Andrew's git / gitweb.git / revision.c
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revision.con commit cvsimport: fix usage of cvsimport.module (67d2324)
   1#include "cache.h"
   2#include "tag.h"
   3#include "blob.h"
   4#include "tree.h"
   5#include "commit.h"
   6#include "diff.h"
   7#include "refs.h"
   8#include "revision.h"
   9#include "grep.h"
  10#include "reflog-walk.h"
  11#include "patch-ids.h"
  12
  13static char *path_name(struct name_path *path, const char *name)
  14{
  15        struct name_path *p;
  16        char *n, *m;
  17        int nlen = strlen(name);
  18        int len = nlen + 1;
  19
  20        for (p = path; p; p = p->up) {
  21                if (p->elem_len)
  22                        len += p->elem_len + 1;
  23        }
  24        n = xmalloc(len);
  25        m = n + len - (nlen + 1);
  26        strcpy(m, name);
  27        for (p = path; p; p = p->up) {
  28                if (p->elem_len) {
  29                        m -= p->elem_len + 1;
  30                        memcpy(m, p->elem, p->elem_len);
  31                        m[p->elem_len] = '/';
  32                }
  33        }
  34        return n;
  35}
  36
  37void add_object(struct object *obj,
  38                struct object_array *p,
  39                struct name_path *path,
  40                const char *name)
  41{
  42        add_object_array(obj, path_name(path, name), p);
  43}
  44
  45static void mark_blob_uninteresting(struct blob *blob)
  46{
  47        if (blob->object.flags & UNINTERESTING)
  48                return;
  49        blob->object.flags |= UNINTERESTING;
  50}
  51
  52void mark_tree_uninteresting(struct tree *tree)
  53{
  54        struct tree_desc desc;
  55        struct name_entry entry;
  56        struct object *obj = &tree->object;
  57
  58        if (obj->flags & UNINTERESTING)
  59                return;
  60        obj->flags |= UNINTERESTING;
  61        if (!has_sha1_file(obj->sha1))
  62                return;
  63        if (parse_tree(tree) < 0)
  64                die("bad tree %s", sha1_to_hex(obj->sha1));
  65
  66        init_tree_desc(&desc, tree->buffer, tree->size);
  67        while (tree_entry(&desc, &entry)) {
  68                switch (object_type(entry.mode)) {
  69                case OBJ_TREE:
  70                        mark_tree_uninteresting(lookup_tree(entry.sha1));
  71                        break;
  72                case OBJ_BLOB:
  73                        mark_blob_uninteresting(lookup_blob(entry.sha1));
  74                        break;
  75                default:
  76                        /* Subproject commit - not in this repository */
  77                        break;
  78                }
  79        }
  80
  81        /*
  82         * We don't care about the tree any more
  83         * after it has been marked uninteresting.
  84         */
  85        free(tree->buffer);
  86        tree->buffer = NULL;
  87}
  88
  89void mark_parents_uninteresting(struct commit *commit)
  90{
  91        struct commit_list *parents = commit->parents;
  92
  93        while (parents) {
  94                struct commit *commit = parents->item;
  95                if (!(commit->object.flags & UNINTERESTING)) {
  96                        commit->object.flags |= UNINTERESTING;
  97
  98                        /*
  99                         * Normally we haven't parsed the parent
 100                         * yet, so we won't have a parent of a parent
 101                         * here. However, it may turn out that we've
 102                         * reached this commit some other way (where it
 103                         * wasn't uninteresting), in which case we need
 104                         * to mark its parents recursively too..
 105                         */
 106                        if (commit->parents)
 107                                mark_parents_uninteresting(commit);
 108                }
 109
 110                /*
 111                 * A missing commit is ok iff its parent is marked
 112                 * uninteresting.
 113                 *
 114                 * We just mark such a thing parsed, so that when
 115                 * it is popped next time around, we won't be trying
 116                 * to parse it and get an error.
 117                 */
 118                if (!has_sha1_file(commit->object.sha1))
 119                        commit->object.parsed = 1;
 120                parents = parents->next;
 121        }
 122}
 123
 124static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 125{
 126        if (revs->no_walk && (obj->flags & UNINTERESTING))
 127                die("object ranges do not make sense when not walking revisions");
 128        if (revs->reflog_info && obj->type == OBJ_COMMIT &&
 129                        add_reflog_for_walk(revs->reflog_info,
 130                                (struct commit *)obj, name))
 131                return;
 132        add_object_array_with_mode(obj, name, &revs->pending, mode);
 133}
 134
 135void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 136{
 137        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 138}
 139
 140static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 141{
 142        struct object *object;
 143
 144        object = parse_object(sha1);
 145        if (!object)
 146                die("bad object %s", name);
 147        object->flags |= flags;
 148        return object;
 149}
 150
 151static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 152{
 153        unsigned long flags = object->flags;
 154
 155        /*
 156         * Tag object? Look what it points to..
 157         */
 158        while (object->type == OBJ_TAG) {
 159                struct tag *tag = (struct tag *) object;
 160                if (revs->tag_objects && !(flags & UNINTERESTING))
 161                        add_pending_object(revs, object, tag->tag);
 162                object = parse_object(tag->tagged->sha1);
 163                if (!object)
 164                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 165        }
 166
 167        /*
 168         * Commit object? Just return it, we'll do all the complex
 169         * reachability crud.
 170         */
 171        if (object->type == OBJ_COMMIT) {
 172                struct commit *commit = (struct commit *)object;
 173                if (parse_commit(commit) < 0)
 174                        die("unable to parse commit %s", name);
 175                if (flags & UNINTERESTING) {
 176                        commit->object.flags |= UNINTERESTING;
 177                        mark_parents_uninteresting(commit);
 178                        revs->limited = 1;
 179                }
 180                return commit;
 181        }
 182
 183        /*
 184         * Tree object? Either mark it uniniteresting, or add it
 185         * to the list of objects to look at later..
 186         */
 187        if (object->type == OBJ_TREE) {
 188                struct tree *tree = (struct tree *)object;
 189                if (!revs->tree_objects)
 190                        return NULL;
 191                if (flags & UNINTERESTING) {
 192                        mark_tree_uninteresting(tree);
 193                        return NULL;
 194                }
 195                add_pending_object(revs, object, "");
 196                return NULL;
 197        }
 198
 199        /*
 200         * Blob object? You know the drill by now..
