Andrew's git / gitweb.git / revision.c
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revision.con commit Add a very basic test script for git mergetool (05e934b)
   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 void add_to_list(struct commit_list **p, struct commit *commit, struct commit_list *n)
 568{
 569        p = &commit_list_insert(commit, p)->next;
 570        *p = n;
 571}
 572
 573static int limit_list(struct rev_info *revs)
 574{
 575        struct commit_list *list = revs->commits;
 576        struct commit_list *newlist = NULL;
 577        struct commit_list **p = &newlist;
 578
 579        while (list) {
 580                struct commit_list *entry = list;
 581                struct commit *commit = list->item;
 582                struct object *obj = &commit->object;
 583                show_early_output_fn_t show;
 584
 585                list = list->next;
 586                free(entry);
 587
 588                if (revs->max_age != -1 && (commit->date < revs->max_age))
 589                        obj->flags |= UNINTERESTING;
 590                if (add_parents_to_list(revs, commit, &list) < 0)
 591                        return -1;
 592                if (obj->flags & UNINTERESTING) {
 593                        mark_parents_uninteresting(commit);
 594                        if (everybody_uninteresting(list)) {
 595                                if (revs->show_all)
 596                                        add_to_list(p, commit, list);
 597                                break;
 598                        }
 599                        if (!revs->show_all)
 600                                continue;
 601                }
 602                if (revs->min_age != -1 && (commit->date > revs->min_age))
 603                        continue;
 604                p = &commit_list_insert(commit, p)->next;
 605
 606                show = show_early_output;
 607                if (!show)
 608                        continue;
 609
 610                show(revs, newlist);
 611                show_early_output = NULL;
 612        }
 613        if (revs->cherry_pick)
 614                cherry_pick_list(newlist, revs);
 615
 616        revs->commits = newlist;
 617        return 0;
 618}
 619
 620struct all_refs_cb {
 621        int all_flags;
 622        int warned_bad_reflog;
 623        struct rev_info *all_revs;
 624        const char *name_for_errormsg;
 625};
 626
 627static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 628{
 629        struct all_refs_cb *cb = cb_data;
 630        struct object *object = get_reference(cb->all_revs, path, sha1,
 631                                              cb->all_flags);
 632        add_pending_object(cb->all_revs, object, path);
 633        return 0;
 634}
 635
 636static void handle_refs(struct rev_info *revs, unsigned flags,
 637                int (*for_each)(each_ref_fn, void *))
 638{
 639        struct all_refs_cb cb;
 640        cb.all_revs = revs;
 641        cb.all_flags = flags;
 642        for_each(handle_one_ref, &cb);
 643}
 644
 645static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 646{
 647        struct all_refs_cb *cb = cb_data;
 648        if (!is_null_sha1(sha1)) {
 649                struct object *o = parse_object(sha1);
 650                if (o) {
 651                        o->flags |= cb->all_flags;
 652                        add_pending_object(cb->all_revs, o, "");
 653                }
 654                else if (!cb->warned_bad_reflog) {
 655                        warning("reflog of '%s' references pruned commits",
 656                                cb->name_for_errormsg);
 657                        cb->warned_bad_reflog = 1;
 658                }
 659        }
 660}
 661
 662static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 663                const char *email, unsigned long timestamp, int tz,
 664                const char *message, void *cb_data)
 665{
 666        handle_one_reflog_commit(osha1, cb_data);
 667        handle_one_reflog_commit(nsha1, cb_data);
 668        return 0;
 669}
 670
 671static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 672{
 673        struct all_refs_cb *cb = cb_data;
 674        cb->warned_bad_reflog = 0;
 675        cb->name_for_errormsg = path;
 676        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 677        return 0;
 678}
 679
 680static void handle_reflog(struct rev_info *revs, unsigned flags)
 681{
 682        struct all_refs_cb cb;
 683        cb.all_revs = revs;
 684        cb.all_flags = flags;
 685        for_each_reflog(handle_one_reflog, &cb);
 686}
 687
 688static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 689{
 690        unsigned char sha1[20];
 691        struct object *it;
 692        struct commit *commit;
 693        struct commit_list *parents;
 694
 695        if (*arg == '^') {
 696                flags ^= UNINTERESTING;
 697                arg++;
 698        }
 699        if (get_sha1(arg, sha1))
 700                return 0;
 701        while (1) {
 702                it = get_reference(revs, arg, sha1, 0);
