revision.con commit t1406: make hash-size independent (b1484ca)
   1#include "cache.h"
   2#include "object-store.h"
   3#include "tag.h"
   4#include "blob.h"
   5#include "tree.h"
   6#include "commit.h"
   7#include "diff.h"
   8#include "refs.h"
   9#include "revision.h"
  10#include "repository.h"
  11#include "graph.h"
  12#include "grep.h"
  13#include "reflog-walk.h"
  14#include "patch-ids.h"
  15#include "decorate.h"
  16#include "log-tree.h"
  17#include "string-list.h"
  18#include "line-log.h"
  19#include "mailmap.h"
  20#include "commit-slab.h"
  21#include "dir.h"
  22#include "cache-tree.h"
  23#include "bisect.h"
  24#include "packfile.h"
  25#include "worktree.h"
  26#include "argv-array.h"
  27
  28volatile show_early_output_fn_t show_early_output;
  29
  30static const char *term_bad;
  31static const char *term_good;
  32
  33implement_shared_commit_slab(revision_sources, char *);
  34
  35void show_object_with_name(FILE *out, struct object *obj, const char *name)
  36{
  37        const char *p;
  38
  39        fprintf(out, "%s ", oid_to_hex(&obj->oid));
  40        for (p = name; *p && *p != '\n'; p++)
  41                fputc(*p, out);
  42        fputc('\n', out);
  43}
  44
  45static void mark_blob_uninteresting(struct blob *blob)
  46{
  47        if (!blob)
  48                return;
  49        if (blob->object.flags & UNINTERESTING)
  50                return;
  51        blob->object.flags |= UNINTERESTING;
  52}
  53
  54static void mark_tree_contents_uninteresting(struct tree *tree)
  55{
  56        struct tree_desc desc;
  57        struct name_entry entry;
  58
  59        if (parse_tree_gently(tree, 1) < 0)
  60                return;
  61
  62        init_tree_desc(&desc, tree->buffer, tree->size);
  63        while (tree_entry(&desc, &entry)) {
  64                switch (object_type(entry.mode)) {
  65                case OBJ_TREE:
  66                        mark_tree_uninteresting(lookup_tree(the_repository, entry.oid));
  67                        break;
  68                case OBJ_BLOB:
  69                        mark_blob_uninteresting(lookup_blob(the_repository, entry.oid));
  70                        break;
  71                default:
  72                        /* Subproject commit - not in this repository */
  73                        break;
  74                }
  75        }
  76
  77        /*
  78         * We don't care about the tree any more
  79         * after it has been marked uninteresting.
  80         */
  81        free_tree_buffer(tree);
  82}
  83
  84void mark_tree_uninteresting(struct tree *tree)
  85{
  86        struct object *obj;
  87
  88        if (!tree)
  89                return;
  90
  91        obj = &tree->object;
  92        if (obj->flags & UNINTERESTING)
  93                return;
  94        obj->flags |= UNINTERESTING;
  95        mark_tree_contents_uninteresting(tree);
  96}
  97
  98struct commit_stack {
  99        struct commit **items;
 100        size_t nr, alloc;
 101};
 102#define COMMIT_STACK_INIT { NULL, 0, 0 }
 103
 104static void commit_stack_push(struct commit_stack *stack, struct commit *commit)
 105{
 106        ALLOC_GROW(stack->items, stack->nr + 1, stack->alloc);
 107        stack->items[stack->nr++] = commit;
 108}
 109
 110static struct commit *commit_stack_pop(struct commit_stack *stack)
 111{
 112        return stack->nr ? stack->items[--stack->nr] : NULL;
 113}
 114
 115static void commit_stack_clear(struct commit_stack *stack)
 116{
 117        FREE_AND_NULL(stack->items);
 118        stack->nr = stack->alloc = 0;
 119}
 120
 121static void mark_one_parent_uninteresting(struct commit *commit,
 122                                          struct commit_stack *pending)
 123{
 124        struct commit_list *l;
 125
 126        if (commit->object.flags & UNINTERESTING)
 127                return;
 128        commit->object.flags |= UNINTERESTING;
 129
 130        /*
 131         * Normally we haven't parsed the parent
 132         * yet, so we won't have a parent of a parent
 133         * here. However, it may turn out that we've
 134         * reached this commit some other way (where it
 135         * wasn't uninteresting), in which case we need
 136         * to mark its parents recursively too..
 137         */
 138        for (l = commit->parents; l; l = l->next)
 139                commit_stack_push(pending, l->item);
 140}
 141
 142void mark_parents_uninteresting(struct commit *commit)
 143{
 144        struct commit_stack pending = COMMIT_STACK_INIT;
 145        struct commit_list *l;
 146
 147        for (l = commit->parents; l; l = l->next)
 148                mark_one_parent_uninteresting(l->item, &pending);
 149
 150        while (pending.nr > 0)
 151                mark_one_parent_uninteresting(commit_stack_pop(&pending),
 152                                              &pending);
 153
 154        commit_stack_clear(&pending);
 155}
 156
 157static void add_pending_object_with_path(struct rev_info *revs,
 158                                         struct object *obj,
 159                                         const char *name, unsigned mode,
 160                                         const char *path)
 161{
 162        if (!obj)
 163                return;
 164        if (revs->no_walk && (obj->flags & UNINTERESTING))
 165                revs->no_walk = 0;
 166        if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 167                struct strbuf buf = STRBUF_INIT;
 168                int len = interpret_branch_name(name, 0, &buf, 0);
 169
 170                if (0 < len && name[len] && buf.len)
 171                        strbuf_addstr(&buf, name + len);
 172                add_reflog_for_walk(revs->reflog_info,
 173                                    (struct commit *)obj,
 174                                    buf.buf[0] ? buf.buf: name);
 175                strbuf_release(&buf);
 176                return; /* do not add the commit itself */
 177        }
 178        obj->flags |= USER_GIVEN;
 179        add_object_array_with_path(obj, name, &revs->pending, mode, path);
 180}
 181
 182static void add_pending_object_with_mode(struct rev_info *revs,
 183                                         struct object *obj,
 184                                         const char *name, unsigned mode)
 185{
 186        add_pending_object_with_path(revs, obj, name, mode, NULL);
 187}
 188
 189void add_pending_object(struct rev_info *revs,
 190                        struct object *obj, const char *name)
 191{
 192        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 193}
 194
 195void add_head_to_pending(struct rev_info *revs)
 196{
 197        struct object_id oid;
 198        struct object *obj;
 199        if (get_oid("HEAD", &oid))
 200                return;
 201        obj = parse_object(the_repository, &oid);
 202        if (!obj)
 203                return;
 204        add_pending_object(revs, obj, "HEAD");
 205}
 206
 207static struct object *get_reference(struct rev_info *revs, const char *name,
 208                                    const struct object_id *oid,
 209                                    unsigned int flags)
 210{
 211        struct object *object;
 212
 213        object = parse_object(the_repository, oid);
 214        if (!object) {
 215                if (revs->ignore_missing)
 216                        return object;
 217                if (revs->exclude_promisor_objects && is_promisor_object(oid))
 218                        return NULL;
 219                die("bad object %s", name);
 220        }
 221        object->flags |= flags;
 222        return object;
 223}
 224
 225void add_pending_oid(struct rev_info *revs, const char *name,
 226                      const struct object_id *oid, unsigned int flags)
 227{
 228        struct object *object = get_reference(revs, name, oid, flags);
 229        add_pending_object(revs, object, name);
 230}
 231
 232static struct commit *handle_commit(struct rev_info *revs,
 233                                    struct object_array_entry *entry)
 234{
 235        struct object *object = entry->item;
 236        const char *name = entry->name;
 237        const char *path = entry->path;
 238        unsigned int mode = entry->mode;
 239        unsigned long flags = object->flags;
 240
 241        /*
 242         * Tag object? Look what it points to..
 243         */
 244        while (object->type == OBJ_TAG) {
 245                struct tag *tag = (struct tag *) object;
 246                if (revs->tag_objects && !(flags & UNINTERESTING))
 247                        add_pending_object(revs, object, tag->tag);
 248                if (!tag->tagged)
 249                        die("bad tag");
 250                object = parse_object(the_repository, &tag->tagged->oid);
 251                if (!object) {
 252                        if (revs->ignore_missing_links || (flags & UNINTERESTING))
 253                                return NULL;
 254                        if (revs->exclude_promisor_objects &&
 255                            is_promisor_object(&tag->tagged->oid))
 256                                return NULL;
 257                        die("bad object %s", oid_to_hex(&tag->tagged->oid));
 258                }
 259                object->flags |= flags;
 260                /*
 261                 * We'll handle the tagged object by looping or dropping
 262                 * through to the non-tag handlers below. Do not
 263                 * propagate path data from the tag's pending entry.
 264                 */
 265                path = NULL;
 266                mode = 0;
 267        }
 268
 269        /*
 270         * Commit object? Just return it, we'll do all the complex
 271         * reachability crud.
 272         */
 273        if (object->type == OBJ_COMMIT) {
 274                struct commit *commit = (struct commit *)object;
 275
 276                if (parse_commit(commit) < 0)
 277                        die("unable to parse commit %s", name);
 278                if (flags & UNINTERESTING) {
 279                        mark_parents_uninteresting(commit);
 280                        revs->limited = 1;
 281                }
 282                if (revs->sources) {
 283                        char **slot = revision_sources_at(revs->sources, commit);
 284
 285                        if (!*slot)
 286                                *slot = xstrdup(name);
 287                }
 288                return commit;
 289        }
 290
 291        /*
 292         * Tree object? Either mark it uninteresting, or add it
 293         * to the list of objects to look at later..
 294         */
 295        if (object->type == OBJ_TREE) {
 296                struct tree *tree = (struct tree *)object;
 297                if (!revs->tree_objects)
 298                        return NULL;
 299                if (flags & UNINTERESTING) {
 300                        mark_tree_contents_uninteresting(tree);
 301                        return NULL;
 302                }
 303                add_pending_object_with_path(revs, object, name, mode, path);
 304                return NULL;
 305        }
 306
 307        /*
 308         * Blob object? You know the drill by now..
 309         */
 310        if (object->type == OBJ_BLOB) {
 311                if (!revs->blob_objects)
 312                        return NULL;
 313                if (flags & UNINTERESTING)
 314                        return NULL;
 315                add_pending_object_with_path(revs, object, name, mode, path);
 316                return NULL;
 317        }
 318        die("%s is unknown object", name);
 319}
 320
 321static int everybody_uninteresting(struct commit_list *orig,
 322                                   struct commit **interesting_cache)
 323{
 324        struct commit_list *list = orig;
 325
 326        if (*interesting_cache) {
 327                struct commit *commit = *interesting_cache;
 328                if (!(commit->object.flags & UNINTERESTING))
 329                        return 0;
 330        }
 331
 332        while (list) {
 333                struct commit *commit = list->item;
 334                list = list->next;
 335                if (commit->object.flags & UNINTERESTING)
 336                        continue;
 337
 338                *interesting_cache = commit;
 339                return 0;
 340        }
 341        return 1;
 342}
 343
 344/*
 345 * A definition of "relevant" commit that we can use to simplify limited graphs
 346 * by eliminating side branches.
 347 *
 348 * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
 349 * in our list), or that is a specified BOTTOM commit. Then after computing
 350 * a limited list, during processing we can generally ignore boundary merges
 351 * coming from outside the graph, (ie from irrelevant parents), and treat
 352 * those merges as if they were single-parent. TREESAME is defined to consider
 353 * only relevant parents, if any. If we are TREESAME to our on-graph parents,
 354 * we don't care if we were !TREESAME to non-graph parents.
 355 *
 356 * Treating bottom commits as relevant ensures that a limited graph's
 357 * connection to the actual bottom commit is not viewed as a side branch, but
 358 * treated as part of the graph. For example:
 359 *
 360 *   ....Z...A---X---o---o---B
 361 *        .     /
 362 *         W---Y
 363 *
 364 * When computing "A..B", the A-X connection is at least as important as
 365 * Y-X, despite A being flagged UNINTERESTING.
 366 *
 367 * And when computing --ancestry-path "A..B", the A-X connection is more
 368 * important than Y-X, despite both A and Y being flagged UNINTERESTING.
 369 */
 370static inline int relevant_commit(struct commit *commit)
 371{
 372        return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
 373}
 374
 375/*
 376 * Return a single relevant commit from a parent list. If we are a TREESAME
 377 * commit, and this selects one of our parents, then we can safely simplify to
 378 * that parent.
 379 */
 380static struct commit *one_relevant_parent(const struct rev_info *revs,
 381                                          struct commit_list *orig)
 382{
 383        struct commit_list *list = orig;
 384        struct commit *relevant = NULL;
 385
 386        if (!orig)
 387                return NULL;
 388
 389        /*
 390         * For 1-parent commits, or if first-parent-only, then return that
 391         * first parent (even if not "relevant" by the above definition).
 392         * TREESAME will have been set purely on that parent.
 393         */
 394        if (revs->first_parent_only || !orig->next)
 395                return orig->item;
 396
 397        /*
 398         * For multi-parent commits, identify a sole relevant parent, if any.
 399         * If we have only one relevant parent, then TREESAME will be set purely
 400         * with regard to that parent, and we can simplify accordingly.
 401         *
 402         * If we have more than one relevant parent, or no relevant parents
 403         * (and multiple irrelevant ones), then we can't select a parent here
 404         * and return NULL.
 405         */
 406        while (list) {
 407                struct commit *commit = list->item;
 408                list = list->next;
 409                if (relevant_commit(commit)) {
 410                        if (relevant)
 411                                return NULL;
 412                        relevant = commit;
 413                }
 414        }
 415        return relevant;
 416}
 417
 418/*
 419 * The goal is to get REV_TREE_NEW as the result only if the
 420 * diff consists of all '+' (and no other changes), REV_TREE_OLD
 421 * if the whole diff is removal of old data, and otherwise
 422 * REV_TREE_DIFFERENT (of course if the trees are the same we
 423 * want REV_TREE_SAME).
 424 *
 425 * The only time we care about the distinction is when
 426 * remove_empty_trees is in effect, in which case we care only about
 427 * whether the whole change is REV_TREE_NEW, or if there's another type
 428 * of change. Which means we can stop the diff early in either of these
 429 * cases:
 430 *
 431 *   1. We're not using remove_empty_trees at all.
 432 *
 433 *   2. We saw anything except REV_TREE_NEW.
