089aa10cc1df7e8ad129471ed1b027843d057800
   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{
  93        struct
  94        {
  95                unsigned mode;
  96                unsigned char sha[20];
  97        } stages[4];
  98        struct rename_df_conflict_info *rename_df_conflict_info;
  99        unsigned processed:1;
 100};
 101
 102static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
 103                                                 struct diff_filepair *pair1,
 104                                                 struct diff_filepair *pair2,
 105                                                 const char *branch1,
 106                                                 const char *branch2,
 107                                                 struct stage_data *dst_entry1,
 108                                                 struct stage_data *dst_entry2)
 109{
 110        struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
 111        ci->rename_type = rename_type;
 112        ci->pair1 = pair1;
 113        ci->branch1 = branch1;
 114        ci->branch2 = branch2;
 115
 116        ci->dst_entry1 = dst_entry1;
 117        dst_entry1->rename_df_conflict_info = ci;
 118        dst_entry1->processed = 0;
 119
 120        assert(!pair2 == !dst_entry2);
 121        if (dst_entry2) {
 122                ci->dst_entry2 = dst_entry2;
 123                ci->pair2 = pair2;
 124                dst_entry2->rename_df_conflict_info = ci;
 125                dst_entry2->processed = 0;
 126        }
 127}
 128
 129static int show(struct merge_options *o, int v)
 130{
 131        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 132}
 133
 134static void flush_output(struct merge_options *o)
 135{
 136        if (o->obuf.len) {
 137                fputs(o->obuf.buf, stdout);
 138                strbuf_reset(&o->obuf);
 139        }
 140}
 141
 142__attribute__((format (printf, 3, 4)))
 143static void output(struct merge_options *o, int v, const char *fmt, ...)
 144{
 145        int len;
 146        va_list ap;
 147
 148        if (!show(o, v))
 149                return;
 150
 151        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 152        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 153        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 154
 155        va_start(ap, fmt);
 156        len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 157        va_end(ap);
 158
 159        if (len < 0)
 160                len = 0;
 161        if (len >= strbuf_avail(&o->obuf)) {
 162                strbuf_grow(&o->obuf, len + 2);
 163                va_start(ap, fmt);
 164                len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 165                va_end(ap);
 166                if (len >= strbuf_avail(&o->obuf)) {
 167                        die("this should not happen, your snprintf is broken");
 168                }
 169        }
 170        strbuf_setlen(&o->obuf, o->obuf.len + len);
 171        strbuf_add(&o->obuf, "\n", 1);
 172        if (!o->buffer_output)
 173                flush_output(o);
 174}
 175
 176static void output_commit_title(struct merge_options *o, struct commit *commit)
 177{
 178        int i;
 179        flush_output(o);
 180        for (i = o->call_depth; i--;)
 181                fputs("  ", stdout);
 182        if (commit->util)
 183                printf("virtual %s\n", (char *)commit->util);
 184        else {
 185                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 186                if (parse_commit(commit) != 0)
 187                        printf("(bad commit)\n");
 188                else {
 189                        const char *title;
 190                        int len = find_commit_subject(commit->buffer, &title);
 191                        if (len)
 192                                printf("%.*s\n", len, title);
 193                }
 194        }
 195}
 196
 197static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 198                const char *path, int stage, int refresh, int options)
 199{
 200        struct cache_entry *ce;
 201        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 202        if (!ce)
 203                return error("addinfo_cache failed for path '%s'", path);
 204        return add_cache_entry(ce, options);
 205}
 206
 207static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 208{
 209        parse_tree(tree);
 210        init_tree_desc(desc, tree->buffer, tree->size);
 211}
 212
 213static int git_merge_trees(int index_only,
 214                           struct tree *common,
 215                           struct tree *head,
 216                           struct tree *merge)
 217{
 218        int rc;
 219        struct tree_desc t[3];
 220        struct unpack_trees_options opts;
 221
 222        memset(&opts, 0, sizeof(opts));
 223        if (index_only)
 224                opts.index_only = 1;
 225        else
 226                opts.update = 1;
 227        opts.merge = 1;
 228        opts.head_idx = 2;
 229        opts.fn = threeway_merge;
 230        opts.src_index = &the_index;
 231        opts.dst_index = &the_index;
 232        setup_unpack_trees_porcelain(&opts, "merge");
 233
 234        init_tree_desc_from_tree(t+0, common);
 235        init_tree_desc_from_tree(t+1, head);
 236        init_tree_desc_from_tree(t+2, merge);
 237
 238        rc = unpack_trees(3, t, &opts);
 239        cache_tree_free(&active_cache_tree);
 240        return rc;
 241}
 242
 243struct tree *write_tree_from_memory(struct merge_options *o)
 244{
 245        struct tree *result = NULL;
 246
 247        if (unmerged_cache()) {
 248                int i;
 249                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 250                for (i = 0; i < active_nr; i++) {
 251                        struct cache_entry *ce = active_cache[i];
 252                        if (ce_stage(ce))
 253                                fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
 254                                        (int)ce_namelen(ce), ce->name);
 255                }
 256                die("Bug in merge-recursive.c");
 257        }
 258
 259        if (!active_cache_tree)
 260                active_cache_tree = cache_tree();
 261
 262        if (!cache_tree_fully_valid(active_cache_tree) &&
 263            cache_tree_update(active_cache_tree,
 264                              active_cache, active_nr, 0, 0) < 0)
 265                die("error building trees");
 266
 267        result = lookup_tree(active_cache_tree->sha1);
 268
 269        return result;
 270}
 271
 272static int save_files_dirs(const unsigned char *sha1,
 273                const char *base, int baselen, const char *path,
 274                unsigned int mode, int stage, void *context)
 275{
 276        int len = strlen(path);
 277        char *newpath = xmalloc(baselen + len + 1);
 278        struct merge_options *o = context;
 279
 280        memcpy(newpath, base, baselen);
 281        memcpy(newpath + baselen, path, len);
 282        newpath[baselen + len] = '\0';
 283
 284        if (S_ISDIR(mode))
 285                string_list_insert(&o->current_directory_set, newpath);
 286        else
 287                string_list_insert(&o->current_file_set, newpath);
 288        free(newpath);
 289
 290        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 291}
 292
 293static int get_files_dirs(struct merge_options *o, struct tree *tree)
 294{
 295        int n;
 296        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 297                return 0;
 298        n = o->current_file_set.nr + o->current_directory_set.nr;
 299        return n;
 300}
 301
 302/*
 303 * Returns an index_entry instance which doesn't have to correspond to
 304 * a real cache entry in Git's index.
 305 */
 306static struct stage_data *insert_stage_data(const char *path,
 307                struct tree *o, struct tree *a, struct tree *b,
 308                struct string_list *entries)
 309{
 310        struct string_list_item *item;
 311        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 312        get_tree_entry(o->object.sha1, path,
 313                        e->stages[1].sha, &e->stages[1].mode);
 314        get_tree_entry(a->object.sha1, path,
 315                        e->stages[2].sha, &e->stages[2].mode);
 316        get_tree_entry(b->object.sha1, path,
 317                        e->stages[3].sha, &e->stages[3].mode);
 318        item = string_list_insert(entries, path);
 319        item->util = e;
 320        return e;
 321}
 322
 323/*
 324 * Create a dictionary mapping file names to stage_data objects. The
 325 * dictionary contains one entry for every path with a non-zero stage entry.