 703                if (it->type != OBJ_TAG)
 704                        break;
 705                if (!((struct tag*)it)->tagged)
 706                        return 0;
 707                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 708        }
 709        if (it->type != OBJ_COMMIT)
 710                return 0;
 711        commit = (struct commit *)it;
 712        for (parents = commit->parents; parents; parents = parents->next) {
 713                it = &parents->item->object;
 714                it->flags |= flags;
 715                add_pending_object(revs, it, arg);
 716        }
 717        return 1;
 718}
 719
 720void init_revisions(struct rev_info *revs, const char *prefix)
 721{
 722        memset(revs, 0, sizeof(*revs));
 723
 724        revs->abbrev = DEFAULT_ABBREV;
 725        revs->ignore_merges = 1;
 726        revs->simplify_history = 1;
 727        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 728        DIFF_OPT_SET(&revs->pruning, QUIET);
 729        revs->pruning.add_remove = file_add_remove;
 730        revs->pruning.change = file_change;
 731        revs->lifo = 1;
 732        revs->dense = 1;
 733        revs->prefix = prefix;
 734        revs->max_age = -1;
 735        revs->min_age = -1;
 736        revs->skip_count = -1;
 737        revs->max_count = -1;
 738
 739        revs->commit_format = CMIT_FMT_DEFAULT;
 740
 741        diff_setup(&revs->diffopt);
 742        if (prefix && !revs->diffopt.prefix) {
 743                revs->diffopt.prefix = prefix;
 744                revs->diffopt.prefix_length = strlen(prefix);
 745        }
 746}
 747
 748static void add_pending_commit_list(struct rev_info *revs,
 749                                    struct commit_list *commit_list,
 750                                    unsigned int flags)
 751{
 752        while (commit_list) {
 753                struct object *object = &commit_list->item->object;
 754                object->flags |= flags;
 755                add_pending_object(revs, object, sha1_to_hex(object->sha1));
 756                commit_list = commit_list->next;
 757        }
 758}
 759
 760static void prepare_show_merge(struct rev_info *revs)
 761{
 762        struct commit_list *bases;
 763        struct commit *head, *other;
 764        unsigned char sha1[20];
 765        const char **prune = NULL;
 766        int i, prune_num = 1; /* counting terminating NULL */
 767
 768        if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 769                die("--merge without HEAD?");
 770        if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 771                die("--merge without MERGE_HEAD?");
 772        add_pending_object(revs, &head->object, "HEAD");
 773        add_pending_object(revs, &other->object, "MERGE_HEAD");
 774        bases = get_merge_bases(head, other, 1);
 775        add_pending_commit_list(revs, bases, UNINTERESTING);
 776        free_commit_list(bases);
 777        head->object.flags |= SYMMETRIC_LEFT;
 778
 779        if (!active_nr)
 780                read_cache();
 781        for (i = 0; i < active_nr; i++) {
 782                struct cache_entry *ce = active_cache[i];
 783                if (!ce_stage(ce))
 784                        continue;
 785                if (ce_path_match(ce, revs->prune_data)) {
 786                        prune_num++;
 787                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
 788                        prune[prune_num-2] = ce->name;
 789                        prune[prune_num-1] = NULL;
 790                }
 791                while ((i+1 < active_nr) &&
 792                       ce_same_name(ce, active_cache[i+1]))
 793                        i++;
 794        }
 795        revs->prune_data = prune;
 796        revs->limited = 1;
 797}
 798
 799int handle_revision_arg(const char *arg, struct rev_info *revs,
 800                        int flags,
 801                        int cant_be_filename)
 802{
 803        unsigned mode;
 804        char *dotdot;
 805        struct object *object;
 806        unsigned char sha1[20];
 807        int local_flags;
 808
 809        dotdot = strstr(arg, "..");
 810        if (dotdot) {
 811                unsigned char from_sha1[20];
 812                const char *next = dotdot + 2;
 813                const char *this = arg;
 814                int symmetric = *next == '.';
 815                unsigned int flags_exclude = flags ^ UNINTERESTING;
 816
 817                *dotdot = 0;
 818                next += symmetric;
 819
 820                if (!*next)
 821                        next = "HEAD";
 822                if (dotdot == arg)
 823                        this = "HEAD";
 824                if (!get_sha1(this, from_sha1) &&
 825                    !get_sha1(next, sha1)) {
 826                        struct commit *a, *b;
 827                        struct commit_list *exclude;
 828
 829                        a = lookup_commit_reference(from_sha1);
 830                        b = lookup_commit_reference(sha1);
 831                        if (!a || !b) {
 832                                die(symmetric ?