 434 */
 435static int tree_difference = REV_TREE_SAME;
 436
 437static void file_add_remove(struct diff_options *options,
 438                    int addremove, unsigned mode,
 439                    const struct object_id *oid,
 440                    int oid_valid,
 441                    const char *fullpath, unsigned dirty_submodule)
 442{
 443        int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 444        struct rev_info *revs = options->change_fn_data;
 445
 446        tree_difference |= diff;
 447        if (!revs->remove_empty_trees || tree_difference != REV_TREE_NEW)
 448                options->flags.has_changes = 1;
 449}
 450
 451static void file_change(struct diff_options *options,
 452                 unsigned old_mode, unsigned new_mode,
 453                 const struct object_id *old_oid,
 454                 const struct object_id *new_oid,
 455                 int old_oid_valid, int new_oid_valid,
 456                 const char *fullpath,
 457                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 458{
 459        tree_difference = REV_TREE_DIFFERENT;
 460        options->flags.has_changes = 1;
 461}
 462
 463static int rev_compare_tree(struct rev_info *revs,
 464                            struct commit *parent, struct commit *commit)
 465{
 466        struct tree *t1 = get_commit_tree(parent);
 467        struct tree *t2 = get_commit_tree(commit);
 468
 469        if (!t1)
 470                return REV_TREE_NEW;
 471        if (!t2)
 472                return REV_TREE_OLD;
 473
 474        if (revs->simplify_by_decoration) {
 475                /*
 476                 * If we are simplifying by decoration, then the commit
 477                 * is worth showing if it has a tag pointing at it.
 478                 */
 479                if (get_name_decoration(&commit->object))
 480                        return REV_TREE_DIFFERENT;
 481                /*
 482                 * A commit that is not pointed by a tag is uninteresting
 483                 * if we are not limited by path.  This means that you will
 484                 * see the usual "commits that touch the paths" plus any
 485                 * tagged commit by specifying both --simplify-by-decoration
 486                 * and pathspec.
 487                 */
 488                if (!revs->prune_data.nr)
 489                        return REV_TREE_SAME;
 490        }
 491
 492        tree_difference = REV_TREE_SAME;
 493        revs->pruning.flags.has_changes = 0;
 494        if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
 495                           &revs->pruning) < 0)
 496                return REV_TREE_DIFFERENT;
 497        return tree_difference;
 498}
 499
 500static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 501{
 502        int retval;
 503        struct tree *t1 = get_commit_tree(commit);
 504
 505        if (!t1)
 506                return 0;
 507
 508        tree_difference = REV_TREE_SAME;
 509        revs->pruning.flags.has_changes = 0;
 510        retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
 511
 512        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 513}
 514
 515struct treesame_state {
 516        unsigned int nparents;
 517        unsigned char treesame[FLEX_ARRAY];
 518};
 519
 520static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
 521{
 522        unsigned n = commit_list_count(commit->parents);
 523        struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n));
 524        st->nparents = n;
 525        add_decoration(&revs->treesame, &commit->object, st);
 526        return st;
 527}
 528
 529/*
 530 * Must be called immediately after removing the nth_parent from a commit's
 531 * parent list, if we are maintaining the per-parent treesame[] decoration.
 532 * This does not recalculate the master TREESAME flag - update_treesame()
 533 * should be called to update it after a sequence of treesame[] modifications
 534 * that may have affected it.
 535 */
 536static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
 537{
 538        struct treesame_state *st;
 539        int old_same;
 540
 541        if (!commit->parents) {
 542                /*
 543                 * Have just removed the only parent from a non-merge.
 544                 * Different handling, as we lack decoration.
 545                 */
 546                if (nth_parent != 0)
 547                        die("compact_treesame %u", nth_parent);
 548                old_same = !!(commit->object.flags & TREESAME);
 549                if (rev_same_tree_as_empty(revs, commit))
 550                        commit->object.flags |= TREESAME;
 551                else
 552                        commit->object.flags &= ~TREESAME;
 553                return old_same;
 554        }
 555
 556        st = lookup_decoration(&revs->treesame, &commit->object);
 557        if (!st || nth_parent >= st->nparents)
 558                die("compact_treesame %u", nth_parent);
 559
 560        old_same = st->treesame[nth_parent];
 561        memmove(st->treesame + nth_parent,
 562                st->treesame + nth_parent + 1,
 563                st->nparents - nth_parent - 1);
 564
 565        /*
 566         * If we've just become a non-merge commit, update TREESAME
 567         * immediately, and remove the no-longer-needed decoration.
 568         * If still a merge, defer update until update_treesame().
 569         */
 570        if (--st->nparents == 1) {
 571                if (commit->parents->next)
 572                        die("compact_treesame parents mismatch");
 573                if (st->treesame[0] && revs->dense)
 574                        commit->object.flags |= TREESAME;
 575                else
 576                        commit->object.flags &= ~TREESAME;
 577                free(add_decoration(&revs->treesame, &commit->object, NULL));
 578        }
 579
 580        return old_same;
 581}
 582
 583static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
 584{
 585        if (commit->parents && commit->parents->next) {
 586                unsigned n;
 587                struct treesame_state *st;
 588                struct commit_list *p;
 589                unsigned relevant_parents;
 590                unsigned relevant_change, irrelevant_change;
 591
 592                st = lookup_decoration(&revs->treesame, &commit->object);
 593                if (!st)
 594                        die("update_treesame %s", oid_to_hex(&commit->object.oid));
 595                relevant_parents = 0;
 596                relevant_change = irrelevant_change = 0;
 597                for (p = commit->parents, n = 0; p; n++, p = p->next) {
 598                        if (relevant_commit(p->item)) {
 599                                relevant_change |= !st->treesame[n];
 600                                relevant_parents++;
 601                        } else
 602                                irrelevant_change |= !st->treesame[n];
 603                }
 604                if (relevant_parents ? relevant_change : irrelevant_change)
 605                        commit->object.flags &= ~TREESAME;
 606                else
 607                        commit->object.flags |= TREESAME;
 608        }
 609
 610        return commit->object.flags & TREESAME;
 611}
 612
 613static inline int limiting_can_increase_treesame(const struct rev_info *revs)
 614{
 615        /*
 616         * TREESAME is irrelevant unless prune && dense;
 617         * if simplify_history is set, we can't have a mixture of TREESAME and
 618         *    !TREESAME INTERESTING parents (and we don't have treesame[]
 619         *    decoration anyway);
 620         * if first_parent_only is set, then the TREESAME flag is locked
 621         *    against the first parent (and again we lack treesame[] decoration).
 622         */
 623        return revs->prune && revs->dense &&
 624               !revs->simplify_history &&
 625               !revs->first_parent_only;
 626}
 627
 628static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 629{
 630        struct commit_list **pp, *parent;
 631        struct treesame_state *ts = NULL;
 632        int relevant_change = 0, irrelevant_change = 0;
 633        int relevant_parents, nth_parent;
 634
 635        /*
 636         * If we don't do pruning, everything is interesting
 637         */
 638        if (!revs->prune)
 639                return;
 640
 641        if (!get_commit_tree(commit))
 642                return;
 643
 644        if (!commit->parents) {
 645                if (rev_same_tree_as_empty(revs, commit))
 646                        commit->object.flags |= TREESAME;
 647                return;
 648        }
 649
 650        /*
 651         * Normal non-merge commit? If we don't want to make the
 652         * history dense, we consider it always to be a change..
 653         */
 654        if (!revs->dense && !commit->parents->next)
 655                return;
 656
 657        for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
 658             (parent = *pp) != NULL;
 659             pp = &parent->next, nth_parent++) {
 660                struct commit *p = parent->item;
 661                if (relevant_commit(p))
 662                        relevant_parents++;
 663
 664                if (nth_parent == 1) {
 665                        /*
 666                         * This our second loop iteration - so we now know
 667                         * we're dealing with a merge.
 668                         *
 669                         * Do not compare with later parents when we care only about
 670                         * the first parent chain, in order to avoid derailing the
 671                         * traversal to follow a side branch that brought everything
 672                         * in the path we are limited to by the pathspec.
 673                         */
 674                        if (revs->first_parent_only)
 675                                break;
 676                        /*
 677                         * If this will remain a potentially-simplifiable
 678                         * merge, remember per-parent treesame if needed.
 679                         * Initialise the array with the comparison from our
 680                         * first iteration.
 681                         */
 682                        if (revs->treesame.name &&
 683                            !revs->simplify_history &&
 684                            !(commit->object.flags & UNINTERESTING)) {
 685                                ts = initialise_treesame(revs, commit);
 686                                if (!(irrelevant_change || relevant_change))
 687                                        ts->treesame[0] = 1;
 688                        }
 689                }
 690                if (parse_commit(p) < 0)
 691                        die("cannot simplify commit %s (because of %s)",
 692                            oid_to_hex(&commit->object.oid),
 693                            oid_to_hex(&p->object.oid));
 694                switch (rev_compare_tree(revs, p, commit)) {
 695                case REV_TREE_SAME:
 696                        if (!revs->simplify_history || !relevant_commit(p)) {
 697                                /* Even if a merge with an uninteresting
 698                                 * side branch brought the entire change
 699                                 * we are interested in, we do not want
 700                                 * to lose the other branches of this
 701                                 * merge, so we just keep going.
 702                                 */
 703                                if (ts)
 704                                        ts->treesame[nth_parent] = 1;
 705                                continue;
 706                        }
 707                        parent->next = NULL;
 708                        commit->parents = parent;
 709                        commit->object.flags |= TREESAME;
 710                        return;
 711
 712                case REV_TREE_NEW:
 713                        if (revs->remove_empty_trees &&
 714                            rev_same_tree_as_empty(revs, p)) {
 715                                /* We are adding all the specified
 716                                 * paths from this parent, so the
 717                                 * history beyond this parent is not
 718                                 * interesting.  Remove its parents
 719                                 * (they are grandparents for us).
 720                                 * IOW, we pretend this parent is a
 721                                 * "root" commit.
 722                                 */
 723                                if (parse_commit(p) < 0)
 724                                        die("cannot simplify commit %s (invalid %s)",
 725                                            oid_to_hex(&commit->object.oid),
 726                                            oid_to_hex(&p->object.oid));
 727                                p->parents = NULL;
 728                        }
 729                /* fallthrough */
 730                case REV_TREE_OLD:
 731                case REV_TREE_DIFFERENT:
 732                        if (relevant_commit(p))
 733                                relevant_change = 1;
 734                        else
 735                                irrelevant_change = 1;
 736                        continue;
 737                }
 738                die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
 739        }
 740
 741        /*
 742         * TREESAME is straightforward for single-parent commits. For merge
 743         * commits, it is most useful to define it so that "irrelevant"
 744         * parents cannot make us !TREESAME - if we have any relevant
 745         * parents, then we only consider TREESAMEness with respect to them,
 746         * allowing irrelevant merges from uninteresting branches to be
 747         * simplified away. Only if we have only irrelevant parents do we
 748         * base TREESAME on them. Note that this logic is replicated in
 749         * update_treesame, which should be kept in sync.
 750         */
 751        if (relevant_parents ? !relevant_change : !irrelevant_change)
 752                commit->object.flags |= TREESAME;
 753}
 754
 755static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 756                    struct commit_list *cached_base, struct commit_list **cache)
 757{
 758        struct commit_list *new_entry;
 759
 760        if (cached_base && p->date < cached_base->item->date)
 761                new_entry = commit_list_insert_by_date(p, &cached_base->next);
 762        else
 763                new_entry = commit_list_insert_by_date(p, head);
 764
 765        if (cache && (!*cache || p->date < (*cache)->item->date))
 766                *cache = new_entry;
 767}
 768
 769static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 770                    struct commit_list **list, struct commit_list **cache_ptr)
 771{
 772        struct commit_list *parent = commit->parents;
 773        unsigned left_flag;
 774        struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 775
 776        if (commit->object.flags & ADDED)
 777                return 0;
 778        commit->object.flags |= ADDED;
 779
 780        if (revs->include_check &&
 781            !revs->include_check(commit, revs->include_check_data))
 782                return 0;
 783
 784        /*
 785         * If the commit is uninteresting, don't try to
 786         * prune parents - we want the maximal uninteresting
 787         * set.
 788         *
 789         * Normally we haven't parsed the parent
 790         * yet, so we won't have a parent of a parent
 791         * here. However, it may turn out that we've
 792         * reached this commit some other way (where it
 793         * wasn't uninteresting), in which case we need
 794         * to mark its parents recursively too..
 795         */
 796        if (commit->object.flags & UNINTERESTING) {
 797                while (parent) {
 798                        struct commit *p = parent->item;
 799                        parent = parent->next;
 800                        if (p)
 801                                p->object.flags |= UNINTERESTING;
 802                        if (parse_commit_gently(p, 1) < 0)
 803                                continue;
 804                        if (p->parents)
 805                                mark_parents_uninteresting(p);
 806                        if (p->object.flags & SEEN)
 807                                continue;
 808                        p->object.flags |= SEEN;
 809                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 810                }
 811                return 0;
 812        }
 813
 814        /*
 815         * Ok, the commit wasn't uninteresting. Try to
 816         * simplify the commit history and find the parent
 817         * that has no differences in the path set if one exists.
 818         */
 819        try_to_simplify_commit(revs, commit);
 820
 821        if (revs->no_walk)
 822                return 0;
 823
 824        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 825
 826        for (parent = commit->parents; parent; parent = parent->next) {
 827                struct commit *p = parent->item;
 828                int gently = revs->ignore_missing_links ||
 829                             revs->exclude_promisor_objects;
 830                if (parse_commit_gently(p, gently) < 0) {
 831                        if (revs->exclude_promisor_objects &&
 832                            is_promisor_object(&p->object.oid)) {
 833                                if (revs->first_parent_only)
 834                                        break;
 835                                continue;
 836                        }
 837                        return -1;
 838                }
 839                if (revs->sources) {
 840                        char **slot = revision_sources_at(revs->sources, p);
 841
 842                        if (!*slot)
 843                                *slot = *revision_sources_at(revs->sources, commit);
 844                }
 845                p->object.flags |= left_flag;
 846                if (!(p->object.flags & SEEN)) {
 847                        p->object.flags |= SEEN;
 848                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 849                }
 850                if (revs->first_parent_only)
 851                        break;
 852        }
 853        return 0;
 854}
 855
 856static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 857{
 858        struct commit_list *p;
 859        int left_count = 0, right_count = 0;
 860        int left_first;
 861        struct patch_ids ids;
 862        unsigned cherry_flag;
 863
 864        /* First count the commits on the left and on the right */
 865        for (p = list; p; p = p->next) {
 866                struct commit *commit = p->item;
 867                unsigned flags = commit->object.flags;
 868                if (flags & BOUNDARY)
 869                        ;
 870                else if (flags & SYMMETRIC_LEFT)
 871                        left_count++;
 872                else
 873                        right_count++;
 874        }
 875
 876        if (!left_count || !right_count)
 877                return;
 878
 879        left_first = left_count < right_count;
 880        init_patch_ids(&ids);
 881        ids.diffopts.pathspec = revs->diffopt.pathspec;
 882
 883        /* Compute patch-ids for one side */
 884        for (p = list; p; p = p->next) {
 885                struct commit *commit = p->item;
 886                unsigned flags = commit->object.flags;
 887
 888                if (flags & BOUNDARY)
 889                        continue;
 890                /*
 891                 * If we have fewer left, left_first is set and we omit
 892                 * commits on the right branch in this loop.  If we have
 893                 * fewer right, we skip the left ones.
