revision.con commit Merge branch 'maint' (e3c58f8)
   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
  13volatile show_early_output_fn_t show_early_output;
  14
  15static char *path_name(struct name_path *path, const char *name)
  16{
  17        struct name_path *p;
  18        char *n, *m;
  19        int nlen = strlen(name);
  20        int len = nlen + 1;
  21
  22        for (p = path; p; p = p->up) {
  23                if (p->elem_len)
  24                        len += p->elem_len + 1;
  25        }
  26        n = xmalloc(len);
  27        m = n + len - (nlen + 1);
  28        strcpy(m, name);
  29        for (p = path; p; p = p->up) {
  30                if (p->elem_len) {
  31                        m -= p->elem_len + 1;
  32                        memcpy(m, p->elem, p->elem_len);
  33                        m[p->elem_len] = '/';
  34                }
  35        }
  36        return n;
  37}
  38
  39void add_object(struct object *obj,
  40                struct object_array *p,
  41                struct name_path *path,
  42                const char *name)
  43{
  44        add_object_array(obj, path_name(path, name), p);
  45}
  46
  47static void mark_blob_uninteresting(struct blob *blob)
  48{
  49        if (!blob)
  50                return;
  51        if (blob->object.flags & UNINTERESTING)
  52                return;
  53        blob->object.flags |= UNINTERESTING;
  54}
  55
  56void mark_tree_uninteresting(struct tree *tree)
  57{
  58        struct tree_desc desc;
  59        struct name_entry entry;
  60        struct object *obj = &tree->object;
  61
  62        if (!tree)
  63                return;
  64        if (obj->flags & UNINTERESTING)
  65                return;
  66        obj->flags |= UNINTERESTING;
  67        if (!has_sha1_file(obj->sha1))
  68                return;
  69        if (parse_tree(tree) < 0)
  70                die("bad tree %s", sha1_to_hex(obj->sha1));
  71
  72        init_tree_desc(&desc, tree->buffer, tree->size);
  73        while (tree_entry(&desc, &entry)) {
  74                switch (object_type(entry.mode)) {
  75                case OBJ_TREE:
  76                        mark_tree_uninteresting(lookup_tree(entry.sha1));
  77                        break;
  78                case OBJ_BLOB:
  79                        mark_blob_uninteresting(lookup_blob(entry.sha1));
  80                        break;
  81                default:
  82                        /* Subproject commit - not in this repository */
  83                        break;
  84                }
  85        }
  86
  87        /*
  88         * We don't care about the tree any more
  89         * after it has been marked uninteresting.
  90         */
  91        free(tree->buffer);
  92        tree->buffer = NULL;
  93}
  94
  95void mark_parents_uninteresting(struct commit *commit)
  96{
  97        struct commit_list *parents = commit->parents;
  98
  99        while (parents) {
 100                struct commit *commit = parents->item;
 101                if (!(commit->object.flags & UNINTERESTING)) {
 102                        commit->object.flags |= UNINTERESTING;
 103
 104                        /*
 105                         * Normally we haven't parsed the parent
 106                         * yet, so we won't have a parent of a parent
 107                         * here. However, it may turn out that we've
 108                         * reached this commit some other way (where it
 109                         * wasn't uninteresting), in which case we need
 110                         * to mark its parents recursively too..
 111                         */
 112                        if (commit->parents)
 113                                mark_parents_uninteresting(commit);
 114                }
 115
 116                /*
 117                 * A missing commit is ok iff its parent is marked
 118                 * uninteresting.
 119                 *
 120                 * We just mark such a thing parsed, so that when
 121                 * it is popped next time around, we won't be trying
 122                 * to parse it and get an error.
 123                 */
 124                if (!has_sha1_file(commit->object.sha1))
 125                        commit->object.parsed = 1;
 126                parents = parents->next;
 127        }
 128}
 129
 130static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 131{
 132        if (revs->no_walk && (obj->flags & UNINTERESTING))
 133                die("object ranges do not make sense when not walking revisions");
 134        if (revs->reflog_info && obj->type == OBJ_COMMIT &&
 135                        add_reflog_for_walk(revs->reflog_info,
 136                                (struct commit *)obj, name))
 137                return;
 138        add_object_array_with_mode(obj, name, &revs->pending, mode);
 139}
 140
 141void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 142{
 143        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 144}
 145
 146void add_head_to_pending(struct rev_info *revs)
 147{
 148        unsigned char sha1[20];
 149        struct object *obj;
 150        if (get_sha1("HEAD", sha1))
 151                return;
 152        obj = parse_object(sha1);
 153        if (!obj)
 154                return;
 155        add_pending_object(revs, obj, "HEAD");
 156}
 157
 158static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 159{
 160        struct object *object;
 161
 162        object = parse_object(sha1);
 163        if (!object)
 164                die("bad object %s", name);
 165        object->flags |= flags;
 166        return object;
 167}
 168
 169static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 170{
 171        unsigned long flags = object->flags;
 172
 173        /*
 174         * Tag object? Look what it points to..
 175         */
 176        while (object->type == OBJ_TAG) {
 177                struct tag *tag = (struct tag *) object;
 178                if (revs->tag_objects && !(flags & UNINTERESTING))
 179                        add_pending_object(revs, object, tag->tag);
 180                if (!tag->tagged)
 181                        die("bad tag");
 182                object = parse_object(tag->tagged->sha1);
 183                if (!object)
 184                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 185        }
 186
 187        /*
 188         * Commit object? Just return it, we'll do all the complex
 189         * reachability crud.
 190         */
 191        if (object->type == OBJ_COMMIT) {
 192                struct commit *commit = (struct commit *)object;
 193                if (parse_commit(commit) < 0)
 194                        die("unable to parse commit %s", name);
 195                if (flags & UNINTERESTING) {
 196                        commit->object.flags |= UNINTERESTING;
 197                        mark_parents_uninteresting(commit);
 198                        revs->limited = 1;
 199                }
 200                return commit;
 201        }
 202
 203        /*
 204         * Tree object? Either mark it uniniteresting, or add it
 205         * to the list of objects to look at later..
 206         */
 207        if (object->type == OBJ_TREE) {
 208                struct tree *tree = (struct tree *)object;
 209                if (!revs->tree_objects)
 210                        return NULL;
 211                if (flags & UNINTERESTING) {
 212                        mark_tree_uninteresting(tree);
 213                        return NULL;
 214                }
 215                add_pending_object(revs, object, "");
 216                return NULL;
 217        }
 218
 219        /*
 220         * Blob object? You know the drill by now..