 326 */
 327static struct string_list *get_unmerged(void)
 328{
 329        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 330        int i;
 331
 332        unmerged->strdup_strings = 1;
 333
 334        for (i = 0; i < active_nr; i++) {
 335                struct string_list_item *item;
 336                struct stage_data *e;
 337                struct cache_entry *ce = active_cache[i];
 338                if (!ce_stage(ce))
 339                        continue;
 340
 341                item = string_list_lookup(unmerged, ce->name);
 342                if (!item) {
 343                        item = string_list_insert(unmerged, ce->name);
 344                        item->util = xcalloc(1, sizeof(struct stage_data));
 345                }
 346                e = item->util;
 347                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 348                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 349        }
 350
 351        return unmerged;
 352}
 353
 354static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 355                                                      struct string_list *entries)
 356{
 357        /* If there are D/F conflicts, and the paths currently exist
 358         * in the working copy as a file, we want to remove them to
 359         * make room for the corresponding directory.  Such paths will
 360         * later be processed in process_df_entry() at the end.  If
 361         * the corresponding directory ends up being removed by the
 362         * merge, then the file will be reinstated at that time;
 363         * otherwise, if the file is not supposed to be removed by the
 364         * merge, the contents of the file will be placed in another
 365         * unique filename.
 366         *
 367         * NOTE: This function relies on the fact that entries for a
 368         * D/F conflict will appear adjacent in the index, with the
 369         * entries for the file appearing before entries for paths
 370         * below the corresponding directory.
 371         */
 372        const char *last_file = NULL;
 373        int last_len = 0;
 374        struct stage_data *last_e;
 375        int i;
 376
 377        for (i = 0; i < entries->nr; i++) {
 378                const char *path = entries->items[i].string;
 379                int len = strlen(path);
 380                struct stage_data *e = entries->items[i].util;
 381
 382                /*
 383                 * Check if last_file & path correspond to a D/F conflict;
 384                 * i.e. whether path is last_file+'/'+<something>.
 385                 * If so, remove last_file to make room for path and friends.
 386                 */
 387                if (last_file &&
 388                    len > last_len &&
 389                    memcmp(path, last_file, last_len) == 0 &&
 390                    path[last_len] == '/') {
 391                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 392                        unlink(last_file);
 393                }
 394
 395                /*
 396                 * Determine whether path could exist as a file in the
 397                 * working directory as a possible D/F conflict.  This
 398                 * will only occur when it exists in stage 2 as a
 399                 * file.
 400                 */
 401                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 402                        last_file = path;
 403                        last_len = len;
 404                        last_e = e;
 405                } else {
 406                        last_file = NULL;
 407                }
 408        }
 409}
 410
 411struct rename
 412{
 413        struct diff_filepair *pair;
 414        struct stage_data *src_entry;
 415        struct stage_data *dst_entry;
 416        unsigned processed:1;
 417};
 418
 419/*
 420 * Get information of all renames which occurred between 'o_tree' and
 421 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 422 * 'b_tree') to be able to associate the correct cache entries with
 423 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 424 */
 425static struct string_list *get_renames(struct merge_options *o,
 426                                       struct tree *tree,
 427                                       struct tree *o_tree,
 428                                       struct tree *a_tree,
 429                                       struct tree *b_tree,
 430                                       struct string_list *entries)
 431{
 432        int i;
 433        struct string_list *renames;
 434        struct diff_options opts;
 435
 436        renames = xcalloc(1, sizeof(struct string_list));
 437        diff_setup(&opts);
 438        DIFF_OPT_SET(&opts, RECURSIVE);
 439        opts.detect_rename = DIFF_DETECT_RENAME;
 440        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 441                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 442                            1000;
 443        opts.rename_score = o->rename_score;
 444        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 445        if (diff_setup_done(&opts) < 0)
 446                die("diff setup failed");
 447        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 448        diffcore_std(&opts);
 449        if (opts.needed_rename_limit > o->needed_rename_limit)
 450                o->needed_rename_limit = opts.needed_rename_limit;
 451        for (i = 0; i < diff_queued_diff.nr; ++i) {
 452                struct string_list_item *item;
 453                struct rename *re;
 454                struct diff_filepair *pair = diff_queued_diff.queue[i];
 455                if (pair->status != 'R') {
 456                        diff_free_filepair(pair);
 457                        continue;
 458                }
 459                re = xmalloc(sizeof(*re));
 460                re->processed = 0;
 461                re->pair = pair;
 462                item = string_list_lookup(entries, re->pair->one->path);
 463                if (!item)
 464                        re->src_entry = insert_stage_data(re->pair->one->path,
 465                                        o_tree, a_tree, b_tree, entries);
 466                else
 467                        re->src_entry = item->util;
 468
 469                item = string_list_lookup(entries, re->pair->two->path);
 470                if (!item)
 471                        re->dst_entry = insert_stage_data(re->pair->two->path,
 472                                        o_tree, a_tree, b_tree, entries);
 473                else
 474                        re->dst_entry = item->util;
 475                item = string_list_insert(renames, pair->one->path);
 476                item->util = re;
 477        }
 478        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 479        diff_queued_diff.nr = 0;
 480        diff_flush(&opts);
 481        return renames;
 482}
 483
 484static int update_stages_options(const char *path, struct diff_filespec *o,
 485                         struct diff_filespec *a, struct diff_filespec *b,
 486                         int clear, int options)
 487{
 488        if (clear)
 489                if (remove_file_from_cache(path))
 490                        return -1;
 491        if (o)
 492                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 493                        return -1;
 494        if (a)
 495                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 496                        return -1;
 497        if (b)
 498                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 499                        return -1;
 500        return 0;
 501}
 502
 503static int update_stages(const char *path, struct diff_filespec *o,
 504                         struct diff_filespec *a, struct diff_filespec *b,
 505                         int clear)
 506{
 507        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 508        return update_stages_options(path, o, a, b, clear, options);
 509}
 510
 511static int update_stages_and_entry(const char *path,
 512                                   struct stage_data *entry,
 513                                   struct diff_filespec *o,
 514                                   struct diff_filespec *a,
 515                                   struct diff_filespec *b,
 516                                   int clear)
 517{
 518        int options;
 519
 520        entry->processed = 0;
 521        entry->stages[1].mode = o->mode;
 522        entry->stages[2].mode = a->mode;
 523        entry->stages[3].mode = b->mode;
 524        hashcpy(entry->stages[1].sha, o->sha1);
 525        hashcpy(entry->stages[2].sha, a->sha1);
 526        hashcpy(entry->stages[3].sha, b->sha1);
 527        options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 528        return update_stages_options(path, o, a, b, clear, options);
 529}
 530
 531static int remove_file(struct merge_options *o, int clean,
 532                       const char *path, int no_wd)
 533{
 534        int update_cache = o->call_depth || clean;
 535        int update_working_directory = !o->call_depth && !no_wd;
 536
 537        if (update_cache) {
 538                if (remove_file_from_cache(path))
 539                        return -1;
 540        }
 541        if (update_working_directory) {
 542                if (remove_path(path))
 543                        return -1;
 544        }
 545        return 0;
 546}
 547
 548static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 549{
 550        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 551        int suffix = 0;
 552        struct stat st;
 553        char *p = newpath + strlen(path);
 554        strcpy(newpath, path);
 555        *(p++) = '~';
 556        strcpy(p, branch);
 557        for (; *p; ++p)
 558                if ('/' == *p)
 559                        *p = '_';
 560        while (string_list_has_string(&o->current_file_set, newpath) ||
 561               string_list_has_string(&o->current_directory_set, newpath) ||
 562               lstat(newpath, &st) == 0)
 563                sprintf(p, "_%d", suffix++);
 564
 565        string_list_insert(&o->current_file_set, newpath);
 566        return newpath;
 567}
 568
 569static void flush_buffer(int fd, const char *buf, unsigned long size)
 570{
 571        while (size > 0) {
 572                long ret = write_in_full(fd, buf, size);
 573                if (ret < 0) {
 574                        /* Ignore epipe */
 575                        if (errno == EPIPE)
 576                                break;
 577                        die_errno("merge-recursive");
 578                } else if (!ret) {
 579                        die("merge-recursive: disk full?");
 580                }
 581                size -= ret;
 582                buf += ret;
 583        }
 584}
 585
 586static int would_lose_untracked(const char *path)
 587{
 588        int pos = cache_name_pos(path, strlen(path));
 589
 590        if (pos < 0)
 591                pos = -1 - pos;
 592        while (pos < active_nr &&
 593               !strcmp(path, active_cache[pos]->name)) {
 594                /*
 595                 * If stage #0, it is definitely tracked.
