merge-recursive.con commit Merge branch 'master' of git://repo.or.cz/git/fastimport (41dc7e0)
   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 "cache.h"
   7#include "cache-tree.h"
   8#include "commit.h"
   9#include "blob.h"
  10#include "tree-walk.h"
  11#include "diff.h"
  12#include "diffcore.h"
  13#include "run-command.h"
  14#include "tag.h"
  15#include "unpack-trees.h"
  16#include "path-list.h"
  17#include "xdiff-interface.h"
  18
  19/*
  20 * A virtual commit has
  21 * - (const char *)commit->util set to the name, and
  22 * - *(int *)commit->object.sha1 set to the virtual id.
  23 */
  24
  25static unsigned commit_list_count(const struct commit_list *l)
  26{
  27        unsigned c = 0;
  28        for (; l; l = l->next )
  29                c++;
  30        return c;
  31}
  32
  33static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
  34{
  35        struct commit *commit = xcalloc(1, sizeof(struct commit));
  36        static unsigned virtual_id = 1;
  37        commit->tree = tree;
  38        commit->util = (void*)comment;
  39        *(int*)commit->object.sha1 = virtual_id++;
  40        /* avoid warnings */
  41        commit->object.parsed = 1;
  42        return commit;
  43}
  44
  45/*
  46 * Since we use get_tree_entry(), which does not put the read object into
  47 * the object pool, we cannot rely on a == b.
  48 */
  49static int sha_eq(const unsigned char *a, const unsigned char *b)
  50{
  51        if (!a && !b)
  52                return 2;
  53        return a && b && hashcmp(a, b) == 0;
  54}
  55
  56/*
  57 * Since we want to write the index eventually, we cannot reuse the index
  58 * for these (temporary) data.
  59 */
  60struct stage_data
  61{
  62        struct
  63        {
  64                unsigned mode;
  65                unsigned char sha[20];
  66        } stages[4];
  67        unsigned processed:1;
  68};
  69
  70struct output_buffer
  71{
  72        struct output_buffer *next;
  73        char *str;
  74};
  75
  76static struct path_list current_file_set = {NULL, 0, 0, 1};
  77static struct path_list current_directory_set = {NULL, 0, 0, 1};
  78
  79static int call_depth = 0;
  80static int verbosity = 2;
  81static int buffer_output = 1;
  82static int do_progress = 1;
  83static unsigned last_percent;
  84static unsigned merged_cnt;
  85static unsigned total_cnt;
  86static volatile sig_atomic_t progress_update;
  87static struct output_buffer *output_list, *output_end;
  88
  89static int show (int v)
  90{
  91        return (!call_depth && verbosity >= v) || verbosity >= 5;
  92}
  93
  94static void output(int v, const char *fmt, ...)
  95{
  96        va_list args;
  97        va_start(args, fmt);
  98        if (buffer_output && show(v)) {
  99                struct output_buffer *b = xmalloc(sizeof(*b));
 100                nfvasprintf(&b->str, fmt, args);
 101                b->next = NULL;
 102                if (output_end)
 103                        output_end->next = b;
 104                else
 105                        output_list = b;
 106                output_end = b;
 107        } else if (show(v)) {
 108                int i;
 109                for (i = call_depth; i--;)
 110                        fputs("  ", stdout);
 111                vfprintf(stdout, fmt, args);
 112                fputc('\n', stdout);
 113        }
 114        va_end(args);
 115}
 116
 117static void flush_output()
 118{
 119        struct output_buffer *b, *n;
 120        for (b = output_list; b; b = n) {
 121                int i;
 122                for (i = call_depth; i--;)
 123                        fputs("  ", stdout);
 124                fputs(b->str, stdout);
 125                fputc('\n', stdout);
 126                n = b->next;
 127                free(b->str);
 128                free(b);
 129        }
 130        output_list = NULL;
 131        output_end = NULL;
 132}
 133
 134static void output_commit_title(struct commit *commit)
 135{
 136        int i;
 137        flush_output();
 138        for (i = call_depth; i--;)
 139                fputs("  ", stdout);
 140        if (commit->util)
 141                printf("virtual %s\n", (char *)commit->util);
 142        else {
 143                printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 144                if (parse_commit(commit) != 0)
 145                        printf("(bad commit)\n");
 146                else {
 147                        const char *s;
 148                        int len;
 149                        for (s = commit->buffer; *s; s++)
 150                                if (*s == '\n' && s[1] == '\n') {
 151                                        s += 2;
 152                                        break;
 153                                }
 154                        for (len = 0; s[len] && '\n' != s[len]; len++)
 155                                ; /* do nothing */
 156                        printf("%.*s\n", len, s);
 157                }
 158        }
 159}
 160
 161static void progress_interval(int signum)
 162{
 163        progress_update = 1;
 164}
 165
 166static void setup_progress_signal(void)
 167{
 168        struct sigaction sa;
 169        struct itimerval v;
 170
 171        memset(&sa, 0, sizeof(sa));
 172        sa.sa_handler = progress_interval;
 173        sigemptyset(&sa.sa_mask);
 174        sa.sa_flags = SA_RESTART;
 175        sigaction(SIGALRM, &sa, NULL);
 176
 177        v.it_interval.tv_sec = 1;
 178        v.it_interval.tv_usec = 0;
 179        v.it_value = v.it_interval;
 180        setitimer(ITIMER_REAL, &v, NULL);
 181}
 182
 183static void display_progress()
 184{
 185        unsigned percent = total_cnt ? merged_cnt * 100 / total_cnt : 0;
 186        if (progress_update || percent != last_percent) {
 187                fprintf(stderr, "%4u%% (%u/%u) done\r",
 188                        percent, merged_cnt, total_cnt);
 189                progress_update = 0;
 190                last_percent = percent;
 191        }
 192}
 193
 194static struct cache_entry *make_cache_entry(unsigned int mode,
 195                const unsigned char *sha1, const char *path, int stage, int refresh)
 196{
 197        int size, len;
 198        struct cache_entry *ce;
 199
 200        if (!verify_path(path))
 201                return NULL;
 202
 203        len = strlen(path);
 204        size = cache_entry_size(len);
 205        ce = xcalloc(1, size);
 206
 207        hashcpy(ce->sha1, sha1);
 208        memcpy(ce->name, path, len);
 209        ce->ce_flags = create_ce_flags(len, stage);
 210        ce->ce_mode = create_ce_mode(mode);
 211
 212        if (refresh)
 213                return refresh_cache_entry(ce, 0);
 214
 215        return ce;
 216}
 217
 218static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 219                const char *path, int stage, int refresh, int options)
 220{
 221        struct cache_entry *ce;
 222        ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 223        if (!ce)
 224                return error("cache_addinfo failed: %s", strerror(cache_errno));
 225        return add_cache_entry(ce, options);
 226}
 227
 228/*
 229 * This is a global variable which is used in a number of places but
 230 * only written to in the 'merge' function.