 833                                    "Invalid symmetric difference expression %s...%s" :
 834                                    "Invalid revision range %s..%s",
 835                                    arg, next);
 836                        }
 837
 838                        if (!cant_be_filename) {
 839                                *dotdot = '.';
 840                                verify_non_filename(revs->prefix, arg);
 841                        }
 842
 843                        if (symmetric) {
 844                                exclude = get_merge_bases(a, b, 1);
 845                                add_pending_commit_list(revs, exclude,
 846                                                        flags_exclude);
 847                                free_commit_list(exclude);
 848                                a->object.flags |= flags | SYMMETRIC_LEFT;
 849                        } else
 850                                a->object.flags |= flags_exclude;
 851                        b->object.flags |= flags;
 852                        add_pending_object(revs, &a->object, this);
 853                        add_pending_object(revs, &b->object, next);
 854                        return 0;
 855                }
 856                *dotdot = '.';
 857        }
 858        dotdot = strstr(arg, "^@");
 859        if (dotdot && !dotdot[2]) {
 860                *dotdot = 0;
 861                if (add_parents_only(revs, arg, flags))
 862                        return 0;
 863                *dotdot = '^';
 864        }
 865        dotdot = strstr(arg, "^!");
 866        if (dotdot && !dotdot[2]) {
 867                *dotdot = 0;
 868                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 869                        *dotdot = '^';
 870        }
 871
 872        local_flags = 0;
 873        if (*arg == '^') {
 874                local_flags = UNINTERESTING;
 875                arg++;
 876        }
 877        if (get_sha1_with_mode(arg, sha1, &mode))
 878                return -1;
 879        if (!cant_be_filename)
 880                verify_non_filename(revs->prefix, arg);
 881        object = get_reference(revs, arg, sha1, flags ^ local_flags);
 882        add_pending_object_with_mode(revs, object, arg, mode);
 883        return 0;
 884}
 885
 886static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 887{
 888        if (!revs->grep_filter) {
 889                struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 890                opt->status_only = 1;
 891                opt->pattern_tail = &(opt->pattern_list);
 892                opt->regflags = REG_NEWLINE;
 893                revs->grep_filter = opt;
 894        }
 895        append_grep_pattern(revs->grep_filter, ptn,
 896                            "command line", 0, what);
 897}
 898
 899static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 900{
 901        char *pat;
 902        const char *prefix;
 903        int patlen, fldlen;
 904
 905        fldlen = strlen(field);
 906        patlen = strlen(pattern);
 907        pat = xmalloc(patlen + fldlen + 10);
 908        prefix = ".*";
 909        if (*pattern == '^') {
 910                prefix = "";
 911                pattern++;
 912        }
 913        sprintf(pat, "^%s %s%s", field, prefix, pattern);
 914        add_grep(revs, pat, GREP_PATTERN_HEAD);
 915}
 916
 917static void add_message_grep(struct rev_info *revs, const char *pattern)
 918{
 919        add_grep(revs, pattern, GREP_PATTERN_BODY);
 920}
 921
 922static void add_ignore_packed(struct rev_info *revs, const char *name)
 923{
 924        int num = ++revs->num_ignore_packed;
 925
 926        revs->ignore_packed = xrealloc(revs->ignore_packed,
 927                                       sizeof(const char **) * (num + 1));
 928        revs->ignore_packed[num-1] = name;
 929        revs->ignore_packed[num] = NULL;
 930}
 931
 932/*
 933 * Parse revision information, filling in the "rev_info" structure,
 934 * and removing the used arguments from the argument list.
 935 *
 936 * Returns the number of arguments left that weren't recognized
 937 * (which are also moved to the head of the argument list)
 938 */
 939int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 940{
 941        int i, flags, seen_dashdash, show_merge;
 942        const char **unrecognized = argv + 1;
 943        int left = 1;
 944        int all_match = 0;
 945        int regflags = 0;
 946        int fixed = 0;
 947
 948        /* First, search for "--" */
 949        seen_dashdash = 0;
 950        for (i = 1; i < argc; i++) {
 951                const char *arg = argv[i];
 952                if (strcmp(arg, "--"))
 953                        continue;
 954                argv[i] = NULL;
 955                argc = i;
 956                if (argv[i + 1])
 957                        revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 958                seen_dashdash = 1;
 959                break;
 960        }
 961
 962        flags = show_merge = 0;
 963        for (i = 1; i < argc; i++) {
 964                const char *arg = argv[i];
 965                if (*arg == '-') {
 966                        int opts;
 967                        if (!prefixcmp(arg, "--max-count=")) {
 968                                revs->max_count = atoi(arg + 12);
 969                                continue;
 970                        }
 971                        if (!prefixcmp(arg, "--skip=")) {
 972                                revs->skip_count = atoi(arg + 7);
 973                                continue;
 974                        }
 975                        /* accept -<digit>, like traditional "head" */
 976                        if ((*arg == '-') && isdigit(arg[1])) {
 977                                revs->max_count = atoi(arg + 1);
 978                                continue;
 979                        }
 980                        if (!strcmp(arg, "-n")) {
 981                                if (argc <= i + 1)
 982                                        die("-n requires an argument");
 983                                revs->max_count = atoi(argv[++i]);
 984                                continue;
 985                        }
 986                        if (!prefixcmp(arg, "-n")) {