 221         */
 222        if (object->type == OBJ_BLOB) {
 223                struct blob *blob = (struct blob *)object;
 224                if (!revs->blob_objects)
 225                        return NULL;
 226                if (flags & UNINTERESTING) {
 227                        mark_blob_uninteresting(blob);
 228                        return NULL;
 229                }
 230                add_pending_object(revs, object, "");
 231                return NULL;
 232        }
 233        die("%s is unknown object", name);
 234}
 235
 236static int everybody_uninteresting(struct commit_list *orig)
 237{
 238        struct commit_list *list = orig;
 239        while (list) {
 240                struct commit *commit = list->item;
 241                list = list->next;
 242                if (commit->object.flags & UNINTERESTING)
 243                        continue;
 244                return 0;
 245        }
 246        return 1;
 247}
 248
 249/*
 250 * The goal is to get REV_TREE_NEW as the result only if the
 251 * diff consists of all '+' (and no other changes), and
 252 * REV_TREE_DIFFERENT otherwise (of course if the trees are
 253 * the same we want REV_TREE_SAME).  That means that once we
 254 * get to REV_TREE_DIFFERENT, we do not have to look any further.
 255 */
 256static int tree_difference = REV_TREE_SAME;
 257
 258static void file_add_remove(struct diff_options *options,
 259                    int addremove, unsigned mode,
 260                    const unsigned char *sha1,
 261                    const char *base, const char *path)
 262{
 263        int diff = REV_TREE_DIFFERENT;
 264
 265        /*
 266         * Is it an add of a new file? It means that the old tree
 267         * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 268         * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 269         * (and if it already was "REV_TREE_NEW", we'll keep it
 270         * "REV_TREE_NEW" of course).
 271         */
 272        if (addremove == '+') {
 273                diff = tree_difference;
 274                if (diff != REV_TREE_SAME)
 275                        return;
 276                diff = REV_TREE_NEW;
 277        }
 278        tree_difference = diff;
 279        if (tree_difference == REV_TREE_DIFFERENT)
 280                DIFF_OPT_SET(options, HAS_CHANGES);
 281}
 282
 283static void file_change(struct diff_options *options,
 284                 unsigned old_mode, unsigned new_mode,
 285                 const unsigned char *old_sha1,
 286                 const unsigned char *new_sha1,
 287                 const char *base, const char *path)
 288{
 289        tree_difference = REV_TREE_DIFFERENT;
 290        DIFF_OPT_SET(options, HAS_CHANGES);
 291}
 292
 293static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 294{
 295        if (!t1)
 296                return REV_TREE_NEW;
 297        if (!t2)
 298                return REV_TREE_DIFFERENT;
 299        tree_difference = REV_TREE_SAME;
 300        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 301        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 302                           &revs->pruning) < 0)
 303                return REV_TREE_DIFFERENT;
 304        return tree_difference;
 305}
 306
 307static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 308{
 309        int retval;
 310        void *tree;
 311        unsigned long size;
 312        struct tree_desc empty, real;
 313
 314        if (!t1)
 315                return 0;
 316
 317        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 318        if (!tree)
 319                return 0;
 320        init_tree_desc(&real, tree, size);
 321        init_tree_desc(&empty, "", 0);
 322
 323        tree_difference = REV_TREE_SAME;
 324        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 325        retval = diff_tree(&empty, &real, "", &revs->pruning);
 326        free(tree);
 327
 328        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 329}
 330
 331static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 332{
 333        struct commit_list **pp, *parent;
 334        int tree_changed = 0, tree_same = 0;
 335
 336        /*
 337         * If we don't do pruning, everything is interesting
 338         */
 339        if (!revs->prune)
 340                return;
 341
 342        if (!commit->tree)
 343                return;
 344
 345        if (!commit->parents) {
 346                if (rev_same_tree_as_empty(revs, commit->tree))
 347                        commit->object.flags |= TREESAME;
 348                return;
 349        }
 350
 351        /*
 352         * Normal non-merge commit? If we don't want to make the
 353         * history dense, we consider it always to be a change..
 354         */
 355        if (!revs->dense && !commit->parents->next)
 356                return;
 357
 358        pp = &commit->parents;
 359        while ((parent = *pp) != NULL) {
 360                struct commit *p = parent->item;
 361
 362                if (parse_commit(p) < 0)
 363                        die("cannot simplify commit %s (because of %s)",
 364                            sha1_to_hex(commit->object.sha1),
 365                            sha1_to_hex(p->object.sha1));
 366                switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 367                case REV_TREE_SAME:
 368                        tree_same = 1;
 369                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 370                                /* Even if a merge with an uninteresting
 371                                 * side branch brought the entire change
 372                                 * we are interested in, we do not want
 373                                 * to lose the other branches of this
 374                                 * merge, so we just keep going.
 375                                 */
 376                                pp = &parent->next;
 377                                continue;
 378                        }
 379                        parent->next = NULL;
 380                        commit->parents = parent;
 381                        commit->object.flags |= TREESAME;
 382                        return;
 383
 384                case REV_TREE_NEW:
 385                        if (revs->remove_empty_trees &&
 386                            rev_same_tree_as_empty(revs, p->tree)) {
 387                                /* We are adding all the specified
 388                                 * paths from this parent, so the
 389                                 * history beyond this parent is not
 390                                 * interesting.  Remove its parents
 391                                 * (they are grandparents for us).
 392                                 * IOW, we pretend this parent is a
 393                                 * "root" commit.
 394                                 */
 395                                if (parse_commit(p) < 0)
 396                                        die("cannot simplify commit %s (invalid %s)",
 397                                            sha1_to_hex(commit->object.sha1),
 398                                            sha1_to_hex(p->object.sha1));
 399                                p->parents = NULL;
 400                        }
 401                /* fallthrough */
 402                case REV_TREE_DIFFERENT:
 403                        tree_changed = 1;
 404                        pp = &parent->next;
 405                        continue;
 406                }
 407                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 408        }
 409        if (tree_changed && !tree_same)
 410                return;
 411        commit->object.flags |= TREESAME;
 412}
 413
 414static int add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 415{
 416        struct commit_list *parent = commit->parents;
 417        unsigned left_flag;
 418        int add, rest;
 419
 420        if (commit->object.flags & ADDED)
 421                return 0;
 422        commit->object.flags |= ADDED;
 423
 424        /*
 425         * If the commit is uninteresting, don't try to
 426         * prune parents - we want the maximal uninteresting
 427         * set.
 428         *
 429         * Normally we haven't parsed the parent
 430         * yet, so we won't have a parent of a parent
 431         * here. However, it may turn out that we've
 432         * reached this commit some other way (where it
 433         * wasn't uninteresting), in which case we need
 434         * to mark its parents recursively too..
