char *a, const unsigned char *b)
  65{
  66        if (!a && !b)
  67                return 2;
  68        return a && b && hashcmp(a, b) == 0;
  69}
  70
  71enum rename_type {
  72        RENAME_NORMAL = 0,
  73        RENAME_DELETE,
  74        RENAME_ONE_FILE_TO_TWO
  75};
  76
  77struct rename_df_conflict_info {
  78        enum rename_type rename_type;
  79        struct diff_filepair *pair1;
  80        struct diff_filepair *pair2;
  81        const char *branch1;
  82        const char *branch2;
  83        struct stage_data *dst_entry1;
  84        struct stage_data *dst_entry2;
  85};
  86
  87/*
  88 * Since we want to write the index eventually, we cannot reuse the index
  89 * for these (temporary) data.
  90 */
  91struct stage_data {
  92        struct {
  93                unsigned mode;
  94                unsigned char sha[20];
  95        } stages[4];
  96        struct rename_df_conflict_info *rename_df_conflict_info;
  97        unsigned processed:1;
  98};
  99
 100static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
 101                                                 struct diff_filepair *pair1,
 102                                                 struct diff_filepair *pair2,
 103                                                 const char *branch1,
 104                                                 const char *branch2,
 105                                                 struct stage_data *dst_entry1,
 106                                                 struct stage_data *dst_entry2)
 107{
 108        struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
 109        ci->rename_type = rename_type;
 110        ci->pair1 = pair1;
 111        ci->branch1 = branch1;
 112        ci->branch2 = branch2;
 113
 114        ci->dst_entry1 = dst_entry1;
 115        dst_entry1->rename_df_conflict_info = ci;
 116        dst_entry1->processed = 0;
 117
 118        assert(!pair2 == !dst_entry2);
 119        if (dst_entry2) {
 120                ci->dst_entry2 = dst_entry2;
 121                ci->pair2 = pair2;
 122                dst_entry2->rename_df_conflict_info = ci;
 123                dst_entry2->processed = 0;
 124        }
 125}
 126
 127static int show(struct merge_options *o, int v)
 128{
 129        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 130}
 131
 132static void flush_output(struct merge_options *o)
 133{
 134        if (o->obuf.len) {
 135                fputs(o->obuf.buf, stdout);
 136                strbuf_reset(&o->obuf);
 137        }
 138}
 139
 140__attribute__((format (printf, 3, 4)))
 141static void output(struct merge_options *o, int v, const char *fmt, ...)
 142{
 143        va_list ap;
 144
 145        if (!show(o, v))
 146                return;
 147
 148        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 149        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 150        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 151
 152        va_start(ap, fmt);
 153        strbuf_vaddf(&o->obuf, fmt, ap);
 154        va_end(ap);
 155
 156        strbuf_add(&o->obuf, "\n", 1);
 157        if (!o->buffer_output)
 158                flush_output(o);
 159}
 160
 161static void output_commit_title(struct merge_options *o, struct commit *commit)
 162{
 163        int i;
 164        flush_output(o);
 165        for (i = o->call_depth; i--;)
 166                fputs("  ", stdout);
 167        if (commit->util)
 168                printf("virtual %s\n", (char *)commit->util);
 169        else {
 170                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 171                if (parse_commit(commit) != 0)
 172                        printf("(bad commit)\n");
 173                else {
 174                        const char *title;
 175                        int len = find_commit_subject(commit->buffer, &title);
 176                        if (len)
 177                                printf("%.*s\n", len, title);
 178                }
 179        }
 180}
 181
 182static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 183                const char *path, int stage, int refresh, int options)
 184{
 185        struct cache_entry *ce;
 186        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 187        if (!ce)
 188                return error("addinfo_cache failed for path '%s'", path);
 189        return add_cache_entry(ce, options);
 190}
 191
 192static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 193{
 194        parse_tree(tree);
 195        init_tree_desc(desc, tree->buffer, tree->size);
 196}
 197
 198static int git_merge_trees(int index_only,
 199                           struct tree *common,
 200                           struct tree *head,
 201                           struct tree *merge)
 202{
 203        int rc;
 204        struct tree_desc t[3];
 205        struct unpack_trees_options opts;
 206
 207        memset(&opts, 0, sizeof(opts));
 208        if (index_only)
 209                opts.index_only = 1;
 210        else
 211                opts.update = 1;
 212        opts.merge = 1;
 213        opts.head_idx = 2;
 214        opts.fn = threeway_merge;
 215        opts.src_index = &the_index;
 216        opts.dst_index = &the_index;
 217        setup_unpack_trees_porcelain(&opts, "merge");
 218
 219        init_tree_desc_from_tree(t+0, common);
 220        init_tree_desc_from_tree(t+1, head);
 221        init_tree_desc_from_tree(t+2, merge);
 222
 223        rc = unpack_trees(3, t, &opts);
 224        cache_tree_free(&active_cache_tree);
 225        return rc;
 226}
 227
 228struct tree *write_tree_from_memory(struct merge_options *o)
 229{
 230        struct tree *result = NULL;
 231
 232        if (unmerged_cache()) {
 233                int i;
 234                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 235                for (i = 0; i < active_nr; i++) {
 236                        struct cache_entry *ce = active_cache[i];
 237                        if (ce_stage(ce))
 238                                fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
 239                                        (int)ce_namelen(ce), ce->name);
 240                }
 241                die("Bug in merge-recursive.c");
 242        }
 243
 244        if (!active_cache_tree)
 245                active_cache_tree = cache_tree();
 246
 247        if (!cache_tree_fully_valid(active_cache_tree) &&
 248            cache_tree_update(active_cache_tree,
 249                              active_cache, active_nr, 0, 0) < 0)
 250                die("error building trees");
 251
 252        result = lookup_tree(active_cache_tree->sha1);
 253
 254        return result;
 255}
 256
 257static int save_files_dirs(const unsigned char *sha1,
 258                const char *base, int baselen, const char *path,
 259                unsigned int mode, int stage, void *context)
 260{
 261        int len = strlen(path);
 262        char *newpath = xmalloc(baselen + len + 1);
 263        struct merge_options *o = context;
 264
 265        memcpy(newpath, base, baselen);
 266        memcpy(newpath + baselen, path, len);
 267        newpath[baselen + len] = '\0';
 268
 269        if (S_ISDIR(mode))
 270                string_list_insert(&o->current_directory_set, newpath);
 271        else
 272                string_list_insert(&o->current_file_set, newpath);
 273        free(newpath);
 274
 275        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 276}
 277
 278static int get_files_dirs(struct merge_options *o, struct tree *tree)
 279{
 280        int n;
 281        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 282                return 0;
 283        n = o->current_file_set.nr + o->current_directory_set.nr;
 284        return n;
 285}
 286
 287/*
 288 * Returns an index_entry instance which doesn't have to correspond to
 289 * a real cache entry in Git's index.