 201         */
 202        if (object->type == OBJ_BLOB) {
 203                struct blob *blob = (struct blob *)object;
 204                if (!revs->blob_objects)
 205                        return NULL;
 206                if (flags & UNINTERESTING) {
 207                        mark_blob_uninteresting(blob);
 208                        return NULL;
 209                }
 210                add_pending_object(revs, object, "");
 211                return NULL;
 212        }
 213        die("%s is unknown object", name);
 214}
 215
 216static int everybody_uninteresting(struct commit_list *orig)
 217{
 218        struct commit_list *list = orig;
 219        while (list) {
 220                struct commit *commit = list->item;
 221                list = list->next;
 222                if (commit->object.flags & UNINTERESTING)
 223                        continue;
 224                return 0;
 225        }
 226        return 1;
 227}
 228
 229/*
 230 * The goal is to get REV_TREE_NEW as the result only if the
 231 * diff consists of all '+' (and no other changes), and
 232 * REV_TREE_DIFFERENT otherwise (of course if the trees are
 233 * the same we want REV_TREE_SAME).  That means that once we
 234 * get to REV_TREE_DIFFERENT, we do not have to look any further.
 235 */
 236static int tree_difference = REV_TREE_SAME;
 237
 238static void file_add_remove(struct diff_options *options,
 239                    int addremove, unsigned mode,
 240                    const unsigned char *sha1,
 241                    const char *base, const char *path)
 242{
 243        int diff = REV_TREE_DIFFERENT;
 244
 245        /*
 246         * Is it an add of a new file? It means that the old tree
 247         * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 248         * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 249         * (and if it already was "REV_TREE_NEW", we'll keep it
 250         * "REV_TREE_NEW" of course).
 251         */
 252        if (addremove == '+') {
 253                diff = tree_difference;
 254                if (diff != REV_TREE_SAME)
 255                        return;
 256                diff = REV_TREE_NEW;
 257        }
 258        tree_difference = diff;
 259        if (tree_difference == REV_TREE_DIFFERENT)
 260                options->has_changes = 1;
 261}
 262
 263static void file_change(struct diff_options *options,
 264                 unsigned old_mode, unsigned new_mode,
 265                 const unsigned char *old_sha1,
 266                 const unsigned char *new_sha1,
 267                 const char *base, const char *path)
 268{
 269        tree_difference = REV_TREE_DIFFERENT;
 270        options->has_changes = 1;
 271}
 272
 273static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 274{
 275        if (!t1)
 276                return REV_TREE_NEW;
 277        if (!t2)
 278                return REV_TREE_DIFFERENT;
 279        tree_difference = REV_TREE_SAME;
 280        revs->pruning.has_changes = 0;
 281        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 282                           &revs->pruning) < 0)
 283                return REV_TREE_DIFFERENT;
 284        return tree_difference;
 285}
 286
 287static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 288{
 289        int retval;
 290        void *tree;
 291        unsigned long size;
 292        struct tree_desc empty, real;
 293
 294        if (!t1)
 295                return 0;
 296
 297        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 298        if (!tree)
 299                return 0;
 300        init_tree_desc(&real, tree, size);
 301        init_tree_desc(&empty, "", 0);
 302
 303        tree_difference = REV_TREE_SAME;
 304        revs->pruning.has_changes = 0;
 305        retval = diff_tree(&empty, &real, "", &revs->pruning);
 306        free(tree);
 307
 308        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 309}
 310
 311static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 312{
 313        struct commit_list **pp, *parent;
 314        int tree_changed = 0, tree_same = 0;
 315
 316        if (!commit->tree)
 317                return;
 318
 319        if (!commit->parents) {
 320                if (!rev_same_tree_as_empty(revs, commit->tree))
 321                        commit->object.flags |= TREECHANGE;
 322                return;
 323        }
 324
 325        pp = &commit->parents;
 326        while ((parent = *pp) != NULL) {
 327                struct commit *p = parent->item;
 328
 329                if (parse_commit(p) < 0)
 330                        die("cannot simplify commit %s (because of %s)",
 331                            sha1_to_hex(commit->object.sha1),
 332                            sha1_to_hex(p->object.sha1));
 333                switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 334                case REV_TREE_SAME:
 335                        tree_same = 1;
 336                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 337                                /* Even if a merge with an uninteresting
 338                                 * side branch brought the entire change
 339                                 * we are interested in, we do not want
 340                                 * to lose the other branches of this
 341                                 * merge, so we just keep going.
 342                                 */
 343                                pp = &parent->next;
 344                                continue;
 345                        }
 346                        parent->next = NULL;
 347                        commit->parents = parent;
 348                        return;
 349
 350                case REV_TREE_NEW:
 351                        if (revs->remove_empty_trees &&
 352                            rev_same_tree_as_empty(revs, p->tree)) {
 353                                /* We are adding all the specified
 354                                 * paths from this parent, so the
 355                                 * history beyond this parent is not
 356                                 * interesting.  Remove its parents
 357                                 * (they are grandparents for us).
 358                                 * IOW, we pretend this parent is a
 359                                 * "root" commit.
 360                                 */
 361                                if (parse_commit(p) < 0)
 362                                        die("cannot simplify commit %s (invalid %s)",
 363                                            sha1_to_hex(commit->object.sha1),
 364                                            sha1_to_hex(p->object.sha1));
 365                                p->parents = NULL;
 366                        }
 367                /* fallthrough */
 368                case REV_TREE_DIFFERENT:
 369                        tree_changed = 1;
 370                        pp = &parent->next;
 371                        continue;
 372                }
 373                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 374        }
 375        if (tree_changed && !tree_same)
 376                commit->object.flags |= TREECHANGE;
 377}
 378
 379static int add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 380{
 381        struct commit_list *parent = commit->parents;
 382        unsigned left_flag;
 383        int add, rest;
 384
 385        if (commit->object.flags & ADDED)
 386                return 0;
 387        commit->object.flags |= ADDED;
 388
 389        /*
 390         * If the commit is uninteresting, don't try to
 391         * prune parents - we want the maximal uninteresting
 392         * set.
 393         *
 394         * Normally we haven't parsed the parent
 395         * yet, so we won't have a parent of a parent
 396         * here. However, it may turn out that we've
 397         * reached this commit some other way (where it
 398         * wasn't uninteresting), in which case we need
 399         * to mark its parents recursively too..
 400         */
 401        if (commit->object.flags & UNINTERESTING) {
 402                while (parent) {
 403                        struct commit *p = parent->item;
 404                        parent = parent->next;
 405                        if (parse_commit(p) < 0)
 406                                return -1;
 407                        p->object.flags |= UNINTERESTING;
 408                        if (p->parents)
 409                                mark_parents_uninteresting(p);
 410                        if (p->object.flags & SEEN)
 411                                continue;
 412                        p->object.flags |= SEEN;
 413                        insert_by_date(p, list);
 414                }
 415                return 0;
 416        }
 417
 418        /*
 419         * Ok, the commit wasn't uninteresting. Try to
 420         * simplify the commit history and find the parent
 421         * that has no differences in the path set if one exists.