 435         */
 436        if (commit->object.flags & UNINTERESTING) {
 437                while (parent) {
 438                        struct commit *p = parent->item;
 439                        parent = parent->next;
 440                        if (parse_commit(p) < 0)
 441                                return -1;
 442                        p->object.flags |= UNINTERESTING;
 443                        if (p->parents)
 444                                mark_parents_uninteresting(p);
 445                        if (p->object.flags & SEEN)
 446                                continue;
 447                        p->object.flags |= SEEN;
 448                        insert_by_date(p, list);
 449                }
 450                return 0;
 451        }
 452
 453        /*
 454         * Ok, the commit wasn't uninteresting. Try to
 455         * simplify the commit history and find the parent
 456         * that has no differences in the path set if one exists.
 457         */
 458        try_to_simplify_commit(revs, commit);
 459
 460        if (revs->no_walk)
 461                return 0;
 462
 463        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 464
 465        rest = !revs->first_parent_only;
 466        for (parent = commit->parents, add = 1; parent; add = rest) {
 467                struct commit *p = parent->item;
 468
 469                parent = parent->next;
 470                if (parse_commit(p) < 0)
 471                        return -1;
 472                p->object.flags |= left_flag;
 473                if (p->object.flags & SEEN)
 474                        continue;
 475                p->object.flags |= SEEN;
 476                if (add)
 477                        insert_by_date(p, list);
 478        }
 479        return 0;
 480}
 481
 482static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 483{
 484        struct commit_list *p;
 485        int left_count = 0, right_count = 0;
 486        int left_first;
 487        struct patch_ids ids;
 488
 489        /* First count the commits on the left and on the right */
 490        for (p = list; p; p = p->next) {
 491                struct commit *commit = p->item;
 492                unsigned flags = commit->object.flags;
 493                if (flags & BOUNDARY)
 494                        ;
 495                else if (flags & SYMMETRIC_LEFT)
 496                        left_count++;
 497                else
 498                        right_count++;
 499        }
 500
 501        left_first = left_count < right_count;
 502        init_patch_ids(&ids);
 503        if (revs->diffopt.nr_paths) {
 504                ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 505                ids.diffopts.paths = revs->diffopt.paths;
 506                ids.diffopts.pathlens = revs->diffopt.pathlens;
 507        }
 508
 509        /* Compute patch-ids for one side */
 510        for (p = list; p; p = p->next) {
 511                struct commit *commit = p->item;
 512                unsigned flags = commit->object.flags;
 513
 514                if (flags & BOUNDARY)
 515                        continue;
 516                /*
 517                 * If we have fewer left, left_first is set and we omit
 518                 * commits on the right branch in this loop.  If we have
 519                 * fewer right, we skip the left ones.
 520                 */
 521                if (left_first != !!(flags & SYMMETRIC_LEFT))
 522                        continue;
 523                commit->util = add_commit_patch_id(commit, &ids);
 524        }
 525
 526        /* Check the other side */
 527        for (p = list; p; p = p->next) {
 528                struct commit *commit = p->item;
 529                struct patch_id *id;
 530                unsigned flags = commit->object.flags;
 531
 532                if (flags & BOUNDARY)
 533                        continue;
 534                /*
 535                 * If we have fewer left, left_first is set and we omit
 536                 * commits on the left branch in this loop.
 537                 */
 538                if (left_first == !!(flags & SYMMETRIC_LEFT))
 539                        continue;
 540
 541                /*
 542                 * Have we seen the same patch id?
 543                 */
 544                id = has_commit_patch_id(commit, &ids);
 545                if (!id)
 546                        continue;
 547                id->seen = 1;
 548                commit->object.flags |= SHOWN;
 549        }
 550
 551        /* Now check the original side for seen ones */
 552        for (p = list; p; p = p->next) {
 553                struct commit *commit = p->item;
 554                struct patch_id *ent;
 555
 556                ent = commit->util;
 557                if (!ent)
 558                        continue;
 559                if (ent->seen)
 560                        commit->object.flags |= SHOWN;
 561                commit->util = NULL;
 562        }
 563
 564        free_patch_ids(&ids);
 565}
 566
 567static int limit_list(struct rev_info *revs)
 568{
 569        struct commit_list *list = revs->commits;
 570        struct commit_list *newlist = NULL;
 571        struct commit_list **p = &newlist;
 572
 573        while (list) {
 574                struct commit_list *entry = list;
 575                struct commit *commit = list->item;
 576                struct object *obj = &commit->object;
 577                show_early_output_fn_t show;
 578
 579                list = list->next;
 580                free(entry);
 581
 582                if (revs->max_age != -1 && (commit->date < revs->max_age))
 583                        obj->flags |= UNINTERESTING;
 584                if (add_parents_to_list(revs, commit, &list) < 0)
 585                        return -1;
 586                if (obj->flags & UNINTERESTING) {
 587                        mark_parents_uninteresting(commit);
 588                        if (everybody_uninteresting(list))
 589                                break;
 590                        continue;
 591                }
 592                if (revs->min_age != -1 && (commit->date > revs->min_age))
 593                        continue;
 594                p = &commit_list_insert(commit, p)->next;
 595
 596                show = show_early_output;
 597                if (!show)
 598                        continue;
 599
 600                show(revs, newlist);
 601                show_early_output = NULL;
 602        }
 603        if (revs->cherry_pick)
 604                cherry_pick_list(newlist, revs);
 605
 606        revs->commits = newlist;
 607        return 0;
 608}
 609
 610struct all_refs_cb {
 611        int all_flags;
 612        int warned_bad_reflog;
 613        struct rev_info *all_revs;
 614        const char *name_for_errormsg;
 615};
 616
 617static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 618{
 619        struct all_refs_cb *cb = cb_data;
 620        struct object *object = get_reference(cb->all_revs, path, sha1,
 621                                              cb->all_flags);
 622        add_pending_object(cb->all_revs, object, path);
 623        return 0;
 624}
 625
 626static void handle_all(struct rev_info *revs, unsigned flags)
 627{
