revision.con commit Merge branch 'nd/i18n-index-pack' (0083f1d)
   1#include "cache.h"
   2#include "tag.h"
   3#include "blob.h"
   4#include "tree.h"
   5#include "commit.h"
   6#include "diff.h"
   7#include "refs.h"
   8#include "revision.h"
   9#include "graph.h"
  10#include "grep.h"
  11#include "reflog-walk.h"
  12#include "patch-ids.h"
  13#include "decorate.h"
  14#include "log-tree.h"
  15#include "string-list.h"
  16
  17volatile show_early_output_fn_t show_early_output;
  18
  19char *path_name(const struct name_path *path, const char *name)
  20{
  21        const struct name_path *p;
  22        char *n, *m;
  23        int nlen = strlen(name);
  24        int len = nlen + 1;
  25
  26        for (p = path; p; p = p->up) {
  27                if (p->elem_len)
  28                        len += p->elem_len + 1;
  29        }
  30        n = xmalloc(len);
  31        m = n + len - (nlen + 1);
  32        strcpy(m, name);
  33        for (p = path; p; p = p->up) {
  34                if (p->elem_len) {
  35                        m -= p->elem_len + 1;
  36                        memcpy(m, p->elem, p->elem_len);
  37                        m[p->elem_len] = '/';
  38                }
  39        }
  40        return n;
  41}
  42
  43static int show_path_component_truncated(FILE *out, const char *name, int len)
  44{
  45        int cnt;
  46        for (cnt = 0; cnt < len; cnt++) {
  47                int ch = name[cnt];
  48                if (!ch || ch == '\n')
  49                        return -1;
  50                fputc(ch, out);
  51        }
  52        return len;
  53}
  54
  55static int show_path_truncated(FILE *out, const struct name_path *path)
  56{
  57        int emitted, ours;
  58
  59        if (!path)
  60                return 0;
  61        emitted = show_path_truncated(out, path->up);
  62        if (emitted < 0)
  63                return emitted;
  64        if (emitted)
  65                fputc('/', out);
  66        ours = show_path_component_truncated(out, path->elem, path->elem_len);
  67        if (ours < 0)
  68                return ours;
  69        return ours || emitted;
  70}
  71
  72void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
  73{
  74        struct name_path leaf;
  75        leaf.up = (struct name_path *)path;
  76        leaf.elem = component;
  77        leaf.elem_len = strlen(component);
  78
  79        fprintf(out, "%s ", sha1_to_hex(obj->sha1));
  80        show_path_truncated(out, &leaf);
  81        fputc('\n', out);
  82}
  83
  84void add_object(struct object *obj,
  85                struct object_array *p,
  86                struct name_path *path,
  87                const char *name)
  88{
  89        add_object_array(obj, path_name(path, name), p);
  90}
  91
  92static void mark_blob_uninteresting(struct blob *blob)
  93{
  94        if (!blob)
  95                return;
  96        if (blob->object.flags & UNINTERESTING)
  97                return;
  98        blob->object.flags |= UNINTERESTING;
  99}
 100
 101void mark_tree_uninteresting(struct tree *tree)
 102{
 103        struct tree_desc desc;
 104        struct name_entry entry;
 105        struct object *obj = &tree->object;
 106
 107        if (!tree)
 108                return;
 109        if (obj->flags & UNINTERESTING)
 110                return;
 111        obj->flags |= UNINTERESTING;
 112        if (!has_sha1_file(obj->sha1))
 113                return;
 114        if (parse_tree(tree) < 0)
 115                die("bad tree %s", sha1_to_hex(obj->sha1));
 116
 117        init_tree_desc(&desc, tree->buffer, tree->size);
 118        while (tree_entry(&desc, &entry)) {
 119                switch (object_type(entry.mode)) {
 120                case OBJ_TREE:
 121                        mark_tree_uninteresting(lookup_tree(entry.sha1));
 122                        break;
 123                case OBJ_BLOB:
 124                        mark_blob_uninteresting(lookup_blob(entry.sha1));
 125                        break;
 126                default:
 127                        /* Subproject commit - not in this repository */
 128                        break;
 129                }
 130        }
 131
 132        /*
 133         * We don't care about the tree any more
 134         * after it has been marked uninteresting.
 135         */
 136        free(tree->buffer);
 137        tree->buffer = NULL;
 138}
 139
 140void mark_parents_uninteresting(struct commit *commit)
 141{
 142        struct commit_list *parents = NULL, *l;
 143
 144        for (l = commit->parents; l; l = l->next)
 145                commit_list_insert(l->item, &parents);
 146
 147        while (parents) {
 148                struct commit *commit = parents->item;
 149                l = parents;
 150                parents = parents->next;
 151                free(l);
 152
 153                while (commit) {
 154                        /*
 155                         * A missing commit is ok iff its parent is marked
 156                         * uninteresting.
 157                         *
 158                         * We just mark such a thing parsed, so that when
 159                         * it is popped next time around, we won't be trying
 160                         * to parse it and get an error.
 161                         */
 162                        if (!has_sha1_file(commit->object.sha1))
 163                                commit->object.parsed = 1;
 164
 165                        if (commit->object.flags & UNINTERESTING)
 166                                break;
 167
 168                        commit->object.flags |= UNINTERESTING;
 169
 170                        /*
 171                         * Normally we haven't parsed the parent
 172                         * yet, so we won't have a parent of a parent
 173                         * here. However, it may turn out that we've
 174                         * reached this commit some other way (where it
 175                         * wasn't uninteresting), in which case we need
 176                         * to mark its parents recursively too..
