merge-recursive.con commit docs: fix filter-branch subdir example for exotic repo names (6cb0186)
   1/*
   2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
   3 * Fredrik Kuivinen.
   4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
   5 */
   6#include "advice.h"
   7#include "cache.h"
   8#include "cache-tree.h"
   9#include "commit.h"
  10#include "blob.h"
  11#include "builtin.h"
  12#include "tree-walk.h"
  13#include "diff.h"
  14#include "diffcore.h"
  15#include "tag.h"
  16#include "unpack-trees.h"
  17#include "string-list.h"
  18#include "xdiff-interface.h"
  19#include "ll-merge.h"
  20#include "attr.h"
  21#include "merge-recursive.h"
  22#include "dir.h"
  23#include "submodule.h"
  24
  25static struct tree *shift_tree_object(struct tree *one, struct tree *two,
  26                                      const char *subtree_shift)
  27{
  28        unsigned char shifted[20];
  29
  30        if (!*subtree_shift) {
  31                shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
  32        } else {
  33                shift_tree_by(one->object.sha1, two->object.sha1, shifted,
  34                              subtree_shift);
  35        }
  36        if (!hashcmp(two->object.sha1, shifted))
  37                return two;
  38        return lookup_tree(shifted);
  39}
  40
  41/*
  42 * A virtual commit has (const char *)commit->util set to the name.
  43 */
  44
  45static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  46{
  47        struct commit *commit = xcalloc(1, sizeof(struct commit));
  48        commit->tree = tree;
  49        commit->util = (void*)comment;
  50        /* avoid warnings */
  51        commit->object.parsed = 1;
  52        return commit;
  53}
  54
  55/*
  56 * Since we use get_tree_entry(), which does not put the read object into
  57 * the object pool, we cannot rely on a == b.
  58 */
  59static int sha_eq(const unsigned char *a, const unsigned char *b)
  60{
  61        if (!a && !b)
  62                return 2;
  63        return a && b && hashcmp(a, b) == 0;
  64}
  65
  66enum rename_type {
  67        RENAME_NORMAL = 0,
  68        RENAME_DELETE,
  69        RENAME_ONE_FILE_TO_TWO
  70};
  71
  72struct rename_df_conflict_info {
  73        enum rename_type rename_type;
  74        struct diff_filepair *pair1;
  75        struct diff_filepair *pair2;
  76        const char *branch1;
  77        const char *branch2;
  78        struct stage_data *dst_entry1;
  79        struct stage_data *dst_entry2;
  80};
  81
  82/*
  83 * Since we want to write the index eventually, we cannot reuse the index
  84 * for these (temporary) data.
  85 */
  86struct stage_data {
  87        struct {
  88                unsigned mode;
  89                unsigned char sha[20];
  90        } stages[4];
  91        struct rename_df_conflict_info *rename_df_conflict_info;
  92        unsigned processed:1;
  93};
  94
  95static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
  96                                                 struct diff_filepair *pair1,
  97                                                 struct diff_filepair *pair2,
  98                                                 const char *branch1,
  99                                                 const char *branch2,
 100                                                 struct stage_data *dst_entry1,
 101                                                 struct stage_data *dst_entry2)
 102{
 103        struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
 104        ci->rename_type = rename_type;
 105        ci->pair1 = pair1;
 106        ci->branch1 = branch1;
 107        ci->branch2 = branch2;
 108
 109        ci->dst_entry1 = dst_entry1;
 110        dst_entry1->rename_df_conflict_info = ci;
 111        dst_entry1->processed = 0;
 112
 113        assert(!pair2 == !dst_entry2);
 114        if (dst_entry2) {
 115                ci->dst_entry2 = dst_entry2;
 116                ci->pair2 = pair2;
 117                dst_entry2->rename_df_conflict_info = ci;
 118                dst_entry2->processed = 0;
 119        }
 120}
 121
 122static int show(struct merge_options *o, int v)
 123{
 124        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 125}
 126
 127static void flush_output(struct merge_options *o)
 128{
 129        if (o->obuf.len) {
 130                fputs(o->obuf.buf, stdout);
 131                strbuf_reset(&o->obuf);
 132        }
 133}
 134
 135__attribute__((format (printf, 3, 4)))
 136static void output(struct merge_options *o, int v, const char *fmt, ...)
 137{
 138        int len;
 139        va_list ap;
 140
 141        if (!show(o, v))
 142                return;
 143
 144        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 145        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 146        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 147
 148        va_start(ap, fmt);
 149        len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 150        va_end(ap);
 151
 152        if (len < 0)
 153                len = 0;
 154        if (len >= strbuf_avail(&o->obuf)) {
 155                strbuf_grow(&o->obuf, len + 2);
 156                va_start(ap, fmt);
 157                len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 158                va_end(ap);
 159                if (len >= strbuf_avail(&o->obuf)) {
 160                        die("this should not happen, your snprintf is broken");
 161                }
 162        }
 163        strbuf_setlen(&o->obuf, o->obuf.len + len);
 164        strbuf_add(&o->obuf, "\n", 1);
 165        if (!o->buffer_output)
 166                flush_output(o);
 167}
 168
 169static void output_commit_title(struct merge_options *o, struct commit *commit)
 170{
 171        int i;
 172        flush_output(o);
 173        for (i = o->call_depth; i--;)
 174                fputs("  ", stdout);
 175        if (commit->util)
 176                printf("virtual %s\n", (char *)commit->util);
 177        else {
 178                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 179                if (parse_commit(commit) != 0)
 180                        printf("(bad commit)\n");
 181                else {
 182                        const char *title;
 183                        int len = find_commit_subject(commit->buffer, &title);
 184                        if (len)
 185                                printf("%.*s\n", len, title);
 186                }
 187        }
 188}
 189
 190static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 191                const char *path, int stage, int refresh, int options)
 192{
 193        struct cache_entry *ce;
 194        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 195        if (!ce)
 196                return error("addinfo_cache failed for path '%s'", path);
 197        return add_cache_entry(ce, options);
 198}
 199
 200static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 201{
 202        parse_tree(tree);
 203        init_tree_desc(desc, tree->buffer, tree->size);
 204}
 205
 206static int git_merge_trees(int index_only,
 207                           struct tree *common,
 208                           struct tree *head,
 209                           struct tree *merge)
 210{
 211        int rc;
 212        struct tree_desc t[3];
 213        struct unpack_trees_options opts;
 214
 215        memset(&opts, 0, sizeof(opts));
 216        if (index_only)
 217                opts.index_only = 1;
 218        else
 219                opts.update = 1;
 220        opts.merge = 1;
 221        opts.head_idx = 2;
 222        opts.fn = threeway_merge;
 223        opts.src_index = &the_index;
 224        opts.dst_index = &the_index;
 225        setup_unpack_trees_porcelain(&opts, "merge");
 226
 227        init_tree_desc_from_tree(t+0, common);
 228        init_tree_desc_from_tree(t+1, head);
 229        init_tree_desc_from_tree(t+2, merge);
 230
 231        rc = unpack_trees(3, t, &opts);
 232        cache_tree_free(&active_cache_tree);
 233        return rc;
 234}
 235
 236struct tree *write_tree_from_memory(struct merge_options *o)
 237{
 238        struct tree *result = NULL;
 239
 240        if (unmerged_cache()) {
 241                int i;
 242                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 243                for (i = 0; i < active_nr; i++) {
 244                        struct cache_entry *ce = active_cache[i];
 245                        if (ce_stage(ce))
 246                                fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
 247                                        (int)ce_namelen(ce), ce->name);
 248                }
 249                die("Bug in merge-recursive.c");
 250        }
 251
 252        if (!active_cache_tree)
 253                active_cache_tree = cache_tree();
 254
 255        if (!cache_tree_fully_valid(active_cache_tree) &&
 256            cache_tree_update(active_cache_tree,
 257                              active_cache, active_nr, 0, 0) < 0)
 258                die("error building trees");
 259
 260        result = lookup_tree(active_cache_tree->sha1);
 261
 262        return result;
 263}
 264
 265static int save_files_dirs(const unsigned char *sha1,
 266                const char *base, int baselen, const char *path,
 267                unsigned int mode, int stage, void *context)
 268{
 269        int len = strlen(path);
 270        char *newpath = xmalloc(baselen + len + 1);
 271        struct merge_options *o = context;
 272
 273        memcpy(newpath, base, baselen);
 274        memcpy(newpath + baselen, path, len);
 275        newpath[baselen + len] = '\0';
 276
 277        if (S_ISDIR(mode))
 278                string_list_insert(&o->current_directory_set, newpath);
 279        else
 280                string_list_insert(&o->current_file_set, newpath);
 281        free(newpath);
 282
 283        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 284}
 285
 286static int get_files_dirs(struct merge_options *o, struct tree *tree)
 287{
 288        int n;
 289        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 290                return 0;
 291        n = o->current_file_set.nr + o->current_directory_set.nr;
 292        return n;
 293}
 294
 295/*
 296 * Returns an index_entry instance which doesn't have to correspond to
 297 * a real cache entry in Git's index.