 422         */
 423        if (revs->prune_fn)
 424                revs->prune_fn(revs, commit);
 425
 426        if (revs->no_walk)
 427                return 0;
 428
 429        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 430
 431        rest = !revs->first_parent_only;
 432        for (parent = commit->parents, add = 1; parent; add = rest) {
 433                struct commit *p = parent->item;
 434
 435                parent = parent->next;
 436                if (parse_commit(p) < 0)
 437                        return -1;
 438                p->object.flags |= left_flag;
 439                if (p->object.flags & SEEN)
 440                        continue;
 441                p->object.flags |= SEEN;
 442                if (add)
 443                        insert_by_date(p, list);
 444        }
 445        return 0;
 446}
 447
 448static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 449{
 450        struct commit_list *p;
 451        int left_count = 0, right_count = 0;
 452        int left_first;
 453        struct patch_ids ids;
 454
 455        /* First count the commits on the left and on the right */
 456        for (p = list; p; p = p->next) {
 457                struct commit *commit = p->item;
 458                unsigned flags = commit->object.flags;
 459                if (flags & BOUNDARY)
 460                        ;
 461                else if (flags & SYMMETRIC_LEFT)
 462                        left_count++;
 463                else
 464                        right_count++;
 465        }
 466
 467        left_first = left_count < right_count;
 468        init_patch_ids(&ids);
 469        if (revs->diffopt.nr_paths) {
 470                ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 471                ids.diffopts.paths = revs->diffopt.paths;
 472                ids.diffopts.pathlens = revs->diffopt.pathlens;
 473        }
 474
 475        /* Compute patch-ids for one side */
 476        for (p = list; p; p = p->next) {
 477                struct commit *commit = p->item;
 478                unsigned flags = commit->object.flags;
 479
 480                if (flags & BOUNDARY)
 481                        continue;
 482                /*
 483                 * If we have fewer left, left_first is set and we omit
 484                 * commits on the right branch in this loop.  If we have
 485                 * fewer right, we skip the left ones.
 486                 */
 487                if (left_first != !!(flags & SYMMETRIC_LEFT))
 488                        continue;
 489                commit->util = add_commit_patch_id(commit, &ids);
 490        }
 491
 492        /* Check the other side */
 493        for (p = list; p; p = p->next) {
 494                struct commit *commit = p->item;
 495                struct patch_id *id;
 496                unsigned flags = commit->object.flags;
 497
 498                if (flags & BOUNDARY)
 499                        continue;
 500                /*
 501                 * If we have fewer left, left_first is set and we omit
 502                 * commits on the left branch in this loop.
 503                 */
 504                if (left_first == !!(flags & SYMMETRIC_LEFT))
 505                        continue;
 506
 507                /*
 508                 * Have we seen the same patch id?
 509                 */
 510                id = has_commit_patch_id(commit, &ids);
 511                if (!id)
 512                        continue;
 513                id->seen = 1;
 514                commit->object.flags |= SHOWN;
 515        }
 516
 517        /* Now check the original side for seen ones */
 518        for (p = list; p; p = p->next) {
 519                struct commit *commit = p->item;
 520                struct patch_id *ent;
 521
 522                ent = commit->util;
 523                if (!ent)
 524                        continue;
 525                if (ent->seen)
 526                        commit->object.flags |= SHOWN;
 527                commit->util = NULL;
 528        }
 529
 530        free_patch_ids(&ids);
 531}
 532
 533static int limit_list(struct rev_info *revs)
 534{
 535        struct commit_list *list = revs->commits;
 536        struct commit_list *newlist = NULL;
 537        struct commit_list **p = &newlist;
 538
 539        while (list) {
 540                struct commit_list *entry = list;
 541                struct commit *commit = list->item;
 542                struct object *obj = &commit->object;
 543
 544                list = list->next;
 545                free(entry);
 546
 547                if (revs->max_age != -1 && (commit->date < revs->max_age))
 548                        obj->flags |= UNINTERESTING;
 549                if (add_parents_to_list(revs, commit, &list) < 0)
 550                        return -1;
 551                if (obj->flags & UNINTERESTING) {
 552                        mark_parents_uninteresting(commit);
 553                        if (everybody_uninteresting(list))
 554                                break;
 555                        continue;
 556                }
 557                if (revs->min_age != -1 && (commit->date > revs->min_age))
 558                        continue;
 559                p = &commit_list_insert(commit, p)->next;
 560        }
 561        if (revs->cherry_pick)
 562                cherry_pick_list(newlist, revs);
 563
 564        revs->commits = newlist;
 565        return 0;
 566}
 567
 568struct all_refs_cb {
 569        int all_flags;
 570        int warned_bad_reflog;
 571        struct rev_info *all_revs;
 572        const char *name_for_errormsg;
 573};
 574
 575static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 576{
 577        struct all_refs_cb *cb = cb_data;
 578        struct object *object = get_reference(cb->all_revs, path, sha1,
 579                                              cb->all_flags);
 580        add_pending_object(cb->all_revs, object, path);
 581        return 0;
 582}
 583
 584static void handle_all(struct rev_info *revs, unsigned flags)
 585{
 586        struct all_refs_cb cb;
 587        cb.all_revs = revs;
 588        cb.all_flags = flags;
 589        for_each_ref(handle_one_ref, &cb);
 590}
 591
 592static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 593{
 594        struct all_refs_cb *cb = cb_data;
 595        if (!is_null_sha1(sha1)) {
 596                struct object *o = parse_object(sha1);
 597                if (o) {
 598                        o->flags |= cb->all_flags;
 599                        add_pending_object(cb->all_revs, o, "");
 600                }
 601                else if (!cb->warned_bad_reflog) {
 602                        warning("reflog of '%s' references pruned commits",