 290 */
 291static struct stage_data *insert_stage_data(const char *path,
 292                struct tree *o, struct tree *a, struct tree *b,
 293                struct string_list *entries)
 294{
 295        struct string_list_item *item;
 296        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 297        get_tree_entry(o->object.sha1, path,
 298                        e->stages[1].sha, &e->stages[1].mode);
 299        get_tree_entry(a->object.sha1, path,
 300                        e->stages[2].sha, &e->stages[2].mode);
 301        get_tree_entry(b->object.sha1, path,
 302                        e->stages[3].sha, &e->stages[3].mode);
 303        item = string_list_insert(entries, path);
 304        item->util = e;
 305        return e;
 306}
 307
 308/*
 309 * Create a dictionary mapping file names to stage_data objects. The
 310 * dictionary contains one entry for every path with a non-zero stage entry.
 311 */
 312static struct string_list *get_unmerged(void)
 313{
 314        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 315        int i;
 316
 317        unmerged->strdup_strings = 1;
 318
 319        for (i = 0; i < active_nr; i++) {
 320                struct string_list_item *item;
 321                struct stage_data *e;
 322                struct cache_entry *ce = active_cache[i];
 323                if (!ce_stage(ce))
 324                        continue;
 325
 326                item = string_list_lookup(unmerged, ce->name);
 327                if (!item) {
 328                        item = string_list_insert(unmerged, ce->name);
 329                        item->util = xcalloc(1, sizeof(struct stage_data));
 330                }
 331                e = item->util;
 332                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 333                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 334        }
 335
 336        return unmerged;
 337}
 338
 339static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 340                                                      struct string_list *entries)
 341{
 342        /* If there are D/F conflicts, and the paths currently exist
 343         * in the working copy as a file, we want to remove them to
 344         * make room for the corresponding directory.  Such paths will
 345         * later be processed in process_df_entry() at the end.  If
 346         * the corresponding directory ends up being removed by the
 347         * merge, then the file will be reinstated at that time;
 348         * otherwise, if the file is not supposed to be removed by the
 349         * merge, the contents of the file will be placed in another
 350         * unique filename.
 351         *
 352         * NOTE: This function relies on the fact that entries for a
 353         * D/F conflict will appear adjacent in the index, with the
 354         * entries for the file appearing before entries for paths
 355         * below the corresponding directory.
 356         */
 357        const char *last_file = NULL;
 358        int last_len = 0;
 359        int i;
 360
 361        for (i = 0; i < entries->nr; i++) {
 362                const char *path = entries->items[i].string;
 363                int len = strlen(path);
 364                struct stage_data *e = entries->items[i].util;
 365
 366                /*
 367                 * Check if last_file & path correspond to a D/F conflict;
 368                 * i.e. whether path is last_file+'/'+<something>.
 369                 * If so, remove last_file to make room for path and friends.
 370                 */
 371                if (last_file &&
 372                    len > last_len &&
 373                    memcmp(path, last_file, last_len) == 0 &&
 374                    path[last_len] == '/') {
 375                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 376                        unlink(last_file);
 377                }
 378
 379                /*
 380                 * Determine whether path could exist as a file in the
 381                 * working directory as a possible D/F conflict.  This
 382                 * will only occur when it exists in stage 2 as a
 383                 * file.
 384                 */
 385                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 386                        last_file = path;
 387                        last_len = len;
 388                } else {
 389                        last_file = NULL;
 390                }
 391        }
 392}
 393
 394struct rename {
 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                            1000;
 425        opts.rename_score = o->rename_score;
 426        opts.show_rename_progress = o->show_rename_progress;
 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        if (opts.needed_rename_limit > o->needed_rename_limit)
 433                o->needed_rename_limit = opts.needed_rename_limit;
 434        for (i = 0; i < diff_queued_diff.nr; ++i) {
 435                struct string_list_item *item;
 436                struct rename *re;
 437                struct diff_filepair *pair = diff_queued_diff.queue[i];
 438                if (pair->status != 'R') {
 439                        diff_free_filepair(pair);
 440                        continue;
 441                }
 442                re = xmalloc(sizeof(*re));
 443                re->processed = 0;
 444                re->pair = pair;
 445                item = string_list_lookup(entries, re->pair->one->path);
 446                if (!item)
 447                        re->src_entry = insert_stage_data(re->pair->one->path,
 448                                        o_tree, a_tree, b_tree, entries);
 449                else
 450                        re->src_entry = item->util;
 451
 452                item = string_list_lookup(entries, re->pair->two->path);
 453                if (!item)
 454                        re->dst_entry = insert_stage_data(re->pair->two->path,
 455                                        o_tree, a_tree, b_tree, entries);
 456                else
 457                        re->dst_entry = item->util;
 458                item = string_list_insert(renames, pair->one->path);
 459                item->util = re;
 460        }
 461        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 462        diff_queued_diff.nr = 0;
 463        diff_flush(&opts);
 464        return renames;
 465}
 466
 467static int update_stages_options(const char *path, struct diff_filespec *o,
 468                         struct diff_filespec *a, struct diff_filespec *b,
 469                         int clear, int options)
 470{
 471        if (clear)
 472                if (remove_file_from_cache(path))
 473                        return -1;
 474        if (o)
 475                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 476                        return -1;
 477        if (a)
 478                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 479                        return -1;
 480        if (b)
 481                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 482                        return -1;
 483        return 0;
 484}
 485
 486static int update_stages(const char *path, struct diff_filespec *o,
 487                         struct diff_filespec *a, struct diff_filespec *b,
 488                         int clear)
 489{
 490        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 491        return update_stages_options(path, o, a, b, clear, options);
 492}
 493
 494static int update_stages_and_entry(const char *path,
 495                                   struct stage_data *entry,
 496                                   struct diff_filespec *o,
 497                                   struct diff_filespec *a,
 498                                   struct diff_filespec *b,
 499                                   int clear)
 500{
 501        int options;
 502
 503        entry->processed = 0;
 504        entry->stages[1].mode = o->mode;
 505        entry->stages[2].mode = a->mode;
 506        entry->stages[3].mode = b->mode;
 507        hashcpy(entry->stages[1].sha, o->sha1);
 508        hashcpy(entry->stages[2].sha, a->sha1);
 509        hashcpy(entry->stages[3].sha, b->sha1);
 510        options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 511        return update_stages_options(path, o, a, b, clear, options);
 512}
 513
 514static int remove_file(struct merge_options *o, int clean,
 515                       const char *path, int no_wd)
 516{
 517        int update_cache = o->call_depth || clean;
 518        int update_working_directory = !o->call_depth && !no_wd;
 519
 520        if (update_cache) {
 521                if (remove_file_from_cache(path))
 522                        return -1;
 523        }
 524        if (update_working_directory) {
 525                if (remove_path(path))
 526                        return -1;
 527        }
 528        return 0;
 529}
 530
 531static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 532{
 533        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 534        int suffix = 0;
 535        struct stat st;
 536        char *p = newpath + strlen(path);
 537        strcpy(newpath, path);
 538        *(p++) = '~';
 539        strcpy(p, branch);
 540        for (; *p; ++p)
 541                if ('/' == *p)
 542                        *p = '_';
 543        while (string_list_has_string(&o->current_file_set, newpath) ||
 544               string_list_has_string(&o->current_directory_set, newpath) ||
 545               lstat(newpath, &st) == 0)
 546                sprintf(p, "_%d", suffix++);
 547
 548        string_list_insert(&o->current_file_set, newpath);
 549        return newpath;
 550}
 551
 552static void flush_buffer(int fd, const char *buf, unsigned long size)
 553{
 554        while (size > 0) {
 555                long ret = write_in_full(fd, buf, size);
 556                if (ret < 0) {
 557                        /* Ignore epipe */
 558                        if (errno == EPIPE)
 559                                break;
 560                        die_errno("merge-recursive");
 561                } else if (!ret) {
 562                        die("merge-recursive: disk full?");
 563                }
 564                size -= ret;
 565                buf += ret;
 566        }
 567}
 568
 569static int would_lose_untracked(const char *path)
 570{
 571        int pos = cache_name_pos(path, strlen(path));
 572
 573        if (pos < 0)
 574                pos = -1 - pos;
 575        while (pos < active_nr &&
 576               !strcmp(path, active_cache[pos]->name)) {
 577                /*
 578                 * If stage #0, it is definitely tracked.