 596                 * If it has stage #2 then it was tracked
 597                 * before this merge started.  All other
 598                 * cases the path was not tracked.
 599                 */
 600                switch (ce_stage(active_cache[pos])) {
 601                case 0:
 602                case 2:
 603                        return 0;
 604                }
 605                pos++;
 606        }
 607        return file_exists(path);
 608}
 609
 610static int make_room_for_path(const char *path)
 611{
 612        int status;
 613        const char *msg = "failed to create path '%s'%s";
 614
 615        status = safe_create_leading_directories_const(path);
 616        if (status) {
 617                if (status == -3) {
 618                        /* something else exists */
 619                        error(msg, path, ": perhaps a D/F conflict?");
 620                        return -1;
 621                }
 622                die(msg, path, "");
 623        }
 624
 625        /*
 626         * Do not unlink a file in the work tree if we are not
 627         * tracking it.
 628         */
 629        if (would_lose_untracked(path))
 630                return error("refusing to lose untracked file at '%s'",
 631                             path);
 632
 633        /* Successful unlink is good.. */
 634        if (!unlink(path))
 635                return 0;
 636        /* .. and so is no existing file */
 637        if (errno == ENOENT)
 638                return 0;
 639        /* .. but not some other error (who really cares what?) */
 640        return error(msg, path, ": perhaps a D/F conflict?");
 641}
 642
 643static void update_file_flags(struct merge_options *o,
 644                              const unsigned char *sha,
 645                              unsigned mode,
 646                              const char *path,
 647                              int update_cache,
 648                              int update_wd)
 649{
 650        if (o->call_depth)
 651                update_wd = 0;
 652
 653        if (update_wd) {
 654                enum object_type type;
 655                void *buf;
 656                unsigned long size;
 657
 658                if (S_ISGITLINK(mode)) {
 659                        /*
 660                         * We may later decide to recursively descend into
 661                         * the submodule directory and update its index
 662                         * and/or work tree, but we do not do that now.
 663                         */
 664                        update_wd = 0;
 665                        goto update_index;
 666                }
 667
 668                buf = read_sha1_file(sha, &type, &size);
 669                if (!buf)
 670                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 671                if (type != OBJ_BLOB)
 672                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 673                if (S_ISREG(mode)) {
 674                        struct strbuf strbuf = STRBUF_INIT;
 675                        if (convert_to_working_tree(path, buf, size, &strbuf)) {
 676                                free(buf);
 677                                size = strbuf.len;
 678                                buf = strbuf_detach(&strbuf, NULL);
 679                        }
 680                }
 681
 682                if (make_room_for_path(path) < 0) {
 683                        update_wd = 0;
 684                        free(buf);
 685                        goto update_index;
 686                }
 687                if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 688                        int fd;
 689                        if (mode & 0100)
 690                                mode = 0777;
 691                        else
 692                                mode = 0666;
 693                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 694                        if (fd < 0)
 695                                die_errno("failed to open '%s'", path);
 696                        flush_buffer(fd, buf, size);
 697                        close(fd);
 698                } else if (S_ISLNK(mode)) {
 699                        char *lnk = xmemdupz(buf, size);
 700                        safe_create_leading_directories_const(path);
 701                        unlink(path);
 702                        if (symlink(lnk, path))
 703                                die_errno("failed to symlink '%s'", path);
 704                        free(lnk);
 705                } else
 706                        die("do not know what to do with %06o %s '%s'",
 707                            mode, sha1_to_hex(sha), path);
 708                free(buf);
 709        }
 710 update_index:
 711        if (update_cache)
 712                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 713}
 714
 715static void update_file(struct merge_options *o,
 716                        int clean,
 717                        const unsigned char *sha,
 718                        unsigned mode,
 719                        const char *path)
 720{
 721        update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 722}
 723
 724/* Low level file merging, update and removal */
 725
 726struct merge_file_info
 727{
 728        unsigned char sha[20];
 729        unsigned mode;
 730        unsigned clean:1,
 731                 merge:1;
 732};
 733
 734static int merge_3way(struct merge_options *o,
 735                      mmbuffer_t *result_buf,
 736                      struct diff_filespec *one,
 737                      struct diff_filespec *a,
 738                      struct diff_filespec *b,
 739                      const char *branch1,
 740                      const char *branch2)
 741{
 742        mmfile_t orig, src1, src2;
 743        struct ll_merge_options ll_opts = {0};
 744        char *base_name, *name1, *name2;
 745        int merge_status;
 746
 747        ll_opts.renormalize = o->renormalize;
 748        ll_opts.xdl_opts = o->xdl_opts;
 749
 750        if (o->call_depth) {
 751                ll_opts.virtual_ancestor = 1;
 752                ll_opts.variant = 0;
 753        } else {
 754                switch (o->recursive_variant) {
 755                case MERGE_RECURSIVE_OURS:
 756                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
 757                        break;
 758                case MERGE_RECURSIVE_THEIRS:
 759                        ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
 760                        break;
 761                default:
 762                        ll_opts.variant = 0;
 763                        break;
 764                }
 765        }
 766
 767        if (strcmp(a->path, b->path) ||
 768            (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
 769                base_name = o->ancestor == NULL ? NULL :
 770                        xstrdup(mkpath("%s:%s", o->ancestor, one->path));
 771                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 772                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 773        } else {
 774                base_name = o->ancestor == NULL ? NULL :
 775                        xstrdup(mkpath("%s", o->ancestor));
 776                name1 = xstrdup(mkpath("%s", branch1));
 777                name2 = xstrdup(mkpath("%s", branch2));
 778        }
 779
 780        read_mmblob(&orig, one->sha1);
 781        read_mmblob(&src1, a->sha1);
 782        read_mmblob(&src2, b->sha1);
 783
 784        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 785                                &src1, name1, &src2, name2, &ll_opts);
 786
 787        free(name1);
 788        free(name2);
 789        free(orig.ptr);
 790        free(src1.ptr);
 791        free(src2.ptr);
 792        return merge_status;
 793}
 794
 795static struct merge_file_info merge_file(struct merge_options *o,
 796                                         struct diff_filespec *one,
 797                                         struct diff_filespec *a,
 798                                         struct diff_filespec *b,
 799                                         const char *branch1,
 800                                         const char *branch2)
 801{
 802        struct merge_file_info result;
 803        result.merge = 0;
 804        result.clean = 1;
 805
 806        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 807                result.clean = 0;
 808                if (S_ISREG(a->mode)) {
 809                        result.mode = a->mode;
 810                        hashcpy(result.sha, a->sha1);
 811                } else {
 812                        result.mode = b->mode;
 813                        hashcpy(result.sha, b->sha1);
 814                }
 815        } else {
 816                if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 817                        result.merge = 1;
 818
 819                /*
 820                 * Merge modes
 821                 */
 822                if (a->mode == b->mode || a->mode == one->mode)
 823                        result.mode = b->mode;
 824                else {
 825                        result.mode = a->mode;
 826                        if (b->mode != one->mode) {
 827                                result.clean = 0;
 828                                result.merge = 1;
 829                        }
 830                }
 831
 832                if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 833                        hashcpy(result.sha, b->sha1);
 834                else if (sha_eq(b->sha1, one->sha1))
 835                        hashcpy(result.sha, a->sha1);