 894                 */
 895                if (left_first != !!(flags & SYMMETRIC_LEFT))
 896                        continue;
 897                add_commit_patch_id(commit, &ids);
 898        }
 899
 900        /* either cherry_mark or cherry_pick are true */
 901        cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 902
 903        /* Check the other side */
 904        for (p = list; p; p = p->next) {
 905                struct commit *commit = p->item;
 906                struct patch_id *id;
 907                unsigned flags = commit->object.flags;
 908
 909                if (flags & BOUNDARY)
 910                        continue;
 911                /*
 912                 * If we have fewer left, left_first is set and we omit
 913                 * commits on the left branch in this loop.
 914                 */
 915                if (left_first == !!(flags & SYMMETRIC_LEFT))
 916                        continue;
 917
 918                /*
 919                 * Have we seen the same patch id?
 920                 */
 921                id = has_commit_patch_id(commit, &ids);
 922                if (!id)
 923                        continue;
 924
 925                commit->object.flags |= cherry_flag;
 926                id->commit->object.flags |= cherry_flag;
 927        }
 928
 929        free_patch_ids(&ids);
 930}
 931
 932/* How many extra uninteresting commits we want to see.. */
 933#define SLOP 5
 934
 935static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
 936                             struct commit **interesting_cache)
 937{
 938        /*
 939         * No source list at all? We're definitely done..
 940         */
 941        if (!src)
 942                return 0;
 943
 944        /*
 945         * Does the destination list contain entries with a date
 946         * before the source list? Definitely _not_ done.
 947         */
 948        if (date <= src->item->date)
 949                return SLOP;
 950
 951        /*
 952         * Does the source list still have interesting commits in
 953         * it? Definitely not done..
 954         */
 955        if (!everybody_uninteresting(src, interesting_cache))
 956                return SLOP;
 957
 958        /* Ok, we're closing in.. */
 959        return slop-1;
 960}
 961
 962/*
 963 * "rev-list --ancestry-path A..B" computes commits that are ancestors
 964 * of B but not ancestors of A but further limits the result to those
 965 * that are descendants of A.  This takes the list of bottom commits and
 966 * the result of "A..B" without --ancestry-path, and limits the latter
 967 * further to the ones that can reach one of the commits in "bottom".
 968 */
 969static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 970{
 971        struct commit_list *p;
 972        struct commit_list *rlist = NULL;
 973        int made_progress;
 974
 975        /*
 976         * Reverse the list so that it will be likely that we would
 977         * process parents before children.
 978         */
 979        for (p = list; p; p = p->next)
 980                commit_list_insert(p->item, &rlist);
 981
 982        for (p = bottom; p; p = p->next)
 983                p->item->object.flags |= TMP_MARK;
 984
 985        /*
 986         * Mark the ones that can reach bottom commits in "list",
 987         * in a bottom-up fashion.
 988         */
 989        do {
 990                made_progress = 0;
 991                for (p = rlist; p; p = p->next) {
 992                        struct commit *c = p->item;
 993                        struct commit_list *parents;
 994                        if (c->object.flags & (TMP_MARK | UNINTERESTING))
 995                                continue;
 996                        for (parents = c->parents;
 997                             parents;
 998                             parents = parents->next) {
 999                                if (!(parents->item->object.flags & TMP_MARK))
1000                                        continue;
1001                                c->object.flags |= TMP_MARK;
1002                                made_progress = 1;
1003                                break;
1004                        }
1005                }
1006        } while (made_progress);
1007
1008        /*
1009         * NEEDSWORK: decide if we want to remove parents that are
1010         * not marked with TMP_MARK from commit->parents for commits
1011         * in the resulting list.  We may not want to do that, though.
1012         */
1013
1014        /*
1015         * The ones that are not marked with TMP_MARK are uninteresting
1016         */
1017        for (p = list; p; p = p->next) {
1018                struct commit *c = p->item;
1019                if (c->object.flags & TMP_MARK)
1020                        continue;
1021                c->object.flags |= UNINTERESTING;
1022        }
1023
1024        /* We are done with the TMP_MARK */
1025        for (p = list; p; p = p->next)
1026                p->item->object.flags &= ~TMP_MARK;
1027        for (p = bottom; p; p = p->next)
1028                p->item->object.flags &= ~TMP_MARK;
1029        free_commit_list(rlist);
1030}
1031
1032/*
1033 * Before walking the history, keep the set of "negative" refs the
1034 * caller has asked to exclude.
1035 *
1036 * This is used to compute "rev-list --ancestry-path A..B", as we need
1037 * to filter the result of "A..B" further to the ones that can actually
1038 * reach A.
1039 */
1040static struct commit_list *collect_bottom_commits(struct commit_list *list)
1041{
1042        struct commit_list *elem, *bottom = NULL;
1043        for (elem = list; elem; elem = elem->next)
1044                if (elem->item->object.flags & BOTTOM)
1045                        commit_list_insert(elem->item, &bottom);
1046        return bottom;
1047}
1048
1049/* Assumes either left_only or right_only is set */
1050static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1051{
1052        struct commit_list *p;
1053
1054        for (p = list; p; p = p->next) {
1055                struct commit *commit = p->item;
1056
1057                if (revs->right_only) {
1058                        if (commit->object.flags & SYMMETRIC_LEFT)
1059                                commit->object.flags |= SHOWN;
1060                } else  /* revs->left_only is set */
1061                        if (!(commit->object.flags & SYMMETRIC_LEFT))
1062                                commit->object.flags |= SHOWN;
1063        }
1064}
1065
1066static int limit_list(struct rev_info *revs)
1067{
1068        int slop = SLOP;
1069        timestamp_t date = TIME_MAX;
1070        struct commit_list *list = revs->commits;
1071        struct commit_list *newlist = NULL;
1072        struct commit_list **p = &newlist;
1073        struct commit_list *bottom = NULL;
1074        struct commit *interesting_cache = NULL;
1075
1076        if (revs->ancestry_path) {
1077                bottom = collect_bottom_commits(list);
1078                if (!bottom)
1079                        die("--ancestry-path given but there are no bottom commits");
1080        }
1081
1082        while (list) {
1083                struct commit *commit = pop_commit(&list);
1084                struct object *obj = &commit->object;
1085                show_early_output_fn_t show;
1086
1087                if (commit == interesting_cache)
1088                        interesting_cache = NULL;
1089
1090                if (revs->max_age != -1 && (commit->date < revs->max_age))
1091                        obj->flags |= UNINTERESTING;
1092                if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1093                        return -1;
1094                if (obj->flags & UNINTERESTING) {
1095                        mark_parents_uninteresting(commit);
1096                        slop = still_interesting(list, date, slop, &interesting_cache);
1097                        if (slop)
1098                                continue;
1099                        break;
1100                }
1101                if (revs->min_age != -1 && (commit->date > revs->min_age))
1102                        continue;
1103                date = commit->date;
1104                p = &commit_list_insert(commit, p)->next;
1105
1106                show = show_early_output;
1107                if (!show)
1108                        continue;
1109
1110                show(revs, newlist);
1111                show_early_output = NULL;
1112        }
1113        if (revs->cherry_pick || revs->cherry_mark)
1114                cherry_pick_list(newlist, revs);
1115
1116        if (revs->left_only || revs->right_only)
1117                limit_left_right(newlist, revs);
1118
1119        if (bottom) {
1120                limit_to_ancestry(bottom, newlist);
1121                free_commit_list(bottom);
1122        }
1123
1124        /*
1125         * Check if any commits have become TREESAME by some of their parents
1126         * becoming UNINTERESTING.
1127         */
1128        if (limiting_can_increase_treesame(revs))
1129                for (list = newlist; list; list = list->next) {
1130                        struct commit *c = list->item;
1131                        if (c->object.flags & (UNINTERESTING | TREESAME))
1132                                continue;
1133                        update_treesame(revs, c);
1134                }
1135
1136        revs->commits = newlist;
1137        return 0;
1138}
1139
1140/*
1141 * Add an entry to refs->cmdline with the specified information.
1142 * *name is copied.
1143 */
1144static void add_rev_cmdline(struct rev_info *revs,
1145                            struct object *item,
1146                            const char *name,
1147                            int whence,
1148                            unsigned flags)
1149{
1150        struct rev_cmdline_info *info = &revs->cmdline;
1151        unsigned int nr = info->nr;
1152
1153        ALLOC_GROW(info->rev, nr + 1, info->alloc);
1154        info->rev[nr].item = item;
1155        info->rev[nr].name = xstrdup(name);
1156        info->rev[nr].whence = whence;
1157        info->rev[nr].flags = flags;
1158        info->nr++;
1159}
1160
1161static void add_rev_cmdline_list(struct rev_info *revs,
1162                                 struct commit_list *commit_list,
1163                                 int whence,
1164                                 unsigned flags)
1165{
1166        while (commit_list) {
1167                struct object *object = &commit_list->item->object;
1168                add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1169                                whence, flags);
1170                commit_list = commit_list->next;
1171        }
1172}
1173
1174struct all_refs_cb {
1175        int all_flags;
1176        int warned_bad_reflog;
1177        struct rev_info *all_revs;
1178        const char *name_for_errormsg;
1179        struct ref_store *refs;
1180};
1181
1182int ref_excluded(struct string_list *ref_excludes, const char *path)
1183{
1184        struct string_list_item *item;
1185
1186        if (!ref_excludes)
1187                return 0;
1188        for_each_string_list_item(item, ref_excludes) {
1189                if (!wildmatch(item->string, path, 0))
1190                        return 1;
1191        }
1192        return 0;
1193}
1194
1195static int handle_one_ref(const char *path, const struct object_id *oid,
1196                          int flag, void *cb_data)
1197{
1198        struct all_refs_cb *cb = cb_data;
1199        struct object *object;
1200
1201        if (ref_excluded(cb->all_revs->ref_excludes, path))
1202            return 0;
1203
1204        object = get_reference(cb->all_revs, path, oid, cb->all_flags);
1205        add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1206        add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
1207        return 0;
1208}
1209
1210static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1211        unsigned flags)
1212{
1213        cb->all_revs = revs;
1214        cb->all_flags = flags;
1215        revs->rev_input_given = 1;
1216        cb->refs = NULL;
1217}
1218
1219void clear_ref_exclusion(struct string_list **ref_excludes_p)
1220{
1221        if (*ref_excludes_p) {
1222                string_list_clear(*ref_excludes_p, 0);
1223                free(*ref_excludes_p);
1224        }
1225        *ref_excludes_p = NULL;
1226}
1227
1228void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1229{
1230        if (!*ref_excludes_p) {
1231                *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1232                (*ref_excludes_p)->strdup_strings = 1;
1233        }
1234        string_list_append(*ref_excludes_p, exclude);
1235}
1236
1237static void handle_refs(struct ref_store *refs,
1238                        struct rev_info *revs, unsigned flags,
1239                        int (*for_each)(struct ref_store *, each_ref_fn, void *))
1240{
1241        struct all_refs_cb cb;
1242
1243        if (!refs) {
1244                /* this could happen with uninitialized submodules */
1245                return;
1246        }
1247
1248        init_all_refs_cb(&cb, revs, flags);
1249        for_each(refs, handle_one_ref, &cb);
1250}
1251
1252static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
1253{
1254        struct all_refs_cb *cb = cb_data;
1255        if (!is_null_oid(oid)) {
1256                struct object *o = parse_object(the_repository, oid);
1257                if (o) {
1258                        o->flags |= cb->all_flags;
1259                        /* ??? CMDLINEFLAGS ??? */
1260                        add_pending_object(cb->all_revs, o, "");
1261                }
1262                else if (!cb->warned_bad_reflog) {
1263                        warning("reflog of '%s' references pruned commits",
1264                                cb->name_for_errormsg);
1265                        cb->warned_bad_reflog = 1;
1266                }
1267        }
1268}
1269
1270static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
1271                const char *email, timestamp_t timestamp, int tz,
1272                const char *message, void *cb_data)
1273{
1274        handle_one_reflog_commit(ooid, cb_data);
1275        handle_one_reflog_commit(noid, cb_data);
1276        return 0;
1277}
1278
1279static int handle_one_reflog(const char *path, const struct object_id *oid,
1280                             int flag, void *cb_data)
1281{
1282        struct all_refs_cb *cb = cb_data;
1283        cb->warned_bad_reflog = 0;
1284        cb->name_for_errormsg = path;
1285        refs_for_each_reflog_ent(cb->refs, path,
1286                                 handle_one_reflog_ent, cb_data);
1287        return 0;
1288}
1289
1290static void add_other_reflogs_to_pending(struct all_refs_cb *cb)
1291{
1292        struct worktree **worktrees, **p;
1293
1294        worktrees = get_worktrees(0);
1295        for (p = worktrees; *p; p++) {
1296                struct worktree *wt = *p;
1297
1298                if (wt->is_current)
1299                        continue;
1300
1301                cb->refs = get_worktree_ref_store(wt);
1302                refs_for_each_reflog(cb->refs,
1303                                     handle_one_reflog,
1304                                     cb);
1305        }
1306        free_worktrees(worktrees);
1307}
1308
1309void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1310{
1311        struct all_refs_cb cb;
1312
1313        cb.all_revs = revs;
1314        cb.all_flags = flags;
1315        cb.refs = get_main_ref_store(the_repository);
1316        for_each_reflog(handle_one_reflog, &cb);
1317
1318        if (!revs->single_worktree)
1319                add_other_reflogs_to_pending(&cb);
1320}
1321
1322static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1323                           struct strbuf *path)
1324{
1325        size_t baselen = path->len;
1326        int i;
1327
1328        if (it->entry_count >= 0) {
1329                struct tree *tree = lookup_tree(the_repository, &it->oid);
1330                add_pending_object_with_path(revs, &tree->object, "",
1331                                             040000, path->buf);
1332        }
1333
1334        for (i = 0; i < it->subtree_nr; i++) {
1335                struct cache_tree_sub *sub = it->down[i];
1336                strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1337                add_cache_tree(sub->cache_tree, revs, path);
1338                strbuf_setlen(path, baselen);
1339        }
1340
1341}
1342
1343static void do_add_index_objects_to_pending(struct rev_info *revs,
1344                                            struct index_state *istate)
1345{
1346        int i;
1347
1348        for (i = 0; i < istate->cache_nr; i++) {
1349                struct cache_entry *ce = istate->cache[i];
1350                struct blob *blob;
1351
1352                if (S_ISGITLINK(ce->ce_mode))
1353                        continue;
1354
1355                blob = lookup_blob(the_repository, &ce->oid);
1356                if (!blob)
1357                        die("unable to add index blob to traversal");
1358                add_pending_object_with_path(revs, &blob->object, "",
1359                                             ce->ce_mode, ce->name);
1360        }
1361
1362        if (istate->cache_tree) {
1363                struct strbuf path = STRBUF_INIT;
1364                add_cache_tree(istate->cache_tree, revs, &path);
1365                strbuf_release(&path);
1366        }
1367}
1368
1369void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
1370{
1371        struct worktree **worktrees, **p;
1372
1373        read_cache();
1374        do_add_index_objects_to_pending(revs, &the_index);
1375
1376        if (revs->single_worktree)
1377                return;
1378
1379        worktrees = get_worktrees(0);
1380        for (p = worktrees; *p; p++) {
1381                struct worktree *wt = *p;
1382                struct index_state istate = { NULL };
1383
1384                if (wt->is_current)
