merge-recursive.con commit Merge branch 'en/merge-recursive' (ac9666f)
   1/*
   2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
   3 * Fredrik Kuivinen.
   4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
   5 */
   6#include "advice.h"
   7#include "cache.h"
   8#include "cache-tree.h"
   9#include "commit.h"
  10#include "blob.h"
  11#include "builtin.h"
  12#include "tree-walk.h"
  13#include "diff.h"
  14#include "diffcore.h"
  15#include "tag.h"
  16#include "unpack-trees.h"
  17#include "string-list.h"
  18#include "xdiff-interface.h"
  19#include "ll-merge.h"
  20#include "attr.h"
  21#include "merge-recursive.h"
  22#include "dir.h"
  23#include "submodule.h"
  24
  25static const char rename_limit_advice[] =
  26"inexact rename detection was skipped because there were too many\n"
  27"  files. You may want to set your merge.renamelimit variable to at least\n"
  28"  %d and retry this merge.";
  29
  30static struct tree *shift_tree_object(struct tree *one, struct tree *two,
  31                                      const char *subtree_shift)
  32{
  33        unsigned char shifted[20];
  34
  35        if (!*subtree_shift) {
  36                shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
  37        } else {
  38                shift_tree_by(one->object.sha1, two->object.sha1, shifted,
  39                              subtree_shift);
  40        }
  41        if (!hashcmp(two->object.sha1, shifted))
  42                return two;
  43        return lookup_tree(shifted);
  44}
  45
  46/*
  47 * A virtual commit has (const char *)commit->util set to the name.
  48 */
  49
  50static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  51{
  52        struct commit *commit = xcalloc(1, sizeof(struct commit));
  53        commit->tree = tree;
  54        commit->util = (void*)comment;
  55        /* avoid warnings */
  56        commit->object.parsed = 1;
  57        return commit;
  58}
  59
  60/*
  61 * Since we use get_tree_entry(), which does not put the read object into
  62 * the object pool, we cannot rely on a == b.
  63 */
  64static int sha_eq(const unsigned char *a, const unsigned char *b)
  65{
  66        if (!a && !b)
  67                return 2;
  68        return a && b && hashcmp(a, b) == 0;
  69}
  70
  71enum rename_type {
  72        RENAME_NORMAL = 0,
  73        RENAME_DELETE,
  74        RENAME_ONE_FILE_TO_TWO
  75};
  76
  77struct rename_df_conflict_info {
  78        enum rename_type rename_type;
  79        struct diff_filepair *pair1;
  80        struct diff_filepair *pair2;
  81        const char *branch1;
  82        const char *branch2;
  83        struct stage_data *dst_entry1;
  84        struct stage_data *dst_entry2;
  85};
  86
  87/*
  88 * Since we want to write the index eventually, we cannot reuse the index
  89 * for these (temporary) data.
  90 */
  91struct stage_data {
  92        struct {
  93                unsigned mode;
  94                unsigned char sha[20];
  95        } stages[4];
  96        struct rename_df_conflict_info *rename_df_conflict_info;
  97        unsigned processed:1;
  98};
  99
 100static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
 101                                                 struct diff_filepair *pair1,
 102                                                 struct diff_filepair *pair2,
 103                                                 const char *branch1,
 104                                                 const char *branch2,
 105                                                 struct stage_data *dst_entry1,
 106                                                 struct stage_data *dst_entry2)
 107{
 108        struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
 109        ci->rename_type = rename_type;
 110        ci->pair1 = pair1;
 111        ci->branch1 = branch1;
 112        ci->branch2 = branch2;
 113
 114        ci->dst_entry1 = dst_entry1;
 115        dst_entry1->rename_df_conflict_info = ci;
 116        dst_entry1->processed = 0;
 117
 118        assert(!pair2 == !dst_entry2);
 119        if (dst_entry2) {
 120                ci->dst_entry2 = dst_entry2;
 121                ci->pair2 = pair2;
 122                dst_entry2->rename_df_conflict_info = ci;
 123                dst_entry2->processed = 0;
 124        }
 125}
 126
 127static int show(struct merge_options *o, int v)
 128{
 129        return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 130}
 131
 132static void flush_output(struct merge_options *o)
 133{
 134        if (o->obuf.len) {
 135                fputs(o->obuf.buf, stdout);
 136                strbuf_reset(&o->obuf);
 137        }
 138}
 139
 140__attribute__((format (printf, 3, 4)))
 141static void output(struct merge_options *o, int v, const char *fmt, ...)