 177                         */
 178                        if (!commit->parents)
 179                                break;
 180
 181                        for (l = commit->parents->next; l; l = l->next)
 182                                commit_list_insert(l->item, &parents);
 183                        commit = commit->parents->item;
 184                }
 185        }
 186}
 187
 188static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 189{
 190        if (!obj)
 191                return;
 192        if (revs->no_walk && (obj->flags & UNINTERESTING))
 193                revs->no_walk = 0;
 194        if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 195                struct strbuf buf = STRBUF_INIT;
 196                int len = interpret_branch_name(name, &buf);
 197                int st;
 198
 199                if (0 < len && name[len] && buf.len)
 200                        strbuf_addstr(&buf, name + len);
 201                st = add_reflog_for_walk(revs->reflog_info,
 202                                         (struct commit *)obj,
 203                                         buf.buf[0] ? buf.buf: name);
 204                strbuf_release(&buf);
 205                if (st)
 206                        return;
 207        }
 208        add_object_array_with_mode(obj, name, &revs->pending, mode);
 209}
 210
 211void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 212{
 213        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 214}
 215
 216void add_head_to_pending(struct rev_info *revs)
 217{
 218        unsigned char sha1[20];
 219        struct object *obj;
 220        if (get_sha1("HEAD", sha1))
 221                return;
 222        obj = parse_object(sha1);
 223        if (!obj)
 224                return;
 225        add_pending_object(revs, obj, "HEAD");
 226}
 227
 228static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 229{
 230        struct object *object;
 231
 232        object = parse_object(sha1);
 233        if (!object) {
 234                if (revs->ignore_missing)
 235                        return object;
 236                die("bad object %s", name);
 237        }
 238        object->flags |= flags;
 239        return object;
 240}
 241
 242void add_pending_sha1(struct rev_info *revs, const char *name,
 243                      const unsigned char *sha1, unsigned int flags)
 244{
 245        struct object *object = get_reference(revs, name, sha1, flags);
 246        add_pending_object(revs, object, name);
 247}
 248
 249static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 250{
 251        unsigned long flags = object->flags;
 252
 253        /*
 254         * Tag object? Look what it points to..
 255         */
 256        while (object->type == OBJ_TAG) {
 257                struct tag *tag = (struct tag *) object;
 258                if (revs->tag_objects && !(flags & UNINTERESTING))
 259                        add_pending_object(revs, object, tag->tag);
 260                if (!tag->tagged)
 261                        die("bad tag");
 262                object = parse_object(tag->tagged->sha1);
 263                if (!object) {
 264                        if (flags & UNINTERESTING)
 265                                return NULL;
 266                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 267                }
 268        }
 269
 270        /*
 271         * Commit object? Just return it, we'll do all the complex
 272         * reachability crud.
 273         */
 274        if (object->type == OBJ_COMMIT) {
 275                struct commit *commit = (struct commit *)object;
 276                if (parse_commit(commit) < 0)
 277                        die("unable to parse commit %s", name);
 278                if (flags & UNINTERESTING) {
 279                        commit->object.flags |= UNINTERESTING;
 280                        mark_parents_uninteresting(commit);
 281                        revs->limited = 1;
 282                }
 283                if (revs->show_source && !commit->util)
 284                        commit->util = (void *) name;
 285                return commit;
 286        }
 287
 288        /*
 289         * Tree object? Either mark it uninteresting, or add it
 290         * to the list of objects to look at later..
 291         */
 292        if (object->type == OBJ_TREE) {
 293                struct tree *tree = (struct tree *)object;
 294                if (!revs->tree_objects)
 295                        return NULL;
 296                if (flags & UNINTERESTING) {
 297                        mark_tree_uninteresting(tree);
 298                        return NULL;
 299                }
 300                add_pending_object(revs, object, "");
 301                return NULL;
 302        }
 303
 304        /*
 305         * Blob object? You know the drill by now..
 306         */
 307        if (object->type == OBJ_BLOB) {
 308                struct blob *blob = (struct blob *)object;
 309                if (!revs->blob_objects)
 310                        return NULL;
 311                if (flags & UNINTERESTING) {
 312                        mark_blob_uninteresting(blob);
 313                        return NULL;
 314                }
 315                add_pending_object(revs, object, "");
 316                return NULL;
 317        }
 318        die("%s is unknown object", name);
 319}
 320
 321static int everybody_uninteresting(struct commit_list *orig)
 322{
 323        struct commit_list *list = orig;
 324        while (list) {
 325                struct commit *commit = list->item;
 326                list = list->next;
 327                if (commit->object.flags & UNINTERESTING)
 328                        continue;
 329                return 0;
 330        }
 331        return 1;
 332}
 333
 334/*
 335 * The goal is to get REV_TREE_NEW as the result only if the
 336 * diff consists of all '+' (and no other changes), REV_TREE_OLD
 337 * if the whole diff is removal of old data, and otherwise
 338 * REV_TREE_DIFFERENT (of course if the trees are the same we
 339 * want REV_TREE_SAME).
 340 * That means that once we get to REV_TREE_DIFFERENT, we do not
 341 * have to look any further.
 342 */
 343static int tree_difference = REV_TREE_SAME;
 344
 345static void file_add_remove(struct diff_options *options,
 346                    int addremove, unsigned mode,
 347                    const unsigned char *sha1,
 348                    int sha1_valid,
 349                    const char *fullpath, unsigned dirty_submodule)
 350{
 351        int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 352
 353        tree_difference |= diff;
 354        if (tree_difference == REV_TREE_DIFFERENT)
 355                DIFF_OPT_SET(options, HAS_CHANGES);
 356}
 357
 358static void file_change(struct diff_options *options,
 359                 unsigned old_mode, unsigned new_mode,
 360                 const unsigned char *old_sha1,
 361                 const unsigned char *new_sha1,
 362                 int old_sha1_valid, int new_sha1_valid,
 363                 const char *fullpath,
 364                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 365{
 366        tree_difference = REV_TREE_DIFFERENT;
 367        DIFF_OPT_SET(options, HAS_CHANGES);
 368}
 369
 370static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 371{
 372        struct tree *t1 = parent->tree;
 373        struct tree *t2 = commit->tree;
 374
 375        if (!t1)
 376                return REV_TREE_NEW;
 377        if (!t2)
 378                return REV_TREE_OLD;
 379
 380        if (revs->simplify_by_decoration) {
 381                /*
 382                 * If we are simplifying by decoration, then the commit
 383                 * is worth showing if it has a tag pointing at it.
 384                 */
 385                if (lookup_decoration(&name_decoration, &commit->object))
 386                        return REV_TREE_DIFFERENT;
 387                /*
 388                 * A commit that is not pointed by a tag is uninteresting
 389                 * if we are not limited by path.  This means that you will
 390                 * see the usual "commits that touch the paths" plus any
 391                 * tagged commit by specifying both --simplify-by-decoration
 392                 * and pathspec.