1385                        continue; /* current index already taken care of */
1386
1387                if (read_index_from(&istate,
1388                                    worktree_git_path(wt, "index"),
1389                                    get_worktree_git_dir(wt)) > 0)
1390                        do_add_index_objects_to_pending(revs, &istate);
1391                discard_index(&istate);
1392        }
1393        free_worktrees(worktrees);
1394}
1395
1396static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
1397                            int exclude_parent)
1398{
1399        struct object_id oid;
1400        struct object *it;
1401        struct commit *commit;
1402        struct commit_list *parents;
1403        int parent_number;
1404        const char *arg = arg_;
1405
1406        if (*arg == '^') {
1407                flags ^= UNINTERESTING | BOTTOM;
1408                arg++;
1409        }
1410        if (get_oid_committish(arg, &oid))
1411                return 0;
1412        while (1) {
1413                it = get_reference(revs, arg, &oid, 0);
1414                if (!it && revs->ignore_missing)
1415                        return 0;
1416                if (it->type != OBJ_TAG)
1417                        break;
1418                if (!((struct tag*)it)->tagged)
1419                        return 0;
1420                oidcpy(&oid, &((struct tag*)it)->tagged->oid);
1421        }
1422        if (it->type != OBJ_COMMIT)
1423                return 0;
1424        commit = (struct commit *)it;
1425        if (exclude_parent &&
1426            exclude_parent > commit_list_count(commit->parents))
1427                return 0;
1428        for (parents = commit->parents, parent_number = 1;
1429             parents;
1430             parents = parents->next, parent_number++) {
1431                if (exclude_parent && parent_number != exclude_parent)
1432                        continue;
1433
1434                it = &parents->item->object;
1435                it->flags |= flags;
1436                add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1437                add_pending_object(revs, it, arg);
1438        }
1439        return 1;
1440}
1441
1442void init_revisions(struct rev_info *revs, const char *prefix)
1443{
1444        memset(revs, 0, sizeof(*revs));
1445
1446        revs->abbrev = DEFAULT_ABBREV;
1447        revs->ignore_merges = 1;
1448        revs->simplify_history = 1;
1449        revs->pruning.flags.recursive = 1;
1450        revs->pruning.flags.quick = 1;
1451        revs->pruning.add_remove = file_add_remove;
1452        revs->pruning.change = file_change;
1453        revs->pruning.change_fn_data = revs;
1454        revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1455        revs->dense = 1;
1456        revs->prefix = prefix;
1457        revs->max_age = -1;
1458        revs->min_age = -1;
1459        revs->skip_count = -1;
1460        revs->max_count = -1;
1461        revs->max_parents = -1;
1462        revs->expand_tabs_in_log = -1;
1463
1464        revs->commit_format = CMIT_FMT_DEFAULT;
1465        revs->expand_tabs_in_log_default = 8;
1466
1467        init_grep_defaults();
1468        grep_init(&revs->grep_filter, prefix);
1469        revs->grep_filter.status_only = 1;
1470
1471        diff_setup(&revs->diffopt);
1472        if (prefix && !revs->diffopt.prefix) {
1473                revs->diffopt.prefix = prefix;
1474                revs->diffopt.prefix_length = strlen(prefix);
1475        }
1476
1477        revs->notes_opt.use_default_notes = -1;
1478}
1479
1480static void add_pending_commit_list(struct rev_info *revs,
1481                                    struct commit_list *commit_list,
1482                                    unsigned int flags)
1483{
1484        while (commit_list) {
1485                struct object *object = &commit_list->item->object;
1486                object->flags |= flags;
1487                add_pending_object(revs, object, oid_to_hex(&object->oid));
1488                commit_list = commit_list->next;
1489        }
1490}
1491
1492static void prepare_show_merge(struct rev_info *revs)
1493{
1494        struct commit_list *bases;
1495        struct commit *head, *other;
1496        struct object_id oid;
1497        const char **prune = NULL;
1498        int i, prune_num = 1; /* counting terminating NULL */
1499
1500        if (get_oid("HEAD", &oid))
1501                die("--merge without HEAD?");
1502        head = lookup_commit_or_die(&oid, "HEAD");
1503        if (get_oid("MERGE_HEAD", &oid))
1504                die("--merge without MERGE_HEAD?");
1505        other = lookup_commit_or_die(&oid, "MERGE_HEAD");
1506        add_pending_object(revs, &head->object, "HEAD");
1507        add_pending_object(revs, &other->object, "MERGE_HEAD");
1508        bases = get_merge_bases(head, other);
1509        add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1510        add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1511        free_commit_list(bases);
1512        head->object.flags |= SYMMETRIC_LEFT;
1513
1514        if (!active_nr)
1515                read_cache();
1516        for (i = 0; i < active_nr; i++) {
1517                const struct cache_entry *ce = active_cache[i];
1518                if (!ce_stage(ce))
1519                        continue;
1520                if (ce_path_match(&the_index, ce, &revs->prune_data, NULL)) {
1521                        prune_num++;
1522                        REALLOC_ARRAY(prune, prune_num);
1523                        prune[prune_num-2] = ce->name;
1524                        prune[prune_num-1] = NULL;
1525                }
1526                while ((i+1 < active_nr) &&
1527                       ce_same_name(ce, active_cache[i+1]))
1528                        i++;
1529        }
1530        clear_pathspec(&revs->prune_data);
1531        parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1532                       PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1533        revs->limited = 1;
1534}
1535
1536static int dotdot_missing(const char *arg, char *dotdot,
1537                          struct rev_info *revs, int symmetric)
1538{
1539        if (revs->ignore_missing)
1540                return 0;
1541        /* de-munge so we report the full argument */
1542        *dotdot = '.';
1543        die(symmetric
1544            ? "Invalid symmetric difference expression %s"
1545            : "Invalid revision range %s", arg);
1546}
1547
1548static int handle_dotdot_1(const char *arg, char *dotdot,
1549                           struct rev_info *revs, int flags,
1550                           int cant_be_filename,
1551                           struct object_context *a_oc,
1552                           struct object_context *b_oc)
1553{
1554        const char *a_name, *b_name;
1555        struct object_id a_oid, b_oid;
1556        struct object *a_obj, *b_obj;
1557        unsigned int a_flags, b_flags;
1558        int symmetric = 0;
1559        unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1560        unsigned int oc_flags = GET_OID_COMMITTISH | GET_OID_RECORD_PATH;
1561
1562        a_name = arg;
1563        if (!*a_name)
1564                a_name = "HEAD";
1565
1566        b_name = dotdot + 2;
1567        if (*b_name == '.') {
1568                symmetric = 1;
1569                b_name++;
1570        }
1571        if (!*b_name)
1572                b_name = "HEAD";
1573
1574        if (get_oid_with_context(a_name, oc_flags, &a_oid, a_oc) ||
1575            get_oid_with_context(b_name, oc_flags, &b_oid, b_oc))
1576                return -1;
1577
1578        if (!cant_be_filename) {
1579                *dotdot = '.';
1580                verify_non_filename(revs->prefix, arg);
1581                *dotdot = '\0';
1582        }
1583
1584        a_obj = parse_object(the_repository, &a_oid);
1585        b_obj = parse_object(the_repository, &b_oid);
1586        if (!a_obj || !b_obj)
1587                return dotdot_missing(arg, dotdot, revs, symmetric);
1588
1589        if (!symmetric) {
1590                /* just A..B */
1591                b_flags = flags;
1592                a_flags = flags_exclude;
1593        } else {
1594                /* A...B -- find merge bases between the two */
1595                struct commit *a, *b;
1596                struct commit_list *exclude;
1597
1598                a = lookup_commit_reference(the_repository, &a_obj->oid);
1599                b = lookup_commit_reference(the_repository, &b_obj->oid);
1600                if (!a || !b)
1601                        return dotdot_missing(arg, dotdot, revs, symmetric);
1602
1603                exclude = get_merge_bases(a, b);
1604                add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
1605                                     flags_exclude);
1606                add_pending_commit_list(revs, exclude, flags_exclude);
1607                free_commit_list(exclude);
1608
1609                b_flags = flags;
1610                a_flags = flags | SYMMETRIC_LEFT;
1611        }
1612
1613        a_obj->flags |= a_flags;
1614        b_obj->flags |= b_flags;
1615        add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
1616        add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
1617        add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
1618        add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
1619        return 0;
1620}
1621
1622static int handle_dotdot(const char *arg,
1623                         struct rev_info *revs, int flags,
1624                         int cant_be_filename)
1625{
1626        struct object_context a_oc, b_oc;
1627        char *dotdot = strstr(arg, "..");
1628        int ret;
1629
1630        if (!dotdot)
1631                return -1;
1632
1633        memset(&a_oc, 0, sizeof(a_oc));
1634        memset(&b_oc, 0, sizeof(b_oc));
1635
1636        *dotdot = '\0';
1637        ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
1638                              &a_oc, &b_oc);
1639        *dotdot = '.';
1640
1641        free(a_oc.path);
1642        free(b_oc.path);
1643
1644        return ret;
1645}
1646
1647int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1648{
1649        struct object_context oc;
1650        char *mark;
1651        struct object *object;
1652        struct object_id oid;
1653        int local_flags;
1654        const char *arg = arg_;
1655        int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1656        unsigned get_sha1_flags = GET_OID_RECORD_PATH;
1657
1658        flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1659
1660        if (!cant_be_filename && !strcmp(arg, "..")) {
1661                /*
1662                 * Just ".."?  That is not a range but the
1663                 * pathspec for the parent directory.
1664                 */
1665                return -1;
1666        }
1667
1668        if (!handle_dotdot(arg, revs, flags, revarg_opt))
1669                return 0;
1670
1671        mark = strstr(arg, "^@");
1672        if (mark && !mark[2]) {
1673                *mark = 0;
1674                if (add_parents_only(revs, arg, flags, 0))
1675                        return 0;
1676                *mark = '^';
1677        }
1678        mark = strstr(arg, "^!");
1679        if (mark && !mark[2]) {
1680                *mark = 0;
1681                if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
1682                        *mark = '^';
1683        }
1684        mark = strstr(arg, "^-");
1685        if (mark) {
1686                int exclude_parent = 1;
1687
1688                if (mark[2]) {
1689                        char *end;
1690                        exclude_parent = strtoul(mark + 2, &end, 10);
1691                        if (*end != '\0' || !exclude_parent)
1692                                return -1;
1693                }
1694
1695                *mark = 0;
1696                if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
1697                        *mark = '^';
1698        }
1699
1700        local_flags = 0;
1701        if (*arg == '^') {
1702                local_flags = UNINTERESTING | BOTTOM;
1703                arg++;
1704        }
1705
1706        if (revarg_opt & REVARG_COMMITTISH)
1707                get_sha1_flags |= GET_OID_COMMITTISH;
1708
1709        if (get_oid_with_context(arg, get_sha1_flags, &oid, &oc))
1710                return revs->ignore_missing ? 0 : -1;
1711        if (!cant_be_filename)
1712                verify_non_filename(revs->prefix, arg);
1713        object = get_reference(revs, arg, &oid, flags ^ local_flags);
1714        add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1715        add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
1716        free(oc.path);
1717        return 0;
1718}
1719
1720static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1721                                     struct argv_array *prune)
1722{
1723        while (strbuf_getline(sb, stdin) != EOF)
1724                argv_array_push(prune, sb->buf);
1725}
1726
1727static void read_revisions_from_stdin(struct rev_info *revs,
1728                                      struct argv_array *prune)
1729{
1730        struct strbuf sb;
1731        int seen_dashdash = 0;
1732        int save_warning;
1733
1734        save_warning = warn_on_object_refname_ambiguity;
1735        warn_on_object_refname_ambiguity = 0;
1736
1737        strbuf_init(&sb, 1000);
1738        while (strbuf_getline(&sb, stdin) != EOF) {
1739                int len = sb.len;
1740                if (!len)
1741                        break;
1742                if (sb.buf[0] == '-') {
1743                        if (len == 2 && sb.buf[1] == '-') {
1744                                seen_dashdash = 1;
1745                                break;
1746                        }
1747                        die("options not supported in --stdin mode");
1748                }
1749                if (handle_revision_arg(sb.buf, revs, 0,
1750                                        REVARG_CANNOT_BE_FILENAME))
1751                        die("bad revision '%s'", sb.buf);
1752        }
1753        if (seen_dashdash)
1754                read_pathspec_from_stdin(revs, &sb, prune);
1755
1756        strbuf_release(&sb);
1757        warn_on_object_refname_ambiguity = save_warning;
1758}
1759
1760static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1761{
1762        append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1763}
1764
1765static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1766{
1767        append_header_grep_pattern(&revs->grep_filter, field, pattern);
1768}
1769
1770static void add_message_grep(struct rev_info *revs, const char *pattern)
1771{
1772        add_grep(revs, pattern, GREP_PATTERN_BODY);
1773}
1774
1775static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1776                               int *unkc, const char **unkv)
1777{
1778        const char *arg = argv[0];
1779        const char *optarg;
1780        int argcount;
1781        const unsigned hexsz = the_hash_algo->hexsz;
1782
1783        /* pseudo revision arguments */
1784        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1785            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1786            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1787            !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1788            !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1789            !strcmp(arg, "--indexed-objects") ||
1790            starts_with(arg, "--exclude=") ||
1791            starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1792            starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1793        {
1794                unkv[(*unkc)++] = arg;
1795                return 1;
1796        }
1797
1798        if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1799                revs->max_count = atoi(optarg);
1800                revs->no_walk = 0;
1801                return argcount;
1802        } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1803                revs->skip_count = atoi(optarg);
1804                return argcount;
1805        } else if ((*arg == '-') && isdigit(arg[1])) {
1806                /* accept -<digit>, like traditional "head" */
1807                if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1808                    revs->max_count < 0)
1809                        die("'%s': not a non-negative integer", arg + 1);
1810                revs->no_walk = 0;
1811        } else if (!strcmp(arg, "-n")) {
1812                if (argc <= 1)
1813                        return error("-n requires an argument");
1814                revs->max_count = atoi(argv[1]);
1815                revs->no_walk = 0;
1816                return 2;
1817        } else if (skip_prefix(arg, "-n", &optarg)) {
1818                revs->max_count = atoi(optarg);
1819                revs->no_walk = 0;
1820        } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1821                revs->max_age = atoi(optarg);
1822                return argcount;
1823        } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1824                revs->max_age = approxidate(optarg);
1825                return argcount;
1826        } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1827                revs->max_age = approxidate(optarg);
1828                return argcount;
1829        } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1830                revs->min_age = atoi(optarg);
1831                return argcount;
1832        } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1833                revs->min_age = approxidate(optarg);
1834                return argcount;
1835        } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1836                revs->min_age = approxidate(optarg);
1837                return argcount;
1838        } else if (!strcmp(arg, "--first-parent")) {
1839                revs->first_parent_only = 1;
1840        } else if (!strcmp(arg, "--ancestry-path")) {