 142{
 143        va_list ap;
 144
 145        if (!show(o, v))
 146                return;
 147
 148        strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 149        memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 150        strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 151
 152        va_start(ap, fmt);
 153        strbuf_vaddf(&o->obuf, fmt, ap);
 154        va_end(ap);
 155
 156        strbuf_add(&o->obuf, "\n", 1);
 157        if (!o->buffer_output)
 158                flush_output(o);
 159}
 160
 161static void output_commit_title(struct merge_options *o, struct commit *commit)
 162{
 163        int i;
 164        flush_output(o);
 165        for (i = o->call_depth; i--;)
 166                fputs("  ", stdout);
 167        if (commit->util)
 168                printf("virtual %s\n", (char *)commit->util);
 169        else {
 170                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 171                if (parse_commit(commit) != 0)
 172                        printf("(bad commit)\n");
 173                else {
 174                        const char *title;
 175                        int len = find_commit_subject(commit->buffer, &title);
 176                        if (len)
 177                                printf("%.*s\n", len, title);
 178                }
 179        }
 180}
 181
 182static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 183                const char *path, int stage, int refresh, int options)
 184{
 185        struct cache_entry *ce;
 186        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 187        if (!ce)
 188                return error("addinfo_cache failed for path '%s'", path);
 189        return add_cache_entry(ce, options);
 190}
 191
 192static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 193{
 194        parse_tree(tree);
 195        init_tree_desc(desc, tree->buffer, tree->size);
 196}
 197
 198static int git_merge_trees(int index_only,
 199                           struct tree *common,
 200                           struct tree *head,
 201                           struct tree *merge)
 202{
 203        int rc;
 204        struct tree_desc t[3];
 205        struct unpack_trees_options opts;
 206
 207        memset(&opts, 0, sizeof(opts));
 208        if (index_only)
 209                opts.index_only = 1;
 210        else
 211                opts.update = 1;
 212        opts.merge = 1;
 213        opts.head_idx = 2;
 214        opts.fn = threeway_merge;
 215        opts.src_index = &the_index;
 216        opts.dst_index = &the_index;
 217        setup_unpack_trees_porcelain(&opts, "merge");
 218
 219        init_tree_desc_from_tree(t+0, common);
 220        init_tree_desc_from_tree(t+1, head);
 221        init_tree_desc_from_tree(t+2, merge);
 222
 223        rc = unpack_trees(3, t, &opts);
 224        cache_tree_free(&active_cache_tree);
 225        return rc;
 226}
 227
 228struct tree *write_tree_from_memory(struct merge_options *o)
 229{
 230        struct tree *result = NULL;
 231
 232        if (unmerged_cache()) {
 233                int i;
 234                fprintf(stderr, "BUG: There are unmerged index entries:\n");
 235                for (i = 0; i < active_nr; i++) {
 236                        struct cache_entry *ce = active_cache[i];
 237                        if (ce_stage(ce))
 238                                fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
 239                                        (int)ce_namelen(ce), ce->name);
 240                }
 241                die("Bug in merge-recursive.c");
 242        }
 243
 244        if (!active_cache_tree)
 245                active_cache_tree = cache_tree();
 246
 247        if (!cache_tree_fully_valid(active_cache_tree) &&
 248            cache_tree_update(active_cache_tree,
 249                              active_cache, active_nr, 0, 0) < 0)
 250                die("error building trees");
 251
 252        result = lookup_tree(active_cache_tree->sha1);
 253
 254        return result;
 255}
 256
 257static int save_files_dirs(const unsigned char *sha1,
 258                const char *base, int baselen, const char *path,
 259                unsigned int mode, int stage, void *context)
 260{
 261        int len = strlen(path);
 262        char *newpath = xmalloc(baselen + len + 1);
 263        struct merge_options *o = context;
 264
 265        memcpy(newpath, base, baselen);
 266        memcpy(newpath + baselen, path, len);
 267        newpath[baselen + len] = '\0';
 268
 269        if (S_ISDIR(mode))
 270                string_list_insert(&o->current_directory_set, newpath);
 271        else
 272                string_list_insert(&o->current_file_set, newpath);
 273        free(newpath);
 274
 275        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 276}
 277
 278static int get_files_dirs(struct merge_options *o, struct tree *tree)
 279{
 280        int n;
 281        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 282                return 0;
 283        n = o->current_file_set.nr + o->current_directory_set.nr;
 284        return n;
 285}
 286
 287/*
 288 * Returns an index_entry instance which doesn't have to correspond to
 289 * a real cache entry in Git's index.
 290 */
 291static struct stage_data *insert_stage_data(const char *path,
 292                struct tree *o, struct tree *a, struct tree *b,
 293                struct string_list *entries)
 294{
 295        struct string_list_item *item;
 296        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 297        get_tree_entry(o->object.sha1, path,
 298                        e->stages[1].sha, &e->stages[1].mode);
 299        get_tree_entry(a->object.sha1, path,
 300                        e->stages[2].sha, &e->stages[2].mode);
 301        get_tree_entry(b->object.sha1, path,
 302                        e->stages[3].sha, &e->stages[3].mode);
 303        item = string_list_insert(entries, path);
 304        item->util = e;
 305        return e;
 306}
 307
 308/*
 309 * Create a dictionary mapping file names to stage_data objects. The
 310 * dictionary contains one entry for every path with a non-zero stage entry.
 311 */
 312static struct string_list *get_unmerged(void)
 313{
 314        struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 315        int i;
 316
 317        unmerged->strdup_strings = 1;
 318
 319        for (i = 0; i < active_nr; i++) {
 320                struct string_list_item *item;
 321                struct stage_data *e;
 322                struct cache_entry *ce = active_cache[i];
 323                if (!ce_stage(ce))
 324                        continue;
 325
 326                item = string_list_lookup(unmerged, ce->name);
 327                if (!item) {
 328                        item = string_list_insert(unmerged, ce->name);
 329                        item->util = xcalloc(1, sizeof(struct stage_data));
 330                }
 331                e = item->util;
 332                e->stages[ce_stage(ce)].mode = ce->ce_mode;
 333                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 334        }
 335
 336        return unmerged;
 337}
 338
 339static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
 340                                                      struct string_list *entries)
 341{
 342        /* If there are D/F conflicts, and the paths currently exist
 343         * in the working copy as a file, we want to remove them to
 344         * make room for the corresponding directory.  Such paths will
 345         * later be processed in process_df_entry() at the end.  If
 346         * the corresponding directory ends up being removed by the
 347         * merge, then the file will be reinstated at that time
 348         * (albeit with a different timestamp!); otherwise, if the
 349         * file is not supposed to be removed by the merge, the
 350         * contents of the file will be placed in another unique
 351         * filename.