 393                 */
 394                if (!revs->prune_data.nr)
 395                        return REV_TREE_SAME;
 396        }
 397
 398        tree_difference = REV_TREE_SAME;
 399        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 400        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 401                           &revs->pruning) < 0)
 402                return REV_TREE_DIFFERENT;
 403        return tree_difference;
 404}
 405
 406static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 407{
 408        int retval;
 409        void *tree;
 410        unsigned long size;
 411        struct tree_desc empty, real;
 412        struct tree *t1 = commit->tree;
 413
 414        if (!t1)
 415                return 0;
 416
 417        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 418        if (!tree)
 419                return 0;
 420        init_tree_desc(&real, tree, size);
 421        init_tree_desc(&empty, "", 0);
 422
 423        tree_difference = REV_TREE_SAME;
 424        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 425        retval = diff_tree(&empty, &real, "", &revs->pruning);
 426        free(tree);
 427
 428        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 429}
 430
 431static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 432{
 433        struct commit_list **pp, *parent;
 434        int tree_changed = 0, tree_same = 0, nth_parent = 0;
 435
 436        /*
 437         * If we don't do pruning, everything is interesting
 438         */
 439        if (!revs->prune)
 440                return;
 441
 442        if (!commit->tree)
 443                return;
 444
 445        if (!commit->parents) {
 446                if (rev_same_tree_as_empty(revs, commit))
 447                        commit->object.flags |= TREESAME;
 448                return;
 449        }
 450
 451        /*
 452         * Normal non-merge commit? If we don't want to make the
 453         * history dense, we consider it always to be a change..
 454         */
 455        if (!revs->dense && !commit->parents->next)
 456                return;
 457
 458        pp = &commit->parents;
 459        while ((parent = *pp) != NULL) {
 460                struct commit *p = parent->item;
 461
 462                /*
 463                 * Do not compare with later parents when we care only about
 464                 * the first parent chain, in order to avoid derailing the
 465                 * traversal to follow a side branch that brought everything
 466                 * in the path we are limited to by the pathspec.
 467                 */
 468                if (revs->first_parent_only && nth_parent++)
 469                        break;
 470                if (parse_commit(p) < 0)
 471                        die("cannot simplify commit %s (because of %s)",
 472                            sha1_to_hex(commit->object.sha1),
 473                            sha1_to_hex(p->object.sha1));
 474                switch (rev_compare_tree(revs, p, commit)) {
 475                case REV_TREE_SAME:
 476                        tree_same = 1;
 477                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 478                                /* Even if a merge with an uninteresting
 479                                 * side branch brought the entire change
 480                                 * we are interested in, we do not want
 481                                 * to lose the other branches of this
 482                                 * merge, so we just keep going.
 483                                 */
 484                                pp = &parent->next;
 485                                continue;
 486                        }
 487                        parent->next = NULL;
 488                        commit->parents = parent;
 489                        commit->object.flags |= TREESAME;
 490                        return;
 491
 492                case REV_TREE_NEW:
 493                        if (revs->remove_empty_trees &&
 494                            rev_same_tree_as_empty(revs, p)) {
 495                                /* We are adding all the specified
 496                                 * paths from this parent, so the
 497                                 * history beyond this parent is not
 498                                 * interesting.  Remove its parents
 499                                 * (they are grandparents for us).
 500                                 * IOW, we pretend this parent is a
 501                                 * "root" commit.
 502                                 */
 503                                if (parse_commit(p) < 0)
 504                                        die("cannot simplify commit %s (invalid %s)",
 505                                            sha1_to_hex(commit->object.sha1),
 506                                            sha1_to_hex(p->object.sha1));
 507                                p->parents = NULL;
 508                        }
 509                /* fallthrough */
 510                case REV_TREE_OLD:
 511                case REV_TREE_DIFFERENT:
 512                        tree_changed = 1;
 513                        pp = &parent->next;
 514                        continue;
 515                }
 516                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 517        }
 518        if (tree_changed && !tree_same)
 519                return;
 520        commit->object.flags |= TREESAME;
 521}
 522
 523static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 524                    struct commit_list *cached_base, struct commit_list **cache)
 525{
 526        struct commit_list *new_entry;
 527
 528        if (cached_base && p->date < cached_base->item->date)
 529                new_entry = commit_list_insert_by_date(p, &cached_base->next);
 530        else
 531                new_entry = commit_list_insert_by_date(p, head);
 532
 533        if (cache && (!*cache || p->date < (*cache)->item->date))
 534                *cache = new_entry;
 535}
 536
 537static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 538                    struct commit_list **list, struct commit_list **cache_ptr)
 539{
 540        struct commit_list *parent = commit->parents;
 541        unsigned left_flag;
 542        struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 543
 544        if (commit->object.flags & ADDED)
 545                return 0;
 546        commit->object.flags |= ADDED;
 547
 548        /*
 549         * If the commit is uninteresting, don't try to
 550         * prune parents - we want the maximal uninteresting
 551         * set.
 552         *
 553         * Normally we haven't parsed the parent
 554         * yet, so we won't have a parent of a parent
 555         * here. However, it may turn out that we've
 556         * reached this commit some other way (where it
 557         * wasn't uninteresting), in which case we need
 558         * to mark its parents recursively too..
 559         */
 560        if (commit->object.flags & UNINTERESTING) {
 561                while (parent) {
 562                        struct commit *p = parent->item;
 563                        parent = parent->next;
 564                        if (p)
 565                                p->object.flags |= UNINTERESTING;
 566                        if (parse_commit(p) < 0)
 567                                continue;
 568                        if (p->parents)
 569                                mark_parents_uninteresting(p);
 570                        if (p->object.flags & SEEN)
 571                                continue;
 572                        p->object.flags |= SEEN;
 573                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 574                }
 575                return 0;
 576        }
 577
 578        /*
 579         * Ok, the commit wasn't uninteresting. Try to
 580         * simplify the commit history and find the parent
 581         * that has no differences in the path set if one exists.
 582         */
 583        try_to_simplify_commit(revs, commit);
 584
 585        if (revs->no_walk)
 586                return 0;
 587
 588        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 589
 590        for (parent = commit->parents; parent; parent = parent->next) {
 591                struct commit *p = parent->item;
 592
 593                if (parse_commit(p) < 0)
 594                        return -1;
 595                if (revs->show_source && !p->util)
 596                        p->util = commit->util;
 597                p->object.flags |= left_flag;
 598                if (!(p->object.flags & SEEN)) {
 599                        p->object.flags |= SEEN;
 600                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 601                }
 602                if (revs->first_parent_only)
 603                        break;
 604        }
 605        return 0;
 606}
 607
 608static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 609{
 610        struct commit_list *p;
 611        int left_count = 0, right_count = 0;
 612        int left_first;
 613        struct patch_ids ids;
 614        unsigned cherry_flag;
 615
 616        /* First count the commits on the left and on the right */
 617        for (p = list; p; p = p->next) {
 618                struct commit *commit = p->item;
 619                unsigned flags = commit->object.flags;
 620                if (flags & BOUNDARY)
 621                        ;
 622                else if (flags & SYMMETRIC_LEFT)
 623                        left_count++;
 624                else
 625                        right_count++;
 626        }
 627
 628        if (!left_count || !right_count)
 629                return;
 630
 631        left_first = left_count < right_count;
 632        init_patch_ids(&ids);
 633        ids.diffopts.pathspec = revs->diffopt.pathspec;
 634
 635        /* Compute patch-ids for one side */
 636        for (p = list; p; p = p->next) {
 637                struct commit *commit = p->item;
 638                unsigned flags = commit->object.flags;
 639
 640                if (flags & BOUNDARY)
 641                        continue;
 642                /*
 643                 * If we have fewer left, left_first is set and we omit
 644                 * commits on the right branch in this loop.  If we have
 645                 * fewer right, we skip the left ones.