 836                else if (S_ISREG(a->mode)) {
 837                        mmbuffer_t result_buf;
 838                        int merge_status;
 839
 840                        merge_status = merge_3way(o, &result_buf, one, a, b,
 841                                                  branch1, branch2);
 842
 843                        if ((merge_status < 0) || !result_buf.ptr)
 844                                die("Failed to execute internal merge");
 845
 846                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 847                                            blob_type, result.sha))
 848                                die("Unable to add %s to database",
 849                                    a->path);
 850
 851                        free(result_buf.ptr);
 852                        result.clean = (merge_status == 0);
 853                } else if (S_ISGITLINK(a->mode)) {
 854                        result.clean = merge_submodule(result.sha, one->path, one->sha1,
 855                                                       a->sha1, b->sha1);
 856                } else if (S_ISLNK(a->mode)) {
 857                        hashcpy(result.sha, a->sha1);
 858
 859                        if (!sha_eq(a->sha1, b->sha1))
 860                                result.clean = 0;
 861                } else {
 862                        die("unsupported object type in the tree");
 863                }
 864        }
 865
 866        return result;
 867}
 868
 869static void conflict_rename_delete(struct merge_options *o,
 870                                   struct diff_filepair *pair,
 871                                   const char *rename_branch,
 872                                   const char *other_branch)
 873{
 874        char *dest_name = pair->two->path;
 875        int df_conflict = 0;
 876        struct stat st;
 877
 878        output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 879               "and deleted in %s",
 880               pair->one->path, pair->two->path, rename_branch,
 881               other_branch);
 882        if (!o->call_depth)
 883                update_stages(dest_name, NULL,
 884                              rename_branch == o->branch1 ? pair->two : NULL,
 885                              rename_branch == o->branch1 ? NULL : pair->two,
 886                              1);
 887        if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
 888                dest_name = unique_path(o, dest_name, rename_branch);
 889                df_conflict = 1;
 890        }
 891        update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
 892        if (df_conflict)
 893                free(dest_name);
 894}
 895
 896static void conflict_rename_rename_1to2(struct merge_options *o,
 897                                        struct diff_filepair *pair1,
 898                                        const char *branch1,
 899                                        struct diff_filepair *pair2,
 900                                        const char *branch2)
 901{
 902        /* One file was renamed in both branches, but to different names. */
 903        char *del[2];
 904        int delp = 0;
 905        const char *ren1_dst = pair1->two->path;
 906        const char *ren2_dst = pair2->two->path;
 907        const char *dst_name1 = ren1_dst;
 908        const char *dst_name2 = ren2_dst;
 909        struct stat st;
 910        if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 911                dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 912                output(o, 1, "%s is a directory in %s adding as %s instead",
 913                       ren1_dst, branch2, dst_name1);
 914        }
 915        if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
 916                dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 917                output(o, 1, "%s is a directory in %s adding as %s instead",
 918                       ren2_dst, branch1, dst_name2);
 919        }
 920        if (o->call_depth) {
 921                remove_file_from_cache(dst_name1);
 922                remove_file_from_cache(dst_name2);
 923                /*
 924                 * Uncomment to leave the conflicting names in the resulting tree
 925                 *
 926                 * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 927                 * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 928                 */
 929        } else {
 930                update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
 931                update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
 932
 933                update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
 934                update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
 935        }
 936        while (delp--)
 937                free(del[delp]);
 938}
 939
 940static void conflict_rename_rename_2to1(struct merge_options *o,
 941                                        struct rename *ren1,
 942                                        const char *branch1,
 943                                        struct rename *ren2,
 944                                        const char *branch2)
 945{
 946        /* Two files were renamed to the same thing. */
 947        char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 948        char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 949        output(o, 1, "Renaming %s to %s and %s to %s instead",
 950               ren1->pair->one->path, new_path1,
 951               ren2->pair->one->path, new_path2);
 952        remove_file(o, 0, ren1->pair->two->path, 0);
 953        update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 954        update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 955        free(new_path2);
 956        free(new_path1);
 957}
 958
 959static int process_renames(struct merge_options *o,
 960                           struct string_list *a_renames,
 961                           struct string_list *b_renames)
 962{
 963        int clean_merge = 1, i, j;
 964        struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
 965        struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
 966        const struct rename *sre;
 967
 968        for (i = 0; i < a_renames->nr; i++) {
 969                sre = a_renames->items[i].util;
 970                string_list_insert(&a_by_dst, sre->pair->two->path)->util
 971                        = sre->dst_entry;
 972        }
 973        for (i = 0; i < b_renames->nr; i++) {
 974                sre = b_renames->items[i].util;
 975                string_list_insert(&b_by_dst, sre->pair->two->path)->util
 976                        = sre->dst_entry;
 977        }
 978
 979        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 980                char *src;
 981                struct string_list *renames1, *renames2Dst;
 982                struct rename *ren1 = NULL, *ren2 = NULL;
 983                const char *branch1, *branch2;
 984                const char *ren1_src, *ren1_dst;
 985
 986                if (i >= a_renames->nr) {
 987                        ren2 = b_renames->items[j++].util;
 988                } else if (j >= b_renames->nr) {
 989                        ren1 = a_renames->items[i++].util;
 990                } else {
 991                        int compare = strcmp(a_renames->items[i].string,
 992                                             b_renames->items[j].string);
 993                        if (compare <= 0)
 994                                ren1 = a_renames->items[i++].util;
 995                        if (compare >= 0)
 996                                ren2 = b_renames->items[j++].util;
 997                }
 998
 999                /* TODO: refactor, so that 1/2 are not needed */
1000                if (ren1) {
1001                        renames1 = a_renames;
1002                        renames2Dst = &b_by_dst;
1003                        branch1 = o->branch1;
1004                        branch2 = o->branch2;
1005                } else {
1006                        struct rename *tmp;
1007                        renames1 = b_renames;
1008                        renames2Dst = &a_by_dst;
1009                        branch1 = o->branch2;
1010                        branch2 = o->branch1;
1011                        tmp = ren2;
1012                        ren2 = ren1;
1013                        ren1 = tmp;
1014                }
1015                src = ren1->pair->one->path;
1016
1017                ren1->dst_entry->processed = 1;
1018                ren1->src_entry->processed = 1;
1019
1020                if (ren1->processed)
1021                        continue;
1022                ren1->processed = 1;
1023
1024                ren1_src = ren1->pair->one->path;
1025                ren1_dst = ren1->pair->two->path;
1026
1027                if (ren2) {
1028                        const char *ren2_src = ren2->pair->one->path;
1029                        const char *ren2_dst = ren2->pair->two->path;
1030                        /* Renamed in 1 and renamed in 2 */
1031                        if (strcmp(ren1_src, ren2_src) != 0)
1032                                die("ren1.src != ren2.src");
1033                        ren2->dst_entry->processed = 1;
1034                        ren2->processed = 1;
1035                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1036                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1037                                                              ren1->pair,
1038                                                              ren2->pair,
1039                                                              branch1,