 352         *
 353         * NOTE: This function relies on the fact that entries for a
 354         * D/F conflict will appear adjacent in the index, with the
 355         * entries for the file appearing before entries for paths
 356         * below the corresponding directory.
 357         */
 358        const char *last_file = NULL;
 359        int last_len = 0;
 360        int i;
 361
 362        /*
 363         * Do not do any of this crazyness during the recursive; we don't
 364         * even write anything to the working tree!
 365         */
 366        if (o->call_depth)
 367                return;
 368
 369        for (i = 0; i < entries->nr; i++) {
 370                const char *path = entries->items[i].string;
 371                int len = strlen(path);
 372                struct stage_data *e = entries->items[i].util;
 373
 374                /*
 375                 * Check if last_file & path correspond to a D/F conflict;
 376                 * i.e. whether path is last_file+'/'+<something>.
 377                 * If so, remove last_file to make room for path and friends.
 378                 */
 379                if (last_file &&
 380                    len > last_len &&
 381                    memcmp(path, last_file, last_len) == 0 &&
 382                    path[last_len] == '/') {
 383                        output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
 384                        unlink(last_file);
 385                }
 386
 387                /*
 388                 * Determine whether path could exist as a file in the
 389                 * working directory as a possible D/F conflict.  This
 390                 * will only occur when it exists in stage 2 as a
 391                 * file.
 392                 */
 393                if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
 394                        last_file = path;
 395                        last_len = len;
 396                } else {
 397                        last_file = NULL;
 398                }
 399        }
 400}
 401
 402struct rename {
 403        struct diff_filepair *pair;
 404        struct stage_data *src_entry;
 405        struct stage_data *dst_entry;
 406        unsigned processed:1;
 407};
 408
 409/*
 410 * Get information of all renames which occurred between 'o_tree' and
 411 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 412 * 'b_tree') to be able to associate the correct cache entries with
 413 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 414 */
 415static struct string_list *get_renames(struct merge_options *o,
 416                                       struct tree *tree,
 417                                       struct tree *o_tree,
 418                                       struct tree *a_tree,
 419                                       struct tree *b_tree,
 420                                       struct string_list *entries)
 421{
 422        int i;
 423        struct string_list *renames;
 424        struct diff_options opts;
 425
 426        renames = xcalloc(1, sizeof(struct string_list));
 427        diff_setup(&opts);
 428        DIFF_OPT_SET(&opts, RECURSIVE);
 429        opts.detect_rename = DIFF_DETECT_RENAME;
 430        opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 431                            o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 432                            1000;
 433        opts.rename_score = o->rename_score;
 434        opts.show_rename_progress = o->show_rename_progress;
 435        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 436        if (diff_setup_done(&opts) < 0)
 437                die("diff setup failed");
 438        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 439        diffcore_std(&opts);
 440        if (opts.needed_rename_limit > o->needed_rename_limit)
 441                o->needed_rename_limit = opts.needed_rename_limit;
 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                struct string_list *renames1, *renames2Dst;
 971                struct rename *ren1 = NULL, *ren2 = NULL;
 972                const char *branch1, *branch2;
 973                const char *ren1_src, *ren1_dst;
 974
 975                if (i >= a_renames->nr) {
 976                        ren2 = b_renames->items[j++].util;
 977                } else if (j >= b_renames->nr) {
 978                        ren1 = a_renames->items[i++].util;
 979                } else {
 980                        int compare = strcmp(a_renames->items[i].string,
 981                                             b_renames->items[j].string);
 982                        if (compare <= 0)
 983                                ren1 = a_renames->items[i++].util;
 984                        if (compare >= 0)
 985                                ren2 = b_renames->items[j++].util;
 986                }
 987
 988                /* TODO: refactor, so that 1/2 are not needed */
 989                if (ren1) {
 990                        renames1 = a_renames;
 991                        renames2Dst = &b_by_dst;
 992                        branch1 = o->branch1;
 993                        branch2 = o->branch2;
 994                } else {
 995                        struct rename *tmp;
 996                        renames1 = b_renames;
 997                        renames2Dst = &a_by_dst;
 998                        branch1 = o->branch2;
 999                        branch2 = o->branch1;
1000                        tmp = ren2;
1001                        ren2 = ren1;
1002                        ren1 = tmp;
1003                }
1004
1005                ren1->dst_entry->processed = 1;
1006                ren1->src_entry->processed = 1;
1007
1008                if (ren1->processed)
1009                        continue;
1010                ren1->processed = 1;
1011
1012                ren1_src = ren1->pair->one->path;
1013                ren1_dst = ren1->pair->two->path;
1014
1015                if (ren2) {
1016                        const char *ren2_src = ren2->pair->one->path;
1017                        const char *ren2_dst = ren2->pair->two->path;
1018                        /* Renamed in 1 and renamed in 2 */
1019                        if (strcmp(ren1_src, ren2_src) != 0)
1020                                die("ren1.src != ren2.src");
1021                        ren2->dst_entry->processed = 1;
1022                        ren2->processed = 1;
1023                        if (strcmp(ren1_dst, ren2_dst) != 0) {
1024                                setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1025                                                              ren1->pair,
1026                                                              ren2->pair,
1027                                                              branch1,
1028                                                              branch2,
1029                                                              ren1->dst_entry,
1030                                                              ren2->dst_entry);
1031                        } else {
1032                                remove_file(o, 1, ren1_src, 1);
1033                                update_stages_and_entry(ren1_dst,
1034                                                        ren1->dst_entry,
1035                                                        ren1->pair->one,
1036                                                        ren1->pair->two,
1037                                                        ren2->pair->two,
1038                                                        1 /* clear */);
1039                        }
1040                } else {
1041                        /* Renamed in 1, maybe changed in 2 */
1042                        struct string_list_item *item;
1043                        /* we only use sha1 and mode of these */
1044                        struct diff_filespec src_other, dst_other;
1045                        int try_merge;
1046
1047                        /*
1048                         * unpack_trees loads entries from common-commit
1049                         * into stage 1, from head-commit into stage 2, and
1050                         * from merge-commit into stage 3.  We keep track
1051                         * of which side corresponds to the rename.