 603                                cb->name_for_errormsg);
 604                        cb->warned_bad_reflog = 1;
 605                }
 606        }
 607}
 608
 609static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 610                const char *email, unsigned long timestamp, int tz,
 611                const char *message, void *cb_data)
 612{
 613        handle_one_reflog_commit(osha1, cb_data);
 614        handle_one_reflog_commit(nsha1, cb_data);
 615        return 0;
 616}
 617
 618static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 619{
 620        struct all_refs_cb *cb = cb_data;
 621        cb->warned_bad_reflog = 0;
 622        cb->name_for_errormsg = path;
 623        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 624        return 0;
 625}
 626
 627static void handle_reflog(struct rev_info *revs, unsigned flags)
 628{
 629        struct all_refs_cb cb;
 630        cb.all_revs = revs;
 631        cb.all_flags = flags;
 632        for_each_reflog(handle_one_reflog, &cb);
 633}
 634
 635static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 636{
 637        unsigned char sha1[20];
 638        struct object *it;
 639        struct commit *commit;
 640        struct commit_list *parents;
 641
 642        if (*arg == '^') {
 643                flags ^= UNINTERESTING;
 644                arg++;
 645        }
 646        if (get_sha1(arg, sha1))
 647                return 0;
 648        while (1) {
 649                it = get_reference(revs, arg, sha1, 0);
 650                if (it->type != OBJ_TAG)
 651                        break;
 652                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 653        }
 654        if (it->type != OBJ_COMMIT)
 655                return 0;
 656        commit = (struct commit *)it;
 657        for (parents = commit->parents; parents; parents = parents->next) {
 658                it = &parents->item->object;
 659                it->flags |= flags;
 660                add_pending_object(revs, it, arg);
 661        }
 662        return 1;
 663}
 664
 665void init_revisions(struct rev_info *revs, const char *prefix)
 666{
 667        memset(revs, 0, sizeof(*revs));
 668
 669        revs->abbrev = DEFAULT_ABBREV;
 670        revs->ignore_merges = 1;
 671        revs->simplify_history = 1;
 672        revs->pruning.recursive = 1;
 673        revs->pruning.quiet = 1;
 674        revs->pruning.add_remove = file_add_remove;
 675        revs->pruning.change = file_change;
 676        revs->lifo = 1;
 677        revs->dense = 1;
 678        revs->prefix = prefix;
 679        revs->max_age = -1;
 680        revs->min_age = -1;
 681        revs->skip_count = -1;
 682        revs->max_count = -1;
 683
 684        revs->prune_fn = NULL;
 685        revs->prune_data = NULL;
 686
 687        revs->topo_setter = topo_sort_default_setter;
 688        revs->topo_getter = topo_sort_default_getter;
 689
 690        revs->commit_format = CMIT_FMT_DEFAULT;
 691
 692        diff_setup(&revs->diffopt);
 693}
 694
 695static void add_pending_commit_list(struct rev_info *revs,
 696                                    struct commit_list *commit_list,
 697                                    unsigned int flags)
 698{
 699        while (commit_list) {
 700                struct object *object = &commit_list->item->object;
 701                object->flags |= flags;
 702                add_pending_object(revs, object, sha1_to_hex(object->sha1));
 703                commit_list = commit_list->next;
 704        }
 705}
 706
 707static void prepare_show_merge(struct rev_info *revs)
 708{
 709        struct commit_list *bases;
 710        struct commit *head, *other;
 711        unsigned char sha1[20];
 712        const char **prune = NULL;
 713        int i, prune_num = 1; /* counting terminating NULL */
 714
 715        if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 716                die("--merge without HEAD?");
 717        if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 718                die("--merge without MERGE_HEAD?");
 719        add_pending_object(revs, &head->object, "HEAD");
 720        add_pending_object(revs, &other->object, "MERGE_HEAD");
 721        bases = get_merge_bases(head, other, 1);
 722        while (bases) {
 723                struct commit *it = bases->item;
 724                struct commit_list *n = bases->next;
 725                free(bases);
 726                bases = n;
 727                it->object.flags |= UNINTERESTING;
 728                add_pending_object(revs, &it->object, "(merge-base)");
 729        }
 730
 731        if (!active_nr)
 732                read_cache();
 733        for (i = 0; i < active_nr; i++) {
 734                struct cache_entry *ce = active_cache[i];
 735                if (!ce_stage(ce))
 736                        continue;
 737                if (ce_path_match(ce, revs->prune_data)) {
 738                        prune_num++;
 739                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
 740                        prune[prune_num-2] = ce->name;
 741                        prune[prune_num-1] = NULL;
 742                }
 743                while ((i+1 < active_nr) &&
 744                       ce_same_name(ce, active_cache[i+1]))
 745                        i++;
 746        }
 747        revs->prune_data = prune;
 748}
 749
 750int handle_revision_arg(const char *arg, struct rev_info *revs,
 751                        int flags,
 752                        int cant_be_filename)
 753{
 754        unsigned mode;
 755        char *dotdot;
 756        struct object *object;
 757        unsigned char sha1[20];
 758        int local_flags;
 759
 760        dotdot = strstr(arg, "..");
 761        if (dotdot) {
 762                unsigned char from_sha1[20];
 763                const char *next = dotdot + 2;
 764                const char *this = arg;
 765                int symmetric = *next == '.';
 766                unsigned int flags_exclude = flags ^ UNINTERESTING;
 767
 768                *dotdot = 0;
 769                next += symmetric;
 770
 771                if (!*next)
 772                        next = "HEAD";
 773                if (dotdot == arg)
 774                        this = "HEAD";
 775                if (!get_sha1(this, from_sha1) &&
 776                    !get_sha1(next, sha1)) {
 777                        struct commit *a, *b;
 778                        struct commit_list *exclude;
 779
 780                        a = lookup_commit_reference(from_sha1);
 781                        b = lookup_commit_reference(sha1);
 782                        if (!a || !b) {
 783                                die(symmetric ?