 231 *
 232 * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
 233 *                       don't update the working directory.
 234 *               0    => Leave unmerged entries in the cache and update
 235 *                       the working directory.
 236 */
 237static int index_only = 0;
 238
 239static int git_merge_trees(int index_only,
 240                           struct tree *common,
 241                           struct tree *head,
 242                           struct tree *merge)
 243{
 244        int rc;
 245        struct object_list *trees = NULL;
 246        struct unpack_trees_options opts;
 247
 248        memset(&opts, 0, sizeof(opts));
 249        if (index_only)
 250                opts.index_only = 1;
 251        else
 252                opts.update = 1;
 253        opts.merge = 1;
 254        opts.head_idx = 2;
 255        opts.fn = threeway_merge;
 256
 257        object_list_append(&common->object, &trees);
 258        object_list_append(&head->object, &trees);
 259        object_list_append(&merge->object, &trees);
 260
 261        rc = unpack_trees(trees, &opts);
 262        cache_tree_free(&active_cache_tree);
 263        return rc;
 264}
 265
 266static int unmerged_index(void)
 267{
 268        int i;
 269        for (i = 0; i < active_nr; i++) {
 270                struct cache_entry *ce = active_cache[i];
 271                if (ce_stage(ce))
 272                        return 1;
 273        }
 274        return 0;
 275}
 276
 277static struct tree *git_write_tree(void)
 278{
 279        struct tree *result = NULL;
 280
 281        if (unmerged_index())
 282                return NULL;
 283
 284        if (!active_cache_tree)
 285                active_cache_tree = cache_tree();
 286
 287        if (!cache_tree_fully_valid(active_cache_tree) &&
 288            cache_tree_update(active_cache_tree,
 289                              active_cache, active_nr, 0, 0) < 0)
 290                die("error building trees");
 291
 292        result = lookup_tree(active_cache_tree->sha1);
 293
 294        return result;
 295}
 296
 297static int save_files_dirs(const unsigned char *sha1,
 298                const char *base, int baselen, const char *path,
 299                unsigned int mode, int stage)
 300{
 301        int len = strlen(path);
 302        char *newpath = xmalloc(baselen + len + 1);
 303        memcpy(newpath, base, baselen);
 304        memcpy(newpath + baselen, path, len);
 305        newpath[baselen + len] = '\0';
 306
 307        if (S_ISDIR(mode))
 308                path_list_insert(newpath, &current_directory_set);
 309        else
 310                path_list_insert(newpath, &current_file_set);
 311        free(newpath);
 312
 313        return READ_TREE_RECURSIVE;
 314}
 315
 316static int get_files_dirs(struct tree *tree)
 317{
 318        int n;
 319        if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
 320                return 0;
 321        n = current_file_set.nr + current_directory_set.nr;
 322        return n;
 323}
 324
 325/*
 326 * Returns a index_entry instance which doesn't have to correspond to
 327 * a real cache entry in Git's index.
 328 */
 329static struct stage_data *insert_stage_data(const char *path,
 330                struct tree *o, struct tree *a, struct tree *b,
 331                struct path_list *entries)
 332{
 333        struct path_list_item *item;
 334        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 335        get_tree_entry(o->object.sha1, path,
 336                        e->stages[1].sha, &e->stages[1].mode);
 337        get_tree_entry(a->object.sha1, path,
 338                        e->stages[2].sha, &e->stages[2].mode);
 339        get_tree_entry(b->object.sha1, path,
 340                        e->stages[3].sha, &e->stages[3].mode);
 341        item = path_list_insert(path, entries);
 342        item->util = e;
 343        return e;
 344}
 345
 346/*
 347 * Create a dictionary mapping file names to stage_data objects. The
 348 * dictionary contains one entry for every path with a non-zero stage entry.
 349 */
 350static struct path_list *get_unmerged(void)
 351{
 352        struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
 353        int i;
 354
 355        unmerged->strdup_paths = 1;
 356        total_cnt += active_nr;
 357
 358        for (i = 0; i < active_nr; i++, merged_cnt++) {
 359                struct path_list_item *item;
 360                struct stage_data *e;
 361                struct cache_entry *ce = active_cache[i];
 362                if (do_progress)
 363                        display_progress();
 364                if (!ce_stage(ce))
 365                        continue;
 366
 367                item = path_list_lookup(ce->name, unmerged);
 368                if (!item) {
 369                        item = path_list_insert(ce->name, unmerged);
 370                        item->util = xcalloc(1, sizeof(struct stage_data));
 371                }
 372                e = item->util;
 373                e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
 374                hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 375        }
 376
 377        return unmerged;
 378}
 379
 380struct rename
 381{
 382        struct diff_filepair *pair;
 383        struct stage_data *src_entry;
 384        struct stage_data *dst_entry;
 385        unsigned processed:1;
 386};
 387
 388/*
 389 * Get information of all renames which occurred between 'o_tree' and
 390 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 391 * 'b_tree') to be able to associate the correct cache entries with
 392 * the rename information. 'tree' is always equal to either a_tree or b_tree.