 987                                revs->max_count = atoi(arg + 2);
 988                                continue;
 989                        }
 990                        if (!prefixcmp(arg, "--max-age=")) {
 991                                revs->max_age = atoi(arg + 10);
 992                                continue;
 993                        }
 994                        if (!prefixcmp(arg, "--since=")) {
 995                                revs->max_age = approxidate(arg + 8);
 996                                continue;
 997                        }
 998                        if (!prefixcmp(arg, "--after=")) {
 999                                revs->max_age = approxidate(arg + 8);
1000                                continue;
1001                        }
1002                        if (!prefixcmp(arg, "--min-age=")) {
1003                                revs->min_age = atoi(arg + 10);
1004                                continue;
1005                        }
1006                        if (!prefixcmp(arg, "--before=")) {
1007                                revs->min_age = approxidate(arg + 9);
1008                                continue;
1009                        }
1010                        if (!prefixcmp(arg, "--until=")) {
1011                                revs->min_age = approxidate(arg + 8);
1012                                continue;
1013                        }
1014                        if (!strcmp(arg, "--all")) {
1015                                handle_refs(revs, flags, for_each_ref);
1016                                continue;
1017                        }
1018                        if (!strcmp(arg, "--branches")) {
1019                                handle_refs(revs, flags, for_each_branch_ref);
1020                                continue;
1021                        }
1022                        if (!strcmp(arg, "--tags")) {
1023                                handle_refs(revs, flags, for_each_tag_ref);
1024                                continue;
1025                        }
1026                        if (!strcmp(arg, "--remotes")) {
1027                                handle_refs(revs, flags, for_each_remote_ref);
1028                                continue;
1029                        }
1030                        if (!strcmp(arg, "--first-parent")) {
1031                                revs->first_parent_only = 1;
1032                                continue;
1033                        }
1034                        if (!strcmp(arg, "--reflog")) {
1035                                handle_reflog(revs, flags);
1036                                continue;
1037                        }
1038                        if (!strcmp(arg, "-g") ||
1039                                        !strcmp(arg, "--walk-reflogs")) {
1040                                init_reflog_walk(&revs->reflog_info);
1041                                continue;
1042                        }
1043                        if (!strcmp(arg, "--not")) {
1044                                flags ^= UNINTERESTING;
1045                                continue;
1046                        }
1047                        if (!strcmp(arg, "--default")) {
1048                                if (++i >= argc)
1049                                        die("bad --default argument");
1050                                def = argv[i];
1051                                continue;
1052                        }
1053                        if (!strcmp(arg, "--merge")) {
1054                                show_merge = 1;
1055                                continue;
1056                        }
1057                        if (!strcmp(arg, "--topo-order")) {
1058                                revs->topo_order = 1;
1059                                continue;
1060                        }
1061                        if (!strcmp(arg, "--date-order")) {
1062                                revs->lifo = 0;
1063                                revs->topo_order = 1;
1064                                continue;
1065                        }
1066                        if (!prefixcmp(arg, "--early-output")) {
1067                                int count = 100;
1068                                switch (arg[14]) {
1069                                case '=':
1070                                        count = atoi(arg+15);
1071                                        /* Fallthrough */
1072                                case 0:
1073                                        revs->topo_order = 1;
1074                                        revs->early_output = count;
1075                                        continue;
1076                                }
1077                        }
1078                        if (!strcmp(arg, "--parents")) {
1079                                revs->parents = 1;
1080                                continue;
1081                        }
1082                        if (!strcmp(arg, "--dense")) {
1083                                revs->dense = 1;
1084                                continue;
1085                        }
1086                        if (!strcmp(arg, "--sparse")) {
1087                                revs->dense = 0;
1088                                continue;
1089                        }
1090                        if (!strcmp(arg, "--show-all")) {
1091                                revs->show_all = 1;
1092                                continue;
1093                        }
1094                        if (!strcmp(arg, "--remove-empty")) {
1095                                revs->remove_empty_trees = 1;
1096                                continue;
1097                        }
1098                        if (!strcmp(arg, "--no-merges")) {
1099                                revs->no_merges = 1;
1100                                continue;
1101                        }
1102                        if (!strcmp(arg, "--boundary")) {
1103                                revs->boundary = 1;
1104                                continue;
1105                        }
1106                        if (!strcmp(arg, "--left-right")) {
1107                                revs->left_right = 1;
1108                                continue;
1109                        }