1040                                                              branch2,
1041                                                              ren1->dst_entry,
1042                                                              ren2->dst_entry);
1043                        } else {
1044                                remove_file(o, 1, ren1_src, 1);
1045                                update_stages_and_entry(ren1_dst,
1046                                                        ren1->dst_entry,
1047                                                        ren1->pair->one,
1048                                                        ren1->pair->two,
1049                                                        ren2->pair->two,
1050                                                        1 /* clear */);
1051                        }
1052                } else {
1053                        /* Renamed in 1, maybe changed in 2 */
1054                        struct string_list_item *item;
1055                        /* we only use sha1 and mode of these */
1056                        struct diff_filespec src_other, dst_other;
1057                        int try_merge;
1058
1059                        /*
1060                         * unpack_trees loads entries from common-commit
1061                         * into stage 1, from head-commit into stage 2, and
1062                         * from merge-commit into stage 3.  We keep track
1063                         * of which side corresponds to the rename.
1064                         */
1065                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1066                        int other_stage =   a_renames == renames1 ? 3 : 2;
1067
1068                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1069
1070                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1071                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1072                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1073                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1074                        try_merge = 0;
1075
1076                        if (sha_eq(src_other.sha1, null_sha1)) {
1077                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1078                                        ren1->dst_entry->processed = 0;
1079                                        setup_rename_df_conflict_info(RENAME_DELETE,
1080                                                                      ren1->pair,
1081                                                                      NULL,
1082                                                                      branch1,
1083                                                                      branch2,
1084                                                                      ren1->dst_entry,
1085                                                                      NULL);
1086                                } else {
1087                                        clean_merge = 0;
1088                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1089                                }
1090                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1091                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1092                                /* Added file on the other side
1093                                   identical to the file being
1094                                   renamed: clean merge */
1095                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1096                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1097                                const char *new_path;
1098                                clean_merge = 0;
1099                                try_merge = 1;
1100                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1101                                       "%s added in %s",
1102                                       ren1_src, ren1_dst, branch1,
1103                                       ren1_dst, branch2);
1104                                if (o->call_depth) {
1105                                        struct merge_file_info mfi;
1106                                        struct diff_filespec one, a, b;
1107
1108                                        one.path = a.path = b.path =
1109                                                (char *)ren1_dst;
1110                                        hashcpy(one.sha1, null_sha1);
1111                                        one.mode = 0;
1112                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1113                                        a.mode = ren1->pair->two->mode;
1114                                        hashcpy(b.sha1, dst_other.sha1);
1115                                        b.mode = dst_other.mode;
1116                                        mfi = merge_file(o, &one, &a, &b,
1117                                                         branch1,
1118                                                         branch2);
1119                                        output(o, 1, "Adding merged %s", ren1_dst);
1120                                        update_file(o, 0,
1121                                                    mfi.sha,
1122                                                    mfi.mode,
1123                                                    ren1_dst);
1124                                        try_merge = 0;
1125                                } else {
1126                                        new_path = unique_path(o, ren1_dst, branch2);
1127                                        output(o, 1, "Adding as %s instead", new_path);
1128                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1129                                }
1130                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1131                                ren2 = item->util;
1132                                clean_merge = 0;
1133                                ren2->processed = 1;
1134                                output(o, 1, "CONFLICT (rename/rename): "
1135                                       "Rename %s->%s in %s. "
1136                                       "Rename %s->%s in %s",
1137                                       ren1_src, ren1_dst, branch1,
1138                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1139                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1140                        } else
1141                                try_merge = 1;
1142
1143                        if (try_merge) {
1144                                struct diff_filespec *one, *a, *b;
1145                                src_other.path = (char *)ren1_src;
1146
1147                                one = ren1->pair->one;
1148                                if (a_renames == renames1) {
1149                                        a = ren1->pair->two;
1150                                        b = &src_other;
1151                                } else {
1152                                        b = ren1->pair->two;
1153                                        a = &src_other;
1154                                }
1155                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1156                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1157                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1158                                                                      ren1->pair,
1159                                                                      NULL,
1160                                                                      branch1,
1161                                                                      NULL,
1162                                                                      ren1->dst_entry,
1163                                                                      NULL);
1164                                }
1165                        }
1166                }
1167        }
1168        string_list_clear(&a_by_dst, 0);
1169        string_list_clear(&b_by_dst, 0);
1170
1171        return clean_merge;
1172}
1173
1174static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1175{
1176        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1177}
1178
1179static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1180{
1181        void *buf;
1182        enum object_type type;
1183        unsigned long size;
1184        buf = read_sha1_file(sha1, &type, &size);
1185        if (!buf)
1186                return error("cannot read object %s", sha1_to_hex(sha1));
1187        if (type != OBJ_BLOB) {
1188                free(buf);
1189                return error("object %s is not a blob", sha1_to_hex(sha1));
1190        }
1191        strbuf_attach(dst, buf, size, size + 1);
1192        return 0;
1193}
1194
1195static int blob_unchanged(const unsigned char *o_sha,
1196                          const unsigned char *a_sha,
1197                          int renormalize, const char *path)
1198{
1199        struct strbuf o = STRBUF_INIT;
1200        struct strbuf a = STRBUF_INIT;
1201        int ret = 0; /* assume changed for safety */
1202
1203        if (sha_eq(o_sha, a_sha))
1204                return 1;
1205        if (!renormalize)
1206                return 0;
1207
1208        assert(o_sha && a_sha);
1209        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1210                goto error_return;
1211        /*
1212         * Note: binary | is used so that both renormalizations are
1213         * performed.  Comparison can be skipped if both files are
1214         * unchanged since their sha1s have already been compared.