 784                                    "Invalid symmetric difference expression %s...%s" :
 785                                    "Invalid revision range %s..%s",
 786                                    arg, next);
 787                        }
 788
 789                        if (!cant_be_filename) {
 790                                *dotdot = '.';
 791                                verify_non_filename(revs->prefix, arg);
 792                        }
 793
 794                        if (symmetric) {
 795                                exclude = get_merge_bases(a, b, 1);
 796                                add_pending_commit_list(revs, exclude,
 797                                                        flags_exclude);
 798                                free_commit_list(exclude);
 799                                a->object.flags |= flags | SYMMETRIC_LEFT;
 800                        } else
 801                                a->object.flags |= flags_exclude;
 802                        b->object.flags |= flags;
 803                        add_pending_object(revs, &a->object, this);
 804                        add_pending_object(revs, &b->object, next);
 805                        return 0;
 806                }
 807                *dotdot = '.';
 808        }
 809        dotdot = strstr(arg, "^@");
 810        if (dotdot && !dotdot[2]) {
 811                *dotdot = 0;
 812                if (add_parents_only(revs, arg, flags))
 813                        return 0;
 814                *dotdot = '^';
 815        }
 816        dotdot = strstr(arg, "^!");
 817        if (dotdot && !dotdot[2]) {
 818                *dotdot = 0;
 819                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 820                        *dotdot = '^';
 821        }
 822
 823        local_flags = 0;
 824        if (*arg == '^') {
 825                local_flags = UNINTERESTING;
 826                arg++;
 827        }
 828        if (get_sha1_with_mode(arg, sha1, &mode))
 829                return -1;
 830        if (!cant_be_filename)
 831                verify_non_filename(revs->prefix, arg);
 832        object = get_reference(revs, arg, sha1, flags ^ local_flags);
 833        add_pending_object_with_mode(revs, object, arg, mode);
 834        return 0;
 835}
 836
 837static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 838{
 839        if (!revs->grep_filter) {
 840                struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 841                opt->status_only = 1;
 842                opt->pattern_tail = &(opt->pattern_list);
 843                opt->regflags = REG_NEWLINE;
 844                revs->grep_filter = opt;
 845        }
 846        append_grep_pattern(revs->grep_filter, ptn,
 847                            "command line", 0, what);
 848}
 849
 850static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 851{
 852        char *pat;
 853        const char *prefix;
 854        int patlen, fldlen;
 855
 856        fldlen = strlen(field);
 857        patlen = strlen(pattern);
 858        pat = xmalloc(patlen + fldlen + 10);
 859        prefix = ".*";
 860        if (*pattern == '^') {
 861                prefix = "";
 862                pattern++;
 863        }
 864        sprintf(pat, "^%s %s%s", field, prefix, pattern);
 865        add_grep(revs, pat, GREP_PATTERN_HEAD);
 866}
 867
 868static void add_message_grep(struct rev_info *revs, const char *pattern)
 869{
 870        add_grep(revs, pattern, GREP_PATTERN_BODY);
 871}
 872
 873static void add_ignore_packed(struct rev_info *revs, const char *name)
 874{
 875        int num = ++revs->num_ignore_packed;
 876
 877        revs->ignore_packed = xrealloc(revs->ignore_packed,
 878                                       sizeof(const char **) * (num + 1));
 879        revs->ignore_packed[num-1] = name;
 880        revs->ignore_packed[num] = NULL;
 881}
 882
 883/*
 884 * Parse revision information, filling in the "rev_info" structure,
 885 * and removing the used arguments from the argument list.
 886 *
 887 * Returns the number of arguments left that weren't recognized
 888 * (which are also moved to the head of the argument list)
 889 */
 890int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 891{
 892        int i, flags, seen_dashdash, show_merge;
 893        const char **unrecognized = argv + 1;
 894        int left = 1;
 895        int all_match = 0;
 896        int regflags = 0;
 897
 898        /* First, search for "--" */
 899        seen_dashdash = 0;
 900        for (i = 1; i < argc; i++) {
 901                const char *arg = argv[i];
 902                if (strcmp(arg, "--"))
 903                        continue;
 904                argv[i] = NULL;
 905                argc = i;
 906                if (argv[i + 1])
 907                        revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 908                seen_dashdash = 1;
 909                break;
 910        }
 911
 912        flags = show_merge = 0;
 913        for (i = 1; i < argc; i++) {
 914                const char *arg = argv[i];
 915                if (*arg == '-') {
 916                        int opts;
 917                        if (!prefixcmp(arg, "--max-count=")) {
 918                                revs->max_count = atoi(arg + 12);
 919                                continue;
 920                        }
 921                        if (!prefixcmp(arg, "--skip=")) {
 922                                revs->skip_count = atoi(arg + 7);
 923                                continue;
 924                        }
 925                        /* accept -<digit>, like traditional "head" */
 926                        if ((*arg == '-') && isdigit(arg[1])) {
 927                                revs->max_count = atoi(arg + 1);
 928                                continue;
 929                        }
 930                        if (!strcmp(arg, "-n")) {
 931                                if (argc <= i + 1)
 932                                        die("-n requires an argument");
 933                                revs->max_count = atoi(argv[++i]);
 934                                continue;
 935                        }
 936                        if (!prefixcmp(arg, "-n")) {
 937                                revs->max_count = atoi(arg + 2);
 938                                continue;
 939                        }
 940                        if (!prefixcmp(arg, "--max-age=")) {
 941                                revs->max_age = atoi(arg + 10);
 942                                continue;
 943                        }
 944                        if (!prefixcmp(arg, "--since=")) {
 945                                revs->max_age = approxidate(arg + 8);
 946                                continue;
 947                        }
 948                        if (!prefixcmp(arg, "--after=")) {
 949                                revs->max_age = approxidate(arg + 8);
 950                                continue;
 951                        }
 952                        if (!prefixcmp(arg, "--min-age=")) {
 953                                revs->min_age = atoi(arg + 10);
 954                                continue;
 955                        }
 956                        if (!prefixcmp(arg, "--before=")) {
 957                                revs->min_age = approxidate(arg + 9);
 958                                continue;
 959                        }
 960                        if (!prefixcmp(arg, "--until=")) {
 961                                revs->min_age = approxidate(arg + 8);
 962                                continue;
 963                        }
 964                        if (!strcmp(arg, "--all")) {
 965                                handle_all(revs, flags);
 966                                continue;
 967                        }
 968                        if (!strcmp(arg, "--first-parent")) {
 969                                revs->first_parent_only = 1;
 970                                continue;
 971                        }
 972                        if (!strcmp(arg, "--reflog")) {
 973                                handle_reflog(revs, flags);
 974                                continue;
 975                        }
 976                        if (!strcmp(arg, "-g") ||
 977                                        !strcmp(arg, "--walk-reflogs")) {
 978                                init_reflog_walk(&revs->reflog_info);
 979                                continue;
 980                        }
 981                        if (!strcmp(arg, "--not")) {
 982                                flags ^= UNINTERESTING;
 983                                continue;
 984                        }
 985                        if (!strcmp(arg, "--default")) {
 986                                if (++i >= argc)
 987                                        die("bad --default argument");
 988                                def = argv[i];
 989                                continue;
 990                        }
 991                        if (!strcmp(arg, "--merge")) {
 992                                show_merge = 1;
 993                                continue;
 994                        }
 995                        if (!strcmp(arg, "--topo-order")) {
 996                                revs->topo_order = 1;
 997                                continue;
 998                        }
 999                        if (!strcmp(arg, "--date-order")) {
1000                                revs->lifo = 0;
1001                                revs->topo_order = 1;
1002                                continue;
1003                        }
1004                        if (!strcmp(arg, "--parents")) {
1005                                revs->parents = 1;
1006                                continue;
1007                        }
1008                        if (!strcmp(arg, "--dense")) {
1009                                revs->dense = 1;
1010                                continue;
1011                        }
1012                        if (!strcmp(arg, "--sparse")) {
1013                                revs->dense = 0;
1014                                continue;
1015                        }
1016                        if (!strcmp(arg, "--remove-empty")) {
1017                                revs->remove_empty_trees = 1;
1018                                continue;
1019                        }
1020                        if (!strcmp(arg, "--no-merges")) {
1021                                revs->no_merges = 1;
1022                                continue;
1023                        }
1024                        if (!strcmp(arg, "--boundary")) {
1025                                revs->boundary = 1;
1026                                continue;
1027                        }