1052                         */
1053                        int renamed_stage = a_renames == renames1 ? 2 : 3;
1054                        int other_stage =   a_renames == renames1 ? 3 : 2;
1055
1056                        remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1057
1058                        hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1059                        src_other.mode = ren1->src_entry->stages[other_stage].mode;
1060                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1061                        dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1062                        try_merge = 0;
1063
1064                        if (sha_eq(src_other.sha1, null_sha1)) {
1065                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1066                                        ren1->dst_entry->processed = 0;
1067                                        setup_rename_df_conflict_info(RENAME_DELETE,
1068                                                                      ren1->pair,
1069                                                                      NULL,
1070                                                                      branch1,
1071                                                                      branch2,
1072                                                                      ren1->dst_entry,
1073                                                                      NULL);
1074                                } else {
1075                                        clean_merge = 0;
1076                                        conflict_rename_delete(o, ren1->pair, branch1, branch2);
1077                                }
1078                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
1079                                   sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1080                                /* Added file on the other side
1081                                   identical to the file being
1082                                   renamed: clean merge */
1083                                update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1084                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1085                                const char *new_path;
1086                                clean_merge = 0;
1087                                try_merge = 1;
1088                                output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1089                                       "%s added in %s",
1090                                       ren1_src, ren1_dst, branch1,
1091                                       ren1_dst, branch2);
1092                                if (o->call_depth) {
1093                                        struct merge_file_info mfi;
1094                                        struct diff_filespec one, a, b;
1095
1096                                        one.path = a.path = b.path =
1097                                                (char *)ren1_dst;
1098                                        hashcpy(one.sha1, null_sha1);
1099                                        one.mode = 0;
1100                                        hashcpy(a.sha1, ren1->pair->two->sha1);
1101                                        a.mode = ren1->pair->two->mode;
1102                                        hashcpy(b.sha1, dst_other.sha1);
1103                                        b.mode = dst_other.mode;
1104                                        mfi = merge_file(o, &one, &a, &b,
1105                                                         branch1,
1106                                                         branch2);
1107                                        output(o, 1, "Adding merged %s", ren1_dst);
1108                                        update_file(o, 0,
1109                                                    mfi.sha,
1110                                                    mfi.mode,
1111                                                    ren1_dst);
1112                                        try_merge = 0;
1113                                } else {
1114                                        new_path = unique_path(o, ren1_dst, branch2);
1115                                        output(o, 1, "Adding as %s instead", new_path);
1116                                        update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1117                                }
1118                        } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1119                                ren2 = item->util;
1120                                clean_merge = 0;
1121                                ren2->processed = 1;
1122                                output(o, 1, "CONFLICT (rename/rename): "
1123                                       "Rename %s->%s in %s. "
1124                                       "Rename %s->%s in %s",
1125                                       ren1_src, ren1_dst, branch1,
1126                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
1127                                conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1128                        } else
1129                                try_merge = 1;
1130
1131                        if (try_merge) {
1132                                struct diff_filespec *one, *a, *b;
1133                                src_other.path = (char *)ren1_src;
1134
1135                                one = ren1->pair->one;
1136                                if (a_renames == renames1) {
1137                                        a = ren1->pair->two;
1138                                        b = &src_other;
1139                                } else {
1140                                        b = ren1->pair->two;
1141                                        a = &src_other;
1142                                }
1143                                update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1144                                if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1145                                        setup_rename_df_conflict_info(RENAME_NORMAL,
1146                                                                      ren1->pair,
1147                                                                      NULL,
1148                                                                      branch1,
1149                                                                      NULL,
1150                                                                      ren1->dst_entry,
1151                                                                      NULL);
1152                                }
1153                        }
1154                }
1155        }
1156        string_list_clear(&a_by_dst, 0);
1157        string_list_clear(&b_by_dst, 0);
1158
1159        return clean_merge;
1160}
1161
1162static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1163{
1164        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1165}
1166
1167static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1168{
1169        void *buf;
1170        enum object_type type;
1171        unsigned long size;
1172        buf = read_sha1_file(sha1, &type, &size);
1173        if (!buf)
1174                return error("cannot read object %s", sha1_to_hex(sha1));
1175        if (type != OBJ_BLOB) {
1176                free(buf);
1177                return error("object %s is not a blob", sha1_to_hex(sha1));
1178        }
1179        strbuf_attach(dst, buf, size, size + 1);
1180        return 0;
1181}
1182
1183static int blob_unchanged(const unsigned char *o_sha,
1184                          const unsigned char *a_sha,
1185                          int renormalize, const char *path)
1186{
1187        struct strbuf o = STRBUF_INIT;
1188        struct strbuf a = STRBUF_INIT;
1189        int ret = 0; /* assume changed for safety */
1190
1191        if (sha_eq(o_sha, a_sha))
1192                return 1;
1193        if (!renormalize)
1194                return 0;
1195
1196        assert(o_sha && a_sha);
1197        if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1198                goto error_return;
1199        /*
1200         * Note: binary | is used so that both renormalizations are
1201         * performed.  Comparison can be skipped if both files are
1202         * unchanged since their sha1s have already been compared.