 579                 * If it has stage #2 then it was tracked
 580                 * before this merge started.  All other
 581                 * cases the path was not tracked.
 582                 */
 583                switch (ce_stage(active_cache[pos])) {
 584                case 0:
 585                case 2:
 586                        return 0;
 587                }
 588                pos++;
 589        }
 590        return file_exists(path);
 591}
 592
 593static int make_room_for_path(const char *path)
 594{
 595        int status;
 596        const char *msg = "failed to create path '%s'%s";
 597
 598        status = safe_create_leading_directories_const(path);
 599        if (status) {
 600                if (status == -3) {
 601                        /* something else exists */
 602                        error(msg, path, ": perhaps a D/F conflict?");
 603                        return -1;
 604                }
 605                die(msg, path, "");
 606        }
 607
 608        /*
 609         * Do not unlink a file in the work tree if we are not
 610         * tracking it.
 611         */
 612        if (would_lose_untracked(path))
 613                return error("refusing to lose untracked file at '%s'",
 614                             path);
 615
 616        /* Successful unlink is good.. */
 617        if (!unlink(path))
 618                return 0;
 619        /* .. and so is no existing file */
 620        if (errno == ENOENT)
 621                return 0;
 622        /* .. but not some other error (who really cares what?) */
 623        return error(msg, path, ": perhaps a D/F conflict?");
 624}
 625
 626static void update_file_flags(struct merge_options *o,
 627                              const unsigned char *sha,
 628                              unsigned mode,
 629                              const char *path,
 630                              int update_cache,
 631                              int update_wd)
 632{
 633        if (o->call_depth)
 634                update_wd = 0;
 635
 636        if (update_wd) {
 637                enum object_type type;
 638                void *buf;
 639                unsigned long size;
 640
 641                if (S_ISGITLINK(mode)) {
 642                        /*
 643                         * We may later decide to recursively descend into
 644                         * the submodule directory and update its index
 645                         * and/or work tree, but we do not do that now.
 646                         */
 647                        update_wd = 0;
 648                        goto update_index;
 649                }
 650
 651                buf = read_sha1_file(sha, &type, &size);
 652                if (!buf)
 653                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 654                if (type != OBJ_BLOB)
 655                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 656                if (S_ISREG(mode)) {
 657                        struct strbuf strbuf = STRBUF_INIT;
 658                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 659                                free(buf);
 660                                size = strbuf.len;
 661                                buf = strbuf_detach(&strbuf, NULL);
 662                        }
 663                }
 664
 665                if (make_room_for_path(path) < 0) {
 666                        update_wd = 0;
 667                        free(buf);
 668                        goto update_index;
 669                }
 670                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 671                        int fd;
 672                        if (mode & 0100)
 673                                mode = 0777;
 674                        else
 675                                mode = 0666;
 676                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 677                        if (fd < 0)
 678                                die_errno("failed to open '%s'", path);
 679                        flush_buffer(fd, buf, size);
 680                        close(fd);
 681                } else if (S_ISLNK(mode)) {
 682                        char *lnk = xmemdupz(buf, size);
 683                        safe_create_leading_directories_const(path);
 684                        unlink(path);
 685                        if (symlink(lnk, path))
 686                                die_errno("failed to symlink '%s'", path);
 687                        free(lnk);
 688                } else
 689                        die("do not know what to do with %06o %s '%s'",
 690                            mode, sha1_to_hex(sha), path);
 691                free(buf);
 692        }
 693 update_index:
 694        if (update_cache)
 695                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 696}
 697
 698static void update_file(struct merge_options *o,
 699                        int clean,
 700                        const unsigned char *sha,
 701                        unsigned mode,
 702                        const char *path)
 703{
 704        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 705}
 706
 707/* Low level file merging, update and removal */
 708
 709struct merge_file_info {
 710        unsigned char sha[20];
 711        unsigned mode;
 712        unsigned clean:1,
 713                 merge:1;
 714};
 715
 716static int merge_3way(struct merge_options *o,
 717                      mmbuffer_t *result_buf,
 718                      struct diff_filespec *one,
 719                      struct diff_filespec *a,
 720                      struct diff_filespec *b,
 721                      const char *branch1,
 722                      const char *branch2)
 723{
 724        mmfile_t orig, src1, src2;
 725        struct ll_merge_options ll_opts = {0};
 726        char *base_name, *name1, *name2;
 727        int merge_status;
 728
 729        ll_opts.renormalize = o->renormalize;
 730        ll_opts.xdl_opts = o->xdl_opts;
 731
 732        if (o->call_depth) {
 733                ll_opts.virtual_ancestor = 1;
 734                ll_opts.variant = 0;
 735        } else {
 736                switch (o->recursive_variant) {
 737                case MERGE_RECURSIVE_OURS:
 738                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 739                        break;
 740                case MERGE_RECURSIVE_THEIRS:
 741                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 742                        break;
 743                default:
 744                        ll_opts.variant = 0;
 745                        break;
 746                }
 747        }
 748
 749        if (strcmp(a->path, b->path) ||
 750            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 751                base_name = o->ancestor == NULL ? NULL :
 752                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 753                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 754                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 755        } else {
 756                base_name = o->ancestor == NULL ? NULL :
 757                        xstrdup(mkpath("%s", o->ancestor));
 758                name1 = xstrdup(mkpath("%s", branch1));
 759                name2 = xstrdup(mkpath("%s", branch2));
 760        }
 761
 762        read_mmblob(&orig, one->sha1);
 763        read_mmblob(&src1, a->sha1);
 764        read_mmblob(&src2, b->sha1);
 765
 766        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 767                                &src1, name1, &src2, name2, &ll_opts);
 768
 769        free(name1);
 770        free(name2);
 771        free(orig.ptr);
 772        free(src1.ptr);
 773        free(src2.ptr);
 774        return merge_status;
 775}
 776
 777static struct merge_file_info merge_file(struct merge_options *o,
 778                                         struct diff_filespec *one,
 779                                         struct diff_filespec *a,
 780                                         struct diff_filespec *b,
 781                                         const char *branch1,
 782                                         const char *branch2)
 783{
 784        struct merge_file_info result;
 785        result.merge = 0;
 786        result.clean = 1;
 787
 788        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 789                result.clean = 0;
 790                if (S_ISREG(a->mode)) {
 791                        result.mode = a->mode;
 792                        hashcpy(result.sha, a->sha1);
 793                } else {
 794                        result.mode = b->mode;
 795                        hashcpy(result.sha, b->sha1);
 796                }
 797        } else {
 798                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 799                        result.merge = 1;
 800
 801                /*
 802                 * Merge modes
 803                 */
 804                if (a->mode == b->mode || a->mode == one->mode)
 805                        result.mode = b->mode;
 806                else {
 807                        result.mode = a->mode;
 808                        if (b->mode != one->mode) {
 809                                result.clean = 0;
 810                                result.merge = 1;
 811                        }
 812                }
 813
 814                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 815                        hashcpy(result.sha, b->sha1);
 816                else if (sha_eq(b->sha1, one->sha1))