 393 */
 394static struct path_list *get_renames(struct tree *tree,
 395                                        struct tree *o_tree,
 396                                        struct tree *a_tree,
 397                                        struct tree *b_tree,
 398                                        struct path_list *entries)
 399{
 400        int i;
 401        struct path_list *renames;
 402        struct diff_options opts;
 403
 404        renames = xcalloc(1, sizeof(struct path_list));
 405        diff_setup(&opts);
 406        opts.recursive = 1;
 407        opts.detect_rename = DIFF_DETECT_RENAME;
 408        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 409        if (diff_setup_done(&opts) < 0)
 410                die("diff setup failed");
 411        diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 412        diffcore_std(&opts);
 413        for (i = 0; i < diff_queued_diff.nr; ++i) {
 414                struct path_list_item *item;
 415                struct rename *re;
 416                struct diff_filepair *pair = diff_queued_diff.queue[i];
 417                if (pair->status != 'R') {
 418                        diff_free_filepair(pair);
 419                        continue;
 420                }
 421                re = xmalloc(sizeof(*re));
 422                re->processed = 0;
 423                re->pair = pair;
 424                item = path_list_lookup(re->pair->one->path, entries);
 425                if (!item)
 426                        re->src_entry = insert_stage_data(re->pair->one->path,
 427                                        o_tree, a_tree, b_tree, entries);
 428                else
 429                        re->src_entry = item->util;
 430
 431                item = path_list_lookup(re->pair->two->path, entries);
 432                if (!item)
 433                        re->dst_entry = insert_stage_data(re->pair->two->path,
 434                                        o_tree, a_tree, b_tree, entries);
 435                else
 436                        re->dst_entry = item->util;
 437                item = path_list_insert(pair->one->path, renames);
 438                item->util = re;
 439        }
 440        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 441        diff_queued_diff.nr = 0;
 442        diff_flush(&opts);
 443        return renames;
 444}
 445
 446static int update_stages(const char *path, struct diff_filespec *o,
 447                         struct diff_filespec *a, struct diff_filespec *b,
 448                         int clear)
 449{
 450        int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 451        if (clear)
 452                if (remove_file_from_cache(path))
 453                        return -1;
 454        if (o)
 455                if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 456                        return -1;
 457        if (a)
 458                if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 459                        return -1;
 460        if (b)
 461                if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 462                        return -1;
 463        return 0;
 464}
 465
 466static int remove_path(const char *name)
 467{
 468        int ret, len;
 469        char *slash, *dirs;
 470
 471        ret = unlink(name);
 472        if (ret)
 473                return ret;
 474        len = strlen(name);
 475        dirs = xmalloc(len+1);
 476        memcpy(dirs, name, len);
 477        dirs[len] = '\0';
 478        while ((slash = strrchr(name, '/'))) {
 479                *slash = '\0';
 480                len = slash - name;
 481                if (rmdir(name) != 0)
 482                        break;
 483        }
 484        free(dirs);
 485        return ret;
 486}
 487
 488static int remove_file(int clean, const char *path, int no_wd)
 489{
 490        int update_cache = index_only || clean;
 491        int update_working_directory = !index_only && !no_wd;
 492
 493        if (update_cache) {
 494                if (remove_file_from_cache(path))
 495                        return -1;
 496        }
 497        if (update_working_directory) {
 498                unlink(path);
 499                if (errno != ENOENT || errno != EISDIR)
 500                        return -1;
 501                remove_path(path);
 502        }
 503        return 0;
 504}
 505
 506static char *unique_path(const char *path, const char *branch)
 507{
 508        char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 509        int suffix = 0;
 510        struct stat st;
 511        char *p = newpath + strlen(path);
 512        strcpy(newpath, path);
 513        *(p++) = '~';
 514        strcpy(p, branch);
 515        for (; *p; ++p)
 516                if ('/' == *p)
 517                        *p = '_';
 518        while (path_list_has_path(&current_file_set, newpath) ||
 519               path_list_has_path(&current_directory_set, newpath) ||
 520               lstat(newpath, &st) == 0)
 521                sprintf(p, "_%d", suffix++);
 522
 523        path_list_insert(newpath, &current_file_set);
 524        return newpath;
 525}
 526
 527static int mkdir_p(const char *path, unsigned long mode)
 528{
 529        /* path points to cache entries, so xstrdup before messing with it */
 530        char *buf = xstrdup(path);
 531        int result = safe_create_leading_directories(buf);
 532        free(buf);
 533        return result;
 534}
 535
 536static void flush_buffer(int fd, const char *buf, unsigned long size)
 537{
 538        while (size > 0) {
 539                long ret = write_in_full(fd, buf, size);
 540                if (ret < 0) {
 541                        /* Ignore epipe */
 542                        if (errno == EPIPE)
 543                                break;
 544                        die("merge-recursive: %s", strerror(errno));
 545                } else if (!ret) {
 546                        die("merge-recursive: disk full?");
 547                }
 548                size -= ret;
 549                buf += ret;
 550        }
 551}
 552
 553static void update_file_flags(const unsigned char *sha,
 554                              unsigned mode,
 555                              const char *path,
 556                              int update_cache,
 557                              int update_wd)
 558{
 559        if (index_only)
 560                update_wd = 0;
 561
 562        if (update_wd) {
 563                char type[20];
 564                void *buf;
 565                unsigned long size;
 566
 567                buf = read_sha1_file(sha, type, &size);
 568                if (!buf)
 569                        die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 570                if (strcmp(type, blob_type) != 0)
 571                        die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 572
 573                if (S_ISREG(mode)) {
 574                        int fd;
 575                        if (mkdir_p(path, 0777))
 576                                die("failed to create path %s: %s", path, strerror(errno));