 298 */
 299static struct stage_data *insert_stage_data(const char *path,
 300                struct tree *o, struct tree *a, struct tree *b,
 301                struct string_list *entries)
 302{
 303        struct string_list_item *item;
 304        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 305        get_tree_entry(o->object.sha1, path,
 306                        e->stages[1].sha, &e->stages[1].mode);
 307        get_tree_entry(a->object.sha1, path,
 308                        e->stages[2].sha, &e->stages[2].mode);
 309        get_tree_entry(b->object.sha1, path,
 310                        e->stages[3].sha, &e->stages[3].mode);
 311        item = string_list_insert(entries, path);
 312        item->util = e;
 313        return e;
 314}
 315
 316/*
 317 * Create a dictionary mapping file names to stage_data objects. The
 318 * dictionary contains one entry for every path with a non-zero stage entry.
 319 */
 320static struct string_list *get_unmerged(void)
 321{
 322        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 323        int i;
 324
 325        unmerged->strdup_strings = 1;
 326
 327        for (i = 0; i < active_nr; i++) {
 328                struct string_list_item *item;
 329                struct stage_data *e;
 330                struct cache_entry *ce = active_cache[i];
 331                if (!ce_stage(ce))
 332                        continue;
 333
 334                item = string_list_lookup(unmerged, ce->name);
 335                if (!item) {
 336                        item = string_list_insert(unmerged, ce->name);
 337                        item->util = xcalloc(1, sizeof(struct stage_data));
 338                }
 339                e = item->util;
 340                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 341                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 342        }
 343
 344        return unmerged;
 345}
 346
 347static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 348                                                      struct string_list *entries)
 349{
 350        /* If there are D/F conflicts, and the paths currently exist
 351         * in the working copy as a file, we want to remove them to
 352         * make room for the corresponding directory.  Such paths will
 353         * later be processed in process_df_entry() at the end.  If
 354         * the corresponding directory ends up being removed by the
 355         * merge, then the file will be reinstated at that time;
 356         * otherwise, if the file is not supposed to be removed by the
 357         * merge, the contents of the file will be placed in another
 358         * unique filename.
 359         *
 360         * NOTE: This function relies on the fact that entries for a
 361         * D/F conflict will appear adjacent in the index, with the
 362         * entries for the file appearing before entries for paths
 363         * below the corresponding directory.
 364         */
 365        const char *last_file = NULL;
 366        int last_len = 0;
 367        struct stage_data *last_e;
 368        int i;
 369
 370        for (i = 0; i < entries->nr; i++) {
 371                const char *path = entries->items[i].string;
 372                int len = strlen(path);
 373                struct stage_data *e = entries->items[i].util;
 374
 375                /*
 376                 * Check if last_file & path correspond to a D/F conflict;
 377                 * i.e. whether path is last_file+'/'+<something>.
 378                 * If so, remove last_file to make room for path and friends.
 379                 */
 380                if (last_file &&
 381                    len > last_len &&
 382                    memcmp(path, last_file, last_len) == 0 &&
 383                    path[last_len] == '/') {
 384                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 385                        unlink(last_file);
 386                }
 387
 388                /*
 389                 * Determine whether path could exist as a file in the
 390                 * working directory as a possible D/F conflict.  This
 391                 * will only occur when it exists in stage 2 as a
 392                 * file.
 393                 */
 394                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 395                        last_file = path;
 396                        last_len = len;
 397                        last_e = e;
 398                } else {
 399                        last_file = NULL;
 400                }
 401        }
 402}
 403
 404struct rename {
 405        struct diff_filepair *pair;
 406        struct stage_data *src_entry;
 407        struct stage_data *dst_entry;
 408        unsigned processed:1;
 409};
 410
 411/*
 412 * Get information of all renames which occurred between 'o_tree' and
 413 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 414 * 'b_tree') to be able to associate the correct cache entries with
 415 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 416 */
 417static struct string_list *get_renames(struct merge_options *o,
 418                                       struct tree *tree,
 419                                       struct tree *o_tree,
 420                                       struct tree *a_tree,
 421                                       struct tree *b_tree,
 422                                       struct string_list *entries)
 423{
 424        int i;
 425        struct string_list *renames;
 426        struct diff_options opts;
 427
 428        renames = xcalloc(1, sizeof(struct string_list));
 429        diff_setup(&opts);
 430        DIFF_OPT_SET(&opts, RECURSIVE);
 431        opts.detect_rename = DIFF_DETECT_RENAME;
 432        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 433                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 434                            500;
 435        opts.rename_score = o->rename_score;
 436        opts.warn_on_too_large_rename = 1;
 437        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 438        if (diff_setup_done(&opts) < 0)
 439                die("diff setup failed");
 440        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 441        diffcore_std(&opts);
 442        for (i = 0; i < diff_queued_diff.nr; ++i) {
 443                struct string_list_item *item;
 444                struct rename *re;
 445                struct diff_filepair *pair = diff_queued_diff.queue[i];
 446                if (pair->status != 'R') {
 447                        diff_free_filepair(pair);
 448                        continue;
 449                }
 450                re = xmalloc(sizeof(*re));
 451                re->processed = 0;
 452                re->pair = pair;
 453                item = string_list_lookup(entries, re->pair->one->path);
 454                if (!item)
 455                        re->src_entry = insert_stage_data(re->pair->one->path,
 456                                        o_tree, a_tree, b_tree, entries);
 457                else
 458                        re->src_entry = item->util;
 459
 460                item = string_list_lookup(entries, re->pair->two->path);
 461                if (!item)
 462                        re->dst_entry = insert_stage_data(re->pair->two->path,