1110                        if (!strcmp(arg, "--cherry-pick")) {
1111                                revs->cherry_pick = 1;
1112                                revs->limited = 1;
1113                                continue;
1114                        }
1115                        if (!strcmp(arg, "--objects")) {
1116                                revs->tag_objects = 1;
1117                                revs->tree_objects = 1;
1118                                revs->blob_objects = 1;
1119                                continue;
1120                        }
1121                        if (!strcmp(arg, "--objects-edge")) {
1122                                revs->tag_objects = 1;
1123                                revs->tree_objects = 1;
1124                                revs->blob_objects = 1;
1125                                revs->edge_hint = 1;
1126                                continue;
1127                        }
1128                        if (!strcmp(arg, "--unpacked")) {
1129                                revs->unpacked = 1;
1130                                free(revs->ignore_packed);
1131                                revs->ignore_packed = NULL;
1132                                revs->num_ignore_packed = 0;
1133                                continue;
1134                        }
1135                        if (!prefixcmp(arg, "--unpacked=")) {
1136                                revs->unpacked = 1;
1137                                add_ignore_packed(revs, arg+11);
1138                                continue;
1139                        }
1140                        if (!strcmp(arg, "-r")) {
1141                                revs->diff = 1;
1142                                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1143                                continue;
1144                        }
1145                        if (!strcmp(arg, "-t")) {
1146                                revs->diff = 1;
1147                                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1148                                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1149                                continue;
1150                        }
1151                        if (!strcmp(arg, "-m")) {
1152                                revs->ignore_merges = 0;
1153                                continue;
1154                        }
1155                        if (!strcmp(arg, "-c")) {
1156                                revs->diff = 1;
1157                                revs->dense_combined_merges = 0;
1158                                revs->combine_merges = 1;
1159                                continue;
1160                        }
1161                        if (!strcmp(arg, "--cc")) {
1162                                revs->diff = 1;
1163                                revs->dense_combined_merges = 1;
1164                                revs->combine_merges = 1;
1165                                continue;
1166                        }
1167                        if (!strcmp(arg, "-v")) {
1168                                revs->verbose_header = 1;
1169                                continue;
1170                        }
1171                        if (!prefixcmp(arg, "--pretty")) {
1172                                revs->verbose_header = 1;
1173                                revs->commit_format = get_commit_format(arg+8);
1174                                continue;
1175                        }
1176                        if (!strcmp(arg, "--root")) {
1177                                revs->show_root_diff = 1;
1178                                continue;
1179                        }
1180                        if (!strcmp(arg, "--no-commit-id")) {
1181                                revs->no_commit_id = 1;
1182                                continue;
1183                        }
1184                        if (!strcmp(arg, "--always")) {
1185                                revs->always_show_header = 1;
1186                                continue;
1187                        }
1188                        if (!strcmp(arg, "--no-abbrev")) {
1189                                revs->abbrev = 0;
1190                                continue;
1191                        }
1192                        if (!strcmp(arg, "--abbrev")) {
1193                                revs->abbrev = DEFAULT_ABBREV;
1194                                continue;
1195                        }
1196                        if (!prefixcmp(arg, "--abbrev=")) {
1197                                revs->abbrev = strtoul(arg + 9, NULL, 10);
1198                                if (revs->abbrev < MINIMUM_ABBREV)
1199                                        revs->abbrev = MINIMUM_ABBREV;
1200                                else if (revs->abbrev > 40)
1201                                        revs->abbrev = 40;
1202                                continue;
1203                        }
1204                        if (!strcmp(arg, "--abbrev-commit")) {
1205                                revs->abbrev_commit = 1;
1206                                continue;
1207                        }
1208                        if (!strcmp(arg, "--full-diff")) {
1209                                revs->diff = 1;
1210                                revs->full_diff = 1;
1211                                continue;
1212                        }
1213                        if (!strcmp(arg, "--full-history")) {
1214                                revs->simplify_history = 0;
1215                                continue;
1216                        }
1217                        if (!strcmp(arg, "--relative-date")) {
1218                                revs->date_mode = DATE_RELATIVE;
1219                                continue;
1220                        }
1221                        if (!strncmp(arg, "--date=", 7)) {
1222                                revs->date_mode = parse_date_format(arg + 7);
1223                                continue;
1224                        }
1225                        if (!strcmp(arg, "--log-size")) {
1226                                revs->show_log_size = 1;
1227                                continue;
1228                        }
1229
1230                        /*