 577                        unlink(path);
 578                        if (mode & 0100)
 579                                mode = 0777;
 580                        else
 581                                mode = 0666;
 582                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 583                        if (fd < 0)
 584                                die("failed to open %s: %s", path, strerror(errno));
 585                        flush_buffer(fd, buf, size);
 586                        close(fd);
 587                } else if (S_ISLNK(mode)) {
 588                        char *lnk = xmalloc(size + 1);
 589                        memcpy(lnk, buf, size);
 590                        lnk[size] = '\0';
 591                        mkdir_p(path, 0777);
 592                        unlink(lnk);
 593                        symlink(lnk, path);
 594                } else
 595                        die("do not know what to do with %06o %s '%s'",
 596                            mode, sha1_to_hex(sha), path);
 597        }
 598        if (update_cache)
 599                add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 600}
 601
 602static void update_file(int clean,
 603                        const unsigned char *sha,
 604                        unsigned mode,
 605                        const char *path)
 606{
 607        update_file_flags(sha, mode, path, index_only || clean, !index_only);
 608}
 609
 610/* Low level file merging, update and removal */
 611
 612struct merge_file_info
 613{
 614        unsigned char sha[20];
 615        unsigned mode;
 616        unsigned clean:1,
 617                 merge:1;
 618};
 619
 620static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
 621{
 622        unsigned long size;
 623        char type[20];
 624
 625        if (!hashcmp(sha1, null_sha1)) {
 626                mm->ptr = xstrdup("");
 627                mm->size = 0;
 628                return;
 629        }
 630
 631        mm->ptr = read_sha1_file(sha1, type, &size);
 632        if (!mm->ptr || strcmp(type, blob_type))
 633                die("unable to read blob object %s", sha1_to_hex(sha1));
 634        mm->size = size;
 635}
 636
 637static struct merge_file_info merge_file(struct diff_filespec *o,
 638                struct diff_filespec *a, struct diff_filespec *b,
 639                const char *branch1, const char *branch2)
 640{
 641        struct merge_file_info result;
 642        result.merge = 0;
 643        result.clean = 1;
 644
 645        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 646                result.clean = 0;
 647                if (S_ISREG(a->mode)) {
 648                        result.mode = a->mode;
 649                        hashcpy(result.sha, a->sha1);
 650                } else {
 651                        result.mode = b->mode;
 652                        hashcpy(result.sha, b->sha1);
 653                }
 654        } else {
 655                if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
 656                        result.merge = 1;
 657
 658                result.mode = a->mode == o->mode ? b->mode: a->mode;
 659
 660                if (sha_eq(a->sha1, o->sha1))
 661                        hashcpy(result.sha, b->sha1);
 662                else if (sha_eq(b->sha1, o->sha1))
 663                        hashcpy(result.sha, a->sha1);
 664                else if (S_ISREG(a->mode)) {
 665                        mmfile_t orig, src1, src2;
 666                        mmbuffer_t result_buf;
 667                        xpparam_t xpp;
 668                        char *name1, *name2;
 669                        int merge_status;
 670
 671                        name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 672                        name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 673
 674                        fill_mm(o->sha1, &orig);
 675                        fill_mm(a->sha1, &src1);
 676                        fill_mm(b->sha1, &src2);
 677
 678                        memset(&xpp, 0, sizeof(xpp));
 679                        merge_status = xdl_merge(&orig,
 680                                                 &src1, name1,
 681                                                 &src2, name2,
 682                                                 &xpp, XDL_MERGE_ZEALOUS,
 683                                                 &result_buf);
 684                        free(name1);
 685                        free(name2);
 686                        free(orig.ptr);
 687                        free(src1.ptr);
 688                        free(src2.ptr);
 689
 690                        if ((merge_status < 0) || !result_buf.ptr)
 691                                die("Failed to execute internal merge");
 692
 693                        if (write_sha1_file(result_buf.ptr, result_buf.size,
 694                                            blob_type, result.sha))
 695                                die("Unable to add %s to database",
 696                                    a->path);
 697
 698                        free(result_buf.ptr);
 699                        result.clean = (merge_status == 0);
 700                } else {
 701                        if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
 702                                die("cannot merge modes?");
 703
 704                        hashcpy(result.sha, a->sha1);
 705
 706                        if (!sha_eq(a->sha1, b->sha1))
 707                                result.clean = 0;
 708                }
 709        }
 710
 711        return result;
 712}
 713
 714static void conflict_rename_rename(struct rename *ren1,
 715                                   const char *branch1,
 716                                   struct rename *ren2,
 717                                   const char *branch2)
 718{
 719        char *del[2];
 720        int delp = 0;
 721        const char *ren1_dst = ren1->pair->two->path;
 722        const char *ren2_dst = ren2->pair->two->path;
 723        const char *dst_name1 = ren1_dst;
 724        const char *dst_name2 = ren2_dst;
 725        if (path_list_has_path(&current_directory_set, ren1_dst)) {
 726                dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
 727                output(1, "%s is a directory in %s added as %s instead",
 728                       ren1_dst, branch2, dst_name1);
 729                remove_file(0, ren1_dst, 0);
 730        }
 731        if (path_list_has_path(&current_directory_set, ren2_dst)) {
 732                dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
 733                output(1, "%s is a directory in %s added as %s instead",
 734                       ren2_dst, branch1, dst_name2);
 735                remove_file(0, ren2_dst, 0);
 736        }
 737        update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
 738        update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
 739        while (delp--)
 740                free(del[delp]);
 741}
 742
 743static void conflict_rename_dir(struct rename *ren1,
 744                                const char *branch1)
 745{