 463                                        o_tree, a_tree, b_tree, entries);
 464                else
 465                        re->dst_entry = item->util;
 466                item = string_list_insert(renames, pair->one->path);
 467                item->util = re;
 468        }
 469        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 470        diff_queued_diff.nr = 0;
 471        diff_flush(&opts);
 472        return renames;
 473}
 474
 475static int update_stages_options(const char *path, struct diff_filespec *o,
 476                         struct diff_filespec *a, struct diff_filespec *b,
 477                         int clear, int options)
 478{
 479        if (clear)
 480                if (remove_file_from_cache(path))
 481                        return -1;
 482        if (o)
 483                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 484                        return -1;
 485        if (a)
 486                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 487                        return -1;
 488        if (b)
 489                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 490                        return -1;
 491        return 0;
 492}
 493
 494static int update_stages(const char *path, struct diff_filespec *o,
 495                         struct diff_filespec *a, struct diff_filespec *b,
 496                         int clear)
 497{
 498        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 499        return update_stages_options(path, o, a, b, clear, options);
 500}
 501
 502static int update_stages_and_entry(const char *path,
 503                                   struct stage_data *entry,
 504                                   struct diff_filespec *o,
 505                                   struct diff_filespec *a,
 506                                   struct diff_filespec *b,
 507                                   int clear)
 508{
 509        int options;
 510
 511        entry->processed = 0;
 512        entry->stages[1].mode = o->mode;
 513        entry->stages[2].mode = a->mode;
 514        entry->stages[3].mode = b->mode;
 515        hashcpy(entry->stages[1].sha, o->sha1);
 516        hashcpy(entry->stages[2].sha, a->sha1);
 517        hashcpy(entry->stages[3].sha, b->sha1);
 518        options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 519        return update_stages_options(path, o, a, b, clear, options);
 520}
 521
 522static int remove_file(struct merge_options *o, int clean,
 523                       const char *path, int no_wd)
 524{
 525        int update_cache = o->call_depth || clean;
 526        int update_working_directory = !o->call_depth && !no_wd;
 527
 528        if (update_cache) {
 529                if (remove_file_from_cache(path))
 530                        return -1;
 531        }
 532        if (update_working_directory) {
 533                if (remove_path(path))
 534                        return -1;
 535        }
 536        return 0;
 537}
 538
 539static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 540{
 541        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 542        int suffix = 0;
 543        struct stat st;
 544        char *p = newpath + strlen(path);
 545        strcpy(newpath, path);
 546        *(p++) = '~';
 547        strcpy(p, branch);
 548        for (; *p; ++p)
 549                if ('/' == *p)
 550                        *p = '_';
 551        while (string_list_has_string(&o->current_file_set, newpath) ||
 552               string_list_has_string(&o->current_directory_set, newpath) ||
 553               lstat(newpath, &st) == 0)
 554                sprintf(p, "_%d", suffix++);
 555
 556        string_list_insert(&o->current_file_set, newpath);
 557        return newpath;
 558}
 559
 560static void flush_buffer(int fd, const char *buf, unsigned long size)
 561{
 562        while (size > 0) {
 563                long ret = write_in_full(fd, buf, size);
 564                if (ret < 0) {
 565                        /* Ignore epipe */
 566                        if (errno == EPIPE)
 567                                break;
 568                        die_errno("merge-recursive");
 569                } else if (!ret) {
 570                        die("merge-recursive: disk full?");
 571                }
 572                size -= ret;
 573                buf += ret;
 574        }
 575}
 576
 577static int would_lose_untracked(const char *path)
 578{
 579        int pos = cache_name_pos(path, strlen(path));
 580
 581        if (pos < 0)
 582                pos = -1 - pos;
 583        while (pos < active_nr &&
 584               !strcmp(path, active_cache[pos]->name)) {
 585                /*
 586                 * If stage #0, it is definitely tracked.
 587                 * If it has stage #2 then it was tracked
 588                 * before this merge started.  All other
 589                 * cases the path was not tracked.
 590                 */
 591                switch (ce_stage(active_cache[pos])) {
 592                case 0:
 593                case 2:
 594                        return 0;
 595                }
 596                pos++;
 597        }
 598        return file_exists(path);
 599}
 600
 601static int make_room_for_path(const char *path)
 602{
 603        int status;
 604        const char *msg = "failed to create path '%s'%s";
 605
 606        status = safe_create_leading_directories_const(path);
 607        if (status) {
 608                if (status == -3) {
 609                        /* something else exists */
 610                        error(msg, path, ": perhaps a D/F conflict?");
 611                        return -1;
 612                }
 613                die(msg, path, "");
 614        }
 615
 616        /*
 617         * Do not unlink a file in the work tree if we are not
 618         * tracking it.
 619         */
 620        if (would_lose_untracked(path))
 621                return error("refusing to lose untracked file at '%s'",
 622                             path);
 623
 624        /* Successful unlink is good.. */
 625        if (!unlink(path))
 626                return 0;
 627        /* .. and so is no existing file */
 628        if (errno == ENOENT)
 629                return 0;
 630        /* .. but not some other error (who really cares what?) */
 631        return error(msg, path, ": perhaps a D/F conflict?");
 632}
 633
 634static void update_file_flags(struct merge_options *o,
 635                              const unsigned char *sha,
 636                              unsigned mode,
 637                              const char *path,
 638                              int update_cache,
 639                              int update_wd)
 640{
 641        if (o->call_depth)
 642                update_wd = 0;
 643
 644        if (update_wd) {
 645                enum object_type type;
 646                void *buf;
 647                unsigned long size;
 648
 649                if (S_ISGITLINK(mode)) {
 650                        /*
 651                         * We may later decide to recursively descend into
 652                         * the submodule directory and update its index
 653                         * and/or work tree, but we do not do that now.