1231                         * Grepping the commit log
1232                         */
1233                        if (!prefixcmp(arg, "--author=")) {
1234                                add_header_grep(revs, "author", arg+9);
1235                                continue;
1236                        }
1237                        if (!prefixcmp(arg, "--committer=")) {
1238                                add_header_grep(revs, "committer", arg+12);
1239                                continue;
1240                        }
1241                        if (!prefixcmp(arg, "--grep=")) {
1242                                add_message_grep(revs, arg+7);
1243                                continue;
1244                        }
1245                        if (!strcmp(arg, "--extended-regexp") ||
1246                            !strcmp(arg, "-E")) {
1247                                regflags |= REG_EXTENDED;
1248                                continue;
1249                        }
1250                        if (!strcmp(arg, "--regexp-ignore-case") ||
1251                            !strcmp(arg, "-i")) {
1252                                regflags |= REG_ICASE;
1253                                continue;
1254                        }
1255                        if (!strcmp(arg, "--fixed-strings") ||
1256                            !strcmp(arg, "-F")) {
1257                                fixed = 1;
1258                                continue;
1259                        }
1260                        if (!strcmp(arg, "--all-match")) {
1261                                all_match = 1;
1262                                continue;
1263                        }
1264                        if (!prefixcmp(arg, "--encoding=")) {
1265                                arg += 11;
1266                                if (strcmp(arg, "none"))
1267                                        git_log_output_encoding = xstrdup(arg);
1268                                else
1269                                        git_log_output_encoding = "";
1270                                continue;
1271                        }
1272                        if (!strcmp(arg, "--reverse")) {
1273                                revs->reverse ^= 1;
1274                                continue;
1275                        }
1276                        if (!strcmp(arg, "--no-walk")) {
1277                                revs->no_walk = 1;
1278                                continue;
1279                        }
1280                        if (!strcmp(arg, "--do-walk")) {
1281                                revs->no_walk = 0;
1282                                continue;
1283                        }
1284
1285                        opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1286                        if (opts > 0) {
1287                                i += opts - 1;
1288                                continue;
1289                        }
1290                        *unrecognized++ = arg;
1291                        left++;
1292                        continue;
1293                }
1294
1295                if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1296                        int j;
1297                        if (seen_dashdash || *arg == '^')
1298                                die("bad revision '%s'", arg);
1299
1300                        /* If we didn't have a "--":
1301                         * (1) all filenames must exist;
1302                         * (2) all rev-args must not be interpretable
1303                         *     as a valid filename.
1304                         * but the latter we have checked in the main loop.
1305                         */
1306                        for (j = i; j < argc; j++)
1307                                verify_filename(revs->prefix, argv[j]);
1308
1309                        revs->prune_data = get_pathspec(revs->prefix,
1310                                                        argv + i);
1311                        break;
1312                }
1313        }
1314
1315        if (revs->grep_filter) {
1316                revs->grep_filter->regflags |= regflags;
1317                revs->grep_filter->fixed = fixed;
1318        }
1319
1320        if (show_merge)
1321                prepare_show_merge(revs);
1322        if (def && !revs->pending.nr) {
1323                unsigned char sha1[20];
1324                struct object *object;
1325                unsigned mode;
1326                if (get_sha1_with_mode(def, sha1, &mode))
1327                        die("bad default revision '%s'", def);
1328                object = get_reference(revs, def, sha1, 0);
1329                add_pending_object_with_mode(revs, object, def, mode);
1330        }
1331
1332        /* Did the user ask for any diff output? Run the diff! */
1333        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1334                revs->diff = 1;
1335
1336        /* Pickaxe, diff-filter and rename following need diffs */
1337        if (revs->diffopt.pickaxe ||
1338            revs->diffopt.filter ||
1339            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1340                revs->diff = 1;
1341
1342        if (revs->topo_order)
1343                revs->limited = 1;
1344
1345        if (revs->prune_data) {
1346                diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1347                /* Can't prune commits with rename following: the paths change.. */
1348                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1349                        revs->prune = 1;
1350                if (!revs->full_diff)
1351                        diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1352        }
1353        if (revs->combine_merges) {
1354                revs->ignore_merges = 0;
1355                if (revs->dense_combined_merges && !revs->diffopt.output_format)
1356                        revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1357        }
1358        revs->diffopt.abbrev = revs->abbrev;
1359        if (diff_setup_done(&revs->diffopt) < 0)
1360                die("diff_setup_done failed");
1361
1362        if (revs->grep_filter) {
1363                revs->grep_filter->all_match = all_match;
1364                compile_grep_patterns(revs->grep_filter);