 817                        hashcpy(result.sha, a->sha1);
 818                else if (S_ISREG(a->mode)) {
 819                        mmbuffer_t result_buf;
 820                        int merge_status;
 821
 822                        merge_status = merge_3way(o, &result_buf, one, a, b,
 823                                                  branch1, branch2);
 824
 825                        if ((merge_status < 0) || !result_buf.ptr)
 826                                die("Failed to execute internal merge");
 827
 828                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 829                                            blob_type, result.sha))
 830                                die("Unable to add %s to database",
 831                                    a->path);
 832
 833                        free(result_buf.ptr);
 834                        result.clean = (merge_status == 0);
 835                } else if (S_ISGITLINK(a->mode)) {
 836                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 837                                                       a->sha1, b->sha1);
 838                } else if (S_ISLNK(a->mode)) {
 839                        hashcpy(result.sha, a->sha1);
 840
 841                        if (!sha_eq(a->sha1, b->sha1))
 842                                result.clean = 0;
 843                } else {
 844                        die("unsupported object type in the tree");
 845                }
 846        }
 847
 848        return result;
 849}
 850
 851static void conflict_rename_delete(struct merge_options *o,
 852                                   struct diff_filepair *pair,
 853                                   const char *rename_branch,
 854                                   const char *other_branch)
 855{
 856        char *dest_name = pair->two->path;
 857        int df_conflict = 0;
 858        struct stat st;
 859
 860        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 861               "and deleted in %s",
 862               pair->one->path, pair->two->path, rename_branch,
 863               other_branch);
 864        if (!o->call_depth)
 865                update_stages(dest_name, NULL,
 866                              rename_branch == o->branch1 ? pair->two : NULL,
 867                              rename_branch == o->branch1 ? NULL : pair->two,
 868                              1);
 869        if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 870                dest_name = unique_path(o, dest_name, rename_branch);
 871                df_conflict = 1;
 872        }
 873        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 874        if (df_conflict)
 875                free(dest_name);
 876}
 877
 878static void conflict_rename_rename_1to2(struct merge_options *o,
 879                                        struct diff_filepair *pair1,
 880                                        const char *branch1,
 881                                        struct diff_filepair *pair2,
 882                                        const char *branch2)
 883{
 884        /* One file was renamed in both branches, but to different names. */
 885        char *del[2];
 886        int delp = 0;
 887        const char *ren1_dst = pair1->two->path;
 888        const char *ren2_dst = pair2->two->path;
 889        const char *dst_name1 = ren1_dst;
 890        const char *dst_name2 = ren2_dst;
 891        struct stat st;
 892        if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 893                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 894                output(o, 1, "%s is a directory in %s adding as %s instead",
 895                       ren1_dst, branch2, dst_name1);
 896        }
 897        if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 898                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 899                output(o, 1, "%s is a directory in %s adding as %s instead",
 900                       ren2_dst, branch1, dst_name2);
 901        }
 902        if (o->call_depth) {
 903                remove_file_from_cache(dst_name1);
 904                remove_file_from_cache(dst_name2);
 905                /*
 906                 * Uncomment to leave the conflicting names in the resulting tree
 907                 *
 908                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 909                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 910                 */
 911        } else {
 912                update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 913                update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 914
 915                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 916                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 917        }
 918        while (delp--)
 919                free(del[delp]);
 920}
 921
 922static void conflict_rename_rename_2to1(struct merge_options *o,
 923                                        struct rename *ren1,
 924                                        const char *branch1,
 925                                        struct rename *ren2,
 926                                        const char *branch2)
 927{
 928        /* Two files were renamed to the same thing. */
 929        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 930        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 931        output(o, 1, "Renaming %s to %s and %s to %s instead",
 932               ren1->pair->one->path, new_path1,
 933               ren2->pair->one->path, new_path2);
 934        remove_file(o, 0, ren1->pair->two->path, 0);
 935        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 936        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 937        free(new_path2);
 938        free(new_path1);
 939}
 940
 941static int process_renames(struct merge_options *o,
 942                           struct string_list *a_renames,
 943                           struct string_list *b_renames)
 944{
 945        int clean_merge = 1, i, j;
 946        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 947        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 948        const struct rename *sre;
 949
 950        for (i = 0; i < a_renames->nr; i++) {
 951                sre = a_renames->items[i].util;
 952                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 953                        = sre->dst_entry;
 954        }
 955        for (i = 0; i < b_renames->nr; i++) {
 956                sre = b_renames->items[i].util;
 957                string_list_insert(&b_by_dst, sre->pair->two->path)->util
 958                        = sre->dst_entry;
 959        }
 960
 961        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 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
 997                ren1->dst_entry->processed = 1;
 998                ren1->src_entry->processed = 1;
 999
1000                if (ren1->processed)
1001                        continue;
1002                ren1->processed = 1;
1003
1004                ren1_src = ren1->pair->one->path;
1005                ren1_dst = ren1->pair->two->path;
1006
1007                if (ren2) {
1008                        const char *ren2_src = ren2->pair->one->path;
1009                        const char *ren2_dst = ren2->pair->two->path;
1010                        /* Renamed in 1 and renamed in 2 */
1011                        if (strcmp(ren1_src, ren2_src) != 0)
1012                                die("ren1.src != ren2.src");
1013                        ren2->dst_entry->processed = 1;
1014                        ren2->processed = 1;
1015                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1016                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1017                                                              ren1->pair,
1018                                                              ren2->pair,
1019                                                              branch1,
1020                                                              branch2,
1021                                                              ren1->dst_entry,
1022                                                              ren2->dst_entry);
1023                        } else {
1024                                remove_file(o, 1, ren1_src, 1);
1025                                update_stages_and_entry(ren1_dst,
1026                                                        ren1->dst_entry,
1027                                                        ren1->pair->one,
1028                                                        ren1->pair->two,
1029                                                        ren2->pair->two,
1030                                                        1 /* clear */);
1031                        }
1032                } else {
1033                        /* Renamed in 1, maybe changed in 2 */
1034                        struct string_list_item *item;
1035                        /* we only use sha1 and mode of these */
1036                        struct diff_filespec src_other, dst_other;
1037                        int try_merge;
1038
1039                        /*
1040                         * unpack_trees loads entries from common-commit
1041                         * into stage 1, from head-commit into stage 2, and
1042                         * from merge-commit into stage 3.  We keep track
1043                         * of which side corresponds to the rename.