 746        char *new_path = unique_path(ren1->pair->two->path, branch1);
 747        output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
 748        remove_file(0, ren1->pair->two->path, 0);
 749        update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 750        free(new_path);
 751}
 752
 753static void conflict_rename_rename_2(struct rename *ren1,
 754                                     const char *branch1,
 755                                     struct rename *ren2,
 756                                     const char *branch2)
 757{
 758        char *new_path1 = unique_path(ren1->pair->two->path, branch1);
 759        char *new_path2 = unique_path(ren2->pair->two->path, branch2);
 760        output(1, "Renamed %s to %s and %s to %s instead",
 761               ren1->pair->one->path, new_path1,
 762               ren2->pair->one->path, new_path2);
 763        remove_file(0, ren1->pair->two->path, 0);
 764        update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 765        update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 766        free(new_path2);
 767        free(new_path1);
 768}
 769
 770static int process_renames(struct path_list *a_renames,
 771                           struct path_list *b_renames,
 772                           const char *a_branch,
 773                           const char *b_branch)
 774{
 775        int clean_merge = 1, i, j;
 776        struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
 777        const struct rename *sre;
 778
 779        for (i = 0; i < a_renames->nr; i++) {
 780                sre = a_renames->items[i].util;
 781                path_list_insert(sre->pair->two->path, &a_by_dst)->util
 782                        = sre->dst_entry;
 783        }
 784        for (i = 0; i < b_renames->nr; i++) {
 785                sre = b_renames->items[i].util;
 786                path_list_insert(sre->pair->two->path, &b_by_dst)->util
 787                        = sre->dst_entry;
 788        }
 789
 790        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 791                int compare;
 792                char *src;
 793                struct path_list *renames1, *renames2, *renames2Dst;
 794                struct rename *ren1 = NULL, *ren2 = NULL;
 795                const char *branch1, *branch2;
 796                const char *ren1_src, *ren1_dst;
 797
 798                if (i >= a_renames->nr) {
 799                        compare = 1;
 800                        ren2 = b_renames->items[j++].util;
 801                } else if (j >= b_renames->nr) {
 802                        compare = -1;
 803                        ren1 = a_renames->items[i++].util;
 804                } else {
 805                        compare = strcmp(a_renames->items[i].path,
 806                                        b_renames->items[j].path);
 807                        if (compare <= 0)
 808                                ren1 = a_renames->items[i++].util;
 809                        if (compare >= 0)
 810                                ren2 = b_renames->items[j++].util;
 811                }
 812
 813                /* TODO: refactor, so that 1/2 are not needed */
 814                if (ren1) {
 815                        renames1 = a_renames;
 816                        renames2 = b_renames;
 817                        renames2Dst = &b_by_dst;
 818                        branch1 = a_branch;
 819                        branch2 = b_branch;
 820                } else {
 821                        struct rename *tmp;
 822                        renames1 = b_renames;
 823                        renames2 = a_renames;
 824                        renames2Dst = &a_by_dst;
 825                        branch1 = b_branch;
 826                        branch2 = a_branch;
 827                        tmp = ren2;
 828                        ren2 = ren1;
 829                        ren1 = tmp;
 830                }
 831                src = ren1->pair->one->path;
 832
 833                ren1->dst_entry->processed = 1;
 834                ren1->src_entry->processed = 1;
 835
 836                if (ren1->processed)
 837                        continue;
 838                ren1->processed = 1;
 839
 840                ren1_src = ren1->pair->one->path;
 841                ren1_dst = ren1->pair->two->path;
 842
 843                if (ren2) {
 844                        const char *ren2_src = ren2->pair->one->path;
 845                        const char *ren2_dst = ren2->pair->two->path;
 846                        /* Renamed in 1 and renamed in 2 */
 847                        if (strcmp(ren1_src, ren2_src) != 0)
 848                                die("ren1.src != ren2.src");
 849                        ren2->dst_entry->processed = 1;
 850                        ren2->processed = 1;
 851                        if (strcmp(ren1_dst, ren2_dst) != 0) {
 852                                clean_merge = 0;
 853                                output(1, "CONFLICT (rename/rename): "
 854                                       "Rename %s->%s in branch %s "
 855                                       "rename %s->%s in %s",
 856                                       src, ren1_dst, branch1,
 857                                       src, ren2_dst, branch2);
 858                                conflict_rename_rename(ren1, branch1, ren2, branch2);
 859                        } else {
 860                                struct merge_file_info mfi;
 861                                remove_file(1, ren1_src, 1);
 862                                mfi = merge_file(ren1->pair->one,
 863                                                 ren1->pair->two,
 864                                                 ren2->pair->two,
 865                                                 branch1,
 866                                                 branch2);
 867                                if (mfi.merge || !mfi.clean)
 868                                        output(1, "Renamed %s->%s", src, ren1_dst);
 869
 870                                if (mfi.merge)
 871                                        output(2, "Auto-merged %s", ren1_dst);
 872
 873                                if (!mfi.clean) {
 874                                        output(1, "CONFLICT (content): merge conflict in %s",
 875                                               ren1_dst);
 876                                        clean_merge = 0;
 877
 878                                        if (!index_only)
 879                                                update_stages(ren1_dst,
 880                                                              ren1->pair->one,
 881                                                              ren1->pair->two,
 882                                                              ren2->pair->two,
 883                                                              1 /* clear */);
 884                                }
 885                                update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 886                        }
 887                } else {