1365        }
1366
1367        if (revs->reverse && revs->reflog_info)
1368                die("cannot combine --reverse with --walk-reflogs");
1369
1370        return left;
1371}
1372
1373int prepare_revision_walk(struct rev_info *revs)
1374{
1375        int nr = revs->pending.nr;
1376        struct object_array_entry *e, *list;
1377
1378        e = list = revs->pending.objects;
1379        revs->pending.nr = 0;
1380        revs->pending.alloc = 0;
1381        revs->pending.objects = NULL;
1382        while (--nr >= 0) {
1383                struct commit *commit = handle_commit(revs, e->item, e->name);
1384                if (commit) {
1385                        if (!(commit->object.flags & SEEN)) {
1386                                commit->object.flags |= SEEN;
1387                                insert_by_date(commit, &revs->commits);
1388                        }
1389                }
1390                e++;
1391        }
1392        free(list);
1393
1394        if (revs->no_walk)
1395                return 0;
1396        if (revs->limited)
1397                if (limit_list(revs) < 0)
1398                        return -1;
1399        if (revs->topo_order)
1400                sort_in_topological_order(&revs->commits, revs->lifo);
1401        return 0;
1402}
1403
1404enum rewrite_result {
1405        rewrite_one_ok,
1406        rewrite_one_noparents,
1407        rewrite_one_error,
1408};
1409
1410static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1411{
1412        for (;;) {
1413                struct commit *p = *pp;
1414                if (!revs->limited)
1415                        if (add_parents_to_list(revs, p, &revs->commits) < 0)
1416                                return rewrite_one_error;
1417                if (p->parents && p->parents->next)
1418                        return rewrite_one_ok;
1419                if (p->object.flags & UNINTERESTING)
1420                        return rewrite_one_ok;
1421                if (!(p->object.flags & TREESAME))
1422                        return rewrite_one_ok;
1423                if (!p->parents)
1424                        return rewrite_one_noparents;
1425                *pp = p->parents->item;
1426        }
1427}
1428
1429static void remove_duplicate_parents(struct commit *commit)
1430{
1431        struct commit_list **pp, *p;
1432
1433        /* Examine existing parents while marking ones we have seen... */
1434        pp = &commit->parents;
1435        while ((p = *pp) != NULL) {
1436                struct commit *parent = p->item;
1437                if (parent->object.flags & TMP_MARK) {
1438                        *pp = p->next;
1439                        continue;
1440                }
1441                parent->object.flags |= TMP_MARK;
1442                pp = &p->next;
1443        }
1444        /* ... and clear the temporary mark */
1445        for (p = commit->parents; p; p = p->next)
1446                p->item->object.flags &= ~TMP_MARK;
1447}
1448
1449static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1450{
1451        struct commit_list **pp = &commit->parents;
1452        while (*pp) {
1453                struct commit_list *parent = *pp;
1454                switch (rewrite_one(revs, &parent->item)) {
1455                case rewrite_one_ok:
1456                        break;
1457                case rewrite_one_noparents:
1458                        *pp = parent->next;
1459                        continue;
1460                case rewrite_one_error:
1461                        return -1;
1462                }
1463                pp = &parent->next;
1464        }
1465        remove_duplicate_parents(commit);
1466        return 0;
1467}
1468
1469static int commit_match(struct commit *commit, struct rev_info *opt)
1470{
1471        if (!opt->grep_filter)
1472                return 1;
1473        return grep_buffer(opt->grep_filter,
1474                           NULL, /* we say nothing, not even filename */
1475                           commit->buffer, strlen(commit->buffer));
1476}
1477
1478enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1479{
1480        if (commit->object.flags & SHOWN)
1481                return commit_ignore;
1482        if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1483                return commit_ignore;
1484        if (revs->show_all)
1485                return commit_show;
1486        if (commit->object.flags & UNINTERESTING)
1487                return commit_ignore;
1488        if (revs->min_age != -1 && (commit->date > revs->min_age))
1489                return commit_ignore;
1490        if (revs->no_merges && commit->parents && commit->parents->next)
1491                return commit_ignore;
1492        if (!commit_match(commit, revs))
1493                return commit_ignore;
1494        if (revs->prune && revs->dense) {
1495                /* Commit without changes? */
1496                if (commit->object.flags & TREESAME) {
1497                        /* drop merges unless we want parenthood */
1498                        if (!revs->parents)
1499                                return commit_ignore;
1500                        /* non-merge - always ignore it */
1501                        if (!commit->parents || !commit->parents->next)
1502                                return commit_ignore;
1503                }
1504                if (revs->parents && rewrite_parents(revs, commit) < 0)
1505                        return commit_error;
1506        }
1507        return commit_show;
1508}
1509
1510static struct commit *get_revision_1(struct rev_info *revs)
1511{
1512        if (!revs->commits)
1513                return NULL;
1514
1515        do {
1516                struct commit_list *entry = revs->commits;
1517                struct commit *commit = entry->item;
1518
1519                revs->commits = entry->next;
1520                free(entry);
1521
1522                if (revs->reflog_info)
1523                        fake_reflog_parent(revs->reflog_info, commit);
1524
1525                /*
1526                 * If we haven't done the list limiting, we need to look at
1527                 * the parents here. We also need to do the date-based limiting
1528                 * that we'd otherwise have done in limit_list().