 646                 */
 647                if (left_first != !!(flags & SYMMETRIC_LEFT))
 648                        continue;
 649                commit->util = add_commit_patch_id(commit, &ids);
 650        }
 651
 652        /* either cherry_mark or cherry_pick are true */
 653        cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 654
 655        /* Check the other side */
 656        for (p = list; p; p = p->next) {
 657                struct commit *commit = p->item;
 658                struct patch_id *id;
 659                unsigned flags = commit->object.flags;
 660
 661                if (flags & BOUNDARY)
 662                        continue;
 663                /*
 664                 * If we have fewer left, left_first is set and we omit
 665                 * commits on the left branch in this loop.
 666                 */
 667                if (left_first == !!(flags & SYMMETRIC_LEFT))
 668                        continue;
 669
 670                /*
 671                 * Have we seen the same patch id?
 672                 */
 673                id = has_commit_patch_id(commit, &ids);
 674                if (!id)
 675                        continue;
 676                id->seen = 1;
 677                commit->object.flags |= cherry_flag;
 678        }
 679
 680        /* Now check the original side for seen ones */
 681        for (p = list; p; p = p->next) {
 682                struct commit *commit = p->item;
 683                struct patch_id *ent;
 684
 685                ent = commit->util;
 686                if (!ent)
 687                        continue;
 688                if (ent->seen)
 689                        commit->object.flags |= cherry_flag;
 690                commit->util = NULL;
 691        }
 692
 693        free_patch_ids(&ids);
 694}
 695
 696/* How many extra uninteresting commits we want to see.. */
 697#define SLOP 5
 698
 699static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 700{
 701        /*
 702         * No source list at all? We're definitely done..
 703         */
 704        if (!src)
 705                return 0;
 706
 707        /*
 708         * Does the destination list contain entries with a date
 709         * before the source list? Definitely _not_ done.
 710         */
 711        if (date < src->item->date)
 712                return SLOP;
 713
 714        /*
 715         * Does the source list still have interesting commits in
 716         * it? Definitely not done..
 717         */
 718        if (!everybody_uninteresting(src))
 719                return SLOP;
 720
 721        /* Ok, we're closing in.. */
 722        return slop-1;
 723}
 724
 725/*
 726 * "rev-list --ancestry-path A..B" computes commits that are ancestors
 727 * of B but not ancestors of A but further limits the result to those
 728 * that are descendants of A.  This takes the list of bottom commits and
 729 * the result of "A..B" without --ancestry-path, and limits the latter
 730 * further to the ones that can reach one of the commits in "bottom".
 731 */
 732static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 733{
 734        struct commit_list *p;
 735        struct commit_list *rlist = NULL;
 736        int made_progress;
 737
 738        /*
 739         * Reverse the list so that it will be likely that we would
 740         * process parents before children.
 741         */
 742        for (p = list; p; p = p->next)
 743                commit_list_insert(p->item, &rlist);
 744
 745        for (p = bottom; p; p = p->next)
 746                p->item->object.flags |= TMP_MARK;
 747
 748        /*
 749         * Mark the ones that can reach bottom commits in "list",
 750         * in a bottom-up fashion.
 751         */
 752        do {
 753                made_progress = 0;
 754                for (p = rlist; p; p = p->next) {
 755                        struct commit *c = p->item;
 756                        struct commit_list *parents;
 757                        if (c->object.flags & (TMP_MARK | UNINTERESTING))
 758                                continue;
 759                        for (parents = c->parents;
 760                             parents;
 761                             parents = parents->next) {
 762                                if (!(parents->item->object.flags & TMP_MARK))
 763                                        continue;
 764                                c->object.flags |= TMP_MARK;
 765                                made_progress = 1;
 766                                break;
 767                        }
 768                }
 769        } while (made_progress);
 770
 771        /*
 772         * NEEDSWORK: decide if we want to remove parents that are
 773         * not marked with TMP_MARK from commit->parents for commits
 774         * in the resulting list.  We may not want to do that, though.
 775         */
 776
 777        /*
 778         * The ones that are not marked with TMP_MARK are uninteresting
 779         */
 780        for (p = list; p; p = p->next) {
 781                struct commit *c = p->item;
 782                if (c->object.flags & TMP_MARK)
 783                        continue;
 784                c->object.flags |= UNINTERESTING;
 785        }
 786
 787        /* We are done with the TMP_MARK */
 788        for (p = list; p; p = p->next)
 789                p->item->object.flags &= ~TMP_MARK;
 790        for (p = bottom; p; p = p->next)
 791                p->item->object.flags &= ~TMP_MARK;
 792        free_commit_list(rlist);
 793}
 794
 795/*
 796 * Before walking the history, keep the set of "negative" refs the
 797 * caller has asked to exclude.
 798 *
 799 * This is used to compute "rev-list --ancestry-path A..B", as we need
 800 * to filter the result of "A..B" further to the ones that can actually
 801 * reach A.