 654                         */
 655                        update_wd = 0;
 656                        goto update_index;
 657                }
 658
 659                buf = read_sha1_file(sha, &type, &size);
 660                if (!buf)
 661                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 662                if (type != OBJ_BLOB)
 663                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 664                if (S_ISREG(mode)) {
 665                        struct strbuf strbuf = STRBUF_INIT;
 666                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 667                                free(buf);
 668                                size = strbuf.len;
 669                                buf = strbuf_detach(&strbuf, NULL);
 670                        }
 671                }
 672
 673                if (make_room_for_path(path) < 0) {
 674                        update_wd = 0;
 675                        free(buf);
 676                        goto update_index;
 677                }
 678                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 679                        int fd;
 680                        if (mode & 0100)
 681                                mode = 0777;
 682                        else
 683                                mode = 0666;
 684                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 685                        if (fd < 0)
 686                                die_errno("failed to open '%s'", path);
 687                        flush_buffer(fd, buf, size);
 688                        close(fd);
 689                } else if (S_ISLNK(mode)) {
 690                        char *lnk = xmemdupz(buf, size);
 691                        safe_create_leading_directories_const(path);
 692                        unlink(path);
 693                        if (symlink(lnk, path))
 694                                die_errno("failed to symlink '%s'", path);
 695                        free(lnk);
 696                } else
 697                        die("do not know what to do with %06o %s '%s'",
 698                            mode, sha1_to_hex(sha), path);
 699                free(buf);
 700        }
 701 update_index:
 702        if (update_cache)
 703                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 704}
 705
 706static void update_file(struct merge_options *o,
 707                        int clean,
 708                        const unsigned char *sha,
 709                        unsigned mode,
 710                        const char *path)
 711{
 712        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 713}
 714
 715/* Low level file merging, update and removal */
 716
 717struct merge_file_info {
 718        unsigned char sha[20];
 719        unsigned mode;
 720        unsigned clean:1,
 721                 merge:1;
 722};
 723
 724static int merge_3way(struct merge_options *o,
 725                      mmbuffer_t *result_buf,
 726                      struct diff_filespec *one,
 727                      struct diff_filespec *a,
 728                      struct diff_filespec *b,
 729                      const char *branch1,
 730                      const char *branch2)
 731{
 732        mmfile_t orig, src1, src2;
 733        struct ll_merge_options ll_opts = {0};
 734        char *base_name, *name1, *name2;
 735        int merge_status;
 736
 737        ll_opts.renormalize = o->renormalize;
 738        ll_opts.xdl_opts = o->xdl_opts;
 739
 740        if (o->call_depth) {
 741                ll_opts.virtual_ancestor = 1;
 742                ll_opts.variant = 0;
 743        } else {
 744                switch (o->recursive_variant) {
 745                case MERGE_RECURSIVE_OURS:
 746                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 747                        break;
 748                case MERGE_RECURSIVE_THEIRS:
 749                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 750                        break;
 751                default:
 752                        ll_opts.variant = 0;
 753                        break;
 754                }
 755        }
 756
 757        if (strcmp(a->path, b->path) ||
 758            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 759                base_name = o->ancestor == NULL ? NULL :
 760                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 761                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 762                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 763        } else {
 764                base_name = o->ancestor == NULL ? NULL :
 765                        xstrdup(mkpath("%s", o->ancestor));
 766                name1 = xstrdup(mkpath("%s", branch1));
 767                name2 = xstrdup(mkpath("%s", branch2));
 768        }
 769
 770        read_mmblob(&orig, one->sha1);
 771        read_mmblob(&src1, a->sha1);
 772        read_mmblob(&src2, b->sha1);
 773
 774        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 775                                &src1, name1, &src2, name2, &ll_opts);
 776
 777        free(name1);
 778        free(name2);
 779        free(orig.ptr);
 780        free(src1.ptr);
 781        free(src2.ptr);
 782        return merge_status;
 783}
 784
 785static struct merge_file_info merge_file(struct merge_options *o,
 786                                         struct diff_filespec *one,
 787                                         struct diff_filespec *a,
 788                                         struct diff_filespec *b,
 789                                         const char *branch1,
 790                                         const char *branch2)
 791{
 792        struct merge_file_info result;
 793        result.merge = 0;
 794        result.clean = 1;
 795
 796        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 797                result.clean = 0;
 798                if (S_ISREG(a->mode)) {
 799                        result.mode = a->mode;
 800                        hashcpy(result.sha, a->sha1);
 801                } else {
 802                        result.mode = b->mode;
 803                        hashcpy(result.sha, b->sha1);
 804                }
 805        } else {
 806                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 807                        result.merge = 1;
 808
 809                /*
 810                 * Merge modes
 811                 */
 812                if (a->mode == b->mode || a->mode == one->mode)
 813                        result.mode = b->mode;
 814                else {
 815                        result.mode = a->mode;
 816                        if (b->mode != one->mode) {
 817                                result.clean = 0;
 818                                result.merge = 1;
 819                        }
 820                }
 821
 822                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 823                        hashcpy(result.sha, b->sha1);
 824                else if (sha_eq(b->sha1, one->sha1))
 825                        hashcpy(result.sha, a->sha1);
 826                else if (S_ISREG(a->mode)) {
 827                        mmbuffer_t result_buf;
 828                        int merge_status;
 829
 830                        merge_status = merge_3way(o, &result_buf, one, a, b,
 831                                                  branch1, branch2);
 832
 833                        if ((merge_status < 0) || !result_buf.ptr)
 834                                die("Failed to execute internal merge");
 835
 836                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 837                                            blob_type, result.sha))
 838                                die("Unable to add %s to database",
 839                                    a->path);
 840
 841                        free(result_buf.ptr);
 842                        result.clean = (merge_status == 0);
 843                } else if (S_ISGITLINK(a->mode)) {
 844                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 845                                                       a->sha1, b->sha1);
 846                } else if (S_ISLNK(a->mode)) {
 847                        hashcpy(result.sha, a->sha1);
 848
 849                        if (!sha_eq(a->sha1, b->sha1))
 850                                result.clean = 0;
 851                } else {
 852                        die("unsupported object type in the tree");
 853                }
 854        }
 855
 856        return result;
 857}
 858
 859static void conflict_rename_delete(struct merge_options *o,
 860                                   struct diff_filepair *pair,
 861                                   const char *rename_branch,
 862                                   const char *other_branch)
 863{
 864        char *dest_name = pair->two->path;
 865        int df_conflict = 0;
 866        struct stat st;
 867
 868        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 869               "and deleted in %s",
 870               pair->one->path, pair->two->path, rename_branch,
 871               other_branch);
 872        if (!o->call_depth)
 873                update_stages(dest_name, NULL,
 874                              rename_branch == o->branch1 ? pair->two : NULL,
 875                              rename_branch == o->branch1 ? NULL : pair->two,
 876                              1);
 877        if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 878                dest_name = unique_path(o, dest_name, rename_branch);
 879                df_conflict = 1;
 880        }
 881        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 882        if (df_conflict)
 883                free(dest_name);
 884}
 885
 886static void conflict_rename_rename_1to2(struct merge_options *o,
 887                                        struct diff_filepair *pair1,
 888                                        const char *branch1,
 889                                        struct diff_filepair *pair2,
 890                                        const char *branch2)
 891{
 892        /* One file was renamed in both branches, but to different names. */
 893        char *del[2];
 894        int delp = 0;
 895        const char *ren1_dst = pair1->two->path;
 896        const char *ren2_dst = pair2->two->path;
 897        const char *dst_name1 = ren1_dst;
 898        const char *dst_name2 = ren2_dst;
 899        struct stat st;
 900        if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 901                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 902                output(o, 1, "%s is a directory in %s adding as %s instead",
 903                       ren1_dst, branch2, dst_name1);
 904        }
 905        if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 906                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 907                output(o, 1, "%s is a directory in %s adding as %s instead",
 908                       ren2_dst, branch1, dst_name2);
 909        }
 910        if (o->call_depth) {
 911                remove_file_from_cache(dst_name1);
 912                remove_file_from_cache(dst_name2);
 913                /*
 914                 * Uncomment to leave the conflicting names in the resulting tree
 915                 *
 916                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 917                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 918                 */
 919        } else {
 920                update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 921                update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 922
 923                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 924                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 925        }
 926        while (delp--)
 927                free(del[delp]);
 928}
 929
 930static void conflict_rename_rename_2to1(struct merge_options *o,
 931                                        struct rename *ren1,
 932                                        const char *branch1,
 933                                        struct rename *ren2,
 934                                        const char *branch2)
 935{
 936        /* Two files were renamed to the same thing. */
 937        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 938        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 939        output(o, 1, "Renaming %s to %s and %s to %s instead",
 940               ren1->pair->one->path, new_path1,
 941               ren2->pair->one->path, new_path2);
 942        remove_file(o, 0, ren1->pair->two->path, 0);
 943        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 944        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 945        free(new_path2);
 946        free(new_path1);
 947}
 948
 949static int process_renames(struct merge_options *o,
 950                           struct string_list *a_renames,
 951                           struct string_list *b_renames)
 952{
 953        int clean_merge = 1, i, j;
 954        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 955        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 956        const struct rename *sre;