 628        struct all_refs_cb cb;
 629        cb.all_revs = revs;
 630        cb.all_flags = flags;
 631        for_each_ref(handle_one_ref, &cb);
 632}
 633
 634static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 635{
 636        struct all_refs_cb *cb = cb_data;
 637        if (!is_null_sha1(sha1)) {
 638                struct object *o = parse_object(sha1);
 639                if (o) {
 640                        o->flags |= cb->all_flags;
 641                        add_pending_object(cb->all_revs, o, "");
 642                }
 643                else if (!cb->warned_bad_reflog) {
 644                        warning("reflog of '%s' references pruned commits",
 645                                cb->name_for_errormsg);
 646                        cb->warned_bad_reflog = 1;
 647                }
 648        }
 649}
 650
 651static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 652                const char *email, unsigned long timestamp, int tz,
 653                const char *message, void *cb_data)
 654{
 655        handle_one_reflog_commit(osha1, cb_data);
 656        handle_one_reflog_commit(nsha1, cb_data);
 657        return 0;
 658}
 659
 660static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 661{
 662        struct all_refs_cb *cb = cb_data;
 663        cb->warned_bad_reflog = 0;
 664        cb->name_for_errormsg = path;
 665        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 666        return 0;
 667}
 668
 669static void handle_reflog(struct rev_info *revs, unsigned flags)
 670{
 671        struct all_refs_cb cb;
 672        cb.all_revs = revs;
 673        cb.all_flags = flags;
 674        for_each_reflog(handle_one_reflog, &cb);
 675}
 676
 677static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 678{
 679        unsigned char sha1[20];
 680        struct object *it;
 681        struct commit *commit;
 682        struct commit_list *parents;
 683
 684        if (*arg == '^') {
 685                flags ^= UNINTERESTING;
 686                arg++;
 687        }
 688        if (get_sha1(arg, sha1))
 689                return 0;
 690        while (1) {
 691                it = get_reference(revs, arg, sha1, 0);
 692                if (it->type != OBJ_TAG)
 693                        break;
 694                if (!((struct tag*)it)->tagged)
 695                        return 0;
 696                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 697        }
 698        if (it->type != OBJ_COMMIT)
 699                return 0;
 700        commit = (struct commit *)it;
 701        for (parents = commit->parents; parents; parents = parents->next) {
 702                it = &parents->item->object;
 703                it->flags |= flags;
 704                add_pending_object(revs, it, arg);
 705        }
 706        return 1;
 707}
 708
 709void init_revisions(struct rev_info *revs, const char *prefix)
 710{
 711        memset(revs, 0, sizeof(*revs));
 712
 713        revs->abbrev = DEFAULT_ABBREV;
 714        revs->ignore_merges = 1;
 715        revs->simplify_history = 1;
 716        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 717        DIFF_OPT_SET(&revs->pruning, QUIET);
 718        revs->pruning.add_remove = file_add_remove;
 719        revs->pruning.change = file_change;
 720        revs->lifo = 1;
 721        revs->dense = 1;
 722        revs->prefix = prefix;
 723        revs->max_age = -1;
 724        revs->min_age = -1;
 725        revs->skip_count = -1;
 726        revs->max_count = -1;
 727
 728        revs->commit_format = CMIT_FMT_DEFAULT;
 729
 730        diff_setup(&revs->diffopt);
 731}
 732
 733static void add_pending_commit_list(struct rev_info *revs,
 734                                    struct commit_list *commit_list,
 735                                    unsigned int flags)
 736{
 737        while (commit_list) {
 738                struct object *object = &commit_list->item->object;
 739                object->flags |= flags;
 740                add_pending_object(revs, object, sha1_to_hex(object->sha1));
 741                commit_list = commit_list->next;
 742        }
 743}
 744
 745static void prepare_show_merge(struct rev_info *revs)
 746{
 747        struct commit_list *bases;
 748        struct commit *head, *other;
 749        unsigned char sha1[20];
 750        const char **prune = NULL;
 751        int i, prune_num = 1; /* counting terminating NULL */
 752
 753        if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 754                die("--merge without HEAD?");
 755        if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 756                die("--merge without MERGE_HEAD?");
 757        add_pending_object(revs, &head->object, "HEAD");
 758        add_pending_object(revs, &other->object, "MERGE_HEAD");
 759        bases = get_merge_bases(head, other, 1);
 760        while (bases) {
 761                struct commit *it = bases->item;
 762                struct commit_list *n = bases->next;
 763                free(bases);
 764                bases = n;
 765                it->object.flags |= UNINTERESTING;
 766                add_pending_object(revs, &it->object, "(merge-base)");
 767        }
 768
 769        if (!active_nr)
 770                read_cache();
 771        for (i = 0; i < active_nr; i++) {
 772                struct cache_entry *ce = active_cache[i];
 773                if (!ce_stage(ce))
 774                        continue;
 775                if (ce_path_match(ce, revs->prune_data)) {
 776                        prune_num++;
 777                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
 778                        prune[prune_num-2] = ce->name;
 779                        prune[prune_num-1] = NULL;
 780                }
 781                while ((i+1 < active_nr) &&
 782                       ce_same_name(ce, active_cache[i+1]))
 783                        i++;
 784        }
 785        revs->prune_data = prune;
 786}
 787
 788int handle_revision_arg(const char *arg, struct rev_info *revs,
 789                        int flags,
 790                        int cant_be_filename)
 791{
 792        unsigned mode;
 793        char *dotdot;
 794        struct object *object;
 795        unsigned char sha1[20];
 796        int local_flags;
 797
 798        dotdot = strstr(arg, "..");
 799        if (dotdot) {
 800                unsigned char from_sha1[20];
 801                const char *next = dotdot + 2;
 802                const char *this = arg;
 803                int symmetric = *next == '.';
 804                unsigned int flags_exclude = flags ^ UNINTERESTING;
 805
 806                *dotdot = 0;
 807                next += symmetric;
 808
 809                if (!*next)
 810                        next = "HEAD";
 811                if (dotdot == arg)
 812                        this = "HEAD";
 813                if (!get_sha1(this, from_sha1) &&
 814                    !get_sha1(next, sha1)) {
 815                        struct commit *a, *b;
 816                        struct commit_list *exclude;
 817
 818                        a = lookup_commit_reference(from_sha1);
 819                        b = lookup_commit_reference(sha1);
 820                        if (!a || !b) {
 821                                die(symmetric ?