1215         */
1216        if (renormalize_buffer(path, o.buf, o.len, &o) |
1217            renormalize_buffer(path, a.buf, o.len, &a))
1218                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1219
1220error_return:
1221        strbuf_release(&o);
1222        strbuf_release(&a);
1223        return ret;
1224}
1225
1226static void handle_delete_modify(struct merge_options *o,
1227                                 const char *path,
1228                                 const char *new_path,
1229                                 unsigned char *a_sha, int a_mode,
1230                                 unsigned char *b_sha, int b_mode)
1231{
1232        if (!a_sha) {
1233                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1234                       "and modified in %s. Version %s of %s left in tree%s%s.",
1235                       path, o->branch1,
1236                       o->branch2, o->branch2, path,
1237                       path == new_path ? "" : " at ",
1238                       path == new_path ? "" : new_path);
1239                update_file(o, 0, b_sha, b_mode, new_path);
1240        } else {
1241                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1242                       "and modified in %s. Version %s of %s left in tree%s%s.",
1243                       path, o->branch2,
1244                       o->branch1, o->branch1, path,
1245                       path == new_path ? "" : " at ",
1246                       path == new_path ? "" : new_path);
1247                update_file(o, 0, a_sha, a_mode, new_path);
1248        }
1249}
1250
1251static int merge_content(struct merge_options *o,
1252                         const char *path,
1253                         unsigned char *o_sha, int o_mode,
1254                         unsigned char *a_sha, int a_mode,
1255                         unsigned char *b_sha, int b_mode,
1256                         const char *df_rename_conflict_branch)
1257{
1258        const char *reason = "content";
1259        struct merge_file_info mfi;
1260        struct diff_filespec one, a, b;
1261        struct stat st;
1262        unsigned df_conflict_remains = 0;
1263
1264        if (!o_sha) {
1265                reason = "add/add";
1266                o_sha = (unsigned char *)null_sha1;
1267        }
1268        one.path = a.path = b.path = (char *)path;
1269        hashcpy(one.sha1, o_sha);
1270        one.mode = o_mode;
1271        hashcpy(a.sha1, a_sha);
1272        a.mode = a_mode;
1273        hashcpy(b.sha1, b_sha);
1274        b.mode = b_mode;
1275
1276        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1277        if (df_rename_conflict_branch &&
1278            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1279                df_conflict_remains = 1;
1280        }
1281
1282        if (mfi.clean && !df_conflict_remains &&
1283            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1284                output(o, 3, "Skipped %s (merged same as existing)", path);
1285        else
1286                output(o, 2, "Auto-merging %s", path);
1287
1288        if (!mfi.clean) {
1289                if (S_ISGITLINK(mfi.mode))
1290                        reason = "submodule";
1291                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1292                                reason, path);
1293        }
1294
1295        if (df_conflict_remains) {
1296                const char *new_path;
1297                update_file_flags(o, mfi.sha, mfi.mode, path,
1298                                  o->call_depth || mfi.clean, 0);
1299                new_path = unique_path(o, path, df_rename_conflict_branch);
1300                mfi.clean = 0;
1301                output(o, 1, "Adding as %s instead", new_path);
1302                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1303        } else {
1304                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1305        }
1306        return mfi.clean;
1307
1308}
1309
1310/* Per entry merge function */
1311static int process_entry(struct merge_options *o,
1312                         const char *path, struct stage_data *entry)
1313{
1314        /*
1315        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1316        print_index_entry("\tpath: ", entry);
1317        */
1318        int clean_merge = 1;
1319        int normalize = o->renormalize;
1320        unsigned o_mode = entry->stages[1].mode;
1321        unsigned a_mode = entry->stages[2].mode;
1322        unsigned b_mode = entry->stages[3].mode;
1323        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1324        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1325        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1326
1327        if (entry->rename_df_conflict_info)
1328                return 1; /* Such cases are handled elsewhere. */
1329
1330        entry->processed = 1;
1331        if (o_sha && (!a_sha || !b_sha)) {
1332                /* Case A: Deleted in one */
1333                if ((!a_sha && !b_sha) ||
1334                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1335                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1336                        /* Deleted in both or deleted in one and
1337                         * unchanged in the other */
1338                        if (a_sha)
1339                                output(o, 2, "Removing %s", path);
1340                        /* do not touch working file if it did not exist */
1341                        remove_file(o, 1, path, !a_sha);
1342                } else if (string_list_has_string(&o->current_directory_set,
1343                                                  path)) {
1344                        entry->processed = 0;
1345                        return 1; /* Assume clean until processed */
1346                } else {
1347                        /* Deleted in one and changed in the other */
1348                        clean_merge = 0;
1349                        handle_delete_modify(o, path, path,
1350                                             a_sha, a_mode, b_sha, b_mode);
1351                }
1352
1353        } else if ((!o_sha && a_sha && !b_sha) ||
1354                   (!o_sha && !a_sha && b_sha)) {
1355                /* Case B: Added in one. */
1356                unsigned mode;
1357                const unsigned char *sha;
1358
1359                if (a_sha) {
1360                        mode = a_mode;
1361                        sha = a_sha;
1362                } else {
1363                        mode = b_mode;
1364                        sha = b_sha;
1365                }
1366                if (string_list_has_string(&o->current_directory_set, path)) {
1367                        /* Handle D->F conflicts after all subfiles */
1368                        entry->processed = 0;
1369                        return 1; /* Assume clean until processed */
1370                } else {
1371                        output(o, 2, "Adding %s", path);
1372                        update_file(o, 1, sha, mode, path);
1373                }
1374        } else if (a_sha && b_sha) {
1375                /* Case C: Added in both (check for same permissions) and */
1376                /* case D: Modified in both, but differently. */
1377                clean_merge = merge_content(o, path,
1378                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1379                                            NULL);
1380        } else if (!o_sha && !a_sha && !b_sha) {
1381                /*
1382                 * this entry was deleted altogether. a_mode == 0 means
1383                 * we had that path and want to actively remove it.
1384                 */
1385                remove_file(o, 1, path, !a_mode);
1386        } else
1387                die("Fatal merge failure, shouldn't happen.");
1388
1389        return clean_merge;
1390}
1391
1392/*
1393 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1394 * cases we can cleanly resolve D/F conflicts, process_entry() can
1395 * clean out all the files below the directory for us.  All D/F
1396 * conflict cases must be handled here at the end to make sure any
1397 * directories that can be cleaned out, are.