 957
 958        for (i = 0; i < a_renames->nr; i++) {
 959                sre = a_renames->items[i].util;
 960                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 961                        = sre->dst_entry;
 962        }
 963        for (i = 0; i < b_renames->nr; i++) {
 964                sre = b_renames->items[i].util;
 965                string_list_insert(&b_by_dst, sre->pair->two->path)->util
 966                        = sre->dst_entry;
 967        }
 968
 969        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 970                char *src;
 971                struct string_list *renames1, *renames2Dst;
 972                struct rename *ren1 = NULL, *ren2 = NULL;
 973                const char *branch1, *branch2;
 974                const char *ren1_src, *ren1_dst;
 975
 976                if (i >= a_renames->nr) {
 977                        ren2 = b_renames->items[j++].util;
 978                } else if (j >= b_renames->nr) {
 979                        ren1 = a_renames->items[i++].util;
 980                } else {
 981                        int compare = strcmp(a_renames->items[i].string,
 982                                             b_renames->items[j].string);
 983                        if (compare <= 0)
 984                                ren1 = a_renames->items[i++].util;
 985                        if (compare >= 0)
 986                                ren2 = b_renames->items[j++].util;
 987                }
 988
 989                /* TODO: refactor, so that 1/2 are not needed */
 990                if (ren1) {
 991                        renames1 = a_renames;
 992                        renames2Dst = &b_by_dst;
 993                        branch1 = o->branch1;
 994                        branch2 = o->branch2;
 995                } else {
 996                        struct rename *tmp;
 997                        renames1 = b_renames;
 998                        renames2Dst = &a_by_dst;
 999                        branch1 = o->branch2;
1000                        branch2 = o->branch1;
1001                        tmp = ren2;
1002                        ren2 = ren1;
1003                        ren1 = tmp;
1004                }
1005                src = ren1->pair->one->path;
1006
1007                ren1->dst_entry->processed = 1;
1008                ren1->src_entry->processed = 1;
1009
1010                if (ren1->processed)
1011                        continue;
1012                ren1->processed = 1;
1013
1014                ren1_src = ren1->pair->one->path;
1015                ren1_dst = ren1->pair->two->path;
1016
1017                if (ren2) {
1018                        const char *ren2_src = ren2->pair->one->path;
1019                        const char *ren2_dst = ren2->pair->two->path;
1020                        /* Renamed in 1 and renamed in 2 */
1021                        if (strcmp(ren1_src, ren2_src) != 0)
1022                                die("ren1.src != ren2.src");
1023                        ren2->dst_entry->processed = 1;
1024                        ren2->processed = 1;
1025                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1026                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1027                                                              ren1->pair,
1028                                                              ren2->pair,
1029                                                              branch1,
1030                                                              branch2,
1031                                                              ren1->dst_entry,
1032                                                              ren2->dst_entry);
1033                        } else {
1034                                remove_file(o, 1, ren1_src, 1);
1035                                update_stages_and_entry(ren1_dst,
1036                                                        ren1->dst_entry,
1037                                                        ren1->pair->one,
1038                                                        ren1->pair->two,
1039                                                        ren2->pair->two,
1040                                                        1 /* clear */);
1041                        }
1042                } else {
1043                        /* Renamed in 1, maybe changed in 2 */
1044                        struct string_list_item *item;
1045                        /* we only use sha1 and mode of these */
1046                        struct diff_filespec src_other, dst_other;
1047                        int try_merge;
1048
1049                        /*
1050                         * unpack_trees loads entries from common-commit
1051                         * into stage 1, from head-commit into stage 2, and
1052                         * from merge-commit into stage 3.  We keep track
1053                         * of which side corresponds to the rename.
1054                         */
1055                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1056                        int other_stage =   a_renames == renames1 ? 3 : 2;
1057
1058                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1059
1060                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1061                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1062                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1063                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1064                        try_merge = 0;
1065
1066                        if (sha_eq(src_other.sha1, null_sha1)) {
1067                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1068                                        ren1->dst_entry->processed = 0;
1069                                        setup_rename_df_conflict_info(RENAME_DELETE,
1070                                                                      ren1->pair,
1071                                                                      NULL,
1072                                                                      branch1,
1073                                                                      branch2,
1074                                                                      ren1->dst_entry,
1075                                                                      NULL);
1076                                } else {
1077                                        clean_merge = 0;
1078                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1079                                }
1080                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1081                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1082                                /* Added file on the other side
1083                                   identical to the file being
1084                                   renamed: clean merge */
1085                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1086                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1087                                const char *new_path;
1088                                clean_merge = 0;
1089                                try_merge = 1;
1090                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1091                                       "%s added in %s",
1092                                       ren1_src, ren1_dst, branch1,
1093                                       ren1_dst, branch2);
1094                                if (o->call_depth) {
1095                                        struct merge_file_info mfi;
1096                                        struct diff_filespec one, a, b;
1097
1098                                        one.path = a.path = b.path =
1099                                                (char *)ren1_dst;
1100                                        hashcpy(one.sha1, null_sha1);
1101                                        one.mode = 0;
1102                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1103                                        a.mode = ren1->pair->two->mode;
1104                                        hashcpy(b.sha1, dst_other.sha1);
1105                                        b.mode = dst_other.mode;
1106                                        mfi = merge_file(o, &one, &a, &b,
1107                                                         branch1,
1108                                                         branch2);
1109                                        output(o, 1, "Adding merged %s", ren1_dst);
1110                                        update_file(o, 0,
1111                                                    mfi.sha,
1112                                                    mfi.mode,
1113                                                    ren1_dst);
1114                                        try_merge = 0;
1115                                } else {
1116                                        new_path = unique_path(o, ren1_dst, branch2);
1117                                        output(o, 1, "Adding as %s instead", new_path);
1118                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1119                                }
1120                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1121                                ren2 = item->util;
1122                                clean_merge = 0;
1123                                ren2->processed = 1;
1124                                output(o, 1, "CONFLICT (rename/rename): "
1125                                       "Rename %s->%s in %s. "
1126                                       "Rename %s->%s in %s",
1127                                       ren1_src, ren1_dst, branch1,
1128                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1129                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1130                        } else
1131                                try_merge = 1;
1132
1133                        if (try_merge) {
1134                                struct diff_filespec *one, *a, *b;
1135                                src_other.path = (char *)ren1_src;
1136
1137                                one = ren1->pair->one;
1138                                if (a_renames == renames1) {
1139                                        a = ren1->pair->two;
1140                                        b = &src_other;
1141                                } else {
1142                                        b = ren1->pair->two;
1143                                        a = &src_other;
1144                                }
1145                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1146                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1147                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1148                                                                      ren1->pair,
1149                                                                      NULL,
1150                                                                      branch1,
1151                                                                      NULL,
1152                                                                      ren1->dst_entry,
1153                                                                      NULL);
1154                                }
1155                        }
1156                }
1157        }
1158        string_list_clear(&a_by_dst, 0);
1159        string_list_clear(&b_by_dst, 0);
1160
1161        return clean_merge;
1162}
1163
1164static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1165{
1166        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1167}
1168
1169static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1170{
1171        void *buf;
1172        enum object_type type;
1173        unsigned long size;
1174        buf = read_sha1_file(sha1, &type, &size);
1175        if (!buf)
1176                return error("cannot read object %s", sha1_to_hex(sha1));
1177        if (type != OBJ_BLOB) {
1178                free(buf);
1179                return error("object %s is not a blob", sha1_to_hex(sha1));
1180        }
1181        strbuf_attach(dst, buf, size, size + 1);
1182        return 0;
1183}
1184
1185static int blob_unchanged(const unsigned char *o_sha,
1186                          const unsigned char *a_sha,
1187                          int renormalize, const char *path)
1188{
1189        struct strbuf o = STRBUF_INIT;
1190        struct strbuf a = STRBUF_INIT;
1191        int ret = 0; /* assume changed for safety */
1192
1193        if (sha_eq(o_sha, a_sha))
1194                return 1;
1195        if (!renormalize)
1196                return 0;
1197
1198        assert(o_sha && a_sha);
1199        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1200                goto error_return;
1201        /*
1202         * Note: binary | is used so that both renormalizations are
1203         * performed.  Comparison can be skipped if both files are
1204         * unchanged since their sha1s have already been compared.