1028                        if (!strcmp(arg, "--left-right")) {
1029                                revs->left_right = 1;
1030                                continue;
1031                        }
1032                        if (!strcmp(arg, "--cherry-pick")) {
1033                                revs->cherry_pick = 1;
1034                                revs->limited = 1;
1035                                continue;
1036                        }
1037                        if (!strcmp(arg, "--objects")) {
1038                                revs->tag_objects = 1;
1039                                revs->tree_objects = 1;
1040                                revs->blob_objects = 1;
1041                                continue;
1042                        }
1043                        if (!strcmp(arg, "--objects-edge")) {
1044                                revs->tag_objects = 1;
1045                                revs->tree_objects = 1;
1046                                revs->blob_objects = 1;
1047                                revs->edge_hint = 1;
1048                                continue;
1049                        }
1050                        if (!strcmp(arg, "--unpacked")) {
1051                                revs->unpacked = 1;
1052                                free(revs->ignore_packed);
1053                                revs->ignore_packed = NULL;
1054                                revs->num_ignore_packed = 0;
1055                                continue;
1056                        }
1057                        if (!prefixcmp(arg, "--unpacked=")) {
1058                                revs->unpacked = 1;
1059                                add_ignore_packed(revs, arg+11);
1060                                continue;
1061                        }
1062                        if (!strcmp(arg, "-r")) {
1063                                revs->diff = 1;
1064                                revs->diffopt.recursive = 1;
1065                                continue;
1066                        }
1067                        if (!strcmp(arg, "-t")) {
1068                                revs->diff = 1;
1069                                revs->diffopt.recursive = 1;
1070                                revs->diffopt.tree_in_recursive = 1;
1071                                continue;
1072                        }
1073                        if (!strcmp(arg, "-m")) {
1074                                revs->ignore_merges = 0;
1075                                continue;
1076                        }
1077                        if (!strcmp(arg, "-c")) {
1078                                revs->diff = 1;
1079                                revs->dense_combined_merges = 0;
1080                                revs->combine_merges = 1;
1081                                continue;
1082                        }
1083                        if (!strcmp(arg, "--cc")) {
1084                                revs->diff = 1;
1085                                revs->dense_combined_merges = 1;
1086                                revs->combine_merges = 1;
1087                                continue;
1088                        }
1089                        if (!strcmp(arg, "-v")) {
1090                                revs->verbose_header = 1;
1091                                continue;
1092                        }
1093                        if (!prefixcmp(arg, "--pretty")) {
1094                                revs->verbose_header = 1;
1095                                revs->commit_format = get_commit_format(arg+8);
1096                                continue;
1097                        }
1098                        if (!strcmp(arg, "--root")) {
1099                                revs->show_root_diff = 1;
1100                                continue;
1101                        }
1102                        if (!strcmp(arg, "--no-commit-id")) {
1103                                revs->no_commit_id = 1;
1104                                continue;
1105                        }
1106                        if (!strcmp(arg, "--always")) {
1107                                revs->always_show_header = 1;
1108                                continue;
1109                        }
1110                        if (!strcmp(arg, "--no-abbrev")) {
1111                                revs->abbrev = 0;
1112                                continue;
1113                        }
1114                        if (!strcmp(arg, "--abbrev")) {
1115                                revs->abbrev = DEFAULT_ABBREV;
1116                                continue;
1117                        }
1118                        if (!prefixcmp(arg, "--abbrev=")) {
1119                                revs->abbrev = strtoul(arg + 9, NULL, 10);
1120                                if (revs->abbrev < MINIMUM_ABBREV)
1121                                        revs->abbrev = MINIMUM_ABBREV;
1122                                else if (revs->abbrev > 40)
1123                                        revs->abbrev = 40;
1124                                continue;
1125                        }
1126                        if (!strcmp(arg, "--abbrev-commit")) {
1127                                revs->abbrev_commit = 1;
1128                                continue;
1129                        }
1130                        if (!strcmp(arg, "--full-diff")) {
1131                                revs->diff = 1;
1132                                revs->full_diff = 1;
1133                                continue;
1134                        }
1135                        if (!strcmp(arg, "--full-history")) {
1136                                revs->simplify_history = 0;
1137                                continue;
1138                        }
1139                        if (!strcmp(arg, "--relative-date")) {
1140                                revs->date_mode = DATE_RELATIVE;
1141                                continue;
1142                        }
1143                        if (!strncmp(arg, "--date=", 7)) {
1144                                if (!strcmp(arg + 7, "relative"))
1145                                        revs->date_mode = DATE_RELATIVE;
1146                                else if (!strcmp(arg + 7, "iso8601") ||
1147                                         !strcmp(arg + 7, "iso"))
1148                                        revs->date_mode = DATE_ISO8601;
1149                                else if (!strcmp(arg + 7, "rfc2822") ||
1150                                         !strcmp(arg + 7, "rfc"))
1151                                        revs->date_mode = DATE_RFC2822;
1152                                else if (!strcmp(arg + 7, "short"))
1153                                        revs->date_mode = DATE_SHORT;
1154                                else if (!strcmp(arg + 7, "local"))
1155                                        revs->date_mode = DATE_LOCAL;
1156                                else if (!strcmp(arg + 7, "default"))
1157                                        revs->date_mode = DATE_NORMAL;
1158                                else
1159                                        die("unknown date format %s", arg);
1160                                continue;
1161                        }
1162                        if (!strcmp(arg, "--log-size")) {
1163                                revs->show_log_size = 1;
1164                                continue;
1165                        }
1166
1167                        /*
1168                         * Grepping the commit log
1169                         */
1170                        if (!prefixcmp(arg, "--author=")) {
1171                                add_header_grep(revs, "author", arg+9);
1172                                continue;
1173                        }
1174                        if (!prefixcmp(arg, "--committer=")) {
1175                                add_header_grep(revs, "committer", arg+12);
1176                                continue;
1177                        }
1178                        if (!prefixcmp(arg, "--grep=")) {
1179                                add_message_grep(revs, arg+7);
1180                                continue;
1181                        }
1182                        if (!strcmp(arg, "--extended-regexp") ||
1183                            !strcmp(arg, "-E")) {
1184                                regflags |= REG_EXTENDED;
1185                                continue;
1186                        }
1187                        if (!strcmp(arg, "--regexp-ignore-case") ||
1188                            !strcmp(arg, "-i")) {
1189                                regflags |= REG_ICASE;
1190                                continue;
1191                        }
1192                        if (!strcmp(arg, "--all-match")) {
1193                                all_match = 1;
1194                                continue;
1195                        }
1196                        if (!prefixcmp(arg, "--encoding=")) {
1197                                arg += 11;
1198                                if (strcmp(arg, "none"))
1199                                        git_log_output_encoding = xstrdup(arg);
1200                                else
1201                                        git_log_output_encoding = "";
1202                                continue;
1203                        }
1204                        if (!strcmp(arg, "--reverse")) {
1205                                revs->reverse ^= 1;
1206                                continue;
1207                        }
1208                        if (!strcmp(arg, "--no-walk")) {
1209                                revs->no_walk = 1;
1210                                continue;
1211                        }
1212                        if (!strcmp(arg, "--do-walk")) {
1213                                revs->no_walk = 0;
1214                                continue;
1215                        }
1216
1217                        opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1218                        if (opts > 0) {
1219                                i += opts - 1;
1220                                continue;
1221                        }
1222                        *unrecognized++ = arg;
1223                        left++;
1224                        continue;
1225                }
1226
1227                if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1228                        int j;
1229                        if (seen_dashdash || *arg == '^')
1230                                die("bad revision '%s'", arg);
1231
1232                        /* If we didn't have a "--":
1233                         * (1) all filenames must exist;
1234                         * (2) all rev-args must not be interpretable
1235                         *     as a valid filename.