 802 */
 803static struct commit_list *collect_bottom_commits(struct rev_info *revs)
 804{
 805        struct commit_list *bottom = NULL;
 806        int i;
 807        for (i = 0; i < revs->cmdline.nr; i++) {
 808                struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
 809                if ((elem->flags & UNINTERESTING) &&
 810                    elem->item->type == OBJ_COMMIT)
 811                        commit_list_insert((struct commit *)elem->item, &bottom);
 812        }
 813        return bottom;
 814}
 815
 816/* Assumes either left_only or right_only is set */
 817static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 818{
 819        struct commit_list *p;
 820
 821        for (p = list; p; p = p->next) {
 822                struct commit *commit = p->item;
 823
 824                if (revs->right_only) {
 825                        if (commit->object.flags & SYMMETRIC_LEFT)
 826                                commit->object.flags |= SHOWN;
 827                } else  /* revs->left_only is set */
 828                        if (!(commit->object.flags & SYMMETRIC_LEFT))
 829                                commit->object.flags |= SHOWN;
 830        }
 831}
 832
 833static int limit_list(struct rev_info *revs)
 834{
 835        int slop = SLOP;
 836        unsigned long date = ~0ul;
 837        struct commit_list *list = revs->commits;
 838        struct commit_list *newlist = NULL;
 839        struct commit_list **p = &newlist;
 840        struct commit_list *bottom = NULL;
 841
 842        if (revs->ancestry_path) {
 843                bottom = collect_bottom_commits(revs);
 844                if (!bottom)
 845                        die("--ancestry-path given but there are no bottom commits");
 846        }
 847
 848        while (list) {
 849                struct commit_list *entry = list;
 850                struct commit *commit = list->item;
 851                struct object *obj = &commit->object;
 852                show_early_output_fn_t show;
 853
 854                list = list->next;
 855                free(entry);
 856
 857                if (revs->max_age != -1 && (commit->date < revs->max_age))
 858                        obj->flags |= UNINTERESTING;
 859                if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 860                        return -1;
 861                if (obj->flags & UNINTERESTING) {
 862                        mark_parents_uninteresting(commit);
 863                        if (revs->show_all)
 864                                p = &commit_list_insert(commit, p)->next;
 865                        slop = still_interesting(list, date, slop);
 866                        if (slop)
 867                                continue;
 868                        /* If showing all, add the whole pending list to the end */
 869                        if (revs->show_all)
 870                                *p = list;
 871                        break;
 872                }
 873                if (revs->min_age != -1 && (commit->date > revs->min_age))
 874                        continue;
 875                date = commit->date;
 876                p = &commit_list_insert(commit, p)->next;
 877
 878                show = show_early_output;
 879                if (!show)
 880                        continue;
 881
 882                show(revs, newlist);
 883                show_early_output = NULL;
 884        }
 885        if (revs->cherry_pick || revs->cherry_mark)
 886                cherry_pick_list(newlist, revs);
 887
 888        if (revs->left_only || revs->right_only)
 889                limit_left_right(newlist, revs);
 890
 891        if (bottom) {
 892                limit_to_ancestry(bottom, newlist);
 893                free_commit_list(bottom);
 894        }
 895
 896        revs->commits = newlist;
 897        return 0;
 898}
 899
 900static void add_rev_cmdline(struct rev_info *revs,
 901                            struct object *item,
 902                            const char *name,
 903                            int whence,
 904                            unsigned flags)
 905{
 906        struct rev_cmdline_info *info = &revs->cmdline;
 907        int nr = info->nr;
 908
 909        ALLOC_GROW(info->rev, nr + 1, info->alloc);
 910        info->rev[nr].item = item;
 911        info->rev[nr].name = name;
 912        info->rev[nr].whence = whence;
 913        info->rev[nr].flags = flags;
 914        info->nr++;
 915}
 916
 917struct all_refs_cb {
 918        int all_flags;
 919        int warned_bad_reflog;
 920        struct rev_info *all_revs;
 921        const char *name_for_errormsg;
 922};
 923
 924static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 925{
 926        struct all_refs_cb *cb = cb_data;
 927        struct object *object = get_reference(cb->all_revs, path, sha1,
 928                                              cb->all_flags);
 929        add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
 930        add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
 931        return 0;
 932}
 933
 934static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 935        unsigned flags)
 936{
 937        cb->all_revs = revs;
 938        cb->all_flags = flags;
 939}
 940
 941static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
 942                int (*for_each)(const char *, each_ref_fn, void *))
 943{
 944        struct all_refs_cb cb;
 945        init_all_refs_cb(&cb, revs, flags);
 946        for_each(submodule, handle_one_ref, &cb);
 947}
 948
 949static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 950{
 951        struct all_refs_cb *cb = cb_data;
 952        if (!is_null_sha1(sha1)) {
 953                struct object *o = parse_object(sha1);
 954                if (o) {
 955                        o->flags |= cb->all_flags;
 956                        /* ??? CMDLINEFLAGS ??? */
 957                        add_pending_object(cb->all_revs, o, "");
 958                }
 959                else if (!cb->warned_bad_reflog) {
 960                        warning("reflog of '%s' references pruned commits",
 961                                cb->name_for_errormsg);
 962                        cb->warned_bad_reflog = 1;
 963                }
 964        }
 965}
 966
 967static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 968                const char *email, unsigned long timestamp, int tz,
 969                const char *message, void *cb_data)
 970{
 971        handle_one_reflog_commit(osha1, cb_data);
 972        handle_one_reflog_commit(nsha1, cb_data);
 973        return 0;
 974}
 975
 976static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 977{
 978        struct all_refs_cb *cb = cb_data;
 979        cb->warned_bad_reflog = 0;
 980        cb->name_for_errormsg = path;
 981        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 982        return 0;
 983}
 984
 985static void handle_reflog(struct rev_info *revs, unsigned flags)
 986{
 987        struct all_refs_cb cb;
 988        cb.all_revs = revs;
 989        cb.all_flags = flags;
 990        for_each_reflog(handle_one_reflog, &cb);
 991}
 992
 993static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
 994{
 995        unsigned char sha1[20];
 996        struct object *it;
 997        struct commit *commit;
 998        struct commit_list *parents;
 999        const char *arg = arg_;
1000
1001        if (*arg == '^') {
1002                flags ^= UNINTERESTING;
1003                arg++;
1004        }
1005        if (get_sha1_committish(arg, sha1))
1006                return 0;
1007        while (1) {
1008                it = get_reference(revs, arg, sha1, 0);
1009                if (!it && revs->ignore_missing)
1010                        return 0;
1011                if (it->type != OBJ_TAG)
1012                        break;
1013                if (!((struct tag*)it)->tagged)
1014                        return 0;
1015                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1016        }
1017        if (it->type != OBJ_COMMIT)
1018                return 0;
1019        commit = (struct commit *)it;