1205         */
1206        if (renormalize_buffer(path, o.buf, o.len, &o) |
1207            renormalize_buffer(path, a.buf, o.len, &a))
1208                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1209
1210error_return:
1211        strbuf_release(&o);
1212        strbuf_release(&a);
1213        return ret;
1214}
1215
1216static void handle_delete_modify(struct merge_options *o,
1217                                 const char *path,
1218                                 const char *new_path,
1219                                 unsigned char *a_sha, int a_mode,
1220                                 unsigned char *b_sha, int b_mode)
1221{
1222        if (!a_sha) {
1223                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1224                       "and modified in %s. Version %s of %s left in tree%s%s.",
1225                       path, o->branch1,
1226                       o->branch2, o->branch2, path,
1227                       path == new_path ? "" : " at ",
1228                       path == new_path ? "" : new_path);
1229                update_file(o, 0, b_sha, b_mode, new_path);
1230        } else {
1231                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1232                       "and modified in %s. Version %s of %s left in tree%s%s.",
1233                       path, o->branch2,
1234                       o->branch1, o->branch1, path,
1235                       path == new_path ? "" : " at ",
1236                       path == new_path ? "" : new_path);
1237                update_file(o, 0, a_sha, a_mode, new_path);
1238        }
1239}
1240
1241static int merge_content(struct merge_options *o,
1242                         const char *path,
1243                         unsigned char *o_sha, int o_mode,
1244                         unsigned char *a_sha, int a_mode,
1245                         unsigned char *b_sha, int b_mode,
1246                         const char *df_rename_conflict_branch)
1247{
1248        const char *reason = "content";
1249        struct merge_file_info mfi;
1250        struct diff_filespec one, a, b;
1251        struct stat st;
1252        unsigned df_conflict_remains = 0;
1253
1254        if (!o_sha) {
1255                reason = "add/add";
1256                o_sha = (unsigned char *)null_sha1;
1257        }
1258        one.path = a.path = b.path = (char *)path;
1259        hashcpy(one.sha1, o_sha);
1260        one.mode = o_mode;
1261        hashcpy(a.sha1, a_sha);
1262        a.mode = a_mode;
1263        hashcpy(b.sha1, b_sha);
1264        b.mode = b_mode;
1265
1266        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1267        if (df_rename_conflict_branch &&
1268            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1269                df_conflict_remains = 1;
1270        }
1271
1272        if (mfi.clean && !df_conflict_remains &&
1273            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1274                output(o, 3, "Skipped %s (merged same as existing)", path);
1275        else
1276                output(o, 2, "Auto-merging %s", path);
1277
1278        if (!mfi.clean) {
1279                if (S_ISGITLINK(mfi.mode))
1280                        reason = "submodule";
1281                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1282                                reason, path);
1283        }
1284
1285        if (df_conflict_remains) {
1286                const char *new_path;
1287                update_file_flags(o, mfi.sha, mfi.mode, path,
1288                                  o->call_depth || mfi.clean, 0);
1289                new_path = unique_path(o, path, df_rename_conflict_branch);
1290                mfi.clean = 0;
1291                output(o, 1, "Adding as %s instead", new_path);
1292                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1293        } else {
1294                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1295        }
1296        return mfi.clean;
1297
1298}
1299
1300/* Per entry merge function */
1301static int process_entry(struct merge_options *o,
1302                         const char *path, struct stage_data *entry)
1303{
1304        /*
1305        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1306        print_index_entry("\tpath: ", entry);
1307        */
1308        int clean_merge = 1;
1309        int normalize = o->renormalize;
1310        unsigned o_mode = entry->stages[1].mode;
1311        unsigned a_mode = entry->stages[2].mode;
1312        unsigned b_mode = entry->stages[3].mode;
1313        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1314        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1315        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1316
1317        if (entry->rename_df_conflict_info)
1318                return 1; /* Such cases are handled elsewhere. */
1319
1320        entry->processed = 1;
1321        if (o_sha && (!a_sha || !b_sha)) {
1322                /* Case A: Deleted in one */
1323                if ((!a_sha && !b_sha) ||
1324                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1325                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1326                        /* Deleted in both or deleted in one and
1327                         * unchanged in the other */
1328                        if (a_sha)
1329                                output(o, 2, "Removing %s", path);
1330                        /* do not touch working file if it did not exist */
1331                        remove_file(o, 1, path, !a_sha);
1332                } else if (string_list_has_string(&o->current_directory_set,
1333                                                  path)) {
1334                        entry->processed = 0;
1335                        return 1; /* Assume clean until processed */
1336                } else {
1337                        /* Deleted in one and changed in the other */
1338                        clean_merge = 0;
1339                        handle_delete_modify(o, path, path,
1340                                             a_sha, a_mode, b_sha, b_mode);
1341                }
1342
1343        } else if ((!o_sha && a_sha && !b_sha) ||
1344                   (!o_sha && !a_sha && b_sha)) {
1345                /* Case B: Added in one. */
1346                unsigned mode;
1347                const unsigned char *sha;
1348
1349                if (a_sha) {
1350                        mode = a_mode;
1351                        sha = a_sha;
1352                } else {
1353                        mode = b_mode;
1354                        sha = b_sha;
1355                }
1356                if (string_list_has_string(&o->current_directory_set, path)) {
1357                        /* Handle D->F conflicts after all subfiles */
1358                        entry->processed = 0;
1359                        return 1; /* Assume clean until processed */
1360                } else {
1361                        output(o, 2, "Adding %s", path);
1362                        update_file(o, 1, sha, mode, path);
1363                }
1364        } else if (a_sha && b_sha) {
1365                /* Case C: Added in both (check for same permissions) and */
1366                /* case D: Modified in both, but differently. */
1367                clean_merge = merge_content(o, path,
1368                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1369                                            NULL);
1370        } else if (!o_sha && !a_sha && !b_sha) {
1371                /*
1372                 * this entry was deleted altogether. a_mode == 0 means
1373                 * we had that path and want to actively remove it.