1236                         * but the latter we have checked in the main loop.
1237                         */
1238                        for (j = i; j < argc; j++)
1239                                verify_filename(revs->prefix, argv[j]);
1240
1241                        revs->prune_data = get_pathspec(revs->prefix,
1242                                                        argv + i);
1243                        break;
1244                }
1245        }
1246
1247        if (revs->grep_filter)
1248                revs->grep_filter->regflags |= regflags;
1249
1250        if (show_merge)
1251                prepare_show_merge(revs);
1252        if (def && !revs->pending.nr) {
1253                unsigned char sha1[20];
1254                struct object *object;
1255                unsigned mode;
1256                if (get_sha1_with_mode(def, sha1, &mode))
1257                        die("bad default revision '%s'", def);
1258                object = get_reference(revs, def, sha1, 0);
1259                add_pending_object_with_mode(revs, object, def, mode);
1260        }
1261
1262        /* Did the user ask for any diff output? Run the diff! */
1263        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1264                revs->diff = 1;
1265
1266        /* Pickaxe and rename following needs diffs */
1267        if (revs->diffopt.pickaxe || revs->diffopt.follow_renames)
1268                revs->diff = 1;
1269
1270        if (revs->topo_order)
1271                revs->limited = 1;
1272
1273        if (revs->prune_data) {
1274                diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1275                /* Can't prune commits with rename following: the paths change.. */
1276                if (!revs->diffopt.follow_renames)
1277                        revs->prune_fn = try_to_simplify_commit;
1278                if (!revs->full_diff)
1279                        diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1280        }
1281        if (revs->combine_merges) {
1282                revs->ignore_merges = 0;
1283                if (revs->dense_combined_merges && !revs->diffopt.output_format)
1284                        revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1285        }
1286        revs->diffopt.abbrev = revs->abbrev;
1287        if (diff_setup_done(&revs->diffopt) < 0)
1288                die("diff_setup_done failed");
1289
1290        if (revs->grep_filter) {
1291                revs->grep_filter->all_match = all_match;
1292                compile_grep_patterns(revs->grep_filter);
1293        }
1294
1295        if (revs->reverse && revs->reflog_info)
1296                die("cannot combine --reverse with --walk-reflogs");
1297
1298        return left;
1299}
1300
1301int prepare_revision_walk(struct rev_info *revs)
1302{
1303        int nr = revs->pending.nr;
1304        struct object_array_entry *e, *list;
1305
1306        e = list = revs->pending.objects;
1307        revs->pending.nr = 0;
1308        revs->pending.alloc = 0;
1309        revs->pending.objects = NULL;
1310        while (--nr >= 0) {
1311                struct commit *commit = handle_commit(revs, e->item, e->name);
1312                if (commit) {
1313                        if (!(commit->object.flags & SEEN)) {
1314                                commit->object.flags |= SEEN;
1315                                insert_by_date(commit, &revs->commits);
1316                        }
1317                }
1318                e++;
1319        }
1320        free(list);
1321
1322        if (revs->no_walk)
1323                return 0;
1324        if (revs->limited)
1325                if (limit_list(revs) < 0)
1326                        return -1;
1327        if (revs->topo_order)
1328                sort_in_topological_order_fn(&revs->commits, revs->lifo,
1329                                             revs->topo_setter,
1330                                             revs->topo_getter);
1331        return 0;
1332}
1333
1334enum rewrite_result {
1335        rewrite_one_ok,
1336        rewrite_one_noparents,
1337        rewrite_one_error,
1338};
1339
1340static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1341{
1342        for (;;) {
1343                struct commit *p = *pp;
1344                if (!revs->limited)
1345                        if (add_parents_to_list(revs, p, &revs->commits) < 0)
1346                                return rewrite_one_error;
1347                if (p->parents && p->parents->next)
1348                        return rewrite_one_ok;
1349                if (p->object.flags & (TREECHANGE | UNINTERESTING))
1350                        return rewrite_one_ok;
1351                if (!p->parents)
1352                        return rewrite_one_noparents;
1353                *pp = p->parents->item;
1354        }
1355}
1356
1357static void remove_duplicate_parents(struct commit *commit)
1358{
1359        struct commit_list **pp, *p;
1360
1361        /* Examine existing parents while marking ones we have seen... */
1362        pp = &commit->parents;
1363        while ((p = *pp) != NULL) {
1364                struct commit *parent = p->item;
1365                if (parent->object.flags & TMP_MARK) {
1366                        *pp = p->next;
1367                        continue;
1368                }
1369                parent->object.flags |= TMP_MARK;
1370                pp = &p->next;
1371        }
1372        /* ... and clear the temporary mark */
1373        for (p = commit->parents; p; p = p->next)
1374                p->item->object.flags &= ~TMP_MARK;
1375}
1376
1377static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1378{
1379        struct commit_list **pp = &commit->parents;
1380        while (*pp) {
1381                struct commit_list *parent = *pp;
1382                switch (rewrite_one(revs, &parent->item)) {
1383                case rewrite_one_ok:
1384                        break;
1385                case rewrite_one_noparents:
1386                        *pp = parent->next;
1387                        continue;
1388                case rewrite_one_error:
1389                        return -1;
1390                }
1391                pp = &parent->next;
1392        }
1393        remove_duplicate_parents(commit);
1394        return 0;
1395}
1396
1397static int commit_match(struct commit *commit, struct rev_info *opt)
1398{
1399        if (!opt->grep_filter)
1400                return 1;
1401        return grep_buffer(opt->grep_filter,
1402                           NULL, /* we say nothing, not even filename */
1403                           commit->buffer, strlen(commit->buffer));
1404}
1405
1406static struct commit *get_revision_1(struct rev_info *revs)
1407{
1408        if (!revs->commits)
1409                return NULL;
1410
1411        do {
1412                struct commit_list *entry = revs->commits;
1413                struct commit *commit = entry->item;
1414
1415                revs->commits = entry->next;
1416                free(entry);
1417
1418                if (revs->reflog_info)
1419                        fake_reflog_parent(revs->reflog_info, commit);
1420
1421                /*
1422                 * If we haven't done the list limiting, we need to look at
1423                 * the parents here. We also need to do the date-based limiting
1424                 * that we'd otherwise have done in limit_list().