1020        for (parents = commit->parents; parents; parents = parents->next) {
1021                it = &parents->item->object;
1022                it->flags |= flags;
1023                add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1024                add_pending_object(revs, it, arg);
1025        }
1026        return 1;
1027}
1028
1029void init_revisions(struct rev_info *revs, const char *prefix)
1030{
1031        memset(revs, 0, sizeof(*revs));
1032
1033        revs->abbrev = DEFAULT_ABBREV;
1034        revs->ignore_merges = 1;
1035        revs->simplify_history = 1;
1036        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1037        DIFF_OPT_SET(&revs->pruning, QUICK);
1038        revs->pruning.add_remove = file_add_remove;
1039        revs->pruning.change = file_change;
1040        revs->lifo = 1;
1041        revs->dense = 1;
1042        revs->prefix = prefix;
1043        revs->max_age = -1;
1044        revs->min_age = -1;
1045        revs->skip_count = -1;
1046        revs->max_count = -1;
1047        revs->max_parents = -1;
1048
1049        revs->commit_format = CMIT_FMT_DEFAULT;
1050
1051        revs->grep_filter.status_only = 1;
1052        revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
1053        revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
1054        revs->grep_filter.regflags = REG_NEWLINE;
1055
1056        diff_setup(&revs->diffopt);
1057        if (prefix && !revs->diffopt.prefix) {
1058                revs->diffopt.prefix = prefix;
1059                revs->diffopt.prefix_length = strlen(prefix);
1060        }
1061
1062        revs->notes_opt.use_default_notes = -1;
1063}
1064
1065static void add_pending_commit_list(struct rev_info *revs,
1066                                    struct commit_list *commit_list,
1067                                    unsigned int flags)
1068{
1069        while (commit_list) {
1070                struct object *object = &commit_list->item->object;
1071                object->flags |= flags;
1072                add_pending_object(revs, object, sha1_to_hex(object->sha1));
1073                commit_list = commit_list->next;
1074        }
1075}
1076
1077static void prepare_show_merge(struct rev_info *revs)
1078{
1079        struct commit_list *bases;
1080        struct commit *head, *other;
1081        unsigned char sha1[20];
1082        const char **prune = NULL;
1083        int i, prune_num = 1; /* counting terminating NULL */
1084
1085        if (get_sha1("HEAD", sha1))
1086                die("--merge without HEAD?");
1087        head = lookup_commit_or_die(sha1, "HEAD");
1088        if (get_sha1("MERGE_HEAD", sha1))
1089                die("--merge without MERGE_HEAD?");
1090        other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1091        add_pending_object(revs, &head->object, "HEAD");
1092        add_pending_object(revs, &other->object, "MERGE_HEAD");
1093        bases = get_merge_bases(head, other, 1);
1094        add_pending_commit_list(revs, bases, UNINTERESTING);
1095        free_commit_list(bases);
1096        head->object.flags |= SYMMETRIC_LEFT;
1097
1098        if (!active_nr)
1099                read_cache();
1100        for (i = 0; i < active_nr; i++) {
1101                struct cache_entry *ce = active_cache[i];
1102                if (!ce_stage(ce))
1103                        continue;
1104                if (ce_path_match(ce, &revs->prune_data)) {
1105                        prune_num++;
1106                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
1107                        prune[prune_num-2] = ce->name;
1108                        prune[prune_num-1] = NULL;
1109                }
1110                while ((i+1 < active_nr) &&
1111                       ce_same_name(ce, active_cache[i+1]))
1112                        i++;
1113        }
1114        free_pathspec(&revs->prune_data);
1115        init_pathspec(&revs->prune_data, prune);
1116        revs->limited = 1;
1117}
1118
1119int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1120{
1121        struct object_context oc;
1122        char *dotdot;
1123        struct object *object;
1124        unsigned char sha1[20];
1125        int local_flags;
1126        const char *arg = arg_;
1127        int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1128        unsigned get_sha1_flags = 0;
1129
1130        dotdot = strstr(arg, "..");
1131        if (dotdot) {
1132                unsigned char from_sha1[20];
1133                const char *next = dotdot + 2;
1134                const char *this = arg;
1135                int symmetric = *next == '.';
1136                unsigned int flags_exclude = flags ^ UNINTERESTING;
1137                static const char head_by_default[] = "HEAD";
1138                unsigned int a_flags;
1139
1140                *dotdot = 0;
1141                next += symmetric;
1142
1143                if (!*next)
1144                        next = head_by_default;
1145                if (dotdot == arg)
1146                        this = head_by_default;
1147                if (this == head_by_default && next == head_by_default &&
1148                    !symmetric) {
1149                        /*
1150                         * Just ".."?  That is not a range but the
1151                         * pathspec for the parent directory.
1152                         */
1153                        if (!cant_be_filename) {
1154                                *dotdot = '.';
1155                                return -1;
1156                        }
1157                }
1158                if (!get_sha1_committish(this, from_sha1) &&
1159                    !get_sha1_committish(next, sha1)) {
1160                        struct commit *a, *b;
1161                        struct commit_list *exclude;
1162
1163                        a = lookup_commit_reference(from_sha1);
1164                        b = lookup_commit_reference(sha1);
1165                        if (!a || !b) {
1166                                if (revs->ignore_missing)
1167                                        return 0;
1168                                die(symmetric ?
1169                                    "Invalid symmetric difference expression %s...%s" :
1170                                    "Invalid revision range %s..%s",
1171                                    arg, next);
1172                        }
1173
1174                        if (!cant_be_filename) {
1175                                *dotdot = '.';
1176                                verify_non_filename(revs->prefix, arg);
1177                        }
1178
1179                        if (symmetric) {
1180                                exclude = get_merge_bases(a, b, 1);
1181                                add_pending_commit_list(revs, exclude,
1182                                                        flags_exclude);
1183                                free_commit_list(exclude);
1184                                a_flags = flags | SYMMETRIC_LEFT;
1185                        } else
1186                                a_flags = flags_exclude;
1187                        a->object.flags |= a_flags;
1188                        b->object.flags |= flags;
1189                        add_rev_cmdline(revs, &a->object, this,
1190                                        REV_CMD_LEFT, a_flags);
1191                        add_rev_cmdline(revs, &b->object, next,
1192                                        REV_CMD_RIGHT, flags);
1193                        add_pending_object(revs, &a->object, this);
1194                        add_pending_object(revs, &b->object, next);
1195                        return 0;
1196                }
1197                *dotdot = '.';
1198        }
1199        dotdot = strstr(arg, "^@");
1200        if (dotdot && !dotdot[2]) {
1201                *dotdot = 0;
1202                if (add_parents_only(revs, arg, flags))
1203                        return 0;
1204                *dotdot = '^';
1205        }
1206        dotdot = strstr(arg, "^!");
1207        if (dotdot && !dotdot[2]) {
1208                *dotdot = 0;
1209                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1210                        *dotdot = '^';