 822                                    "Invalid symmetric difference expression %s...%s" :
 823                                    "Invalid revision range %s..%s",
 824                                    arg, next);
 825                        }
 826
 827                        if (!cant_be_filename) {
 828                                *dotdot = '.';
 829                                verify_non_filename(revs->prefix, arg);
 830                        }
 831
 832                        if (symmetric) {
 833                                exclude = get_merge_bases(a, b, 1);
 834                                add_pending_commit_list(revs, exclude,
 835                                                        flags_exclude);
 836                                free_commit_list(exclude);
 837                                a->object.flags |= flags | SYMMETRIC_LEFT;
 838                        } else
 839                                a->object.flags |= flags_exclude;
 840                        b->object.flags |= flags;
 841                        add_pending_object(revs, &a->object, this);
 842                        add_pending_object(revs, &b->object, next);
 843                        return 0;
 844                }
 845                *dotdot = '.';
 846        }
 847        dotdot = strstr(arg, "^@");
 848        if (dotdot && !dotdot[2]) {
 849                *dotdot = 0;
 850                if (add_parents_only(revs, arg, flags))
 851                        return 0;
 852                *dotdot = '^';
 853        }
 854        dotdot = strstr(arg, "^!");
 855        if (dotdot && !dotdot[2]) {
 856                *dotdot = 0;
 857                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 858                        *dotdot = '^';
 859        }
 860
 861        local_flags = 0;
 862        if (*arg == '^') {
 863                local_flags = UNINTERESTING;
 864                arg++;
 865        }
 866        if (get_sha1_with_mode(arg, sha1, &mode))
 867                return -1;
 868        if (!cant_be_filename)
 869                verify_non_filename(revs->prefix, arg);
 870        object = get_reference(revs, arg, sha1, flags ^ local_flags);
 871        add_pending_object_with_mode(revs, object, arg, mode);
 872        return 0;
 873}
 874
 875static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 876{
 877        if (!revs->grep_filter) {
 878                struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 879                opt->status_only = 1;
 880                opt->pattern_tail = &(opt->pattern_list);
 881                opt->regflags = REG_NEWLINE;
 882                revs->grep_filter = opt;
 883        }
 884        append_grep_pattern(revs->grep_filter, ptn,
 885                            "command line", 0, what);
 886}
 887
 888static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 889{
 890        char *pat;
 891        const char *prefix;
 892        int patlen, fldlen;
 893
 894        fldlen = strlen(field);
 895        patlen = strlen(pattern);
 896        pat = xmalloc(patlen + fldlen + 10);
 897        prefix = ".*";
 898        if (*pattern == '^') {
 899                prefix = "";
 900                pattern++;
 901        }
 902        sprintf(pat, "^%s %s%s", field, prefix, pattern);
 903        add_grep(revs, pat, GREP_PATTERN_HEAD);
 904}
 905
 906static void add_message_grep(struct rev_info *revs, const char *pattern)
 907{
 908        add_grep(revs, pattern, GREP_PATTERN_BODY);
 909}
 910
 911static void add_ignore_packed(struct rev_info *revs, const char *name)
 912{
 913        int num = ++revs->num_ignore_packed;
 914
 915        revs->ignore_packed = xrealloc(revs->ignore_packed,
 916                                       sizeof(const char **) * (num + 1));
 917        revs->ignore_packed[num-1] = name;
 918        revs->ignore_packed[num] = NULL;
 919}
 920
 921/*
 922 * Parse revision information, filling in the "rev_info" structure,
 923 * and removing the used arguments from the argument list.
 924 *
 925 * Returns the number of arguments left that weren't recognized
 926 * (which are also moved to the head of the argument list)
 927 */
 928int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 929{
 930        int i, flags, seen_dashdash, show_merge;
 931        const char **unrecognized = argv + 1;
 932        int left = 1;
 933        int all_match = 0;
 934        int regflags = 0;
 935
 936        /* First, search for "--" */
 937        seen_dashdash = 0;
 938        for (i = 1; i < argc; i++) {
 939                const char *arg = argv[i];
 940                if (strcmp(arg, "--"))
 941                        continue;
 942                argv[i] = NULL;
 943                argc = i;
 944                if (argv[i + 1])
 945                        revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 946                seen_dashdash = 1;
 947                break;
 948        }
 949
 950        flags = show_merge = 0;
 951        for (i = 1; i < argc; i++) {
 952                const char *arg = argv[i];
 953                if (*arg == '-') {
 954                        int opts;
 955                        if (!prefixcmp(arg, "--max-count=")) {
 956                                revs->max_count = atoi(arg + 12);
 957                                continue;
 958                        }
 959                        if (!prefixcmp(arg, "--skip=")) {
 960                                revs->skip_count = atoi(arg + 7);
 961                                continue;
 962                        }
 963                        /* accept -<digit>, like traditional "head" */
 964                        if ((*arg == '-') && isdigit(arg[1])) {
 965                                revs->max_count = atoi(arg + 1);
 966                                continue;
 967                        }
 968                        if (!strcmp(arg, "-n")) {
 969                                if (argc <= i + 1)
 970                                        die("-n requires an argument");
 971                                revs->max_count = atoi(argv[++i]);
 972                                continue;
 973                        }
 974                        if (!prefixcmp(arg, "-n")) {
 975                                revs->max_count = atoi(arg + 2);
 976                                continue;
 977                        }
 978                        if (!prefixcmp(arg, "--max-age=")) {
 979                                revs->max_age = atoi(arg + 10);
 980                                continue;
 981                        }
 982                        if (!prefixcmp(arg, "--since=")) {
 983                                revs->max_age = approxidate(arg + 8);
 984                                continue;
 985                        }
 986                        if (!prefixcmp(arg, "--after=")) {
 987                                revs->max_age = approxidate(arg + 8);
 988                                continue;
 989                        }
 990                        if (!prefixcmp(arg, "--min-age=")) {
 991                                revs->min_age = atoi(arg + 10);
 992                                continue;
 993                        }
 994                        if (!prefixcmp(arg, "--before=")) {
 995                                revs->min_age = approxidate(arg + 9);
 996                                continue;
 997                        }
 998                        if (!prefixcmp(arg, "--until=")) {
 999                                revs->min_age = approxidate(arg + 8);
1000                                continue;
1001                        }
1002                        if (!strcmp(arg, "--all")) {
1003                                handle_all(revs, flags);
1004                                continue;
1005                        }
1006                        if (!strcmp(arg, "--first-parent")) {
1007                                revs->first_parent_only = 1;
1008                                continue;
1009                        }
1010                        if (!strcmp(arg, "--reflog")) {
1011                                handle_reflog(revs, flags);
1012                                continue;
1013                        }
1014                        if (!strcmp(arg, "-g") ||
1015                                        !strcmp(arg, "--walk-reflogs")) {
1016                                init_reflog_walk(&revs->reflog_info);
1017                                continue;
1018                        }
1019                        if (!strcmp(arg, "--not")) {
1020                                flags ^= UNINTERESTING;
1021                                continue;
1022                        }
1023                        if (!strcmp(arg, "--default")) {
1024                                if (++i >= argc)
1025                                        die("bad --default argument");
1026                                def = argv[i];
1027                                continue;
1028                        }
1029                        if (!strcmp(arg, "--merge")) {
1030                                show_merge = 1;
1031                                continue;
1032                        }
1033                        if (!strcmp(arg, "--topo-order")) {
1034                                revs->topo_order = 1;
1035                                continue;
1036                        }
1037                        if (!strcmp(arg, "--date-order")) {
1038                                revs->lifo = 0;
1039                                revs->topo_order = 1;
1040                                continue;
1041                        }
1042                        if (!prefixcmp(arg, "--early-output")) {
1043                                int count = 100;
1044                                switch (arg[14]) {
1045                                case '=':
1046                                        count = atoi(arg+15);
1047                                        /* Fallthrough */
1048                                case 0:
1049                                        revs->topo_order = 1;
1050                                        revs->early_output = count;
1051                                        continue;
1052                                }
1053                        }
1054                        if (!strcmp(arg, "--parents")) {
1055                                revs->parents = 1;
1056                                continue;
1057                        }
1058                        if (!strcmp(arg, "--dense")) {
1059                                revs->dense = 1;
1060                                continue;