1374                 */
1375                remove_file(o, 1, path, !a_mode);
1376        } else
1377                die("Fatal merge failure, shouldn't happen.");
1378
1379        return clean_merge;
1380}
1381
1382/*
1383 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1384 * cases we can cleanly resolve D/F conflicts, process_entry() can
1385 * clean out all the files below the directory for us.  All D/F
1386 * conflict cases must be handled here at the end to make sure any
1387 * directories that can be cleaned out, are.
1388 *
1389 * Some rename conflicts may also be handled here that don't necessarily
1390 * involve D/F conflicts, since the code to handle them is generic enough
1391 * to handle those rename conflicts with or without D/F conflicts also
1392 * being involved.
1393 */
1394static int process_df_entry(struct merge_options *o,
1395                            const char *path, struct stage_data *entry)
1396{
1397        int clean_merge = 1;
1398        unsigned o_mode = entry->stages[1].mode;
1399        unsigned a_mode = entry->stages[2].mode;
1400        unsigned b_mode = entry->stages[3].mode;
1401        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1402        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1403        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1404        struct stat st;
1405
1406        entry->processed = 1;
1407        if (entry->rename_df_conflict_info) {
1408                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1409                char *src;
1410                switch (conflict_info->rename_type) {
1411                case RENAME_NORMAL:
1412                        clean_merge = merge_content(o, path,
1413                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1414                                                    conflict_info->branch1);
1415                        break;
1416                case RENAME_DELETE:
1417                        clean_merge = 0;
1418                        conflict_rename_delete(o, conflict_info->pair1,
1419                                               conflict_info->branch1,
1420                                               conflict_info->branch2);
1421                        break;
1422                case RENAME_ONE_FILE_TO_TWO:
1423                        src = conflict_info->pair1->one->path;
1424                        clean_merge = 0;
1425                        output(o, 1, "CONFLICT (rename/rename): "
1426                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1427                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1428                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1429                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1430                               o->call_depth ? " (left unresolved)" : "");
1431                        if (o->call_depth) {
1432                                remove_file_from_cache(src);
1433                                update_file(o, 0, conflict_info->pair1->one->sha1,
1434                                            conflict_info->pair1->one->mode, src);
1435                        }
1436                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1437                                                    conflict_info->branch1,
1438                                                    conflict_info->pair2,
1439                                                    conflict_info->branch2);
1440                        conflict_info->dst_entry2->processed = 1;
1441                        break;
1442                default:
1443                        entry->processed = 0;
1444                        break;
1445                }
1446        } else if (o_sha && (!a_sha || !b_sha)) {
1447                /* Modify/delete; deleted side may have put a directory in the way */
1448                const char *new_path = path;
1449                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1450                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1451                clean_merge = 0;
1452                handle_delete_modify(o, path, new_path,
1453                                     a_sha, a_mode, b_sha, b_mode);
1454        } else if (!o_sha && !!a_sha != !!b_sha) {
1455                /* directory -> (directory, file) */
1456                const char *add_branch;
1457                const char *other_branch;
1458                unsigned mode;
1459                const unsigned char *sha;
1460                const char *conf;
1461
1462                if (a_sha) {
1463                        add_branch = o->branch1;
1464                        other_branch = o->branch2;
1465                        mode = a_mode;
1466                        sha = a_sha;
1467                        conf = "file/directory";
1468                } else {
1469                        add_branch = o->branch2;
1470                        other_branch = o->branch1;
1471                        mode = b_mode;
1472                        sha = b_sha;
1473                        conf = "directory/file";
1474                }
1475                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1476                        const char *new_path = unique_path(o, path, add_branch);
1477                        clean_merge = 0;
1478                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1479                               "Adding %s as %s",
1480                               conf, path, other_branch, path, new_path);
1481                        update_file(o, 0, sha, mode, new_path);
1482                } else {
1483                        output(o, 2, "Adding %s", path);
1484                        update_file(o, 1, sha, mode, path);
1485                }
1486        } else {
1487                entry->processed = 0;
1488                return 1; /* not handled; assume clean until processed */
1489        }
1490
1491        return clean_merge;
1492}
1493
1494int merge_trees(struct merge_options *o,
1495                struct tree *head,
1496                struct tree *merge,
1497                struct tree *common,
1498                struct tree **result)
1499{
1500        int code, clean;
1501
1502        if (o->subtree_shift) {
1503                merge = shift_tree_object(head, merge, o->subtree_shift);
1504                common = shift_tree_object(head, common, o->subtree_shift);
1505        }
1506
1507        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1508                output(o, 0, "Already up-to-date!");
1509                *result = head;
1510                return 1;
1511        }
1512
1513        code = git_merge_trees(o->call_depth, common, head, merge);
1514
1515        if (code != 0) {
1516                if (show(o, 4) || o->call_depth)
1517                        die("merging of trees %s and %s failed",
1518                            sha1_to_hex(head->object.sha1),
1519                            sha1_to_hex(merge->object.sha1));
1520                else
1521                        exit(128);
1522        }
1523
1524        if (unmerged_cache()) {
1525                struct string_list *entries, *re_head, *re_merge;
1526                int i;
1527                string_list_clear(&o->current_file_set, 1);
1528                string_list_clear(&o->current_directory_set, 1);
1529                get_files_dirs(o, head);
1530                get_files_dirs(o, merge);
1531
1532                entries = get_unmerged();
1533                make_room_for_directories_of_df_conflicts(o, entries);
1534                re_head  = get_renames(o, head, common, head, merge, entries);
1535                re_merge = get_renames(o, merge, common, head, merge, entries);
1536                clean = process_renames(o, re_head, re_merge);
1537                for (i = 0; i < entries->nr; i++) {
1538                        const char *path = entries->items[i].string;
1539                        struct stage_data *e = entries->items[i].util;
1540                        if (!e->processed
1541                                && !process_entry(o, path, e))
1542                                clean = 0;
1543                }
1544                for (i = 0; i < entries->nr; i++) {
1545                        const char *path = entries->items[i].string;
1546                        struct stage_data *e = entries->items[i].util;
1547                        if (!e->processed
1548                                && !process_df_entry(o, path, e))
1549                                clean = 0;
1550                }
1551                for (i = 0; i < entries->nr; i++) {
1552                        struct stage_data *e = entries->items[i].util;
1553                        if (!e->processed)
1554                                die("Unprocessed path??? %s",
1555                                    entries->items[i].string);
1556                }
1557
1558                string_list_clear(re_merge, 0);
1559                string_list_clear(re_head, 0);
1560                string_list_clear(entries, 1);
1561
1562        }
1563        else
1564                clean = 1;
1565
1566        if (o->call_depth)
1567                *result = write_tree_from_memory(o);
1568
1569        return clean;
1570}
1571
1572static struct commit_list *reverse_commit_list(struct commit_list *list)
1573{
1574        struct commit_list *next = NULL, *current, *backup;
1575        for (current = list; current; current = backup) {
1576                backup = current->next;
1577                current->next = next;
1578                next = current;
1579        }
1580        return next;
1581}
1582
1583/*
1584 * Merge the commits h1 and h2, return the resulting virtual
1585 * commit object and a flag indicating the cleanness of the merge.