1211        }
1212
1213        local_flags = 0;
1214        if (*arg == '^') {
1215                local_flags = UNINTERESTING;
1216                arg++;
1217        }
1218
1219        if (revarg_opt & REVARG_COMMITTISH)
1220                get_sha1_flags = GET_SHA1_COMMITTISH;
1221
1222        if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1223                return revs->ignore_missing ? 0 : -1;
1224        if (!cant_be_filename)
1225                verify_non_filename(revs->prefix, arg);
1226        object = get_reference(revs, arg, sha1, flags ^ local_flags);
1227        add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1228        add_pending_object_with_mode(revs, object, arg, oc.mode);
1229        return 0;
1230}
1231
1232struct cmdline_pathspec {
1233        int alloc;
1234        int nr;
1235        const char **path;
1236};
1237
1238static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1239{
1240        while (*av) {
1241                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1242                prune->path[prune->nr++] = *(av++);
1243        }
1244}
1245
1246static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1247                                     struct cmdline_pathspec *prune)
1248{
1249        while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1250                int len = sb->len;
1251                if (len && sb->buf[len - 1] == '\n')
1252                        sb->buf[--len] = '\0';
1253                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1254                prune->path[prune->nr++] = xstrdup(sb->buf);
1255        }
1256}
1257
1258static void read_revisions_from_stdin(struct rev_info *revs,
1259                                      struct cmdline_pathspec *prune)
1260{
1261        struct strbuf sb;
1262        int seen_dashdash = 0;
1263
1264        strbuf_init(&sb, 1000);
1265        while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1266                int len = sb.len;
1267                if (len && sb.buf[len - 1] == '\n')
1268                        sb.buf[--len] = '\0';
1269                if (!len)
1270                        break;
1271                if (sb.buf[0] == '-') {
1272                        if (len == 2 && sb.buf[1] == '-') {
1273                                seen_dashdash = 1;
1274                                break;
1275                        }
1276                        die("options not supported in --stdin mode");
1277                }
1278                if (handle_revision_arg(sb.buf, revs, 0, REVARG_CANNOT_BE_FILENAME))
1279                        die("bad revision '%s'", sb.buf);
1280        }
1281        if (seen_dashdash)
1282                read_pathspec_from_stdin(revs, &sb, prune);
1283        strbuf_release(&sb);
1284}
1285
1286static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1287{
1288        append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1289}
1290
1291static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1292{
1293        append_header_grep_pattern(&revs->grep_filter, field, pattern);
1294}
1295
1296static void add_message_grep(struct rev_info *revs, const char *pattern)
1297{
1298        add_grep(revs, pattern, GREP_PATTERN_BODY);
1299}
1300
1301static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1302                               int *unkc, const char **unkv)
1303{
1304        const char *arg = argv[0];
1305        const char *optarg;
1306        int argcount;
1307
1308        /* pseudo revision arguments */
1309        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1310            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1311            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1312            !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1313            !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1314            !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1315            !prefixcmp(arg, "--remotes=") || !prefixcmp(arg, "--no-walk="))
1316        {
1317                unkv[(*unkc)++] = arg;
1318                return 1;
1319        }
1320
1321        if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1322                revs->max_count = atoi(optarg);
1323                revs->no_walk = 0;
1324                return argcount;
1325        } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1326                revs->skip_count = atoi(optarg);
1327                return argcount;
1328        } else if ((*arg == '-') && isdigit(arg[1])) {
1329        /* accept -<digit>, like traditional "head" */
1330                revs->max_count = atoi(arg + 1);
1331                revs->no_walk = 0;
1332        } else if (!strcmp(arg, "-n")) {
1333                if (argc <= 1)
1334                        return error("-n requires an argument");
1335                revs->max_count = atoi(argv[1]);
1336                revs->no_walk = 0;
1337                return 2;
1338        } else if (!prefixcmp(arg, "-n")) {
1339                revs->max_count = atoi(arg + 2);
1340                revs->no_walk = 0;
1341        } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1342                revs->max_age = atoi(optarg);
1343                return argcount;
1344        } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1345                revs->max_age = approxidate(optarg);
1346                return argcount;
1347        } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1348                revs->max_age = approxidate(optarg);
1349                return argcount;
1350        } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1351                revs->min_age = atoi(optarg);
1352                return argcount;
1353        } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1354                revs->min_age = approxidate(optarg);
1355                return argcount;
1356        } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1357                revs->min_age = approxidate(optarg);
1358                return argcount;
1359        } else if (!strcmp(arg, "--first-parent")) {
1360                revs->first_parent_only = 1;
1361        } else if (!strcmp(arg, "--ancestry-path")) {
1362                revs->ancestry_path = 1;
1363                revs->simplify_history = 0;
1364                revs->limited = 1;
1365        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1366                init_reflog_walk(&revs->reflog_info);
1367        } else if (!strcmp(arg, "--default")) {
1368                if (argc <= 1)
1369                        return error("bad --default argument");
1370                revs->def = argv[1];
1371                return 2;
1372        } else if (!strcmp(arg, "--merge")) {
1373                revs->show_merge = 1;
1374        } else if (!strcmp(arg, "--topo-order")) {
1375                revs->lifo = 1;
1376                revs->topo_order = 1;
1377        } else if (!strcmp(arg, "--simplify-merges")) {
1378                revs->simplify_merges = 1;
1379                revs->topo_order = 1;
1380                revs->rewrite_parents = 1;
1381                revs->simplify_history = 0;
1382                revs->limited = 1;
1383        } else if (!strcmp(arg, "--simplify-by-decoration")) {
1384                revs->simplify_merges = 1;
1385                revs->topo_order = 1;
1386                revs->rewrite_parents = 1;
1387                revs->simplify_history = 0;
1388                revs->simplify_by_decoration = 1;
1389                revs->limited = 1;
1390                revs->prune = 1;
1391                load_ref_decorations(DECORATE_SHORT_REFS);
1392        } else if (!strcmp(arg, "--date-order")) {
1393                revs->lifo = 0;
1394                revs->topo_order = 1;
1395        } else if (!prefixcmp(arg, "--early-output")) {
1396                int count = 100;
1397                switch (arg[14]) {
1398                case '=':
1399                        count = atoi(arg+15);
1400                        /* Fallthrough */
1401                case 0:
1402                        revs->topo_order = 1;