1203         */
1204        if (renormalize_buffer(path, o.buf, o.len, &o) |
1205            renormalize_buffer(path, a.buf, o.len, &a))
1206                ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1207
1208error_return:
1209        strbuf_release(&o);
1210        strbuf_release(&a);
1211        return ret;
1212}
1213
1214static void handle_delete_modify(struct merge_options *o,
1215                                 const char *path,
1216                                 const char *new_path,
1217                                 unsigned char *a_sha, int a_mode,
1218                                 unsigned char *b_sha, int b_mode)
1219{
1220        if (!a_sha) {
1221                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1222                       "and modified in %s. Version %s of %s left in tree%s%s.",
1223                       path, o->branch1,
1224                       o->branch2, o->branch2, path,
1225                       path == new_path ? "" : " at ",
1226                       path == new_path ? "" : new_path);
1227                update_file(o, 0, b_sha, b_mode, new_path);
1228        } else {
1229                output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1230                       "and modified in %s. Version %s of %s left in tree%s%s.",
1231                       path, o->branch2,
1232                       o->branch1, o->branch1, path,
1233                       path == new_path ? "" : " at ",
1234                       path == new_path ? "" : new_path);
1235                update_file(o, 0, a_sha, a_mode, new_path);
1236        }
1237}
1238
1239static int merge_content(struct merge_options *o,
1240                         const char *path,
1241                         unsigned char *o_sha, int o_mode,
1242                         unsigned char *a_sha, int a_mode,
1243                         unsigned char *b_sha, int b_mode,
1244                         const char *df_rename_conflict_branch)
1245{
1246        const char *reason = "content";
1247        struct merge_file_info mfi;
1248        struct diff_filespec one, a, b;
1249        struct stat st;
1250        unsigned df_conflict_remains = 0;
1251
1252        if (!o_sha) {
1253                reason = "add/add";
1254                o_sha = (unsigned char *)null_sha1;
1255        }
1256        one.path = a.path = b.path = (char *)path;
1257        hashcpy(one.sha1, o_sha);
1258        one.mode = o_mode;
1259        hashcpy(a.sha1, a_sha);
1260        a.mode = a_mode;
1261        hashcpy(b.sha1, b_sha);
1262        b.mode = b_mode;
1263
1264        mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1265        if (df_rename_conflict_branch &&
1266            lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1267                df_conflict_remains = 1;
1268        }
1269
1270        if (mfi.clean && !df_conflict_remains &&
1271            sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode &&
1272            !o->call_depth && !lstat(path, &st)) {
1273                output(o, 3, "Skipped %s (merged same as existing)", path);
1274                add_cacheinfo(mfi.mode, mfi.sha, path,
1275                              0 /*stage*/, 1 /*refresh*/, 0 /*options*/);
1276                return mfi.clean;
1277        } else
1278                output(o, 2, "Auto-merging %s", path);
1279
1280        if (!mfi.clean) {
1281                if (S_ISGITLINK(mfi.mode))
1282                        reason = "submodule";
1283                output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1284                                reason, path);
1285        }
1286
1287        if (df_conflict_remains) {
1288                const char *new_path;
1289                update_file_flags(o, mfi.sha, mfi.mode, path,
1290                                  o->call_depth || mfi.clean, 0);
1291                new_path = unique_path(o, path, df_rename_conflict_branch);
1292                mfi.clean = 0;
1293                output(o, 1, "Adding as %s instead", new_path);
1294                update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1295        } else {
1296                update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1297        }
1298        return mfi.clean;
1299
1300}
1301
1302/* Per entry merge function */
1303static int process_entry(struct merge_options *o,
1304                         const char *path, struct stage_data *entry)
1305{
1306        /*
1307        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1308        print_index_entry("\tpath: ", entry);
1309        */
1310        int clean_merge = 1;
1311        int normalize = o->renormalize;
1312        unsigned o_mode = entry->stages[1].mode;
1313        unsigned a_mode = entry->stages[2].mode;
1314        unsigned b_mode = entry->stages[3].mode;
1315        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1316        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1317        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1318
1319        if (entry->rename_df_conflict_info)
1320                return 1; /* Such cases are handled elsewhere. */
1321
1322        entry->processed = 1;
1323        if (o_sha && (!a_sha || !b_sha)) {
1324                /* Case A: Deleted in one */
1325                if ((!a_sha && !b_sha) ||
1326                    (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1327                    (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1328                        /* Deleted in both or deleted in one and
1329                         * unchanged in the other */
1330                        if (a_sha)
1331                                output(o, 2, "Removing %s", path);
1332                        /* do not touch working file if it did not exist */
1333                        remove_file(o, 1, path, !a_sha);
1334                } else if (string_list_has_string(&o->current_directory_set,
1335                                                  path)) {
1336                        entry->processed = 0;
1337                        return 1; /* Assume clean until processed */
1338                } else {
1339                        /* Deleted in one and changed in the other */
1340                        clean_merge = 0;
1341                        handle_delete_modify(o, path, path,
1342                                             a_sha, a_mode, b_sha, b_mode);
1343                }
1344
1345        } else if ((!o_sha && a_sha && !b_sha) ||
1346                   (!o_sha && !a_sha && b_sha)) {
1347                /* Case B: Added in one. */
1348                unsigned mode;
1349                const unsigned char *sha;
1350
1351                if (a_sha) {
1352                        mode = a_mode;
1353                        sha = a_sha;
1354                } else {
1355                        mode = b_mode;
1356                        sha = b_sha;
1357                }
1358                if (string_list_has_string(&o->current_directory_set, path)) {
1359                        /* Handle D->F conflicts after all subfiles */
1360                        entry->processed = 0;
1361                        return 1; /* Assume clean until processed */
1362                } else {
1363                        output(o, 2, "Adding %s", path);
1364                        update_file(o, 1, sha, mode, path);
1365                }
1366        } else if (a_sha && b_sha) {
1367                /* Case C: Added in both (check for same permissions) and */
1368                /* case D: Modified in both, but differently. */
1369                clean_merge = merge_content(o, path,
1370                                            o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1371                                            NULL);
1372        } else if (!o_sha && !a_sha && !b_sha) {
1373                /*
1374                 * this entry was deleted altogether. a_mode == 0 means
1375                 * we had that path and want to actively remove it.