 888                        /* Renamed in 1, maybe changed in 2 */
 889                        struct path_list_item *item;
 890                        /* we only use sha1 and mode of these */
 891                        struct diff_filespec src_other, dst_other;
 892                        int try_merge, stage = a_renames == renames1 ? 3: 2;
 893
 894                        remove_file(1, ren1_src, index_only || stage == 3);
 895
 896                        hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
 897                        src_other.mode = ren1->src_entry->stages[stage].mode;
 898                        hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
 899                        dst_other.mode = ren1->dst_entry->stages[stage].mode;
 900
 901                        try_merge = 0;
 902
 903                        if (path_list_has_path(&current_directory_set, ren1_dst)) {
 904                                clean_merge = 0;
 905                                output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
 906                                       " directory %s added in %s",
 907                                       ren1_src, ren1_dst, branch1,
 908                                       ren1_dst, branch2);
 909                                conflict_rename_dir(ren1, branch1);
 910                        } else if (sha_eq(src_other.sha1, null_sha1)) {
 911                                clean_merge = 0;
 912                                output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
 913                                       "and deleted in %s",
 914                                       ren1_src, ren1_dst, branch1,
 915                                       branch2);
 916                                update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 917                        } else if (!sha_eq(dst_other.sha1, null_sha1)) {
 918                                const char *new_path;
 919                                clean_merge = 0;
 920                                try_merge = 1;
 921                                output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
 922                                       "%s added in %s",
 923                                       ren1_src, ren1_dst, branch1,
 924                                       ren1_dst, branch2);
 925                                new_path = unique_path(ren1_dst, branch2);
 926                                output(1, "Added as %s instead", new_path);
 927                                update_file(0, dst_other.sha1, dst_other.mode, new_path);
 928                        } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
 929                                ren2 = item->util;
 930                                clean_merge = 0;
 931                                ren2->processed = 1;
 932                                output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
 933                                       "Renamed %s->%s in %s",
 934                                       ren1_src, ren1_dst, branch1,
 935                                       ren2->pair->one->path, ren2->pair->two->path, branch2);
 936                                conflict_rename_rename_2(ren1, branch1, ren2, branch2);
 937                        } else
 938                                try_merge = 1;
 939
 940                        if (try_merge) {
 941                                struct diff_filespec *o, *a, *b;
 942                                struct merge_file_info mfi;
 943                                src_other.path = (char *)ren1_src;
 944
 945                                o = ren1->pair->one;
 946                                if (a_renames == renames1) {
 947                                        a = ren1->pair->two;
 948                                        b = &src_other;
 949                                } else {
 950                                        b = ren1->pair->two;
 951                                        a = &src_other;
 952                                }
 953                                mfi = merge_file(o, a, b,
 954                                                a_branch, b_branch);
 955
 956                                if (mfi.merge || !mfi.clean)
 957                                        output(1, "Renamed %s => %s", ren1_src, ren1_dst);
 958                                if (mfi.merge)
 959                                        output(2, "Auto-merged %s", ren1_dst);
 960                                if (!mfi.clean) {
 961                                        output(1, "CONFLICT (rename/modify): Merge conflict in %s",
 962                                               ren1_dst);
 963                                        clean_merge = 0;
 964
 965                                        if (!index_only)
 966                                                update_stages(ren1_dst,
 967                                                                o, a, b, 1);
 968                                }
 969                                update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 970                        }
 971                }
 972        }
 973        path_list_clear(&a_by_dst, 0);
 974        path_list_clear(&b_by_dst, 0);
 975
 976        return clean_merge;
 977}
 978
 979static unsigned char *has_sha(const unsigned char *sha)
 980{
 981        return is_null_sha1(sha) ? NULL: (unsigned char *)sha;
 982}
 983
 984/* Per entry merge function */
 985static int process_entry(const char *path, struct stage_data *entry,
 986                         const char *branch1,
 987                         const char *branch2)
 988{
 989        /*
 990        printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
 991        print_index_entry("\tpath: ", entry);
 992        */
 993        int clean_merge = 1;
 994        unsigned char *o_sha = has_sha(entry->stages[1].sha);
 995        unsigned char *a_sha = has_sha(entry->stages[2].sha);
 996        unsigned char *b_sha = has_sha(entry->stages[3].sha);
 997        unsigned o_mode = entry->stages[1].mode;
 998        unsigned a_mode = entry->stages[2].mode;
 999        unsigned b_mode = entry->stages[3].mode;
1000
1001        if (o_sha && (!a_sha || !b_sha)) {
1002                /* Case A: Deleted in one */
1003                if ((!a_sha && !b_sha) ||
1004                    (sha_eq(a_sha, o_sha) && !b_sha) ||
1005                    (!a_sha && sha_eq(b_sha, o_sha))) {
1006                        /* Deleted in both or deleted in one and
1007                         * unchanged in the other */
1008                        if (a_sha)
1009                                output(2, "Removed %s", path);
1010                        /* do not touch working file if it did not exist */
1011                        remove_file(1, path, !a_sha);
1012                } else {
1013                        /* Deleted in one and changed in the other */
1014                        clean_merge = 0;
1015                        if (!a_sha) {
1016                                output(1, "CONFLICT (delete/modify): %s deleted in %s "