1586 */
1587int merge_recursive(struct merge_options *o,
1588                    struct commit *h1,
1589                    struct commit *h2,
1590                    struct commit_list *ca,
1591                    struct commit **result)
1592{
1593        struct commit_list *iter;
1594        struct commit *merged_common_ancestors;
1595        struct tree *mrtree = mrtree;
1596        int clean;
1597
1598        if (show(o, 4)) {
1599                output(o, 4, "Merging:");
1600                output_commit_title(o, h1);
1601                output_commit_title(o, h2);
1602        }
1603
1604        if (!ca) {
1605                ca = get_merge_bases(h1, h2, 1);
1606                ca = reverse_commit_list(ca);
1607        }
1608
1609        if (show(o, 5)) {
1610                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1611                for (iter = ca; iter; iter = iter->next)
1612                        output_commit_title(o, iter->item);
1613        }
1614
1615        merged_common_ancestors = pop_commit(&ca);
1616        if (merged_common_ancestors == NULL) {
1617                /* if there is no common ancestor, make an empty tree */
1618                struct tree *tree = xcalloc(1, sizeof(struct tree));
1619
1620                tree->object.parsed = 1;
1621                tree->object.type = OBJ_TREE;
1622                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1623                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1624        }
1625
1626        for (iter = ca; iter; iter = iter->next) {
1627                const char *saved_b1, *saved_b2;
1628                o->call_depth++;
1629                /*
1630                 * When the merge fails, the result contains files
1631                 * with conflict markers. The cleanness flag is
1632                 * ignored, it was never actually used, as result of
1633                 * merge_trees has always overwritten it: the committed
1634                 * "conflicts" were already resolved.
1635                 */
1636                discard_cache();
1637                saved_b1 = o->branch1;
1638                saved_b2 = o->branch2;
1639                o->branch1 = "Temporary merge branch 1";
1640                o->branch2 = "Temporary merge branch 2";
1641                merge_recursive(o, merged_common_ancestors, iter->item,
1642                                NULL, &merged_common_ancestors);
1643                o->branch1 = saved_b1;
1644                o->branch2 = saved_b2;
1645                o->call_depth--;
1646
1647                if (!merged_common_ancestors)
1648                        die("merge returned no commit");
1649        }
1650
1651        discard_cache();
1652        if (!o->call_depth)
1653                read_cache();
1654
1655        o->ancestor = "merged common ancestors";
1656        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1657                            &mrtree);
1658
1659        if (o->call_depth) {
1660                *result = make_virtual_commit(mrtree, "merged tree");
1661                commit_list_insert(h1, &(*result)->parents);
1662                commit_list_insert(h2, &(*result)->parents->next);
1663        }
1664        flush_output(o);
1665        return clean;
1666}
1667
1668static struct commit *get_ref(const unsigned char *sha1, const char *name)
1669{
1670        struct object *object;
1671
1672        object = deref_tag(parse_object(sha1), name, strlen(name));
1673        if (!object)
1674                return NULL;
1675        if (object->type == OBJ_TREE)
1676                return make_virtual_commit((struct tree*)object, name);
1677        if (object->type != OBJ_COMMIT)
1678                return NULL;
1679        if (parse_commit((struct commit *)object))
1680                return NULL;
1681        return (struct commit *)object;
1682}
1683
1684int merge_recursive_generic(struct merge_options *o,
1685                            const unsigned char *head,
1686                            const unsigned char *merge,
1687                            int num_base_list,
1688                            const unsigned char **base_list,
1689                            struct commit **result)
1690{
1691        int clean, index_fd;
1692        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1693        struct commit *head_commit = get_ref(head, o->branch1);
1694        struct commit *next_commit = get_ref(merge, o->branch2);
1695        struct commit_list *ca = NULL;
1696
1697        if (base_list) {
1698                int i;
1699                for (i = 0; i < num_base_list; ++i) {
1700                        struct commit *base;
1701                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1702                                return error("Could not parse object '%s'",
1703                                        sha1_to_hex(base_list[i]));
1704                        commit_list_insert(base, &ca);
1705                }
1706        }
1707
1708        index_fd = hold_locked_index(lock, 1);
1709        clean = merge_recursive(o, head_commit, next_commit, ca,
1710                        result);
1711        if (active_cache_changed &&
1712                        (write_cache(index_fd, active_cache, active_nr) ||
1713                         commit_locked_index(lock)))
1714                return error("Unable to write index.");
1715
1716        return clean ? 0 : 1;
1717}
1718
1719static int merge_recursive_config(const char *var, const char *value, void *cb)
1720{
1721        struct merge_options *o = cb;
1722        if (!strcasecmp(var, "merge.verbosity")) {
1723                o->verbosity = git_config_int(var, value);
1724                return 0;
1725        }
1726        if (!strcasecmp(var, "diff.renamelimit")) {
1727                o->diff_rename_limit = git_config_int(var, value);
1728                return 0;
1729        }
1730        if (!strcasecmp(var, "merge.renamelimit")) {
1731                o->merge_rename_limit = git_config_int(var, value);
1732                return 0;
1733        }
1734        return git_xmerge_config(var, value, cb);
1735}
1736
1737void init_merge_options(struct merge_options *o)
1738{
1739        memset(o, 0, sizeof(struct merge_options));
1740        o->verbosity = 2;
1741        o->buffer_output = 1;
1742        o->diff_rename_limit = -1;
1743        o->merge_rename_limit = -1;
1744        o->renormalize = 0;
1745        git_config(merge_recursive_config, o);
1746        if (getenv("GIT_MERGE_VERBOSITY"))
1747                o->verbosity =
1748                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1749        if (o->verbosity >= 5)
1750                o->buffer_output = 0;
1751        strbuf_init(&o->obuf, 0);
1752        memset(&o->current_file_set, 0, sizeof(struct string_list));
1753        o->current_file_set.strdup_strings = 1;
1754        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1755        o->current_directory_set.strdup_strings = 1;
1756}
1757
1758int parse_merge_opt(struct merge_options *o, const char *s)
1759{
1760        if (!s || !*s)
1761                return -1;
1762        if (!strcmp(s, "ours"))
1763                o->recursive_variant = MERGE_RECURSIVE_OURS;
1764        else if (!strcmp(s, "theirs"))
1765                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1766        else if (!strcmp(s, "subtree"))
1767                o->subtree_shift = "";
1768        else if (!prefixcmp(s, "subtree="))
1769                o->subtree_shift = s + strlen("subtree=");
1770        else if (!strcmp(s, "patience"))
1771                o->xdl_opts |= XDF_PATIENCE_DIFF;
1772        else if (!strcmp(s, "ignore-space-change"))
1773                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1774        else if (!strcmp(s, "ignore-all-space"))
1775                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1776        else if (!strcmp(s, "ignore-space-at-eol"))
1777                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1778        else if (!strcmp(s, "renormalize"))
1779                o->renormalize = 1;
1780        else if (!strcmp(s, "no-renormalize"))
1781                o->renormalize = 0;
1782        else if (!prefixcmp(s, "rename-threshold=")) {
1783                const char *score = s + strlen("rename-threshold=");
1784                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1785                        return -1;
1786        }
1787        else
1788                return -1;
1789        return 0;
1790}