1376                 */
1377                remove_file(o, 1, path, !a_mode);
1378        } else
1379                die("Fatal merge failure, shouldn't happen.");
1380
1381        return clean_merge;
1382}
1383
1384/*
1385 * Per entry merge function for D/F (and/or rename) conflicts.  In the
1386 * cases we can cleanly resolve D/F conflicts, process_entry() can
1387 * clean out all the files below the directory for us.  All D/F
1388 * conflict cases must be handled here at the end to make sure any
1389 * directories that can be cleaned out, are.
1390 *
1391 * Some rename conflicts may also be handled here that don't necessarily
1392 * involve D/F conflicts, since the code to handle them is generic enough
1393 * to handle those rename conflicts with or without D/F conflicts also
1394 * being involved.
1395 */
1396static int process_df_entry(struct merge_options *o,
1397                            const char *path, struct stage_data *entry)
1398{
1399        int clean_merge = 1;
1400        unsigned o_mode = entry->stages[1].mode;
1401        unsigned a_mode = entry->stages[2].mode;
1402        unsigned b_mode = entry->stages[3].mode;
1403        unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1404        unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1405        unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1406        struct stat st;
1407
1408        entry->processed = 1;
1409        if (entry->rename_df_conflict_info) {
1410                struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1411                char *src;
1412                switch (conflict_info->rename_type) {
1413                case RENAME_NORMAL:
1414                        clean_merge = merge_content(o, path,
1415                                                    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1416                                                    conflict_info->branch1);
1417                        break;
1418                case RENAME_DELETE:
1419                        clean_merge = 0;
1420                        conflict_rename_delete(o, conflict_info->pair1,
1421                                               conflict_info->branch1,
1422                                               conflict_info->branch2);
1423                        break;
1424                case RENAME_ONE_FILE_TO_TWO:
1425                        src = conflict_info->pair1->one->path;
1426                        clean_merge = 0;
1427                        output(o, 1, "CONFLICT (rename/rename): "
1428                               "Rename \"%s\"->\"%s\" in branch \"%s\" "
1429                               "rename \"%s\"->\"%s\" in \"%s\"%s",
1430                               src, conflict_info->pair1->two->path, conflict_info->branch1,
1431                               src, conflict_info->pair2->two->path, conflict_info->branch2,
1432                               o->call_depth ? " (left unresolved)" : "");
1433                        if (o->call_depth) {
1434                                remove_file_from_cache(src);
1435                                update_file(o, 0, conflict_info->pair1->one->sha1,
1436                                            conflict_info->pair1->one->mode, src);
1437                        }
1438                        conflict_rename_rename_1to2(o, conflict_info->pair1,
1439                                                    conflict_info->branch1,
1440                                                    conflict_info->pair2,
1441                                                    conflict_info->branch2);
1442                        conflict_info->dst_entry2->processed = 1;
1443                        break;
1444                default:
1445                        entry->processed = 0;
1446                        break;
1447                }
1448        } else if (o_sha && (!a_sha || !b_sha)) {
1449                /* Modify/delete; deleted side may have put a directory in the way */
1450                const char *new_path = path;
1451                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1452                        new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1453                clean_merge = 0;
1454                handle_delete_modify(o, path, new_path,
1455                                     a_sha, a_mode, b_sha, b_mode);
1456        } else if (!o_sha && !!a_sha != !!b_sha) {
1457                /* directory -> (directory, file) */
1458                const char *add_branch;
1459                const char *other_branch;
1460                unsigned mode;
1461                const unsigned char *sha;
1462                const char *conf;
1463
1464                if (a_sha) {
1465                        add_branch = o->branch1;
1466                        other_branch = o->branch2;
1467                        mode = a_mode;
1468                        sha = a_sha;
1469                        conf = "file/directory";
1470                } else {
1471                        add_branch = o->branch2;
1472                        other_branch = o->branch1;
1473                        mode = b_mode;
1474                        sha = b_sha;
1475                        conf = "directory/file";
1476                }
1477                if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1478                        const char *new_path = unique_path(o, path, add_branch);
1479                        clean_merge = 0;
1480                        output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1481                               "Adding %s as %s",
1482                               conf, path, other_branch, path, new_path);
1483                        update_file(o, 0, sha, mode, new_path);
1484                } else {
1485                        output(o, 2, "Adding %s", path);
1486                        update_file(o, 1, sha, mode, path);
1487                }
1488        } else {
1489                entry->processed = 0;