1398 *
1399 * Some rename conflicts may also be handled here that don't necessarily
1400 * involve D/F conflicts, since the code to handle them is generic enough
1401 * to handle those rename conflicts with or without D/F conflicts also
1402 * being involved.
1403 */
1404static int process_df_entry(struct merge_options *o,
1405                            const char *path, struct stage_data *entry)
1406{
1407        int clean_merge = 1;
1408        unsigned o_mode = entry->stages[1].mode;
1409        unsigned a_mode = entry->stages[2].mode;
1410        unsigned b_mode = entry->stages[3].mode;
1411        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1412        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1413        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1414        struct stat st;
1415
1416        entry->processed = 1;
1417        if (entry->rename_df_conflict_info) {
1418                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1419                char *src;
1420                switch (conflict_info->rename_type) {
1421                case RENAME_NORMAL:
1422                        clean_merge = merge_content(o, path,
1423                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1424                                                    conflict_info->branch1);
1425                        break;
1426                case RENAME_DELETE:
1427                        clean_merge = 0;
1428                        conflict_rename_delete(o, conflict_info->pair1,
1429                                               conflict_info->branch1,
1430                                               conflict_info->branch2);
1431                        break;
1432                case RENAME_ONE_FILE_TO_TWO:
1433                        src = conflict_info->pair1->one->path;
1434                        clean_merge = 0;
1435                        output(o, 1, "CONFLICT (rename/rename): "
1436                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1437                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1438                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1439                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1440                               o->call_depth ? " (left unresolved)" : "");
1441                        if (o->call_depth) {
1442                                remove_file_from_cache(src);
1443                                update_file(o, 0, conflict_info->pair1->one->sha1,
1444                                            conflict_info->pair1->one->mode, src);
1445                        }
1446                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1447                                                    conflict_info->branch1,
1448                                                    conflict_info->pair2,
1449                                                    conflict_info->branch2);
1450                        conflict_info->dst_entry2->processed = 1;
1451                        break;
1452                default:
1453                        entry->processed = 0;
1454                        break;
1455                }
1456        } else if (o_sha && (!a_sha || !b_sha)) {
1457                /* Modify/delete; deleted side may have put a directory in the way */
1458                const char *new_path = path;
1459                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1460                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1461                clean_merge = 0;
1462                handle_delete_modify(o, path, new_path,
1463                                     a_sha, a_mode, b_sha, b_mode);
1464        } else if (!o_sha && !!a_sha != !!b_sha) {
1465                /* directory -> (directory, file) */
1466                const char *add_branch;
1467                const char *other_branch;
1468                unsigned mode;
1469                const unsigned char *sha;
1470                const char *conf;
1471
1472                if (a_sha) {
1473                        add_branch = o->branch1;
1474                        other_branch = o->branch2;
1475                        mode = a_mode;
1476                        sha = a_sha;
1477                        conf = "file/directory";
1478                } else {
1479                        add_branch = o->branch2;
1480                        other_branch = o->branch1;
1481                        mode = b_mode;
1482                        sha = b_sha;
1483                        conf = "directory/file";
1484                }
1485                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1486                        const char *new_path = unique_path(o, path, add_branch);
1487                        clean_merge = 0;
1488                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1489                               "Adding %s as %s",
1490                               conf, path, other_branch, path, new_path);
1491                        update_file(o, 0, sha, mode, new_path);
1492                } else {
1493                        output(o, 2, "Adding %s", path);
1494                        update_file(o, 1, sha, mode, path);
1495                }
1496        } else {
1497                entry->processed = 0;
1498                return 1; /* not handled; assume clean until processed */
1499        }
1500
1501        return clean_merge;
1502}
1503
1504int merge_trees(struct merge_options *o,
1505                struct tree *head,
1506                struct tree *merge,
1507                struct tree *common,
1508                struct tree **result)
1509{
1510        int code, clean;
1511
1512        if (o->subtree_shift) {
1513                merge = shift_tree_object(head, merge, o->subtree_shift);
1514                common = shift_tree_object(head, common, o->subtree_shift);
1515        }
1516
1517        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1518                output(o, 0, "Already up-to-date!");
1519                *result = head;
1520                return 1;
1521        }
1522
1523        code = git_merge_trees(o->call_depth, common, head, merge);
1524
1525        if (code != 0) {
1526                if (show(o, 4) || o->call_depth)
1527                        die("merging of trees %s and %s failed",
1528                            sha1_to_hex(head->object.sha1),
1529                            sha1_to_hex(merge->object.sha1));
1530                else
1531                        exit(128);
1532        }
1533
1534        if (unmerged_cache()) {
1535                struct string_list *entries, *re_head, *re_merge;
1536                int i;
1537                string_list_clear(&o->current_file_set, 1);
1538                string_list_clear(&o->current_directory_set, 1);
1539                get_files_dirs(o, head);
1540                get_files_dirs(o, merge);
1541
1542                entries = get_unmerged();
1543                make_room_for_directories_of_df_conflicts(o, entries);
1544                re_head  = get_renames(o, head, common, head, merge, entries);
1545                re_merge = get_renames(o, merge, common, head, merge, entries);
1546                clean = process_renames(o, re_head, re_merge);
1547                for (i = 0; i < entries->nr; i++) {
1548                        const char *path = entries->items[i].string;
1549                        struct stage_data *e = entries->items[i].util;
1550                        if (!e->processed
1551                                && !process_entry(o, path, e))
1552                                clean = 0;
1553                }
1554                for (i = 0; i < entries->nr; i++) {
1555                        const char *path = entries->items[i].string;
1556                        struct stage_data *e = entries->items[i].util;
1557                        if (!e->processed
1558                                && !process_df_entry(o, path, e))
1559                                clean = 0;
1560                }
1561                for (i = 0; i < entries->nr; i++) {
1562                        struct stage_data *e = entries->items[i].util;
1563                        if (!e->processed)
1564                                die("Unprocessed path??? %s",
1565                                    entries->items[i].string);
1566                }
1567
1568                string_list_clear(re_merge, 0);
1569                string_list_clear(re_head, 0);
1570                string_list_clear(entries, 1);
1571
1572        }
1573        else
1574                clean = 1;
1575
1576        if (o->call_depth)
1577                *result = write_tree_from_memory(o);
1578
1579        return clean;
1580}
1581
1582static struct commit_list *reverse_commit_list(struct commit_list *list)
1583{
1584        struct commit_list *next = NULL, *current, *backup;
1585        for (current = list; current; current = backup) {
1586                backup = current->next;
1587                current->next = next;
1588                next = current;
1589        }
1590        return next;
1591}
1592
1593/*
1594 * Merge the commits h1 and h2, return the resulting virtual
1595 * commit object and a flag indicating the cleanness of the merge.