1044                         */
1045                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1046                        int other_stage =   a_renames == renames1 ? 3 : 2;
1047
1048                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1049
1050                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1051                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1052                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1053                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1054                        try_merge = 0;
1055
1056                        if (sha_eq(src_other.sha1, null_sha1)) {
1057                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1058                                        ren1->dst_entry->processed = 0;
1059                                        setup_rename_df_conflict_info(RENAME_DELETE,
1060                                                                      ren1->pair,
1061                                                                      NULL,
1062                                                                      branch1,
1063                                                                      branch2,
1064                                                                      ren1->dst_entry,
1065                                                                      NULL);
1066                                } else {
1067                                        clean_merge = 0;
1068                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1069                                }
1070                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1071                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1072                                /* Added file on the other side
1073                                   identical to the file being
1074                                   renamed: clean merge */
1075                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1076                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1077                                const char *new_path;
1078                                clean_merge = 0;
1079                                try_merge = 1;
1080                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1081                                       "%s added in %s",
1082                                       ren1_src, ren1_dst, branch1,
1083                                       ren1_dst, branch2);
1084                                if (o->call_depth) {
1085                                        struct merge_file_info mfi;
1086                                        struct diff_filespec one, a, b;
1087
1088                                        one.path = a.path = b.path =
1089                                                (char *)ren1_dst;
1090                                        hashcpy(one.sha1, null_sha1);
1091                                        one.mode = 0;
1092                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1093                                        a.mode = ren1->pair->two->mode;
1094                                        hashcpy(b.sha1, dst_other.sha1);
1095                                        b.mode = dst_other.mode;
1096                                        mfi = merge_file(o, &one, &a, &b,
1097                                                         branch1,
1098                                                         branch2);
1099                                        output(o, 1, "Adding merged %s", ren1_dst);
1100                                        update_file(o, 0,
1101                                                    mfi.sha,
1102                                                    mfi.mode,
1103                                                    ren1_dst);
1104                                        try_merge = 0;
1105                                } else {
1106                                        new_path = unique_path(o, ren1_dst, branch2);
1107                                        output(o, 1, "Adding as %s instead", new_path);
1108                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1109                                }
1110                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1111                                ren2 = item->util;
1112                                clean_merge = 0;
1113                                ren2->processed = 1;
1114                                output(o, 1, "CONFLICT (rename/rename): "
1115                                       "Rename %s->%s in %s. "
1116                                       "Rename %s->%s in %s",
1117                                       ren1_src, ren1_dst, branch1,
1118                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1119                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1120                        } else
1121                                try_merge = 1;
1122
1123                        if (try_merge) {
1124                                struct diff_filespec *one, *a, *b;
1125                                src_other.path = (char *)ren1_src;
1126
1127                                one = ren1->pair->one;
1128                                if (a_renames == renames1) {
1129                                        a = ren1->pair->two;
1130                                        b = &src_other;
1131                                } else {
1132                                        b = ren1->pair->two;
1133                                        a = &src_other;
1134                                }
1135                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1136                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1137                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1138                                                                      ren1->pair,
1139                                                                      NULL,
1140                                                                      branch1,
1141                                                                      NULL,
1142                                                                      ren1->dst_entry,
1143                                                                      NULL);
1144                                }
1145                        }
1146                }
1147        }
1148        string_list_clear(&a_by_dst, 0);
1149        string_list_clear(&b_by_dst, 0);
1150
1151        return clean_merge;
1152}
1153
1154static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1155{
1156        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1157}
1158
1159static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1160{
1161        void *buf;
1162        enum object_type type;
1163        unsigned long size;
1164        buf = read_sha1_file(sha1, &type, &size);
1165        if (!buf)
1166                return error("cannot read object %s", sha1_to_hex(sha1));
1167        if (type != OBJ_BLOB) {
1168                free(buf);
1169                return error("object %s is not a blob", sha1_to_hex(sha1));
1170        }
1171        strbuf_attach(dst, buf, size, size + 1);
1172        return 0;
1173}
1174
1175static int blob_unchanged(const unsigned char *o_sha,
1176                          const unsigned char *a_sha,
1177                          int renormalize, const char *path)
1178{
1179        struct strbuf o = STRBUF_INIT;
1180        struct strbuf a = STRBUF_INIT;
1181        int ret = 0; /* assume changed for safety */
1182
1183        if (sha_eq(o_sha, a_sha))
1184                return 1;
1185        if (!renormalize)
1186                return 0;
1187
1188        assert(o_sha && a_sha);
1189        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1190                goto error_return;
1191        /*
1192         * Note: binary | is used so that both renormalizations are
1193         * performed.  Comparison can be skipped if both files are
1194         * unchanged since their sha1s have already been compared.