1490                return 1; /* not handled; assume clean until processed */
1491        }
1492
1493        return clean_merge;
1494}
1495
1496int merge_trees(struct merge_options *o,
1497                struct tree *head,
1498                struct tree *merge,
1499                struct tree *common,
1500                struct tree **result)
1501{
1502        int code, clean;
1503
1504        if (o->subtree_shift) {
1505                merge = shift_tree_object(head, merge, o->subtree_shift);
1506                common = shift_tree_object(head, common, o->subtree_shift);
1507        }
1508
1509        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1510                output(o, 0, "Already up-to-date!");
1511                *result = head;
1512                return 1;
1513        }
1514
1515        code = git_merge_trees(o->call_depth, common, head, merge);
1516
1517        if (code != 0) {
1518                if (show(o, 4) || o->call_depth)
1519                        die("merging of trees %s and %s failed",
1520                            sha1_to_hex(head->object.sha1),
1521                            sha1_to_hex(merge->object.sha1));
1522                else
1523                        exit(128);
1524        }
1525
1526        if (unmerged_cache()) {
1527                struct string_list *entries, *re_head, *re_merge;
1528                int i;
1529                string_list_clear(&o->current_file_set, 1);
1530                string_list_clear(&o->current_directory_set, 1);
1531                get_files_dirs(o, head);
1532                get_files_dirs(o, merge);
1533
1534                entries = get_unmerged();
1535                make_room_for_directories_of_df_conflicts(o, entries);
1536                re_head  = get_renames(o, head, common, head, merge, entries);
1537                re_merge = get_renames(o, merge, common, head, merge, entries);
1538                clean = process_renames(o, re_head, re_merge);
1539                for (i = 0; i < entries->nr; i++) {
1540                        const char *path = entries->items[i].string;
1541                        struct stage_data *e = entries->items[i].util;
1542                        if (!e->processed
1543                                && !process_entry(o, path, e))
1544                                clean = 0;
1545                }
1546                for (i = 0; i < entries->nr; i++) {
1547                        const char *path = entries->items[i].string;
1548                        struct stage_data *e = entries->items[i].util;
1549                        if (!e->processed
1550                                && !process_df_entry(o, path, e))
1551                                clean = 0;
1552                }
1553                for (i = 0; i < entries->nr; i++) {
1554                        struct stage_data *e = entries->items[i].util;
1555                        if (!e->processed)
1556                                die("Unprocessed path??? %s",
1557                                    entries->items[i].string);
1558                }
1559
1560                string_list_clear(re_merge, 0);
1561                string_list_clear(re_head, 0);
1562                string_list_clear(entries, 1);
1563
1564        }
1565        else
1566                clean = 1;
1567
1568        if (o->call_depth)
1569                *result = write_tree_from_memory(o);
1570
1571        return clean;
1572}
1573
1574static struct commit_list *reverse_commit_list(struct commit_list *list)
1575{
1576        struct commit_list *next = NULL, *current, *backup;
1577        for (current = list; current; current = backup) {
1578                backup = current->next;
1579                current->next = next;
1580                next = current;
1581        }
1582        return next;
1583}
1584
1585/*
1586 * Merge the commits h1 and h2, return the resulting virtual
1587 * commit object and a flag indicating the cleanness of the merge.
1588 */
1589int merge_recursive(struct merge_options *o,
1590                    struct commit *h1,
1591                    struct commit *h2,
1592                    struct commit_list *ca,
1593                    struct commit **result)
1594{
1595        struct commit_list *iter;
1596        struct commit *merged_common_ancestors;
1597        struct tree *mrtree = mrtree;
1598        int clean;
1599
1600        if (show(o, 4)) {
1601                output(o, 4, "Merging:");
1602                output_commit_title(o, h1);
1603                output_commit_title(o, h2);
1604        }
1605
1606        if (!ca) {
1607                ca = get_merge_bases(h1, h2, 1);
1608                ca = reverse_commit_list(ca);
1609        }
1610
1611        if (show(o, 5)) {
1612                output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1613                for (iter = ca; iter; iter = iter->next)
1614                        output_commit_title(o, iter->item);
1615        }
1616
1617        merged_common_ancestors = pop_commit(&ca);
1618        if (merged_common_ancestors == NULL) {
1619                /* if there is no common ancestor, make an empty tree */
1620                struct tree *tree = xcalloc(1, sizeof(struct tree));
1621
1622                tree->object.parsed = 1;
1623                tree->object.type = OBJ_TREE;
1624                pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1625                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1626        }
1627
1628        for (iter = ca; iter; iter = iter->next) {
1629                const char *saved_b1, *saved_b2;
1630                o->call_depth++;
1631                /*
1632                 * When the merge fails, the result contains files
1633                 * with conflict markers. The cleanness flag is
1634                 * ignored, it was never actually used, as result of
1635                 * merge_trees has always overwritten it: the committed
1636                 * "conflicts" were already resolved.