1596 */
1597int merge_recursive(struct merge_options *o,
1598                    struct commit *h1,
1599                    struct commit *h2,
1600                    struct commit_list *ca,
1601                    struct commit **result)
1602{
1603        struct commit_list *iter;
1604        struct commit *merged_common_ancestors;
1605        struct tree *mrtree = mrtree;
1606        int clean;
1607
1608        if (show(o, 4)) {
1609                output(o, 4, "Merging:");
1610                output_commit_title(o, h1);
1611                output_commit_title(o, h2);
1612        }
1613
1614        if (!ca) {
1615                ca = get_merge_bases(h1, h2, 1);
1616                ca = reverse_commit_list(ca);
1617        }
1618
1619        if (show(o, 5)) {
1620                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1621                for (iter = ca; iter; iter = iter->next)
1622                        output_commit_title(o, iter->item);
1623        }
1624
1625        merged_common_ancestors = pop_commit(&ca);
1626        if (merged_common_ancestors == NULL) {
1627                /* if there is no common ancestor, make an empty tree */
1628                struct tree *tree = xcalloc(1, sizeof(struct tree));
1629
1630                tree->object.parsed = 1;
1631                tree->object.type = OBJ_TREE;
1632                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1633                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1634        }
1635
1636        for (iter = ca; iter; iter = iter->next) {
1637                const char *saved_b1, *saved_b2;
1638                o->call_depth++;
1639                /*
1640                 * When the merge fails, the result contains files
1641                 * with conflict markers. The cleanness flag is
1642                 * ignored, it was never actually used, as result of
1643                 * merge_trees has always overwritten it: the committed
1644                 * "conflicts" were already resolved.
1645                 */
1646                discard_cache();
1647                saved_b1 = o->branch1;
1648                saved_b2 = o->branch2;
1649                o->branch1 = "Temporary merge branch 1";
1650                o->branch2 = "Temporary merge branch 2";
1651                merge_recursive(o, merged_common_ancestors, iter->item,
1652                                NULL, &merged_common_ancestors);
1653                o->branch1 = saved_b1;
1654                o->branch2 = saved_b2;
1655                o->call_depth--;
1656
1657                if (!merged_common_ancestors)
1658                        die("merge returned no commit");
1659        }
1660
1661        discard_cache();
1662        if (!o->call_depth)
1663                read_cache();
1664
1665        o->ancestor = "merged common ancestors";
1666        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1667                            &mrtree);
1668
1669        if (o->call_depth) {
1670                *result = make_virtual_commit(mrtree, "merged tree");
1671                commit_list_insert(h1, &(*result)->parents);
1672                commit_list_insert(h2, &(*result)->parents->next);
1673        }
1674        flush_output(o);
1675        if (o->needed_rename_limit)
1676                warning(rename_limit_advice, o->needed_rename_limit);
1677        return clean;
1678}
1679
1680static struct commit *get_ref(const unsigned char *sha1, const char *name)
1681{
1682        struct object *object;
1683
1684        object = deref_tag(parse_object(sha1), name, strlen(name));
1685        if (!object)
1686                return NULL;
1687        if (object->type == OBJ_TREE)
1688                return make_virtual_commit((struct tree*)object, name);
1689        if (object->type != OBJ_COMMIT)
1690                return NULL;
1691        if (parse_commit((struct commit *)object))
1692                return NULL;
1693        return (struct commit *)object;
1694}
1695
1696int merge_recursive_generic(struct merge_options *o,
1697                            const unsigned char *head,
1698                            const unsigned char *merge,
1699                            int num_base_list,
1700                            const unsigned char **base_list,
1701                            struct commit **result)
1702{
1703        int clean, index_fd;
1704        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1705        struct commit *head_commit = get_ref(head, o->branch1);
1706        struct commit *next_commit = get_ref(merge, o->branch2);
1707        struct commit_list *ca = NULL;
1708
1709        if (base_list) {
1710                int i;
1711                for (i = 0; i < num_base_list; ++i) {
1712                        struct commit *base;
1713                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1714                                return error("Could not parse object '%s'",
1715                                        sha1_to_hex(base_list[i]));
1716                        commit_list_insert(base, &ca);
1717                }
1718        }
1719
1720        index_fd = hold_locked_index(lock, 1);
1721        clean = merge_recursive(o, head_commit, next_commit, ca,
1722                        result);
1723        if (active_cache_changed &&
1724                        (write_cache(index_fd, active_cache, active_nr) ||
1725                         commit_locked_index(lock)))
1726                return error("Unable to write index.");
1727
1728        return clean ? 0 : 1;
1729}
1730
1731static int merge_recursive_config(const char *var, const char *value, void *cb)
1732{
1733        struct merge_options *o = cb;
1734        if (!strcasecmp(var, "merge.verbosity")) {
1735                o->verbosity = git_config_int(var, value);
1736                return 0;
1737        }
1738        if (!strcasecmp(var, "diff.renamelimit")) {
1739                o->diff_rename_limit = git_config_int(var, value);
1740                return 0;
1741        }
1742        if (!strcasecmp(var, "merge.renamelimit")) {
1743                o->merge_rename_limit = git_config_int(var, value);
1744                return 0;
1745        }
1746        return git_xmerge_config(var, value, cb);
1747}
1748
1749void init_merge_options(struct merge_options *o)
1750{
1751        memset(o, 0, sizeof(struct merge_options));
1752        o->verbosity = 2;
1753        o->buffer_output = 1;
1754        o->diff_rename_limit = -1;
1755        o->merge_rename_limit = -1;
1756        o->renormalize = 0;
1757        git_config(merge_recursive_config, o);
1758        if (getenv("GIT_MERGE_VERBOSITY"))
1759                o->verbosity =
1760                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1761        if (o->verbosity >= 5)
1762                o->buffer_output = 0;
1763        strbuf_init(&o->obuf, 0);
1764        memset(&o->current_file_set, 0, sizeof(struct string_list));
1765        o->current_file_set.strdup_strings = 1;
1766        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1767        o->current_directory_set.strdup_strings = 1;
1768}
1769
1770int parse_merge_opt(struct merge_options *o, const char *s)
1771{
1772        if (!s || !*s)
1773                return -1;
1774        if (!strcmp(s, "ours"))
1775                o->recursive_variant = MERGE_RECURSIVE_OURS;
1776        else if (!strcmp(s, "theirs"))
1777                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1778        else if (!strcmp(s, "subtree"))
1779                o->subtree_shift = "";
1780        else if (!prefixcmp(s, "subtree="))
1781                o->subtree_shift = s + strlen("subtree=");
1782        else if (!strcmp(s, "patience"))
1783                o->xdl_opts |= XDF_PATIENCE_DIFF;
1784        else if (!strcmp(s, "ignore-space-change"))
1785                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1786        else if (!strcmp(s, "ignore-all-space"))
1787                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1788        else if (!strcmp(s, "ignore-space-at-eol"))
1789                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1790        else if (!strcmp(s, "renormalize"))
1791                o->renormalize = 1;
1792        else if (!strcmp(s, "no-renormalize"))
1793                o->renormalize = 0;
1794        else if (!prefixcmp(s, "rename-threshold=")) {
1795                const char *score = s + strlen("rename-threshold=");
1796                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1797                        return -1;
1798        }
1799        else
1800                return -1;
1801        return 0;
1802}