1017                                       "and modified in %s. Version %s of %s left in tree.",
1018                                       path, branch1,
1019                                       branch2, branch2, path);
1020                                update_file(0, b_sha, b_mode, path);
1021                        } else {
1022                                output(1, "CONFLICT (delete/modify): %s deleted in %s "
1023                                       "and modified in %s. Version %s of %s left in tree.",
1024                                       path, branch2,
1025                                       branch1, branch1, path);
1026                                update_file(0, a_sha, a_mode, path);
1027                        }
1028                }
1029
1030        } else if ((!o_sha && a_sha && !b_sha) ||
1031                   (!o_sha && !a_sha && b_sha)) {
1032                /* Case B: Added in one. */
1033                const char *add_branch;
1034                const char *other_branch;
1035                unsigned mode;
1036                const unsigned char *sha;
1037                const char *conf;
1038
1039                if (a_sha) {
1040                        add_branch = branch1;
1041                        other_branch = branch2;
1042                        mode = a_mode;
1043                        sha = a_sha;
1044                        conf = "file/directory";
1045                } else {
1046                        add_branch = branch2;
1047                        other_branch = branch1;
1048                        mode = b_mode;
1049                        sha = b_sha;
1050                        conf = "directory/file";
1051                }
1052                if (path_list_has_path(&current_directory_set, path)) {
1053                        const char *new_path = unique_path(path, add_branch);
1054                        clean_merge = 0;
1055                        output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1056                               "Added %s as %s",
1057                               conf, path, other_branch, path, new_path);
1058                        remove_file(0, path, 0);
1059                        update_file(0, sha, mode, new_path);
1060                } else {
1061                        output(2, "Added %s", path);
1062                        update_file(1, sha, mode, path);
1063                }
1064        } else if (a_sha && b_sha) {
1065                /* Case C: Added in both (check for same permissions) and */
1066                /* case D: Modified in both, but differently. */
1067                const char *reason = "content";
1068                struct merge_file_info mfi;
1069                struct diff_filespec o, a, b;
1070
1071                if (!o_sha) {
1072                        reason = "add/add";
1073                        o_sha = (unsigned char *)null_sha1;
1074                }
1075                output(2, "Auto-merged %s", path);
1076                o.path = a.path = b.path = (char *)path;
1077                hashcpy(o.sha1, o_sha);
1078                o.mode = o_mode;
1079                hashcpy(a.sha1, a_sha);
1080                a.mode = a_mode;
1081                hashcpy(b.sha1, b_sha);
1082                b.mode = b_mode;
1083
1084                mfi = merge_file(&o, &a, &b,
1085                                 branch1, branch2);
1086
1087                if (mfi.clean)
1088                        update_file(1, mfi.sha, mfi.mode, path);
1089                else {
1090                        clean_merge = 0;
1091                        output(1, "CONFLICT (%s): Merge conflict in %s",
1092                                        reason, path);
1093
1094                        if (index_only)
1095                                update_file(0, mfi.sha, mfi.mode, path);
1096                        else
1097                                update_file_flags(mfi.sha, mfi.mode, path,
1098                                              0 /* update_cache */, 1 /* update_working_directory */);
1099                }
1100        } else
1101                die("Fatal merge failure, shouldn't happen.");
1102
1103        return clean_merge;
1104}
1105
1106static int merge_trees(struct tree *head,
1107                       struct tree *merge,
1108                       struct tree *common,
1109                       const char *branch1,
1110                       const char *branch2,
1111                       struct tree **result)
1112{
1113        int code, clean;
1114        if (sha_eq(common->object.sha1, merge->object.sha1)) {
1115                output(0, "Already uptodate!");
1116                *result = head;
1117                return 1;
1118        }
1119
1120        code = git_merge_trees(index_only, common, head, merge);
1121
1122        if (code != 0)
1123                die("merging of trees %s and %s failed",
1124                    sha1_to_hex(head->object.sha1),
1125                    sha1_to_hex(merge->object.sha1));
1126
1127        if (unmerged_index()) {
1128                struct path_list *entries, *re_head, *re_merge;
1129                int i;
1130                path_list_clear(&current_file_set, 1);
1131                path_list_clear(&current_directory_set, 1);
1132                get_files_dirs(head);
1133                get_files_dirs(merge);
1134
1135                entries = get_unmerged();
1136                re_head  = get_renames(head, common, head, merge, entries);
1137                re_merge = get_renames(merge, common, head, merge, entries);
1138                clean = process_renames(re_head, re_merge,
1139                                branch1, branch2);
1140                total_cnt += entries->nr;
1141                for (i = 0; i < entries->nr; i++, merged_cnt++) {
1142                        const char *path = entries->items[i].path;
1143                        struct stage_data *e = entries->items[i].util;
1144                        if (!e->processed
1145                                && !process_entry(path, e, branch1, branch2))
1146                                clean = 0;
1147                        if (do_progress)
1148                                display_progress();
1149                }
1150
1151                path_list_clear(re_merge, 0);
1152                path_list_clear(re_head, 0);
1153                path_list_clear(entries, 1);
1154
1155        }
1156        else
1157                clean = 1;
1158
1159        if (index_only)
1160                *result = git_write_tree();
1161
1162        return clean;
1163}
1164
1165static struct commit_list *reverse_commit_list(struct commit_list *list)
1166{
1167        struct commit_list *next = NULL, *current, *backup;
1168        for (current = list; current; current = backup) {
1169                backup = current->next;
1170                current->next = next;
1171                next = current;
1172        }
1173        return next;
1174}
1175
1176/*
1177 * Merge the commits h1 and h2, return the resulting virtual
1178 * commit object and a flag indicating the cleanness of the merge.