1195         */
1196        if (renormalize_buffer(path, o.buf, o.len, &o) |
1197            renormalize_buffer(path, a.buf, o.len, &a))
1198                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1199
1200error_return:
1201        strbuf_release(&o);
1202        strbuf_release(&a);
1203        return ret;
1204}
1205
1206static void handle_delete_modify(struct merge_options *o,
1207                                 const char *path,
1208                                 const char *new_path,
1209                                 unsigned char *a_sha, int a_mode,
1210                                 unsigned char *b_sha, int b_mode)
1211{
1212        if (!a_sha) {
1213                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1214                       "and modified in %s. Version %s of %s left in tree%s%s.",
1215                       path, o->branch1,
1216                       o->branch2, o->branch2, path,
1217                       path == new_path ? "" : " at ",
1218                       path == new_path ? "" : new_path);
1219                update_file(o, 0, b_sha, b_mode, new_path);
1220        } else {
1221                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1222                       "and modified in %s. Version %s of %s left in tree%s%s.",
1223                       path, o->branch2,
1224                       o->branch1, o->branch1, path,
1225                       path == new_path ? "" : " at ",
1226                       path == new_path ? "" : new_path);
1227                update_file(o, 0, a_sha, a_mode, new_path);
1228        }
1229}
1230
1231static int merge_content(struct merge_options *o,
1232                         const char *path,
1233                         unsigned char *o_sha, int o_mode,
1234                         unsigned char *a_sha, int a_mode,
1235                         unsigned char *b_sha, int b_mode,
1236                         const char *df_rename_conflict_branch)
1237{
1238        const char *reason = "content";
1239        struct merge_file_info mfi;
1240        struct diff_filespec one, a, b;
1241        struct stat st;
1242        unsigned df_conflict_remains = 0;
1243
1244        if (!o_sha) {
1245                reason = "add/add";
1246                o_sha = (unsigned char *)null_sha1;
1247        }
1248        one.path = a.path = b.path = (char *)path;
1249        hashcpy(one.sha1, o_sha);
1250        one.mode = o_mode;
1251        hashcpy(a.sha1, a_sha);
1252        a.mode = a_mode;
1253        hashcpy(b.sha1, b_sha);
1254        b.mode = b_mode;
1255
1256        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1257        if (df_rename_conflict_branch &&
1258            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1259                df_conflict_remains = 1;
1260        }
1261
1262        if (mfi.clean && !df_conflict_remains &&
1263            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1264                output(o, 3, "Skipped %s (merged same as existing)", path);
1265        else
1266                output(o, 2, "Auto-merging %s", path);
1267
1268        if (!mfi.clean) {
1269                if (S_ISGITLINK(mfi.mode))
1270                        reason = "submodule";
1271                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1272                                reason, path);
1273        }
1274
1275        if (df_conflict_remains) {
1276                const char *new_path;
1277                update_file_flags(o, mfi.sha, mfi.mode, path,
1278                                  o->call_depth || mfi.clean, 0);
1279                new_path = unique_path(o, path, df_rename_conflict_branch);
1280                mfi.clean = 0;
1281                output(o, 1, "Adding as %s instead", new_path);
1282                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1283        } else {
1284                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1285        }
1286        return mfi.clean;
1287
1288}
1289
1290/* Per entry merge function */
1291static int process_entry(struct merge_options *o,
1292                         const char *path, struct stage_data *entry)
1293{
1294        /*
1295        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1296        print_index_entry("\tpath: ", entry);
1297        */
1298        int clean_merge = 1;
1299        int normalize = o->renormalize;
1300        unsigned o_mode = entry->stages[1].mode;
1301        unsigned a_mode = entry->stages[2].mode;
1302        unsigned b_mode = entry->stages[3].mode;
1303        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1304        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1305        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1306
1307        if (entry->rename_df_conflict_info)
1308                return 1; /* Such cases are handled elsewhere. */
1309
1310        entry->processed = 1;
1311        if (o_sha && (!a_sha || !b_sha)) {
1312                /* Case A: Deleted in one */
1313                if ((!a_sha && !b_sha) ||
1314                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1315                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1316                        /* Deleted in both or deleted in one and
1317                         * unchanged in the other */
1318                        if (a_sha)
1319                                output(o, 2, "Removing %s", path);
1320                        /* do not touch working file if it did not exist */
1321                        remove_file(o, 1, path, !a_sha);
1322                } else if (string_list_has_string(&o->current_directory_set,
1323                                                  path)) {
1324                        entry->processed = 0;
1325                        return 1; /* Assume clean until processed */
1326                } else {
1327                        /* Deleted in one and changed in the other */
1328                        clean_merge = 0;
1329                        handle_delete_modify(o, path, path,
1330                                             a_sha, a_mode, b_sha, b_mode);
1331                }
1332
1333        } else if ((!o_sha && a_sha && !b_sha) ||
1334                   (!o_sha && !a_sha && b_sha)) {
1335                /* Case B: Added in one. */
1336                unsigned mode;
1337                const unsigned char *sha;
1338
1339                if (a_sha) {
1340                        mode = a_mode;
1341                        sha = a_sha;
1342                } else {
1343                        mode = b_mode;
1344                        sha = b_sha;
1345                }
1346                if (string_list_has_string(&o->current_directory_set, path)) {
1347                        /* Handle D->F conflicts after all subfiles */
1348                        entry->processed = 0;
1349                        return 1; /* Assume clean until processed */
1350                } else {
1351                        output(o, 2, "Adding %s", path);
1352                        update_file(o, 1, sha, mode, path);
1353                }
1354        } else if (a_sha && b_sha) {
1355                /* Case C: Added in both (check for same permissions) and */
1356                /* case D: Modified in both, but differently. */
1357                clean_merge = merge_content(o, path,
1358                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1359                                            NULL);
1360        } else if (!o_sha && !a_sha && !b_sha) {
1361                /*
1362                 * this entry was deleted altogether. a_mode == 0 means
1363                 * we had that path and want to actively remove it.
1364                 */
1365                remove_file(o, 1, path, !a_mode);
1366        } else
1367                die("Fatal merge failure, shouldn't happen.");
1368
1369        return clean_merge;
1370}
1371
1372/*
1373 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1374 * cases we can cleanly resolve D/F conflicts, process_entry() can
1375 * clean out all the files below the directory for us.  All D/F
1376 * conflict cases must be handled here at the end to make sure any
1377 * directories that can be cleaned out, are.
1378 *
1379 * Some rename conflicts may also be handled here that don't necessarily
1380 * involve D/F conflicts, since the code to handle them is generic enough
1381 * to handle those rename conflicts with or without D/F conflicts also
1382 * being involved.