1061                        }
1062                        if (!strcmp(arg, "--sparse")) {
1063                                revs->dense = 0;
1064                                continue;
1065                        }
1066                        if (!strcmp(arg, "--remove-empty")) {
1067                                revs->remove_empty_trees = 1;
1068                                continue;
1069                        }
1070                        if (!strcmp(arg, "--no-merges")) {
1071                                revs->no_merges = 1;
1072                                continue;
1073                        }
1074                        if (!strcmp(arg, "--boundary")) {
1075                                revs->boundary = 1;
1076                                continue;
1077                        }
1078                        if (!strcmp(arg, "--left-right")) {
1079                                revs->left_right = 1;
1080                                continue;
1081                        }
1082                        if (!strcmp(arg, "--cherry-pick")) {
1083                                revs->cherry_pick = 1;
1084                                revs->limited = 1;
1085                                continue;
1086                        }
1087                        if (!strcmp(arg, "--objects")) {
1088                                revs->tag_objects = 1;
1089                                revs->tree_objects = 1;
1090                                revs->blob_objects = 1;
1091                                continue;
1092                        }
1093                        if (!strcmp(arg, "--objects-edge")) {
1094                                revs->tag_objects = 1;
1095                                revs->tree_objects = 1;
1096                                revs->blob_objects = 1;
1097                                revs->edge_hint = 1;
1098                                continue;
1099                        }
1100                        if (!strcmp(arg, "--unpacked")) {
1101                                revs->unpacked = 1;
1102                                free(revs->ignore_packed);
1103                                revs->ignore_packed = NULL;
1104                                revs->num_ignore_packed = 0;
1105                                continue;
1106                        }
1107                        if (!prefixcmp(arg, "--unpacked=")) {
1108                                revs->unpacked = 1;
1109                                add_ignore_packed(revs, arg+11);
1110                                continue;
1111                        }
1112                        if (!strcmp(arg, "-r")) {
1113                                revs->diff = 1;
1114                                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1115                                continue;
1116                        }
1117                        if (!strcmp(arg, "-t")) {
1118                                revs->diff = 1;
1119                                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1120                                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1121                                continue;
1122                        }
1123                        if (!strcmp(arg, "-m")) {
1124                                revs->ignore_merges = 0;
1125                                continue;
1126                        }
1127                        if (!strcmp(arg, "-c")) {
1128                                revs->diff = 1;
1129                                revs->dense_combined_merges = 0;
1130                                revs->combine_merges = 1;
1131                                continue;
1132                        }
1133                        if (!strcmp(arg, "--cc")) {
1134                                revs->diff = 1;
1135                                revs->dense_combined_merges = 1;
1136                                revs->combine_merges = 1;
1137                                continue;
1138                        }
1139                        if (!strcmp(arg, "-v")) {
1140                                revs->verbose_header = 1;
1141                                continue;
1142                        }
1143                        if (!prefixcmp(arg, "--pretty")) {
1144                                revs->verbose_header = 1;
1145                                revs->commit_format = get_commit_format(arg+8);
1146                                continue;
1147                        }
1148                        if (!strcmp(arg, "--root")) {
1149                                revs->show_root_diff = 1;
1150                                continue;
1151                        }
1152                        if (!strcmp(arg, "--no-commit-id")) {
1153                                revs->no_commit_id = 1;
1154                                continue;
1155                        }
1156                        if (!strcmp(arg, "--always")) {
1157                                revs->always_show_header = 1;
1158                                continue;
1159                        }
1160                        if (!strcmp(arg, "--no-abbrev")) {
1161                                revs->abbrev = 0;
1162                                continue;
1163                        }
1164                        if (!strcmp(arg, "--abbrev")) {
1165                                revs->abbrev = DEFAULT_ABBREV;
1166                                continue;
1167                        }
1168                        if (!prefixcmp(arg, "--abbrev=")) {
1169                                revs->abbrev = strtoul(arg + 9, NULL, 10);
1170                                if (revs->abbrev < MINIMUM_ABBREV)
1171                                        revs->abbrev = MINIMUM_ABBREV;
1172                                else if (revs->abbrev > 40)
1173                                        revs->abbrev = 40;
1174                                continue;
1175                        }
1176                        if (!strcmp(arg, "--abbrev-commit")) {
1177                                revs->abbrev_commit = 1;
1178                                continue;
1179                        }
1180                        if (!strcmp(arg, "--full-diff")) {
1181                                revs->diff = 1;
1182                                revs->full_diff = 1;
1183                                continue;
1184                        }
1185                        if (!strcmp(arg, "--full-history")) {
1186                                revs->simplify_history = 0;
1187                                continue;
1188                        }
1189                        if (!strcmp(arg, "--relative-date")) {
1190                                revs->date_mode = DATE_RELATIVE;
1191                                continue;
1192                        }
1193                        if (!strncmp(arg, "--date=", 7)) {
1194                                revs->date_mode = parse_date_format(arg + 7);
1195                                continue;
1196                        }
1197                        if (!strcmp(arg, "--log-size")) {
1198                                revs->show_log_size = 1;
1199                                continue;
1200                        }
1201
1202                        /*
1203                         * Grepping the commit log
1204                         */
1205                        if (!prefixcmp(arg, "--author=")) {
1206                                add_header_grep(revs, "author", arg+9);
1207                                continue;
1208                        }
1209                        if (!prefixcmp(arg, "--committer=")) {
1210                                add_header_grep(revs, "committer", arg+12);
1211                                continue;
1212                        }
1213                        if (!prefixcmp(arg, "--grep=")) {
1214                                add_message_grep(revs, arg+7);
1215                                continue;
1216                        }
1217                        if (!strcmp(arg, "--extended-regexp") ||
1218                            !strcmp(arg, "-E")) {
1219                                regflags |= REG_EXTENDED;
1220                                continue;
1221                        }
1222                        if (!strcmp(arg, "--regexp-ignore-case") ||
1223                            !strcmp(arg, "-i")) {
1224                                regflags |= REG_ICASE;
1225                                continue;
1226                        }
1227                        if (!strcmp(arg, "--all-match")) {
1228                                all_match = 1;
1229                                continue;
1230                        }
1231                        if (!prefixcmp(arg, "--encoding=")) {
1232                                arg += 11;
1233                                if (strcmp(arg, "none"))
1234                                        git_log_output_encoding = xstrdup(arg);
1235                                else
1236                                        git_log_output_encoding = "";
1237                                continue;
1238                        }
1239                        if (!strcmp(arg, "--reverse")) {
1240                                revs->reverse ^= 1;
1241                                continue;
1242                        }
1243                        if (!strcmp(arg, "--no-walk")) {
1244                                revs->no_walk = 1;
1245                                continue;
1246                        }
1247                        if (!strcmp(arg, "--do-walk")) {
1248                                revs->no_walk = 0;
1249                                continue;
1250                        }
1251
1252                        opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1253                        if (opts > 0) {
1254                                i += opts - 1;
1255                                continue;
1256                        }
1257                        *unrecognized++ = arg;
1258                        left++;
1259                        continue;
1260                }
1261
1262                if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1263                        int j;
1264                        if (seen_dashdash || *arg == '^')
1265                                die("bad revision '%s'", arg);
1266
1267                        /* If we didn't have a "--":
1268                         * (1) all filenames must exist;
1269                         * (2) all rev-args must not be interpretable
1270                         *     as a valid filename.