1179 */
1180static int merge(struct commit *h1,
1181                 struct commit *h2,
1182                 const char *branch1,
1183                 const char *branch2,
1184                 struct commit_list *ca,
1185                 struct commit **result)
1186{
1187        struct commit_list *iter;
1188        struct commit *merged_common_ancestors;
1189        struct tree *mrtree;
1190        int clean;
1191
1192        if (show(4)) {
1193                output(4, "Merging:");
1194                output_commit_title(h1);
1195                output_commit_title(h2);
1196        }
1197
1198        if (!ca) {
1199                ca = get_merge_bases(h1, h2, 1);
1200                ca = reverse_commit_list(ca);
1201        }
1202
1203        if (show(5)) {
1204                output(5, "found %u common ancestor(s):", commit_list_count(ca));
1205                for (iter = ca; iter; iter = iter->next)
1206                        output_commit_title(iter->item);
1207        }
1208
1209        merged_common_ancestors = pop_commit(&ca);
1210        if (merged_common_ancestors == NULL) {
1211                /* if there is no common ancestor, make an empty tree */
1212                struct tree *tree = xcalloc(1, sizeof(struct tree));
1213
1214                tree->object.parsed = 1;
1215                tree->object.type = OBJ_TREE;
1216                pretend_sha1_file(NULL, 0, tree_type, tree->object.sha1);
1217                merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1218        }
1219
1220        for (iter = ca; iter; iter = iter->next) {
1221                call_depth++;
1222                /*
1223                 * When the merge fails, the result contains files
1224                 * with conflict markers. The cleanness flag is
1225                 * ignored, it was never actually used, as result of
1226                 * merge_trees has always overwritten it: the committed
1227                 * "conflicts" were already resolved.
1228                 */
1229                discard_cache();
1230                merge(merged_common_ancestors, iter->item,
1231                      "Temporary merge branch 1",
1232                      "Temporary merge branch 2",
1233                      NULL,
1234                      &merged_common_ancestors);
1235                call_depth--;
1236
1237                if (!merged_common_ancestors)
1238                        die("merge returned no commit");
1239        }
1240
1241        discard_cache();
1242        if (!call_depth) {
1243                read_cache();
1244                index_only = 0;
1245        } else
1246                index_only = 1;
1247
1248        clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1249                            branch1, branch2, &mrtree);
1250
1251        if (index_only) {
1252                *result = make_virtual_commit(mrtree, "merged tree");
1253                commit_list_insert(h1, &(*result)->parents);
1254                commit_list_insert(h2, &(*result)->parents->next);
1255        }
1256        if (!call_depth && do_progress) {
1257                /* Make sure we end at 100% */
1258                if (!total_cnt)
1259                        total_cnt = 1;
1260                merged_cnt = total_cnt;
1261                progress_update = 1;
1262                display_progress();
1263                fputc('\n', stderr);
1264        }
1265        flush_output();
1266        return clean;
1267}
1268
1269static const char *better_branch_name(const char *branch)
1270{
1271        static char githead_env[8 + 40 + 1];
1272        char *name;
1273
1274        if (strlen(branch) != 40)
1275                return branch;
1276        sprintf(githead_env, "GITHEAD_%s", branch);
1277        name = getenv(githead_env);
1278        return name ? name : branch;
1279}
1280
1281static struct commit *get_ref(const char *ref)
1282{
1283        unsigned char sha1[20];
1284        struct object *object;
1285
1286        if (get_sha1(ref, sha1))
1287                die("Could not resolve ref '%s'", ref);
1288        object = deref_tag(parse_object(sha1), ref, strlen(ref));
1289        if (object->type == OBJ_TREE)
1290                return make_virtual_commit((struct tree*)object,
1291                        better_branch_name(ref));
1292        if (object->type != OBJ_COMMIT)
1293                return NULL;
1294        if (parse_commit((struct commit *)object))
1295                die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1296        return (struct commit *)object;
1297}
1298
1299static int merge_config(const char *var, const char *value)
1300{
1301        if (!strcasecmp(var, "merge.verbosity")) {
1302                verbosity = git_config_int(var, value);
1303                return 0;
1304        }
1305        return git_default_config(var, value);
1306}
1307
1308int main(int argc, char *argv[])
1309{
1310        static const char *bases[20];
1311        static unsigned bases_count = 0;
1312        int i, clean;
1313        const char *branch1, *branch2;
1314        struct commit *result, *h1, *h2;
1315        struct commit_list *ca = NULL;
1316        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1317        int index_fd;
1318
1319        git_config(merge_config);
1320        if (getenv("GIT_MERGE_VERBOSITY"))
1321                verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1322
1323        if (argc < 4)
1324                die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1325
1326        for (i = 1; i < argc; ++i) {
1327                if (!strcmp(argv[i], "--"))
1328                        break;
1329                if (bases_count < sizeof(bases)/sizeof(*bases))
1330                        bases[bases_count++] = argv[i];
1331        }
1332        if (argc - i != 3) /* "--" "<head>" "<remote>" */
1333                die("Not handling anything other than two heads merge.");
1334        if (verbosity >= 5) {
1335                buffer_output = 0;
1336                do_progress = 0;
1337        }
1338        else
1339                do_progress = isatty(1);
1340
1341        branch1 = argv[++i];
1342        branch2 = argv[++i];
1343
1344        h1 = get_ref(branch1);
1345        h2 = get_ref(branch2);
1346
1347        branch1 = better_branch_name(branch1);
1348        branch2 = better_branch_name(branch2);
1349
1350        if (do_progress)
1351                setup_progress_signal();
1352        if (show(3))
1353                printf("Merging %s with %s\n", branch1, branch2);
1354
1355        index_fd = hold_lock_file_for_update(lock, get_index_file(), 1);
1356
1357        for (i = 0; i < bases_count; i++) {
1358                struct commit *ancestor = get_ref(bases[i]);
1359                ca = commit_list_insert(ancestor, &ca);
1360        }
1361        clean = merge(h1, h2, branch1, branch2, ca, &result);
1362
1363        if (active_cache_changed &&
1364            (write_cache(index_fd, active_cache, active_nr) ||
1365             close(index_fd) || commit_lock_file(lock)))
1366                        die ("unable to write %s", get_index_file());
1367
1368        return clean ? 0: 1;
1369}