1383 */
1384static int process_df_entry(struct merge_options *o,
1385                            const char *path, struct stage_data *entry)
1386{
1387        int clean_merge = 1;
1388        unsigned o_mode = entry->stages[1].mode;
1389        unsigned a_mode = entry->stages[2].mode;
1390        unsigned b_mode = entry->stages[3].mode;
1391        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1392        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1393        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1394        struct stat st;
1395
1396        entry->processed = 1;
1397        if (entry->rename_df_conflict_info) {
1398                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1399                char *src;
1400                switch (conflict_info->rename_type) {
1401                case RENAME_NORMAL:
1402                        clean_merge = merge_content(o, path,
1403                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1404                                                    conflict_info->branch1);
1405                        break;
1406                case RENAME_DELETE:
1407                        clean_merge = 0;
1408                        conflict_rename_delete(o, conflict_info->pair1,
1409                                               conflict_info->branch1,
1410                                               conflict_info->branch2);
1411                        break;
1412                case RENAME_ONE_FILE_TO_TWO:
1413                        src = conflict_info->pair1->one->path;
1414                        clean_merge = 0;
1415                        output(o, 1, "CONFLICT (rename/rename): "
1416                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1417                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1418                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1419                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1420                               o->call_depth ? " (left unresolved)" : "");
1421                        if (o->call_depth) {
1422                                remove_file_from_cache(src);
1423                                update_file(o, 0, conflict_info->pair1->one->sha1,
1424                                            conflict_info->pair1->one->mode, src);
1425                        }
1426                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1427                                                    conflict_info->branch1,
1428                                                    conflict_info->pair2,
1429                                                    conflict_info->branch2);
1430                        conflict_info->dst_entry2->processed = 1;
1431                        break;
1432                default:
1433                        entry->processed = 0;
1434                        break;
1435                }
1436        } else if (o_sha && (!a_sha || !b_sha)) {
1437                /* Modify/delete; deleted side may have put a directory in the way */
1438                const char *new_path = path;
1439                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1440                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1441                clean_merge = 0;
1442                handle_delete_modify(o, path, new_path,
1443                                     a_sha, a_mode, b_sha, b_mode);
1444        } else if (!o_sha && !!a_sha != !!b_sha) {
1445                /* directory -> (directory, file) */
1446                const char *add_branch;
1447                const char *other_branch;
1448                unsigned mode;
1449                const unsigned char *sha;
1450                const char *conf;
1451
1452                if (a_sha) {
1453                        add_branch = o->branch1;
1454                        other_branch = o->branch2;
1455                        mode = a_mode;
1456                        sha = a_sha;
1457                        conf = "file/directory";
1458                } else {
1459                        add_branch = o->branch2;
1460                        other_branch = o->branch1;
1461                        mode = b_mode;
1462                        sha = b_sha;
1463                        conf = "directory/file";
1464                }
1465                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1466                        const char *new_path = unique_path(o, path, add_branch);
1467                        clean_merge = 0;
1468                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1469                               "Adding %s as %s",
1470                               conf, path, other_branch, path, new_path);
1471                        update_file(o, 0, sha, mode, new_path);
1472                } else {
1473                        output(o, 2, "Adding %s", path);
1474                        update_file(o, 1, sha, mode, path);
1475                }
1476        } else {
1477                entry->processed = 0;
1478                return 1; /* not handled; assume clean until processed */
1479        }
1480
1481        return clean_merge;
1482}
1483
1484int merge_trees(struct merge_options *o,
1485                struct tree *head,
1486                struct tree *merge,
1487                struct tree *common,
1488                struct tree **result)
1489{
1490        int code, clean;
1491
1492        if (o->subtree_shift) {
1493                merge = shift_tree_object(head, merge, o->subtree_shift);
1494                common = shift_tree_object(head, common, o->subtree_shift);
1495        }
1496
1497        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1498                output(o, 0, "Already up-to-date!");
1499                *result = head;
1500                return 1;
1501        }
1502
1503        code = git_merge_trees(o->call_depth, common, head, merge);
1504
1505        if (code != 0) {
1506                if (show(o, 4) || o->call_depth)
1507                        die("merging of trees %s and %s failed",
1508                            sha1_to_hex(head->object.sha1),
1509                            sha1_to_hex(merge->object.sha1));
1510                else
1511                        exit(128);
1512        }
1513
1514        if (unmerged_cache()) {
1515                struct string_list *entries, *re_head, *re_merge;
1516                int i;
1517                string_list_clear(&o->current_file_set, 1);
1518                string_list_clear(&o->current_directory_set, 1);
1519                get_files_dirs(o, head);
1520                get_files_dirs(o, merge);
1521
1522                entries = get_unmerged();
1523                make_room_for_directories_of_df_conflicts(o, entries);
1524                re_head  = get_renames(o, head, common, head, merge, entries);
1525                re_merge = get_renames(o, merge, common, head, merge, entries);
1526                clean = process_renames(o, re_head, re_merge);
1527                for (i = 0; i < entries->nr; i++) {
1528                        const char *path = entries->items[i].string;
1529                        struct stage_data *e = entries->items[i].util;
1530                        if (!e->processed
1531                                && !process_entry(o, path, e))
1532                                clean = 0;
1533                }
1534                for (i = 0; i < entries->nr; i++) {
1535                        const char *path = entries->items[i].string;
1536                        struct stage_data *e = entries->items[i].util;
1537                        if (!e->processed
1538                                && !process_df_entry(o, path, e))
1539                                clean = 0;
1540                }
1541                for (i = 0; i < entries->nr; i++) {
1542                        struct stage_data *e = entries->items[i].util;
1543                        if (!e->processed)
1544                                die("Unprocessed path??? %s",
1545                                    entries->items[i].string);
1546                }
1547
1548                string_list_clear(re_merge, 0);
1549                string_list_clear(re_head, 0);
1550                string_list_clear(entries, 1);
1551
1552        }
1553        else
1554                clean = 1;
1555
1556        if (o->call_depth)
1557                *result = write_tree_from_memory(o);
1558
1559        return clean;
1560}
1561
1562static struct commit_list *reverse_commit_list(struct commit_list *list)
1563{
1564        struct commit_list *next = NULL, *current, *backup;
1565        for (current = list; current; current = backup) {
1566                backup = current->next;
1567                current->next = next;
1568                next = current;
1569        }
1570        return next;
1571}
1572
1573/*
1574 * Merge the commits h1 and h2, return the resulting virtual
1575 * commit object and a flag indicating the cleanness of the merge.