1841                revs->ancestry_path = 1;
1842                revs->simplify_history = 0;
1843                revs->limited = 1;
1844        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1845                init_reflog_walk(&revs->reflog_info);
1846        } else if (!strcmp(arg, "--default")) {
1847                if (argc <= 1)
1848                        return error("bad --default argument");
1849                revs->def = argv[1];
1850                return 2;
1851        } else if (!strcmp(arg, "--merge")) {
1852                revs->show_merge = 1;
1853        } else if (!strcmp(arg, "--topo-order")) {
1854                revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1855                revs->topo_order = 1;
1856        } else if (!strcmp(arg, "--simplify-merges")) {
1857                revs->simplify_merges = 1;
1858                revs->topo_order = 1;
1859                revs->rewrite_parents = 1;
1860                revs->simplify_history = 0;
1861                revs->limited = 1;
1862        } else if (!strcmp(arg, "--simplify-by-decoration")) {
1863                revs->simplify_merges = 1;
1864                revs->topo_order = 1;
1865                revs->rewrite_parents = 1;
1866                revs->simplify_history = 0;
1867                revs->simplify_by_decoration = 1;
1868                revs->limited = 1;
1869                revs->prune = 1;
1870                load_ref_decorations(NULL, DECORATE_SHORT_REFS);
1871        } else if (!strcmp(arg, "--date-order")) {
1872                revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1873                revs->topo_order = 1;
1874        } else if (!strcmp(arg, "--author-date-order")) {
1875                revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1876                revs->topo_order = 1;
1877        } else if (!strcmp(arg, "--early-output")) {
1878                revs->early_output = 100;
1879                revs->topo_order = 1;
1880        } else if (skip_prefix(arg, "--early-output=", &optarg)) {
1881                if (strtoul_ui(optarg, 10, &revs->early_output) < 0)
1882                        die("'%s': not a non-negative integer", optarg);
1883                revs->topo_order = 1;
1884        } else if (!strcmp(arg, "--parents")) {
1885                revs->rewrite_parents = 1;
1886                revs->print_parents = 1;
1887        } else if (!strcmp(arg, "--dense")) {
1888                revs->dense = 1;
1889        } else if (!strcmp(arg, "--sparse")) {
1890                revs->dense = 0;
1891        } else if (!strcmp(arg, "--in-commit-order")) {
1892                revs->tree_blobs_in_commit_order = 1;
1893        } else if (!strcmp(arg, "--remove-empty")) {
1894                revs->remove_empty_trees = 1;
1895        } else if (!strcmp(arg, "--merges")) {
1896                revs->min_parents = 2;
1897        } else if (!strcmp(arg, "--no-merges")) {
1898                revs->max_parents = 1;
1899        } else if (skip_prefix(arg, "--min-parents=", &optarg)) {
1900                revs->min_parents = atoi(optarg);
1901        } else if (!strcmp(arg, "--no-min-parents")) {
1902                revs->min_parents = 0;
1903        } else if (skip_prefix(arg, "--max-parents=", &optarg)) {
1904                revs->max_parents = atoi(optarg);
1905        } else if (!strcmp(arg, "--no-max-parents")) {
1906                revs->max_parents = -1;
1907        } else if (!strcmp(arg, "--boundary")) {
1908                revs->boundary = 1;
1909        } else if (!strcmp(arg, "--left-right")) {
1910                revs->left_right = 1;
1911        } else if (!strcmp(arg, "--left-only")) {
1912                if (revs->right_only)
1913                        die("--left-only is incompatible with --right-only"
1914                            " or --cherry");
1915                revs->left_only = 1;
1916        } else if (!strcmp(arg, "--right-only")) {
1917                if (revs->left_only)
1918                        die("--right-only is incompatible with --left-only");
1919                revs->right_only = 1;
1920        } else if (!strcmp(arg, "--cherry")) {
1921                if (revs->left_only)
1922                        die("--cherry is incompatible with --left-only");
1923                revs->cherry_mark = 1;
1924                revs->right_only = 1;
1925                revs->max_parents = 1;
1926                revs->limited = 1;
1927        } else if (!strcmp(arg, "--count")) {
1928                revs->count = 1;
1929        } else if (!strcmp(arg, "--cherry-mark")) {
1930                if (revs->cherry_pick)
1931                        die("--cherry-mark is incompatible with --cherry-pick");
1932                revs->cherry_mark = 1;
1933                revs->limited = 1; /* needs limit_list() */
1934        } else if (!strcmp(arg, "--cherry-pick")) {
1935                if (revs->cherry_mark)
1936                        die("--cherry-pick is incompatible with --cherry-mark");
1937                revs->cherry_pick = 1;
1938                revs->limited = 1;
1939        } else if (!strcmp(arg, "--objects")) {
1940                revs->tag_objects = 1;
1941                revs->tree_objects = 1;
1942                revs->blob_objects = 1;
1943        } else if (!strcmp(arg, "--objects-edge")) {
1944                revs->tag_objects = 1;
1945                revs->tree_objects = 1;
1946                revs->blob_objects = 1;
1947                revs->edge_hint = 1;
1948        } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1949                revs->tag_objects = 1;
1950                revs->tree_objects = 1;
1951                revs->blob_objects = 1;
1952                revs->edge_hint = 1;
1953                revs->edge_hint_aggressive = 1;
1954        } else if (!strcmp(arg, "--verify-objects")) {
1955                revs->tag_objects = 1;
1956                revs->tree_objects = 1;
1957                revs->blob_objects = 1;
1958                revs->verify_objects = 1;
1959        } else if (!strcmp(arg, "--unpacked")) {
1960                revs->unpacked = 1;
1961        } else if (starts_with(arg, "--unpacked=")) {
1962                die("--unpacked=<packfile> no longer supported.");
1963        } else if (!strcmp(arg, "-r")) {
1964                revs->diff = 1;
1965                revs->diffopt.flags.recursive = 1;
1966        } else if (!strcmp(arg, "-t")) {
1967                revs->diff = 1;
1968                revs->diffopt.flags.recursive = 1;
1969                revs->diffopt.flags.tree_in_recursive = 1;
1970        } else if (!strcmp(arg, "-m")) {
1971                revs->ignore_merges = 0;
1972        } else if (!strcmp(arg, "-c")) {
1973                revs->diff = 1;
1974                revs->dense_combined_merges = 0;
1975                revs->combine_merges = 1;
1976        } else if (!strcmp(arg, "--cc")) {
1977                revs->diff = 1;
1978                revs->dense_combined_merges = 1;
1979                revs->combine_merges = 1;
1980        } else if (!strcmp(arg, "-v")) {
1981                revs->verbose_header = 1;
1982        } else if (!strcmp(arg, "--pretty")) {
1983                revs->verbose_header = 1;
1984                revs->pretty_given = 1;
1985                get_commit_format(NULL, revs);
1986        } else if (skip_prefix(arg, "--pretty=", &optarg) ||
1987                   skip_prefix(arg, "--format=", &optarg)) {
1988                /*
1989                 * Detached form ("--pretty X" as opposed to "--pretty=X")
1990                 * not allowed, since the argument is optional.
1991                 */
1992                revs->verbose_header = 1;
1993                revs->pretty_given = 1;
1994                get_commit_format(optarg, revs);
1995        } else if (!strcmp(arg, "--expand-tabs")) {
1996                revs->expand_tabs_in_log = 8;
1997        } else if (!strcmp(arg, "--no-expand-tabs")) {
1998                revs->expand_tabs_in_log = 0;
1999        } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
2000                int val;
2001                if (strtol_i(arg, 10, &val) < 0 || val < 0)
2002                        die("'%s': not a non-negative integer", arg);
2003                revs->expand_tabs_in_log = val;
2004        } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
2005                revs->show_notes = 1;
2006                revs->show_notes_given = 1;
2007                revs->notes_opt.use_default_notes = 1;
2008        } else if (!strcmp(arg, "--show-signature")) {
2009                revs->show_signature = 1;
2010        } else if (!strcmp(arg, "--no-show-signature")) {
2011                revs->show_signature = 0;
2012        } else if (!strcmp(arg, "--show-linear-break")) {
2013                revs->break_bar = "                    ..........";
2014                revs->track_linear = 1;
2015                revs->track_first_time = 1;
2016        } else if (skip_prefix(arg, "--show-linear-break=", &optarg)) {
2017                revs->break_bar = xstrdup(optarg);
2018                revs->track_linear = 1;
2019                revs->track_first_time = 1;
2020        } else if (skip_prefix(arg, "--show-notes=", &optarg) ||
2021                   skip_prefix(arg, "--notes=", &optarg)) {
2022                struct strbuf buf = STRBUF_INIT;
2023                revs->show_notes = 1;
2024                revs->show_notes_given = 1;
2025                if (starts_with(arg, "--show-notes=") &&
2026                    revs->notes_opt.use_default_notes < 0)
2027                        revs->notes_opt.use_default_notes = 1;
2028                strbuf_addstr(&buf, optarg);
2029                expand_notes_ref(&buf);
2030                string_list_append(&revs->notes_opt.extra_notes_refs,
2031                                   strbuf_detach(&buf, NULL));
2032        } else if (!strcmp(arg, "--no-notes")) {
2033                revs->show_notes = 0;
2034                revs->show_notes_given = 1;
2035                revs->notes_opt.use_default_notes = -1;
2036                /* we have been strdup'ing ourselves, so trick
2037                 * string_list into free()ing strings */
2038                revs->notes_opt.extra_notes_refs.strdup_strings = 1;
2039                string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
2040                revs->notes_opt.extra_notes_refs.strdup_strings = 0;
2041        } else if (!strcmp(arg, "--standard-notes")) {
2042                revs->show_notes_given = 1;
2043                revs->notes_opt.use_default_notes = 1;
2044        } else if (!strcmp(arg, "--no-standard-notes")) {
2045                revs->notes_opt.use_default_notes = 0;
2046        } else if (!strcmp(arg, "--oneline")) {
2047                revs->verbose_header = 1;
2048                get_commit_format("oneline", revs);
2049                revs->pretty_given = 1;
2050                revs->abbrev_commit = 1;
2051        } else if (!strcmp(arg, "--graph")) {
2052                revs->topo_order = 1;
2053                revs->rewrite_parents = 1;
2054                revs->graph = graph_init(revs);
2055        } else if (!strcmp(arg, "--root")) {
2056                revs->show_root_diff = 1;
2057        } else if (!strcmp(arg, "--no-commit-id")) {
2058                revs->no_commit_id = 1;
2059        } else if (!strcmp(arg, "--always")) {
2060                revs->always_show_header = 1;
2061        } else if (!strcmp(arg, "--no-abbrev")) {
2062                revs->abbrev = 0;
2063        } else if (!strcmp(arg, "--abbrev")) {
2064                revs->abbrev = DEFAULT_ABBREV;
2065        } else if (skip_prefix(arg, "--abbrev=", &optarg)) {
2066                revs->abbrev = strtoul(optarg, NULL, 10);
2067                if (revs->abbrev < MINIMUM_ABBREV)
2068                        revs->abbrev = MINIMUM_ABBREV;
2069                else if (revs->abbrev > hexsz)
2070                        revs->abbrev = hexsz;
2071        } else if (!strcmp(arg, "--abbrev-commit")) {
2072                revs->abbrev_commit = 1;
2073                revs->abbrev_commit_given = 1;
2074        } else if (!strcmp(arg, "--no-abbrev-commit")) {
2075                revs->abbrev_commit = 0;
2076        } else if (!strcmp(arg, "--full-diff")) {
2077                revs->diff = 1;
2078                revs->full_diff = 1;
2079        } else if (!strcmp(arg, "--full-history")) {
2080                revs->simplify_history = 0;
2081        } else if (!strcmp(arg, "--relative-date")) {
2082                revs->date_mode.type = DATE_RELATIVE;
2083                revs->date_mode_explicit = 1;
2084        } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
2085                parse_date_format(optarg, &revs->date_mode);
2086                revs->date_mode_explicit = 1;
2087                return argcount;
2088        } else if (!strcmp(arg, "--log-size")) {
2089                revs->show_log_size = 1;
2090        }
2091        /*
2092         * Grepping the commit log
2093         */
2094        else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2095                add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2096                return argcount;
2097        } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2098                add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2099                return argcount;
2100        } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2101                add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2102                return argcount;
2103        } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2104                add_message_grep(revs, optarg);
2105                return argcount;
2106        } else if (!strcmp(arg, "--grep-debug")) {
2107                revs->grep_filter.debug = 1;
2108        } else if (!strcmp(arg, "--basic-regexp")) {
2109                revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
2110        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2111                revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
2112        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2113                revs->grep_filter.ignore_case = 1;
2114                revs->diffopt.pickaxe_opts |= DIFF_PICKAXE_IGNORE_CASE;
2115        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2116                revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
2117        } else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
2118                revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
2119        } else if (!strcmp(arg, "--all-match")) {
2120                revs->grep_filter.all_match = 1;
2121        } else if (!strcmp(arg, "--invert-grep")) {
2122                revs->invert_grep = 1;
2123        } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2124                if (strcmp(optarg, "none"))
2125                        git_log_output_encoding = xstrdup(optarg);
2126                else
2127                        git_log_output_encoding = "";
2128                return argcount;
2129        } else if (!strcmp(arg, "--reverse")) {
2130                revs->reverse ^= 1;
2131        } else if (!strcmp(arg, "--children")) {
2132                revs->children.name = "children";
2133                revs->limited = 1;
2134        } else if (!strcmp(arg, "--ignore-missing")) {
2135                revs->ignore_missing = 1;
2136        } else if (!strcmp(arg, "--exclude-promisor-objects")) {
2137                if (fetch_if_missing)
2138                        BUG("exclude_promisor_objects can only be used when fetch_if_missing is 0");
2139                revs->exclude_promisor_objects = 1;
2140        } else {
2141                int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2142                if (!opts)
2143                        unkv[(*unkc)++] = arg;
2144                return opts;
2145        }
2146        if (revs->graph && revs->track_linear)
2147                die("--show-linear-break and --graph are incompatible");
2148
2149        return 1;
2150}
2151
2152void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2153                        const struct option *options,
2154                        const char * const usagestr[])
2155{
2156        int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2157                                    &ctx->cpidx, ctx->out);
2158        if (n <= 0) {
2159                error("unknown option `%s'", ctx->argv[0]);
2160                usage_with_options(usagestr, options);
2161        }
2162        ctx->argv += n;
2163        ctx->argc -= n;
2164}
2165
2166static int for_each_bisect_ref(struct ref_store *refs, each_ref_fn fn,
2167                               void *cb_data, const char *term)
2168{
2169        struct strbuf bisect_refs = STRBUF_INIT;
2170        int status;
2171        strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2172        status = refs_for_each_fullref_in(refs, bisect_refs.buf, fn, cb_data, 0);
2173        strbuf_release(&bisect_refs);
2174        return status;
2175}
2176
2177static int for_each_bad_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2178{
2179        return for_each_bisect_ref(refs, fn, cb_data, term_bad);
2180}
2181
2182static int for_each_good_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2183{
2184        return for_each_bisect_ref(refs, fn, cb_data, term_good);
2185}
2186
2187static int handle_revision_pseudo_opt(const char *submodule,
2188                                struct rev_info *revs,
2189                                int argc, const char **argv, int *flags)
2190{
2191        const char *arg = argv[0];
2192        const char *optarg;
2193        struct ref_store *refs;
2194        int argcount;
2195
2196        if (submodule) {
2197                /*
2198                 * We need some something like get_submodule_worktrees()
2199                 * before we can go through all worktrees of a submodule,
2200                 * .e.g with adding all HEADs from --all, which is not
2201                 * supported right now, so stick to single worktree.