1271                         * but the latter we have checked in the main loop.
1272                         */
1273                        for (j = i; j < argc; j++)
1274                                verify_filename(revs->prefix, argv[j]);
1275
1276                        revs->prune_data = get_pathspec(revs->prefix,
1277                                                        argv + i);
1278                        break;
1279                }
1280        }
1281
1282        if (revs->grep_filter)
1283                revs->grep_filter->regflags |= regflags;
1284
1285        if (show_merge)
1286                prepare_show_merge(revs);
1287        if (def && !revs->pending.nr) {
1288                unsigned char sha1[20];
1289                struct object *object;
1290                unsigned mode;
1291                if (get_sha1_with_mode(def, sha1, &mode))
1292                        die("bad default revision '%s'", def);
1293                object = get_reference(revs, def, sha1, 0);
1294                add_pending_object_with_mode(revs, object, def, mode);
1295        }
1296
1297        /* Did the user ask for any diff output? Run the diff! */
1298        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1299                revs->diff = 1;
1300
1301        /* Pickaxe, diff-filter and rename following need diffs */
1302        if (revs->diffopt.pickaxe ||
1303            revs->diffopt.filter ||
1304            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1305                revs->diff = 1;
1306
1307        if (revs->topo_order)
1308                revs->limited = 1;
1309
1310        if (revs->prune_data) {
1311                diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1312                /* Can't prune commits with rename following: the paths change.. */
1313                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1314                        revs->prune = 1;
1315                if (!revs->full_diff)
1316                        diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1317        }
1318        if (revs->combine_merges) {
1319                revs->ignore_merges = 0;
1320                if (revs->dense_combined_merges && !revs->diffopt.output_format)
1321                        revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1322        }
1323        revs->diffopt.abbrev = revs->abbrev;
1324        if (diff_setup_done(&revs->diffopt) < 0)
1325                die("diff_setup_done failed");
1326
1327        if (revs->grep_filter) {
1328                revs->grep_filter->all_match = all_match;
1329                compile_grep_patterns(revs->grep_filter);
1330        }
1331
1332        if (revs->reverse && revs->reflog_info)
1333                die("cannot combine --reverse with --walk-reflogs");
1334
1335        return left;
1336}
1337
1338int prepare_revision_walk(struct rev_info *revs)
1339{
1340        int nr = revs->pending.nr;
1341        struct object_array_entry *e, *list;
1342
1343        e = list = revs->pending.objects;
1344        revs->pending.nr = 0;
1345        revs->pending.alloc = 0;
1346        revs->pending.objects = NULL;
1347        while (--nr >= 0) {
1348                struct commit *commit = handle_commit(revs, e->item, e->name);
1349                if (commit) {
1350                        if (!(commit->object.flags & SEEN)) {
1351                                commit->object.flags |= SEEN;
1352                                insert_by_date(commit, &revs->commits);
1353                        }
1354                }
1355                e++;
1356        }
1357        free(list);
1358
1359        if (revs->no_walk)
1360                return 0;
1361        if (revs->limited)
1362                if (limit_list(revs) < 0)
1363                        return -1;
1364        if (revs->topo_order)
1365                sort_in_topological_order(&revs->commits, revs->lifo);
1366        return 0;
1367}
1368
1369enum rewrite_result {
1370        rewrite_one_ok,
1371        rewrite_one_noparents,
1372        rewrite_one_error,
1373};
1374
1375static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1376{
1377        for (;;) {
1378                struct commit *p = *pp;
1379                if (!revs->limited)
1380                        if (add_parents_to_list(revs, p, &revs->commits) < 0)
1381                                return rewrite_one_error;
1382                if (p->parents && p->parents->next)
1383                        return rewrite_one_ok;
1384                if (p->object.flags & UNINTERESTING)
1385                        return rewrite_one_ok;
1386                if (!(p->object.flags & TREESAME))
1387                        return rewrite_one_ok;
1388                if (!p->parents)
1389                        return rewrite_one_noparents;
1390                *pp = p->parents->item;
1391        }
1392}
1393
1394static void remove_duplicate_parents(struct commit *commit)
1395{
1396        struct commit_list **pp, *p;
1397
1398        /* Examine existing parents while marking ones we have seen... */
1399        pp = &commit->parents;
1400        while ((p = *pp) != NULL) {
1401                struct commit *parent = p->item;
1402                if (parent->object.flags & TMP_MARK) {
1403                        *pp = p->next;
1404                        continue;
1405                }
1406                parent->object.flags |= TMP_MARK;
1407                pp = &p->next;
1408        }
1409        /* ... and clear the temporary mark */
1410        for (p = commit->parents; p; p = p->next)
1411                p->item->object.flags &= ~TMP_MARK;
1412}
1413
1414static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1415{
1416        struct commit_list **pp = &commit->parents;
1417        while (*pp) {
1418                struct commit_list *parent = *pp;
1419                switch (rewrite_one(revs, &parent->item)) {
1420                case rewrite_one_ok:
1421                        break;
1422                case rewrite_one_noparents:
1423                        *pp = parent->next;
1424                        continue;
1425                case rewrite_one_error:
1426                        return -1;
1427                }
1428                pp = &parent->next;
1429        }
1430        remove_duplicate_parents(commit);
1431        return 0;
1432}
1433
1434static int commit_match(struct commit *commit, struct rev_info *opt)
1435{
1436        if (!opt->grep_filter)
1437                return 1;
1438        return grep_buffer(opt->grep_filter,
1439                           NULL, /* we say nothing, not even filename */
1440                           commit->buffer, strlen(commit->buffer));
1441}
1442
1443enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1444{
1445        if (commit->object.flags & SHOWN)
1446                return commit_ignore;
1447        if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1448                return commit_ignore;
1449        if (commit->object.flags & UNINTERESTING)
1450                return commit_ignore;