1576 */
1577int merge_recursive(struct merge_options *o,
1578                    struct commit *h1,
1579                    struct commit *h2,
1580                    struct commit_list *ca,
1581                    struct commit **result)
1582{
1583        struct commit_list *iter;
1584        struct commit *merged_common_ancestors;
1585        struct tree *mrtree = mrtree;
1586        int clean;
1587
1588        if (show(o, 4)) {
1589                output(o, 4, "Merging:");
1590                output_commit_title(o, h1);
1591                output_commit_title(o, h2);
1592        }
1593
1594        if (!ca) {
1595                ca = get_merge_bases(h1, h2, 1);
1596                ca = reverse_commit_list(ca);
1597        }
1598
1599        if (show(o, 5)) {
1600                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1601                for (iter = ca; iter; iter = iter->next)
1602                        output_commit_title(o, iter->item);
1603        }
1604
1605        merged_common_ancestors = pop_commit(&ca);
1606        if (merged_common_ancestors == NULL) {
1607                /* if there is no common ancestor, make an empty tree */
1608                struct tree *tree = xcalloc(1, sizeof(struct tree));
1609
1610                tree->object.parsed = 1;
1611                tree->object.type = OBJ_TREE;
1612                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1613                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1614        }
1615
1616        for (iter = ca; iter; iter = iter->next) {
1617                const char *saved_b1, *saved_b2;
1618                o->call_depth++;
1619                /*
1620                 * When the merge fails, the result contains files
1621                 * with conflict markers. The cleanness flag is
1622                 * ignored, it was never actually used, as result of
1623                 * merge_trees has always overwritten it: the committed
1624                 * "conflicts" were already resolved.
1625                 */
1626                discard_cache();
1627                saved_b1 = o->branch1;
1628                saved_b2 = o->branch2;
1629                o->branch1 = "Temporary merge branch 1";
1630                o->branch2 = "Temporary merge branch 2";
1631                merge_recursive(o, merged_common_ancestors, iter->item,
1632                                NULL, &merged_common_ancestors);
1633                o->branch1 = saved_b1;
1634                o->branch2 = saved_b2;
1635                o->call_depth--;
1636
1637                if (!merged_common_ancestors)
1638                        die("merge returned no commit");
1639        }
1640
1641        discard_cache();
1642        if (!o->call_depth)
1643                read_cache();
1644
1645        o->ancestor = "merged common ancestors";
1646        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1647                            &mrtree);
1648
1649        if (o->call_depth) {
1650                *result = make_virtual_commit(mrtree, "merged tree");
1651                commit_list_insert(h1, &(*result)->parents);
1652                commit_list_insert(h2, &(*result)->parents->next);
1653        }
1654        flush_output(o);
1655        if (o->needed_rename_limit)
1656                warning(rename_limit_advice, o->needed_rename_limit);
1657        return clean;
1658}
1659
1660static struct commit *get_ref(const unsigned char *sha1, const char *name)
1661{
1662        struct object *object;
1663
1664        object = deref_tag(parse_object(sha1), name, strlen(name));
1665        if (!object)
1666                return NULL;
1667        if (object->type == OBJ_TREE)
1668                return make_virtual_commit((struct tree*)object, name);
1669        if (object->type != OBJ_COMMIT)
1670                return NULL;
1671        if (parse_commit((struct commit *)object))
1672                return NULL;
1673        return (struct commit *)object;
1674}
1675
1676int merge_recursive_generic(struct merge_options *o,
1677                            const unsigned char *head,
1678                            const unsigned char *merge,
1679                            int num_base_list,
1680                            const unsigned char **base_list,
1681                            struct commit **result)
1682{
1683        int clean, index_fd;
1684        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1685        struct commit *head_commit = get_ref(head, o->branch1);
1686        struct commit *next_commit = get_ref(merge, o->branch2);
1687        struct commit_list *ca = NULL;
1688
1689        if (base_list) {
1690                int i;
1691                for (i = 0; i < num_base_list; ++i) {
1692                        struct commit *base;
1693                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1694                                return error("Could not parse object '%s'",
1695                                        sha1_to_hex(base_list[i]));
1696                        commit_list_insert(base, &ca);
1697                }
1698        }
1699
1700        index_fd = hold_locked_index(lock, 1);
1701        clean = merge_recursive(o, head_commit, next_commit, ca,
1702                        result);
1703        if (active_cache_changed &&
1704                        (write_cache(index_fd, active_cache, active_nr) ||
1705                         commit_locked_index(lock)))
1706                return error("Unable to write index.");
1707
1708        return clean ? 0 : 1;
1709}
1710
1711static int merge_recursive_config(const char *var, const char *value, void *cb)
1712{
1713        struct merge_options *o = cb;
1714        if (!strcmp(var, "merge.verbosity")) {
1715                o->verbosity = git_config_int(var, value);
1716                return 0;
1717        }
1718        if (!strcmp(var, "diff.renamelimit")) {
1719                o->diff_rename_limit = git_config_int(var, value);
1720                return 0;
1721        }
1722        if (!strcmp(var, "merge.renamelimit")) {
1723                o->merge_rename_limit = git_config_int(var, value);
1724                return 0;
1725        }
1726        return git_xmerge_config(var, value, cb);
1727}
1728
1729void init_merge_options(struct merge_options *o)
1730{
1731        memset(o, 0, sizeof(struct merge_options));
1732        o->verbosity = 2;
1733        o->buffer_output = 1;
1734        o->diff_rename_limit = -1;
1735        o->merge_rename_limit = -1;
1736        o->renormalize = 0;
1737        git_config(merge_recursive_config, o);
1738        if (getenv("GIT_MERGE_VERBOSITY"))
1739                o->verbosity =
1740                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1741        if (o->verbosity >= 5)
1742                o->buffer_output = 0;
1743        strbuf_init(&o->obuf, 0);
1744        memset(&o->current_file_set, 0, sizeof(struct string_list));
1745        o->current_file_set.strdup_strings = 1;
1746        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1747        o->current_directory_set.strdup_strings = 1;
1748}
1749
1750int parse_merge_opt(struct merge_options *o, const char *s)
1751{
1752        if (!s || !*s)
1753                return -1;
1754        if (!strcmp(s, "ours"))
1755                o->recursive_variant = MERGE_RECURSIVE_OURS;
1756        else if (!strcmp(s, "theirs"))
1757                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1758        else if (!strcmp(s, "subtree"))
1759                o->subtree_shift = "";
1760        else if (!prefixcmp(s, "subtree="))
1761                o->subtree_shift = s + strlen("subtree=");
1762        else if (!strcmp(s, "patience"))
1763                o->xdl_opts |= XDF_PATIENCE_DIFF;
1764        else if (!strcmp(s, "ignore-space-change"))
1765                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1766        else if (!strcmp(s, "ignore-all-space"))
1767                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1768        else if (!strcmp(s, "ignore-space-at-eol"))
1769                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1770        else if (!strcmp(s, "renormalize"))
1771                o->renormalize = 1;
1772        else if (!strcmp(s, "no-renormalize"))
1773                o->renormalize = 0;
1774        else if (!prefixcmp(s, "rename-threshold=")) {
1775                const char *score = s + strlen("rename-threshold=");
1776                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1777                        return -1;
1778        }
1779        else
1780                return -1;
1781        return 0;
1782}