1425                 */
1426                if (!revs->limited) {
1427                        if (revs->max_age != -1 &&
1428                            (commit->date < revs->max_age))
1429                                continue;
1430                        if (add_parents_to_list(revs, commit, &revs->commits) < 0)
1431                                return NULL;
1432                }
1433                if (commit->object.flags & SHOWN)
1434                        continue;
1435
1436                if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1437                                                    revs->ignore_packed))
1438                    continue;
1439
1440                if (commit->object.flags & UNINTERESTING)
1441                        continue;
1442                if (revs->min_age != -1 && (commit->date > revs->min_age))
1443                        continue;
1444                if (revs->no_merges &&
1445                    commit->parents && commit->parents->next)
1446                        continue;
1447                if (!commit_match(commit, revs))
1448                        continue;
1449                if (revs->prune_fn && revs->dense) {
1450                        /* Commit without changes? */
1451                        if (!(commit->object.flags & TREECHANGE)) {
1452                                /* drop merges unless we want parenthood */
1453                                if (!revs->parents)
1454                                        continue;
1455                                /* non-merge - always ignore it */
1456                                if (!commit->parents || !commit->parents->next)
1457                                        continue;
1458                        }
1459                        if (revs->parents && rewrite_parents(revs, commit) < 0)
1460                                return NULL;
1461                }
1462                return commit;
1463        } while (revs->commits);
1464        return NULL;
1465}
1466
1467static void gc_boundary(struct object_array *array)
1468{
1469        unsigned nr = array->nr;
1470        unsigned alloc = array->alloc;
1471        struct object_array_entry *objects = array->objects;
1472
1473        if (alloc <= nr) {
1474                unsigned i, j;
1475                for (i = j = 0; i < nr; i++) {
1476                        if (objects[i].item->flags & SHOWN)
1477                                continue;
1478                        if (i != j)
1479                                objects[j] = objects[i];
1480                        j++;
1481                }
1482                for (i = j; i < nr; i++)
1483                        objects[i].item = NULL;
1484                array->nr = j;
1485        }
1486}
1487
1488struct commit *get_revision(struct rev_info *revs)
1489{
1490        struct commit *c = NULL;
1491        struct commit_list *l;
1492
1493        if (revs->boundary == 2) {
1494                unsigned i;
1495                struct object_array *array = &revs->boundary_commits;
1496                struct object_array_entry *objects = array->objects;
1497                for (i = 0; i < array->nr; i++) {
1498                        c = (struct commit *)(objects[i].item);
1499                        if (!c)
1500                                continue;
1501                        if (!(c->object.flags & CHILD_SHOWN))
1502                                continue;
1503                        if (!(c->object.flags & SHOWN))
1504                                break;
1505                }
1506                if (array->nr <= i)
1507                        return NULL;
1508
1509                c->object.flags |= SHOWN | BOUNDARY;
1510                return c;
1511        }
1512
1513        if (revs->reverse) {
1514                int limit = -1;
1515
1516                if (0 <= revs->max_count) {
1517                        limit = revs->max_count;
1518                        if (0 < revs->skip_count)
1519                                limit += revs->skip_count;
1520                }
1521                l = NULL;
1522                while ((c = get_revision_1(revs))) {
1523                        commit_list_insert(c, &l);
1524                        if ((0 < limit) && !--limit)
1525                                break;
1526                }
1527                revs->commits = l;
1528                revs->reverse = 0;
1529                revs->max_count = -1;
1530                c = NULL;
1531        }
1532
1533        /*
1534         * Now pick up what they want to give us
1535         */
1536        c = get_revision_1(revs);
1537        if (c) {
1538                while (0 < revs->skip_count) {
1539                        revs->skip_count--;
1540                        c = get_revision_1(revs);
1541                        if (!c)
1542                                break;
1543                }
1544        }
1545
1546        /*
1547         * Check the max_count.
1548         */
1549        switch (revs->max_count) {
1550        case -1:
1551                break;
1552        case 0:
1553                c = NULL;
1554                break;
1555        default:
1556                revs->max_count--;
1557        }
1558
1559        if (c)
1560                c->object.flags |= SHOWN;
1561
1562        if (!revs->boundary) {
1563                return c;
1564        }
1565
1566        if (!c) {
1567                /*
1568                 * get_revision_1() runs out the commits, and
1569                 * we are done computing the boundaries.
1570                 * switch to boundary commits output mode.
1571                 */
1572                revs->boundary = 2;
1573                return get_revision(revs);
1574        }
1575
1576        /*
1577         * boundary commits are the commits that are parents of the
1578         * ones we got from get_revision_1() but they themselves are
1579         * not returned from get_revision_1().  Before returning
1580         * 'c', we need to mark its parents that they could be boundaries.
1581         */
1582
1583        for (l = c->parents; l; l = l->next) {
1584                struct object *p;
1585                p = &(l->item->object);
1586                if (p->flags & (CHILD_SHOWN | SHOWN))
1587                        continue;
1588                p->flags |= CHILD_SHOWN;
1589                gc_boundary(&revs->boundary_commits);
1590                add_object_array(p, NULL, &revs->boundary_commits);
1591        }
1592
1593        return c;
1594}