2202                 */
2203                if (!revs->single_worktree)
2204                        BUG("--single-worktree cannot be used together with submodule");
2205                refs = get_submodule_ref_store(submodule);
2206        } else
2207                refs = get_main_ref_store(the_repository);
2208
2209        /*
2210         * NOTE!
2211         *
2212         * Commands like "git shortlog" will not accept the options below
2213         * unless parse_revision_opt queues them (as opposed to erroring
2214         * out).
2215         *
2216         * When implementing your new pseudo-option, remember to
2217         * register it in the list at the top of handle_revision_opt.
2218         */
2219        if (!strcmp(arg, "--all")) {
2220                handle_refs(refs, revs, *flags, refs_for_each_ref);
2221                handle_refs(refs, revs, *flags, refs_head_ref);
2222                if (!revs->single_worktree) {
2223                        struct all_refs_cb cb;
2224
2225                        init_all_refs_cb(&cb, revs, *flags);
2226                        other_head_refs(handle_one_ref, &cb);
2227                }
2228                clear_ref_exclusion(&revs->ref_excludes);
2229        } else if (!strcmp(arg, "--branches")) {
2230                handle_refs(refs, revs, *flags, refs_for_each_branch_ref);
2231                clear_ref_exclusion(&revs->ref_excludes);
2232        } else if (!strcmp(arg, "--bisect")) {
2233                read_bisect_terms(&term_bad, &term_good);
2234                handle_refs(refs, revs, *flags, for_each_bad_bisect_ref);
2235                handle_refs(refs, revs, *flags ^ (UNINTERESTING | BOTTOM),
2236                            for_each_good_bisect_ref);
2237                revs->bisect = 1;
2238        } else if (!strcmp(arg, "--tags")) {
2239                handle_refs(refs, revs, *flags, refs_for_each_tag_ref);
2240                clear_ref_exclusion(&revs->ref_excludes);
2241        } else if (!strcmp(arg, "--remotes")) {
2242                handle_refs(refs, revs, *flags, refs_for_each_remote_ref);
2243                clear_ref_exclusion(&revs->ref_excludes);
2244        } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2245                struct all_refs_cb cb;
2246                init_all_refs_cb(&cb, revs, *flags);
2247                for_each_glob_ref(handle_one_ref, optarg, &cb);
2248                clear_ref_exclusion(&revs->ref_excludes);
2249                return argcount;
2250        } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2251                add_ref_exclusion(&revs->ref_excludes, optarg);
2252                return argcount;
2253        } else if (skip_prefix(arg, "--branches=", &optarg)) {
2254                struct all_refs_cb cb;
2255                init_all_refs_cb(&cb, revs, *flags);
2256                for_each_glob_ref_in(handle_one_ref, optarg, "refs/heads/", &cb);
2257                clear_ref_exclusion(&revs->ref_excludes);
2258        } else if (skip_prefix(arg, "--tags=", &optarg)) {
2259                struct all_refs_cb cb;
2260                init_all_refs_cb(&cb, revs, *flags);
2261                for_each_glob_ref_in(handle_one_ref, optarg, "refs/tags/", &cb);
2262                clear_ref_exclusion(&revs->ref_excludes);
2263        } else if (skip_prefix(arg, "--remotes=", &optarg)) {
2264                struct all_refs_cb cb;
2265                init_all_refs_cb(&cb, revs, *flags);
2266                for_each_glob_ref_in(handle_one_ref, optarg, "refs/remotes/", &cb);
2267                clear_ref_exclusion(&revs->ref_excludes);
2268        } else if (!strcmp(arg, "--reflog")) {
2269                add_reflogs_to_pending(revs, *flags);
2270        } else if (!strcmp(arg, "--indexed-objects")) {
2271                add_index_objects_to_pending(revs, *flags);
2272        } else if (!strcmp(arg, "--not")) {
2273                *flags ^= UNINTERESTING | BOTTOM;
2274        } else if (!strcmp(arg, "--no-walk")) {
2275                revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2276        } else if (skip_prefix(arg, "--no-walk=", &optarg)) {
2277                /*
2278                 * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2279                 * not allowed, since the argument is optional.
2280                 */
2281                if (!strcmp(optarg, "sorted"))
2282                        revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2283                else if (!strcmp(optarg, "unsorted"))
2284                        revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2285                else
2286                        return error("invalid argument to --no-walk");
2287        } else if (!strcmp(arg, "--do-walk")) {
2288                revs->no_walk = 0;
2289        } else if (!strcmp(arg, "--single-worktree")) {
2290                revs->single_worktree = 1;
2291        } else {
2292                return 0;
2293        }
2294
2295        return 1;
2296}
2297
2298static void NORETURN diagnose_missing_default(const char *def)
2299{
2300        int flags;
2301        const char *refname;
2302
2303        refname = resolve_ref_unsafe(def, 0, NULL, &flags);
2304        if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2305                die(_("your current branch appears to be broken"));
2306
2307        skip_prefix(refname, "refs/heads/", &refname);
2308        die(_("your current branch '%s' does not have any commits yet"),
2309            refname);
2310}
2311
2312/*
2313 * Parse revision information, filling in the "rev_info" structure,
2314 * and removing the used arguments from the argument list.
2315 *
2316 * Returns the number of arguments left that weren't recognized
2317 * (which are also moved to the head of the argument list)
2318 */
2319int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2320{
2321        int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2322        struct argv_array prune_data = ARGV_ARRAY_INIT;
2323        const char *submodule = NULL;
2324
2325        if (opt)
2326                submodule = opt->submodule;
2327
2328        /* First, search for "--" */
2329        if (opt && opt->assume_dashdash) {
2330                seen_dashdash = 1;
2331        } else {
2332                seen_dashdash = 0;
2333                for (i = 1; i < argc; i++) {
2334                        const char *arg = argv[i];
2335                        if (strcmp(arg, "--"))
2336                                continue;
2337                        argv[i] = NULL;
2338                        argc = i;
2339                        if (argv[i + 1])
2340                                argv_array_pushv(&prune_data, argv + i + 1);
2341                        seen_dashdash = 1;
2342                        break;
2343                }
2344        }
2345
2346        /* Second, deal with arguments and options */
2347        flags = 0;
2348        revarg_opt = opt ? opt->revarg_opt : 0;
2349        if (seen_dashdash)
2350                revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2351        read_from_stdin = 0;
2352        for (left = i = 1; i < argc; i++) {
2353                const char *arg = argv[i];
2354                if (*arg == '-') {
2355                        int opts;
2356
2357                        opts = handle_revision_pseudo_opt(submodule,
2358                                                revs, argc - i, argv + i,
2359                                                &flags);
2360                        if (opts > 0) {
2361                                i += opts - 1;
2362                                continue;
2363                        }
2364
2365                        if (!strcmp(arg, "--stdin")) {
2366                                if (revs->disable_stdin) {
2367                                        argv[left++] = arg;
2368                                        continue;
2369                                }
2370                                if (read_from_stdin++)
2371                                        die("--stdin given twice?");
2372                                read_revisions_from_stdin(revs, &prune_data);
2373                                continue;
2374                        }
2375
2376                        opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2377                        if (opts > 0) {
2378                                i += opts - 1;
2379                                continue;
2380                        }
2381                        if (opts < 0)
2382                                exit(128);
2383                        continue;
2384                }
2385
2386
2387                if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2388                        int j;
2389                        if (seen_dashdash || *arg == '^')
2390                                die("bad revision '%s'", arg);
2391
2392                        /* If we didn't have a "--":
2393                         * (1) all filenames must exist;
2394                         * (2) all rev-args must not be interpretable
2395                         *     as a valid filename.
2396                         * but the latter we have checked in the main loop.
2397                         */
2398                        for (j = i; j < argc; j++)
2399                                verify_filename(revs->prefix, argv[j], j == i);
2400
2401                        argv_array_pushv(&prune_data, argv + i);
2402                        break;
2403                }
2404                else
2405                        got_rev_arg = 1;
2406        }
2407
2408        if (prune_data.argc) {
2409                /*
2410                 * If we need to introduce the magic "a lone ':' means no
2411                 * pathspec whatsoever", here is the place to do so.
2412                 *
2413                 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2414                 *      prune_data.nr = 0;
2415                 *      prune_data.alloc = 0;
2416                 *      free(prune_data.path);
2417                 *      prune_data.path = NULL;
2418                 * } else {
2419                 *      terminate prune_data.alloc with NULL and
2420                 *      call init_pathspec() to set revs->prune_data here.
2421                 * }
2422                 */
2423                parse_pathspec(&revs->prune_data, 0, 0,
2424                               revs->prefix, prune_data.argv);
2425        }
2426        argv_array_clear(&prune_data);
2427
2428        if (revs->def == NULL)
2429                revs->def = opt ? opt->def : NULL;
2430        if (opt && opt->tweak)
2431                opt->tweak(revs, opt);
2432        if (revs->show_merge)
2433                prepare_show_merge(revs);
2434        if (revs->def && !revs->pending.nr && !revs->rev_input_given && !got_rev_arg) {
2435                struct object_id oid;
2436                struct object *object;
2437                struct object_context oc;
2438                if (get_oid_with_context(revs->def, 0, &oid, &oc))
2439                        diagnose_missing_default(revs->def);
2440                object = get_reference(revs, revs->def, &oid, 0);
2441                add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2442        }
2443
2444        /* Did the user ask for any diff output? Run the diff! */
2445        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2446                revs->diff = 1;
2447
2448        /* Pickaxe, diff-filter and rename following need diffs */
2449        if ((revs->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
2450            revs->diffopt.filter ||
2451            revs->diffopt.flags.follow_renames)
2452                revs->diff = 1;
2453
2454        if (revs->diffopt.objfind)
2455                revs->simplify_history = 0;
2456
2457        if (revs->topo_order)
2458                revs->limited = 1;
2459
2460        if (revs->prune_data.nr) {
2461                copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2462                /* Can't prune commits with rename following: the paths change.. */
2463                if (!revs->diffopt.flags.follow_renames)
2464                        revs->prune = 1;
2465                if (!revs->full_diff)
2466                        copy_pathspec(&revs->diffopt.pathspec,
2467                                      &revs->prune_data);
2468        }
2469        if (revs->combine_merges)
2470                revs->ignore_merges = 0;
2471        revs->diffopt.abbrev = revs->abbrev;
2472
2473        if (revs->line_level_traverse) {
2474                revs->limited = 1;
2475                revs->topo_order = 1;
2476        }
2477
2478        diff_setup_done(&revs->diffopt);
2479
2480        grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2481                                 &revs->grep_filter);
2482        compile_grep_patterns(&revs->grep_filter);
2483
2484        if (revs->reverse && revs->reflog_info)
2485                die("cannot combine --reverse with --walk-reflogs");
2486        if (revs->reflog_info && revs->limited)
2487                die("cannot combine --walk-reflogs with history-limiting options");
2488        if (revs->rewrite_parents && revs->children.name)
2489                die("cannot combine --parents and --children");
2490
2491        /*
2492         * Limitations on the graph functionality
2493         */
2494        if (revs->reverse && revs->graph)
2495                die("cannot combine --reverse with --graph");
2496
2497        if (revs->reflog_info && revs->graph)
2498                die("cannot combine --walk-reflogs with --graph");
2499        if (revs->no_walk && revs->graph)
2500                die("cannot combine --no-walk with --graph");
2501        if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2502                die("cannot use --grep-reflog without --walk-reflogs");
2503
2504        if (revs->first_parent_only && revs->bisect)
2505                die(_("--first-parent is incompatible with --bisect"));
2506
2507        if (revs->expand_tabs_in_log < 0)
2508                revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2509
2510        return left;
2511}
2512
2513static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2514{
2515        struct commit_list *l = xcalloc(1, sizeof(*l));
2516
2517        l->item = child;
2518        l->next = add_decoration(&revs->children, &parent->object, l);
2519}
2520
2521static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2522{
2523        struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2524        struct commit_list **pp, *p;
2525        int surviving_parents;
2526
2527        /* Examine existing parents while marking ones we have seen... */
2528        pp = &commit->parents;
2529        surviving_parents = 0;
2530        while ((p = *pp) != NULL) {
2531                struct commit *parent = p->item;
2532                if (parent->object.flags & TMP_MARK) {
2533                        *pp = p->next;
2534                        if (ts)
2535                                compact_treesame(revs, commit, surviving_parents);
2536                        continue;
2537                }
2538                parent->object.flags |= TMP_MARK;
2539                surviving_parents++;
2540                pp = &p->next;
2541        }
2542        /* clear the temporary mark */
2543        for (p = commit->parents; p; p = p->next) {
2544                p->item->object.flags &= ~TMP_MARK;
2545        }
2546        /* no update_treesame() - removing duplicates can't affect TREESAME */
2547        return surviving_parents;
2548}
2549
2550struct merge_simplify_state {
2551        struct commit *simplified;
2552};
2553
2554static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2555{
2556        struct merge_simplify_state *st;
2557
2558        st = lookup_decoration(&revs->merge_simplification, &commit->object);
2559        if (!st) {
2560                st = xcalloc(1, sizeof(*st));
2561                add_decoration(&revs->merge_simplification, &commit->object, st);
2562        }
2563        return st;
2564}
2565
2566static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2567{
2568        struct commit_list *h = reduce_heads(commit->parents);
2569        int i = 0, marked = 0;
2570        struct commit_list *po, *pn;
2571
2572        /* Want these for sanity-checking only */
2573        int orig_cnt = commit_list_count(commit->parents);
2574        int cnt = commit_list_count(h);
2575
2576        /*
2577         * Not ready to remove items yet, just mark them for now, based
2578         * on the output of reduce_heads(). reduce_heads outputs the reduced
2579         * set in its original order, so this isn't too hard.