1637                 */
1638                discard_cache();
1639                saved_b1 = o->branch1;
1640                saved_b2 = o->branch2;
1641                o->branch1 = "Temporary merge branch 1";
1642                o->branch2 = "Temporary merge branch 2";
1643                merge_recursive(o, merged_common_ancestors, iter->item,
1644                                NULL, &merged_common_ancestors);
1645                o->branch1 = saved_b1;
1646                o->branch2 = saved_b2;
1647                o->call_depth--;
1648
1649                if (!merged_common_ancestors)
1650                        die("merge returned no commit");
1651        }
1652
1653        discard_cache();
1654        if (!o->call_depth)
1655                read_cache();
1656
1657        o->ancestor = "merged common ancestors";
1658        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1659                            &mrtree);
1660
1661        if (o->call_depth) {
1662                *result = make_virtual_commit(mrtree, "merged tree");
1663                commit_list_insert(h1, &(*result)->parents);
1664                commit_list_insert(h2, &(*result)->parents->next);
1665        }
1666        flush_output(o);
1667        if (o->needed_rename_limit)
1668                warning(rename_limit_advice, o->needed_rename_limit);
1669        return clean;
1670}
1671
1672static struct commit *get_ref(const unsigned char *sha1, const char *name)
1673{
1674        struct object *object;
1675
1676        object = deref_tag(parse_object(sha1), name, strlen(name));
1677        if (!object)
1678                return NULL;
1679        if (object->type == OBJ_TREE)
1680                return make_virtual_commit((struct tree*)object, name);
1681        if (object->type != OBJ_COMMIT)
1682                return NULL;
1683        if (parse_commit((struct commit *)object))
1684                return NULL;
1685        return (struct commit *)object;
1686}
1687
1688int merge_recursive_generic(struct merge_options *o,
1689                            const unsigned char *head,
1690                            const unsigned char *merge,
1691                            int num_base_list,
1692                            const unsigned char **base_list,
1693                            struct commit **result)
1694{
1695        int clean, index_fd;
1696        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1697        struct commit *head_commit = get_ref(head, o->branch1);
1698        struct commit *next_commit = get_ref(merge, o->branch2);
1699        struct commit_list *ca = NULL;
1700
1701        if (base_list) {
1702                int i;
1703                for (i = 0; i < num_base_list; ++i) {
1704                        struct commit *base;
1705                        if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1706                                return error("Could not parse object '%s'",
1707                                        sha1_to_hex(base_list[i]));
1708                        commit_list_insert(base, &ca);
1709                }
1710        }
1711
1712        index_fd = hold_locked_index(lock, 1);
1713        clean = merge_recursive(o, head_commit, next_commit, ca,
1714                        result);
1715        if (active_cache_changed &&
1716                        (write_cache(index_fd, active_cache, active_nr) ||
1717                         commit_locked_index(lock)))
1718                return error("Unable to write index.");
1719
1720        return clean ? 0 : 1;
1721}
1722
1723static int merge_recursive_config(const char *var, const char *value, void *cb)
1724{
1725        struct merge_options *o = cb;
1726        if (!strcasecmp(var, "merge.verbosity")) {
1727                o->verbosity = git_config_int(var, value);
1728                return 0;
1729        }
1730        if (!strcasecmp(var, "diff.renamelimit")) {
1731                o->diff_rename_limit = git_config_int(var, value);
1732                return 0;
1733        }
1734        if (!strcasecmp(var, "merge.renamelimit")) {
1735                o->merge_rename_limit = git_config_int(var, value);
1736                return 0;
1737        }
1738        return git_xmerge_config(var, value, cb);
1739}
1740
1741void init_merge_options(struct merge_options *o)
1742{
1743        memset(o, 0, sizeof(struct merge_options));
1744        o->verbosity = 2;
1745        o->buffer_output = 1;
1746        o->diff_rename_limit = -1;
1747        o->merge_rename_limit = -1;
1748        o->renormalize = 0;
1749        git_config(merge_recursive_config, o);
1750        if (getenv("GIT_MERGE_VERBOSITY"))
1751                o->verbosity =
1752                        strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1753        if (o->verbosity >= 5)
1754                o->buffer_output = 0;
1755        strbuf_init(&o->obuf, 0);
1756        memset(&o->current_file_set, 0, sizeof(struct string_list));
1757        o->current_file_set.strdup_strings = 1;
1758        memset(&o->current_directory_set, 0, sizeof(struct string_list));
1759        o->current_directory_set.strdup_strings = 1;
1760}
1761
1762int parse_merge_opt(struct merge_options *o, const char *s)
1763{
1764        if (!s || !*s)
1765                return -1;
1766        if (!strcmp(s, "ours"))
1767                o->recursive_variant = MERGE_RECURSIVE_OURS;
1768        else if (!strcmp(s, "theirs"))
1769                o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1770        else if (!strcmp(s, "subtree"))
1771                o->subtree_shift = "";
1772        else if (!prefixcmp(s, "subtree="))
1773                o->subtree_shift = s + strlen("subtree=");
1774        else if (!strcmp(s, "patience"))
1775                o->xdl_opts |= XDF_PATIENCE_DIFF;
1776        else if (!strcmp(s, "ignore-space-change"))
1777                o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1778        else if (!strcmp(s, "ignore-all-space"))
1779                o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1780        else if (!strcmp(s, "ignore-space-at-eol"))
1781                o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1782        else if (!strcmp(s, "renormalize"))
1783                o->renormalize = 1;
1784        else if (!strcmp(s, "no-renormalize"))
1785                o->renormalize = 0;
1786        else if (!prefixcmp(s, "rename-threshold=")) {
1787                const char *score = s + strlen("rename-threshold=");
1788                if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1789                        return -1;
1790        }
1791        else
1792                return -1;
1793        return 0;
1794}