1451        if (revs->min_age != -1 && (commit->date > revs->min_age))
1452                return commit_ignore;
1453        if (revs->no_merges && commit->parents && commit->parents->next)
1454                return commit_ignore;
1455        if (!commit_match(commit, revs))
1456                return commit_ignore;
1457        if (revs->prune && revs->dense) {
1458                /* Commit without changes? */
1459                if (commit->object.flags & TREESAME) {
1460                        /* drop merges unless we want parenthood */
1461                        if (!revs->parents)
1462                                return commit_ignore;
1463                        /* non-merge - always ignore it */
1464                        if (!commit->parents || !commit->parents->next)
1465                                return commit_ignore;
1466                }
1467                if (revs->parents && rewrite_parents(revs, commit) < 0)
1468                        return commit_error;
1469        }
1470        return commit_show;
1471}
1472
1473static struct commit *get_revision_1(struct rev_info *revs)
1474{
1475        if (!revs->commits)
1476                return NULL;
1477
1478        do {
1479                struct commit_list *entry = revs->commits;
1480                struct commit *commit = entry->item;
1481
1482                revs->commits = entry->next;
1483                free(entry);
1484
1485                if (revs->reflog_info)
1486                        fake_reflog_parent(revs->reflog_info, commit);
1487
1488                /*
1489                 * If we haven't done the list limiting, we need to look at
1490                 * the parents here. We also need to do the date-based limiting
1491                 * that we'd otherwise have done in limit_list().
1492                 */
1493                if (!revs->limited) {
1494                        if (revs->max_age != -1 &&
1495                            (commit->date < revs->max_age))
1496                                continue;
1497                        if (add_parents_to_list(revs, commit, &revs->commits) < 0)
1498                                return NULL;
1499                }
1500
1501                switch (simplify_commit(revs, commit)) {
1502                case commit_ignore:
1503                        continue;
1504                case commit_error:
1505                        return NULL;
1506                default:
1507                        return commit;
1508                }
1509        } while (revs->commits);
1510        return NULL;
1511}
1512
1513static void gc_boundary(struct object_array *array)
1514{
1515        unsigned nr = array->nr;
1516        unsigned alloc = array->alloc;
1517        struct object_array_entry *objects = array->objects;
1518
1519        if (alloc <= nr) {
1520                unsigned i, j;
1521                for (i = j = 0; i < nr; i++) {
1522                        if (objects[i].item->flags & SHOWN)
1523                                continue;
1524                        if (i != j)
1525                                objects[j] = objects[i];
1526                        j++;
1527                }
1528                for (i = j; i < nr; i++)
1529                        objects[i].item = NULL;
1530                array->nr = j;
1531        }
1532}
1533
1534struct commit *get_revision(struct rev_info *revs)
1535{
1536        struct commit *c = NULL;
1537        struct commit_list *l;
1538
1539        if (revs->boundary == 2) {
1540                unsigned i;
1541                struct object_array *array = &revs->boundary_commits;
1542                struct object_array_entry *objects = array->objects;
1543                for (i = 0; i < array->nr; i++) {
1544                        c = (struct commit *)(objects[i].item);
1545                        if (!c)
1546                                continue;
1547                        if (!(c->object.flags & CHILD_SHOWN))
1548                                continue;
1549                        if (!(c->object.flags & SHOWN))
1550                                break;
1551                }
1552                if (array->nr <= i)
1553                        return NULL;
1554
1555                c->object.flags |= SHOWN | BOUNDARY;
1556                return c;
1557        }
1558
1559        if (revs->reverse) {
1560                int limit = -1;
1561
1562                if (0 <= revs->max_count) {
1563                        limit = revs->max_count;
1564                        if (0 < revs->skip_count)
1565                                limit += revs->skip_count;
1566                }
1567                l = NULL;
1568                while ((c = get_revision_1(revs))) {
1569                        commit_list_insert(c, &l);
1570                        if ((0 < limit) && !--limit)
1571                                break;
1572                }
1573                revs->commits = l;
1574                revs->reverse = 0;
1575                revs->max_count = -1;
1576                c = NULL;
1577        }
1578
1579        /*
1580         * Now pick up what they want to give us
1581         */
1582        c = get_revision_1(revs);
1583        if (c) {
1584                while (0 < revs->skip_count) {
1585                        revs->skip_count--;
1586                        c = get_revision_1(revs);
1587                        if (!c)
1588                                break;
1589                }
1590        }
1591
1592        /*
1593         * Check the max_count.
1594         */
1595        switch (revs->max_count) {
1596        case -1:
1597                break;
1598        case 0:
1599                c = NULL;
1600                break;
1601        default:
1602                revs->max_count--;
1603        }
1604
1605        if (c)
1606                c->object.flags |= SHOWN;
1607
1608        if (!revs->boundary) {
1609                return c;
1610        }
1611
1612        if (!c) {
1613                /*
1614                 * get_revision_1() runs out the commits, and
1615                 * we are done computing the boundaries.
1616                 * switch to boundary commits output mode.
1617                 */
1618                revs->boundary = 2;
1619                return get_revision(revs);
1620        }
1621
1622        /*
1623         * boundary commits are the commits that are parents of the
1624         * ones we got from get_revision_1() but they themselves are
1625         * not returned from get_revision_1().  Before returning
1626         * 'c', we need to mark its parents that they could be boundaries.
1627         */
1628
1629        for (l = c->parents; l; l = l->next) {
1630                struct object *p;
1631                p = &(l->item->object);
1632                if (p->flags & (CHILD_SHOWN | SHOWN))
1633                        continue;
1634                p->flags |= CHILD_SHOWN;
1635                gc_boundary(&revs->boundary_commits);
1636                add_object_array(p, NULL, &revs->boundary_commits);
1637        }
1638
1639        return c;
1640}