2580         */
2581        po = commit->parents;
2582        pn = h;
2583        while (po) {
2584                if (pn && po->item == pn->item) {
2585                        pn = pn->next;
2586                        i++;
2587                } else {
2588                        po->item->object.flags |= TMP_MARK;
2589                        marked++;
2590                }
2591                po=po->next;
2592        }
2593
2594        if (i != cnt || cnt+marked != orig_cnt)
2595                die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2596
2597        free_commit_list(h);
2598
2599        return marked;
2600}
2601
2602static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2603{
2604        struct commit_list *p;
2605        int marked = 0;
2606
2607        for (p = commit->parents; p; p = p->next) {
2608                struct commit *parent = p->item;
2609                if (!parent->parents && (parent->object.flags & TREESAME)) {
2610                        parent->object.flags |= TMP_MARK;
2611                        marked++;
2612                }
2613        }
2614
2615        return marked;
2616}
2617
2618/*
2619 * Awkward naming - this means one parent we are TREESAME to.
2620 * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2621 * empty tree). Better name suggestions?
2622 */
2623static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2624{
2625        struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2626        struct commit *unmarked = NULL, *marked = NULL;
2627        struct commit_list *p;
2628        unsigned n;
2629
2630        for (p = commit->parents, n = 0; p; p = p->next, n++) {
2631                if (ts->treesame[n]) {
2632                        if (p->item->object.flags & TMP_MARK) {
2633                                if (!marked)
2634                                        marked = p->item;
2635                        } else {
2636                                if (!unmarked) {
2637                                        unmarked = p->item;
2638                                        break;
2639                                }
2640                        }
2641                }
2642        }
2643
2644        /*
2645         * If we are TREESAME to a marked-for-deletion parent, but not to any
2646         * unmarked parents, unmark the first TREESAME parent. This is the
2647         * parent that the default simplify_history==1 scan would have followed,
2648         * and it doesn't make sense to omit that path when asking for a
2649         * simplified full history. Retaining it improves the chances of
2650         * understanding odd missed merges that took an old version of a file.
2651         *
2652         * Example:
2653         *
2654         *   I--------*X       A modified the file, but mainline merge X used
2655         *    \       /        "-s ours", so took the version from I. X is
2656         *     `-*A--'         TREESAME to I and !TREESAME to A.
2657         *
2658         * Default log from X would produce "I". Without this check,
2659         * --full-history --simplify-merges would produce "I-A-X", showing
2660         * the merge commit X and that it changed A, but not making clear that
2661         * it had just taken the I version. With this check, the topology above
2662         * is retained.
2663         *
2664         * Note that it is possible that the simplification chooses a different
2665         * TREESAME parent from the default, in which case this test doesn't
2666         * activate, and we _do_ drop the default parent. Example:
2667         *
2668         *   I------X         A modified the file, but it was reverted in B,
2669         *    \    /          meaning mainline merge X is TREESAME to both
2670         *    *A-*B           parents.
2671         *
2672         * Default log would produce "I" by following the first parent;
2673         * --full-history --simplify-merges will produce "I-A-B". But this is a
2674         * reasonable result - it presents a logical full history leading from
2675         * I to X, and X is not an important merge.
2676         */
2677        if (!unmarked && marked) {
2678                marked->object.flags &= ~TMP_MARK;
2679                return 1;
2680        }
2681
2682        return 0;
2683}
2684
2685static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2686{
2687        struct commit_list **pp, *p;
2688        int nth_parent, removed = 0;
2689
2690        pp = &commit->parents;
2691        nth_parent = 0;
2692        while ((p = *pp) != NULL) {
2693                struct commit *parent = p->item;
2694                if (parent->object.flags & TMP_MARK) {
2695                        parent->object.flags &= ~TMP_MARK;
2696                        *pp = p->next;
2697                        free(p);
2698                        removed++;
2699                        compact_treesame(revs, commit, nth_parent);
2700                        continue;
2701                }
2702                pp = &p->next;
2703                nth_parent++;
2704        }
2705
2706        /* Removing parents can only increase TREESAMEness */
2707        if (removed && !(commit->object.flags & TREESAME))
2708                update_treesame(revs, commit);
2709
2710        return nth_parent;
2711}
2712
2713static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2714{
2715        struct commit_list *p;
2716        struct commit *parent;
2717        struct merge_simplify_state *st, *pst;
2718        int cnt;
2719
2720        st = locate_simplify_state(revs, commit);
2721
2722        /*
2723         * Have we handled this one?
2724         */
2725        if (st->simplified)
2726                return tail;
2727
2728        /*
2729         * An UNINTERESTING commit simplifies to itself, so does a
2730         * root commit.  We do not rewrite parents of such commit
2731         * anyway.
2732         */
2733        if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2734                st->simplified = commit;
2735                return tail;
2736        }
2737
2738        /*
2739         * Do we know what commit all of our parents that matter
2740         * should be rewritten to?  Otherwise we are not ready to
2741         * rewrite this one yet.
2742         */
2743        for (cnt = 0, p = commit->parents; p; p = p->next) {
2744                pst = locate_simplify_state(revs, p->item);
2745                if (!pst->simplified) {
2746                        tail = &commit_list_insert(p->item, tail)->next;
2747                        cnt++;
2748                }
2749                if (revs->first_parent_only)
2750                        break;
2751        }
2752        if (cnt) {
2753                tail = &commit_list_insert(commit, tail)->next;
2754                return tail;
2755        }
2756
2757        /*
2758         * Rewrite our list of parents. Note that this cannot
2759         * affect our TREESAME flags in any way - a commit is
2760         * always TREESAME to its simplification.
2761         */
2762        for (p = commit->parents; p; p = p->next) {
2763                pst = locate_simplify_state(revs, p->item);
2764                p->item = pst->simplified;
2765                if (revs->first_parent_only)
2766                        break;
2767        }
2768
2769        if (revs->first_parent_only)
2770                cnt = 1;
2771        else
2772                cnt = remove_duplicate_parents(revs, commit);
2773
2774        /*
2775         * It is possible that we are a merge and one side branch
2776         * does not have any commit that touches the given paths;
2777         * in such a case, the immediate parent from that branch
2778         * will be rewritten to be the merge base.
2779         *
2780         *      o----X          X: the commit we are looking at;
2781         *     /    /           o: a commit that touches the paths;
2782         * ---o----'
2783         *
2784         * Further, a merge of an independent branch that doesn't
2785         * touch the path will reduce to a treesame root parent:
2786         *
2787         *  ----o----X          X: the commit we are looking at;
2788         *          /           o: a commit that touches the paths;
2789         *         r            r: a root commit not touching the paths
2790         *
2791         * Detect and simplify both cases.
2792         */
2793        if (1 < cnt) {
2794                int marked = mark_redundant_parents(revs, commit);
2795                marked += mark_treesame_root_parents(revs, commit);
2796                if (marked)
2797                        marked -= leave_one_treesame_to_parent(revs, commit);
2798                if (marked)
2799                        cnt = remove_marked_parents(revs, commit);
2800        }
2801
2802        /*
2803         * A commit simplifies to itself if it is a root, if it is
2804         * UNINTERESTING, if it touches the given paths, or if it is a
2805         * merge and its parents don't simplify to one relevant commit
2806         * (the first two cases are already handled at the beginning of
2807         * this function).
2808         *
2809         * Otherwise, it simplifies to what its sole relevant parent
2810         * simplifies to.
2811         */
2812        if (!cnt ||
2813            (commit->object.flags & UNINTERESTING) ||
2814            !(commit->object.flags & TREESAME) ||
2815            (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2816                st->simplified = commit;
2817        else {
2818                pst = locate_simplify_state(revs, parent);
2819                st->simplified = pst->simplified;
2820        }
2821        return tail;
2822}
2823
2824static void simplify_merges(struct rev_info *revs)
2825{
2826        struct commit_list *list, *next;
2827        struct commit_list *yet_to_do, **tail;
2828        struct commit *commit;
2829
2830        if (!revs->prune)
2831                return;
2832
2833        /* feed the list reversed */
2834        yet_to_do = NULL;
2835        for (list = revs->commits; list; list = next) {
2836                commit = list->item;
2837                next = list->next;
2838                /*
2839                 * Do not free(list) here yet; the original list
2840                 * is used later in this function.
2841                 */
2842                commit_list_insert(commit, &yet_to_do);
2843        }
2844        while (yet_to_do) {
2845                list = yet_to_do;
2846                yet_to_do = NULL;
2847                tail = &yet_to_do;
2848                while (list) {
2849                        commit = pop_commit(&list);
2850                        tail = simplify_one(revs, commit, tail);
2851                }
2852        }
2853
2854        /* clean up the result, removing the simplified ones */
2855        list = revs->commits;
2856        revs->commits = NULL;
2857        tail = &revs->commits;
2858        while (list) {
2859                struct merge_simplify_state *st;
2860
2861                commit = pop_commit(&list);
2862                st = locate_simplify_state(revs, commit);
2863                if (st->simplified == commit)
2864                        tail = &commit_list_insert(commit, tail)->next;
2865        }
2866}
2867
2868static void set_children(struct rev_info *revs)
2869{
2870        struct commit_list *l;
2871        for (l = revs->commits; l; l = l->next) {
2872                struct commit *commit = l->item;
2873                struct commit_list *p;
2874
2875                for (p = commit->parents; p; p = p->next)
2876                        add_child(revs, p->item, commit);
2877        }
2878}
2879
2880void reset_revision_walk(void)
2881{
2882        clear_object_flags(SEEN | ADDED | SHOWN);
2883}
2884
2885static int mark_uninteresting(const struct object_id *oid,
2886                              struct packed_git *pack,
2887                              uint32_t pos,
2888                              void *unused)
2889{
2890        struct object *o = parse_object(the_repository, oid);
2891        o->flags |= UNINTERESTING | SEEN;
2892        return 0;
2893}
2894
2895int prepare_revision_walk(struct rev_info *revs)
2896{
2897        int i;
2898        struct object_array old_pending;
2899        struct commit_list **next = &revs->commits;
2900
2901        memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2902        revs->pending.nr = 0;
2903        revs->pending.alloc = 0;
2904        revs->pending.objects = NULL;
2905        for (i = 0; i < old_pending.nr; i++) {
2906                struct object_array_entry *e = old_pending.objects + i;
2907                struct commit *commit = handle_commit(revs, e);
2908                if (commit) {
2909                        if (!(commit->object.flags & SEEN)) {
2910                                commit->object.flags |= SEEN;
2911                                next = commit_list_append(commit, next);
2912                        }
2913                }
2914        }
2915        object_array_clear(&old_pending);
2916
2917        /* Signal whether we need per-parent treesame decoration */
2918        if (revs->simplify_merges ||
2919            (revs->limited && limiting_can_increase_treesame(revs)))
2920                revs->treesame.name = "treesame";
2921
2922        if (revs->exclude_promisor_objects) {
2923                for_each_packed_object(mark_uninteresting, NULL,
2924                                       FOR_EACH_OBJECT_PROMISOR_ONLY);
2925        }
2926
2927        if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2928                commit_list_sort_by_date(&revs->commits);
2929        if (revs->no_walk)
2930                return 0;
2931        if (revs->limited)
2932                if (limit_list(revs) < 0)
2933                        return -1;
2934        if (revs->topo_order)
2935                sort_in_topological_order(&revs->commits, revs->sort_order);
2936        if (revs->line_level_traverse)
2937                line_log_filter(revs);
2938        if (revs->simplify_merges)
2939                simplify_merges(revs);
2940        if (revs->children.name)
2941                set_children(revs);
2942        return 0;
2943}
2944
2945static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2946{
2947        struct commit_list *cache = NULL;
2948
2949        for (;;) {
2950                struct commit *p = *pp;
2951                if (!revs->limited)
2952                        if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2953                                return rewrite_one_error;
2954                if (p->object.flags & UNINTERESTING)
2955                        return rewrite_one_ok;
2956                if (!(p->object.flags & TREESAME))
2957                        return rewrite_one_ok;
2958                if (!p->parents)
2959                        return rewrite_one_noparents;
2960                if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2961                        return rewrite_one_ok;
2962                *pp = p;
2963        }
2964}
2965
2966int rewrite_parents(struct rev_info *revs, struct commit *commit,
2967        rewrite_parent_fn_t rewrite_parent)
2968{
2969        struct commit_list **pp = &commit->parents;
2970        while (*pp) {
2971                struct commit_list *parent = *pp;
2972                switch (rewrite_parent(revs, &parent->item)) {
2973                case rewrite_one_ok:
2974                        break;
2975                case rewrite_one_noparents:
2976                        *pp = parent->next;
2977                        continue;
2978                case rewrite_one_error:
2979                        return -1;
2980                }
2981                pp = &parent->next;
2982        }
2983        remove_duplicate_parents(revs, commit);
2984        return 0;
2985}
2986
2987static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2988{
2989        char *person, *endp;
2990        size_t len, namelen, maillen;
2991        const char *name;
2992        const char *mail;
2993        struct ident_split ident;
2994
2995        person = strstr(buf->buf, what);
2996        if (!person)
2997                return 0;
2998
2999        person += strlen(what);
3000        endp = strchr(person, '\n');
3001        if (!endp)
3002                return 0;
3003
3004        len = endp - person;
3005
3006        if (split_ident_line(&ident, person, len))
3007                return 0;
3008
3009        mail = ident.mail_begin;
3010        maillen = ident.mail_end - ident.mail_begin;
3011        name = ident.name_begin;
3012        namelen = ident.name_end - ident.name_begin;
3013
3014        if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
3015                struct strbuf namemail = STRBUF_INIT;
3016
3017                strbuf_addf(&namemail, "%.*s <%.*s>",
3018                            (int)namelen, name, (int)maillen, mail);
3019
3020                strbuf_splice(buf, ident.name_begin - buf->buf,
3021                              ident.mail_end - ident.name_begin + 1,
3022                              namemail.buf, namemail.len);
3023
3024                strbuf_release(&namemail);
3025
3026                return 1;
3027        }
3028
3029        return 0;
3030}
3031
3032static int commit_match(struct commit *commit, struct rev_info *opt)
3033{
3034        int retval;
3035        const char *encoding;
3036        const char *message;
3037        struct strbuf buf = STRBUF_INIT;
3038
3039        if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
3040                return 1;
3041
3042        /* Prepend "fake" headers as needed */
3043        if (opt->grep_filter.use_reflog_filter) {
3044                strbuf_addstr(&buf, "reflog ");
3045                get_reflog_message(&buf, opt->reflog_info);
3046                strbuf_addch(&buf, '\n');
3047        }
3048
3049        /*
3050         * We grep in the user's output encoding, under the assumption that it
3051         * is the encoding they are most likely to write their grep pattern
3052         * for. In addition, it means we will match the "notes" encoding below,
3053         * so we will not end up with a buffer that has two different encodings
3054         * in it.