1529                 */
1530                if (!revs->limited) {
1531                        if (revs->max_age != -1 &&
1532                            (commit->date < revs->max_age))
1533                                continue;
1534                        if (add_parents_to_list(revs, commit, &revs->commits) < 0)
1535                                return NULL;
1536                }
1537
1538                switch (simplify_commit(revs, commit)) {
1539                case commit_ignore:
1540                        continue;
1541                case commit_error:
1542                        return NULL;
1543                default:
1544                        return commit;
1545                }
1546        } while (revs->commits);
1547        return NULL;
1548}
1549
1550static void gc_boundary(struct object_array *array)
1551{
1552        unsigned nr = array->nr;
1553        unsigned alloc = array->alloc;
1554        struct object_array_entry *objects = array->objects;
1555
1556        if (alloc <= nr) {
1557                unsigned i, j;
1558                for (i = j = 0; i < nr; i++) {
1559                        if (objects[i].item->flags & SHOWN)
1560                                continue;
1561                        if (i != j)
1562                                objects[j] = objects[i];
1563                        j++;
1564                }
1565                for (i = j; i < nr; i++)
1566                        objects[i].item = NULL;
1567                array->nr = j;
1568        }
1569}
1570
1571struct commit *get_revision(struct rev_info *revs)
1572{
1573        struct commit *c = NULL;
1574        struct commit_list *l;
1575
1576        if (revs->boundary == 2) {
1577                unsigned i;
1578                struct object_array *array = &revs->boundary_commits;
1579                struct object_array_entry *objects = array->objects;
1580                for (i = 0; i < array->nr; i++) {
1581                        c = (struct commit *)(objects[i].item);
1582                        if (!c)
1583                                continue;
1584                        if (!(c->object.flags & CHILD_SHOWN))
1585                                continue;
1586                        if (!(c->object.flags & SHOWN))
1587                                break;
1588                }
1589                if (array->nr <= i)
1590                        return NULL;
1591
1592                c->object.flags |= SHOWN | BOUNDARY;
1593                return c;
1594        }
1595
1596        if (revs->reverse) {
1597                int limit = -1;
1598
1599                if (0 <= revs->max_count) {
1600                        limit = revs->max_count;
1601                        if (0 < revs->skip_count)
1602                                limit += revs->skip_count;
1603                }
1604                l = NULL;
1605                while ((c = get_revision_1(revs))) {
1606                        commit_list_insert(c, &l);
1607                        if ((0 < limit) && !--limit)
1608                                break;
1609                }
1610                revs->commits = l;
1611                revs->reverse = 0;
1612                revs->max_count = -1;
1613                c = NULL;
1614        }
1615
1616        /*
1617         * Now pick up what they want to give us
1618         */
1619        c = get_revision_1(revs);
1620        if (c) {
1621                while (0 < revs->skip_count) {
1622                        revs->skip_count--;
1623                        c = get_revision_1(revs);
1624                        if (!c)
1625                                break;
1626                }
1627        }
1628
1629        /*
1630         * Check the max_count.
1631         */
1632        switch (revs->max_count) {
1633        case -1:
1634                break;
1635        case 0:
1636                c = NULL;
1637                break;
1638        default:
1639                revs->max_count--;
1640        }
1641
1642        if (c)
1643                c->object.flags |= SHOWN;
1644
1645        if (!revs->boundary) {
1646                return c;
1647        }
1648
1649        if (!c) {
1650                /*
1651                 * get_revision_1() runs out the commits, and
1652                 * we are done computing the boundaries.
1653                 * switch to boundary commits output mode.
1654                 */
1655                revs->boundary = 2;
1656                return get_revision(revs);
1657        }
1658
1659        /*
1660         * boundary commits are the commits that are parents of the
1661         * ones we got from get_revision_1() but they themselves are
1662         * not returned from get_revision_1().  Before returning
1663         * 'c', we need to mark its parents that they could be boundaries.
1664         */
1665
1666        for (l = c->parents; l; l = l->next) {
1667                struct object *p;
1668                p = &(l->item->object);
1669                if (p->flags & (CHILD_SHOWN | SHOWN))
1670                        continue;
1671                p->flags |= CHILD_SHOWN;
1672                gc_boundary(&revs->boundary_commits);
1673                add_object_array(p, NULL, &revs->boundary_commits);
1674        }
1675
1676        return c;
1677}