3055         */
3056        encoding = get_log_output_encoding();
3057        message = logmsg_reencode(commit, NULL, encoding);
3058
3059        /* Copy the commit to temporary if we are using "fake" headers */
3060        if (buf.len)
3061                strbuf_addstr(&buf, message);
3062
3063        if (opt->grep_filter.header_list && opt->mailmap) {
3064                if (!buf.len)
3065                        strbuf_addstr(&buf, message);
3066
3067                commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
3068                commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
3069        }
3070
3071        /* Append "fake" message parts as needed */
3072        if (opt->show_notes) {
3073                if (!buf.len)
3074                        strbuf_addstr(&buf, message);
3075                format_display_notes(&commit->object.oid, &buf, encoding, 1);
3076        }
3077
3078        /*
3079         * Find either in the original commit message, or in the temporary.
3080         * Note that we cast away the constness of "message" here. It is
3081         * const because it may come from the cached commit buffer. That's OK,
3082         * because we know that it is modifiable heap memory, and that while
3083         * grep_buffer may modify it for speed, it will restore any
3084         * changes before returning.
3085         */
3086        if (buf.len)
3087                retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
3088        else
3089                retval = grep_buffer(&opt->grep_filter,
3090                                     (char *)message, strlen(message));
3091        strbuf_release(&buf);
3092        unuse_commit_buffer(commit, message);
3093        return opt->invert_grep ? !retval : retval;
3094}
3095
3096static inline int want_ancestry(const struct rev_info *revs)
3097{
3098        return (revs->rewrite_parents || revs->children.name);
3099}
3100
3101/*
3102 * Return a timestamp to be used for --since/--until comparisons for this
3103 * commit, based on the revision options.
3104 */
3105static timestamp_t comparison_date(const struct rev_info *revs,
3106                                   struct commit *commit)
3107{
3108        return revs->reflog_info ?
3109                get_reflog_timestamp(revs->reflog_info) :
3110                commit->date;
3111}
3112
3113enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
3114{
3115        if (commit->object.flags & SHOWN)
3116                return commit_ignore;
3117        if (revs->unpacked && has_object_pack(&commit->object.oid))
3118                return commit_ignore;
3119        if (commit->object.flags & UNINTERESTING)
3120                return commit_ignore;
3121        if (revs->min_age != -1 &&
3122            comparison_date(revs, commit) > revs->min_age)
3123                        return commit_ignore;
3124        if (revs->min_parents || (revs->max_parents >= 0)) {
3125                int n = commit_list_count(commit->parents);
3126                if ((n < revs->min_parents) ||
3127                    ((revs->max_parents >= 0) && (n > revs->max_parents)))
3128                        return commit_ignore;
3129        }
3130        if (!commit_match(commit, revs))
3131                return commit_ignore;
3132        if (revs->prune && revs->dense) {
3133                /* Commit without changes? */
3134                if (commit->object.flags & TREESAME) {
3135                        int n;
3136                        struct commit_list *p;
3137                        /* drop merges unless we want parenthood */
3138                        if (!want_ancestry(revs))
3139                                return commit_ignore;
3140                        /*
3141                         * If we want ancestry, then need to keep any merges
3142                         * between relevant commits to tie together topology.
3143                         * For consistency with TREESAME and simplification
3144                         * use "relevant" here rather than just INTERESTING,
3145                         * to treat bottom commit(s) as part of the topology.
3146                         */
3147                        for (n = 0, p = commit->parents; p; p = p->next)
3148                                if (relevant_commit(p->item))
3149                                        if (++n >= 2)
3150                                                return commit_show;
3151                        return commit_ignore;
3152                }
3153        }
3154        return commit_show;
3155}
3156
3157define_commit_slab(saved_parents, struct commit_list *);
3158
3159#define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3160
3161/*
3162 * You may only call save_parents() once per commit (this is checked
3163 * for non-root commits).
3164 */
3165static void save_parents(struct rev_info *revs, struct commit *commit)
3166{
3167        struct commit_list **pp;
3168
3169        if (!revs->saved_parents_slab) {
3170                revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3171                init_saved_parents(revs->saved_parents_slab);
3172        }
3173
3174        pp = saved_parents_at(revs->saved_parents_slab, commit);
3175
3176        /*
3177         * When walking with reflogs, we may visit the same commit
3178         * several times: once for each appearance in the reflog.
3179         *
3180         * In this case, save_parents() will be called multiple times.
3181         * We want to keep only the first set of parents.  We need to
3182         * store a sentinel value for an empty (i.e., NULL) parent
3183         * list to distinguish it from a not-yet-saved list, however.
3184         */
3185        if (*pp)
3186                return;
3187        if (commit->parents)
3188                *pp = copy_commit_list(commit->parents);
3189        else
3190                *pp = EMPTY_PARENT_LIST;
3191}
3192
3193static void free_saved_parents(struct rev_info *revs)
3194{
3195        if (revs->saved_parents_slab)
3196                clear_saved_parents(revs->saved_parents_slab);
3197}
3198
3199struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3200{
3201        struct commit_list *parents;
3202
3203        if (!revs->saved_parents_slab)
3204                return commit->parents;
3205
3206        parents = *saved_parents_at(revs->saved_parents_slab, commit);
3207        if (parents == EMPTY_PARENT_LIST)
3208                return NULL;
3209        return parents;
3210}
3211
3212enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3213{
3214        enum commit_action action = get_commit_action(revs, commit);
3215
3216        if (action == commit_show &&
3217            revs->prune && revs->dense && want_ancestry(revs)) {
3218                /*
3219                 * --full-diff on simplified parents is no good: it
3220                 * will show spurious changes from the commits that
3221                 * were elided.  So we save the parents on the side
3222                 * when --full-diff is in effect.
3223                 */
3224                if (revs->full_diff)
3225                        save_parents(revs, commit);
3226                if (rewrite_parents(revs, commit, rewrite_one) < 0)
3227                        return commit_error;
3228        }
3229        return action;
3230}
3231
3232static void track_linear(struct rev_info *revs, struct commit *commit)
3233{
3234        if (revs->track_first_time) {
3235                revs->linear = 1;
3236                revs->track_first_time = 0;
3237        } else {
3238                struct commit_list *p;
3239                for (p = revs->previous_parents; p; p = p->next)
3240                        if (p->item == NULL || /* first commit */
3241                            !oidcmp(&p->item->object.oid, &commit->object.oid))
3242                                break;
3243                revs->linear = p != NULL;
3244        }
3245        if (revs->reverse) {
3246                if (revs->linear)
3247                        commit->object.flags |= TRACK_LINEAR;
3248        }
3249        free_commit_list(revs->previous_parents);
3250        revs->previous_parents = copy_commit_list(commit->parents);
3251}
3252
3253static struct commit *get_revision_1(struct rev_info *revs)
3254{
3255        while (1) {
3256                struct commit *commit;
3257
3258                if (revs->reflog_info)
3259                        commit = next_reflog_entry(revs->reflog_info);
3260                else
3261                        commit = pop_commit(&revs->commits);
3262
3263                if (!commit)
3264                        return NULL;
3265
3266                if (revs->reflog_info)
3267                        commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3268
3269                /*
3270                 * If we haven't done the list limiting, we need to look at
3271                 * the parents here. We also need to do the date-based limiting
3272                 * that we'd otherwise have done in limit_list().
3273                 */
3274                if (!revs->limited) {
3275                        if (revs->max_age != -1 &&
3276                            comparison_date(revs, commit) < revs->max_age)
3277                                continue;
3278
3279                        if (revs->reflog_info)
3280                                try_to_simplify_commit(revs, commit);
3281                        else if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3282                                if (!revs->ignore_missing_links)
3283                                        die("Failed to traverse parents of commit %s",
3284                                                oid_to_hex(&commit->object.oid));
3285                        }
3286                }
3287
3288                switch (simplify_commit(revs, commit)) {
3289                case commit_ignore:
3290                        continue;
3291                case commit_error:
3292                        die("Failed to simplify parents of commit %s",
3293                            oid_to_hex(&commit->object.oid));
3294                default:
3295                        if (revs->track_linear)
3296                                track_linear(revs, commit);
3297                        return commit;
3298                }
3299        }
3300}
3301
3302/*
3303 * Return true for entries that have not yet been shown.  (This is an
3304 * object_array_each_func_t.)
3305 */
3306static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3307{
3308        return !(entry->item->flags & SHOWN);
3309}
3310
3311/*
3312 * If array is on the verge of a realloc, garbage-collect any entries
3313 * that have already been shown to try to free up some space.
3314 */
3315static void gc_boundary(struct object_array *array)
3316{
3317        if (array->nr == array->alloc)
3318                object_array_filter(array, entry_unshown, NULL);
3319}
3320
3321static void create_boundary_commit_list(struct rev_info *revs)
3322{
3323        unsigned i;
3324        struct commit *c;
3325        struct object_array *array = &revs->boundary_commits;
3326        struct object_array_entry *objects = array->objects;
3327
3328        /*
3329         * If revs->commits is non-NULL at this point, an error occurred in
3330         * get_revision_1().  Ignore the error and continue printing the
3331         * boundary commits anyway.  (This is what the code has always
3332         * done.)
3333         */
3334        if (revs->commits) {
3335                free_commit_list(revs->commits);
3336                revs->commits = NULL;
3337        }
3338
3339        /*
3340         * Put all of the actual boundary commits from revs->boundary_commits
3341         * into revs->commits
3342         */
3343        for (i = 0; i < array->nr; i++) {
3344                c = (struct commit *)(objects[i].item);
3345                if (!c)
3346                        continue;
3347                if (!(c->object.flags & CHILD_SHOWN))
3348                        continue;
3349                if (c->object.flags & (SHOWN | BOUNDARY))
3350                        continue;
3351                c->object.flags |= BOUNDARY;
3352                commit_list_insert(c, &revs->commits);
3353        }
3354
3355        /*
3356         * If revs->topo_order is set, sort the boundary commits
3357         * in topological order
3358         */
3359        sort_in_topological_order(&revs->commits, revs->sort_order);
3360}
3361
3362static struct commit *get_revision_internal(struct rev_info *revs)
3363{
3364        struct commit *c = NULL;
3365        struct commit_list *l;
3366
3367        if (revs->boundary == 2) {
3368                /*
3369                 * All of the normal commits have already been returned,
3370                 * and we are now returning boundary commits.
3371                 * create_boundary_commit_list() has populated
3372                 * revs->commits with the remaining commits to return.
3373                 */
3374                c = pop_commit(&revs->commits);
3375                if (c)
3376                        c->object.flags |= SHOWN;
3377                return c;
3378        }
3379
3380        /*
3381         * If our max_count counter has reached zero, then we are done. We
3382         * don't simply return NULL because we still might need to show
3383         * boundary commits. But we want to avoid calling get_revision_1, which
3384         * might do a considerable amount of work finding the next commit only
3385         * for us to throw it away.
3386         *
3387         * If it is non-zero, then either we don't have a max_count at all
3388         * (-1), or it is still counting, in which case we decrement.
3389         */
3390        if (revs->max_count) {
3391                c = get_revision_1(revs);
3392                if (c) {
3393                        while (revs->skip_count > 0) {
3394                                revs->skip_count--;
3395                                c = get_revision_1(revs);
3396                                if (!c)
3397                                        break;
3398                        }
3399                }
3400
3401                if (revs->max_count > 0)
3402                        revs->max_count--;
3403        }
3404
3405        if (c)
3406                c->object.flags |= SHOWN;
3407
3408        if (!revs->boundary)
3409                return c;
3410
3411        if (!c) {
3412                /*
3413                 * get_revision_1() runs out the commits, and
3414                 * we are done computing the boundaries.
3415                 * switch to boundary commits output mode.
3416                 */
3417                revs->boundary = 2;
3418
3419                /*
3420                 * Update revs->commits to contain the list of
3421                 * boundary commits.
3422                 */
3423                create_boundary_commit_list(revs);
3424
3425                return get_revision_internal(revs);
3426        }
3427
3428        /*
3429         * boundary commits are the commits that are parents of the
3430         * ones we got from get_revision_1() but they themselves are
3431         * not returned from get_revision_1().  Before returning
3432         * 'c', we need to mark its parents that they could be boundaries.
3433         */
3434
3435        for (l = c->parents; l; l = l->next) {
3436                struct object *p;
3437                p = &(l->item->object);
3438                if (p->flags & (CHILD_SHOWN | SHOWN))
3439                        continue;
3440                p->flags |= CHILD_SHOWN;
3441                gc_boundary(&revs->boundary_commits);
3442                add_object_array(p, NULL, &revs->boundary_commits);
3443        }
3444
3445        return c;
3446}
3447
3448struct commit *get_revision(struct rev_info *revs)
3449{
3450        struct commit *c;
3451        struct commit_list *reversed;
3452
3453        if (revs->reverse) {
3454                reversed = NULL;
3455                while ((c = get_revision_internal(revs)))
3456                        commit_list_insert(c, &reversed);
3457                revs->commits = reversed;
3458                revs->reverse = 0;
3459                revs->reverse_output_stage = 1;
3460        }
3461
3462        if (revs->reverse_output_stage) {
3463                c = pop_commit(&revs->commits);
3464                if (revs->track_linear)
3465                        revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3466                return c;
3467        }
3468
3469        c = get_revision_internal(revs);
3470        if (c && revs->graph)
3471                graph_update(revs->graph, c);
3472        if (!c) {
3473                free_saved_parents(revs);
3474                if (revs->previous_parents) {
3475                        free_commit_list(revs->previous_parents);
3476                        revs->previous_parents = NULL;
3477                }
3478        }
3479        return c;
3480}
3481
3482char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3483{
3484        if (commit->object.flags & BOUNDARY)
3485                return "-";
3486        else if (commit->object.flags & UNINTERESTING)
3487                return "^";
3488        else if (commit->object.flags & PATCHSAME)
3489                return "=";
3490        else if (!revs || revs->left_right) {
3491                if (commit->object.flags & SYMMETRIC_LEFT)
3492                        return "<";
3493                else
3494                        return ">";
3495        } else if (revs->graph)
3496                return "*";
3497        else if (revs->cherry_mark)
3498                return "+";
3499        return "";
3500}
3501
3502void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3503{
3504        char *mark = get_revision_mark(revs, commit);
3505        if (!strlen(mark))
3506                return;
3507        fputs(mark, stdout);
3508        putchar(' ');
3509}