1403                       revs->early_output = count;
1404                }
1405        } else if (!strcmp(arg, "--parents")) {
1406                revs->rewrite_parents = 1;
1407                revs->print_parents = 1;
1408        } else if (!strcmp(arg, "--dense")) {
1409                revs->dense = 1;
1410        } else if (!strcmp(arg, "--sparse")) {
1411                revs->dense = 0;
1412        } else if (!strcmp(arg, "--show-all")) {
1413                revs->show_all = 1;
1414        } else if (!strcmp(arg, "--remove-empty")) {
1415                revs->remove_empty_trees = 1;
1416        } else if (!strcmp(arg, "--merges")) {
1417                revs->min_parents = 2;
1418        } else if (!strcmp(arg, "--no-merges")) {
1419                revs->max_parents = 1;
1420        } else if (!prefixcmp(arg, "--min-parents=")) {
1421                revs->min_parents = atoi(arg+14);
1422        } else if (!prefixcmp(arg, "--no-min-parents")) {
1423                revs->min_parents = 0;
1424        } else if (!prefixcmp(arg, "--max-parents=")) {
1425                revs->max_parents = atoi(arg+14);
1426        } else if (!prefixcmp(arg, "--no-max-parents")) {
1427                revs->max_parents = -1;
1428        } else if (!strcmp(arg, "--boundary")) {
1429                revs->boundary = 1;
1430        } else if (!strcmp(arg, "--left-right")) {
1431                revs->left_right = 1;
1432        } else if (!strcmp(arg, "--left-only")) {
1433                if (revs->right_only)
1434                        die("--left-only is incompatible with --right-only"
1435                            " or --cherry");
1436                revs->left_only = 1;
1437        } else if (!strcmp(arg, "--right-only")) {
1438                if (revs->left_only)
1439                        die("--right-only is incompatible with --left-only");
1440                revs->right_only = 1;
1441        } else if (!strcmp(arg, "--cherry")) {
1442                if (revs->left_only)
1443                        die("--cherry is incompatible with --left-only");
1444                revs->cherry_mark = 1;
1445                revs->right_only = 1;
1446                revs->max_parents = 1;
1447                revs->limited = 1;
1448        } else if (!strcmp(arg, "--count")) {
1449                revs->count = 1;
1450        } else if (!strcmp(arg, "--cherry-mark")) {
1451                if (revs->cherry_pick)
1452                        die("--cherry-mark is incompatible with --cherry-pick");
1453                revs->cherry_mark = 1;
1454                revs->limited = 1; /* needs limit_list() */
1455        } else if (!strcmp(arg, "--cherry-pick")) {
1456                if (revs->cherry_mark)
1457                        die("--cherry-pick is incompatible with --cherry-mark");
1458                revs->cherry_pick = 1;
1459                revs->limited = 1;
1460        } else if (!strcmp(arg, "--objects")) {
1461                revs->tag_objects = 1;
1462                revs->tree_objects = 1;
1463                revs->blob_objects = 1;
1464        } else if (!strcmp(arg, "--objects-edge")) {
1465                revs->tag_objects = 1;
1466                revs->tree_objects = 1;
1467                revs->blob_objects = 1;
1468                revs->edge_hint = 1;
1469        } else if (!strcmp(arg, "--verify-objects")) {
1470                revs->tag_objects = 1;
1471                revs->tree_objects = 1;
1472                revs->blob_objects = 1;
1473                revs->verify_objects = 1;
1474        } else if (!strcmp(arg, "--unpacked")) {
1475                revs->unpacked = 1;
1476        } else if (!prefixcmp(arg, "--unpacked=")) {
1477                die("--unpacked=<packfile> no longer supported.");
1478        } else if (!strcmp(arg, "-r")) {
1479                revs->diff = 1;
1480                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1481        } else if (!strcmp(arg, "-t")) {
1482                revs->diff = 1;
1483                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1484                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1485        } else if (!strcmp(arg, "-m")) {
1486                revs->ignore_merges = 0;
1487        } else if (!strcmp(arg, "-c")) {
1488                revs->diff = 1;
1489                revs->dense_combined_merges = 0;
1490                revs->combine_merges = 1;
1491        } else if (!strcmp(arg, "--cc")) {
1492                revs->diff = 1;
1493                revs->dense_combined_merges = 1;
1494                revs->combine_merges = 1;
1495        } else if (!strcmp(arg, "-v")) {
1496                revs->verbose_header = 1;
1497        } else if (!strcmp(arg, "--pretty")) {
1498                revs->verbose_header = 1;
1499                revs->pretty_given = 1;
1500                get_commit_format(arg+8, revs);
1501        } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1502                /*
1503                 * Detached form ("--pretty X" as opposed to "--pretty=X")
1504                 * not allowed, since the argument is optional.
1505                 */
1506                revs->verbose_header = 1;
1507                revs->pretty_given = 1;
1508                get_commit_format(arg+9, revs);
1509        } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1510                revs->show_notes = 1;
1511                revs->show_notes_given = 1;
1512                revs->notes_opt.use_default_notes = 1;
1513        } else if (!strcmp(arg, "--show-signature")) {
1514                revs->show_signature = 1;
1515        } else if (!prefixcmp(arg, "--show-notes=") ||
1516                   !prefixcmp(arg, "--notes=")) {
1517                struct strbuf buf = STRBUF_INIT;
1518                revs->show_notes = 1;
1519                revs->show_notes_given = 1;
1520                if (!prefixcmp(arg, "--show-notes")) {
1521                        if (revs->notes_opt.use_default_notes < 0)
1522                                revs->notes_opt.use_default_notes = 1;
1523                        strbuf_addstr(&buf, arg+13);
1524                }
1525                else
1526                        strbuf_addstr(&buf, arg+8);
1527                expand_notes_ref(&buf);
1528                string_list_append(&revs->notes_opt.extra_notes_refs,
1529                                   strbuf_detach(&buf, NULL));
1530        } else if (!strcmp(arg, "--no-notes")) {
1531                revs->show_notes = 0;
1532                revs->show_notes_given = 1;
1533                revs->notes_opt.use_default_notes = -1;
1534                /* we have been strdup'ing ourselves, so trick
1535                 * string_list into free()ing strings */
1536                revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1537                string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1538                revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1539        } else if (!strcmp(arg, "--standard-notes")) {
1540                revs->show_notes_given = 1;
1541                revs->notes_opt.use_default_notes = 1;
1542        } else if (!strcmp(arg, "--no-standard-notes")) {
1543                revs->notes_opt.use_default_notes = 0;
1544        } else if (!strcmp(arg, "--oneline")) {
1545                revs->verbose_header = 1;
1546                get_commit_format("oneline", revs);
1547                revs->pretty_given = 1;
1548                revs->abbrev_commit = 1;
1549        } else if (!strcmp(arg, "--graph")) {
1550                revs->topo_order = 1;
1551                revs->rewrite_parents = 1;
1552                revs->graph = graph_init(revs);
1553        } else if (!strcmp(arg, "--root")) {
1554                revs->show_root_diff = 1;
1555        } else if (!strcmp(arg, "--no-commit-id")) {
1556                revs->no_commit_id = 1;
1557        } else if (!strcmp(arg, "--always")) {
1558                revs->always_show_header = 1;
1559        } else if (!strcmp(arg, "--no-abbrev")) {
1560                revs->abbrev = 0;
1561        } else if (!strcmp(arg, "--abbrev")) {
1562                revs->abbrev = DEFAULT_ABBREV;
1563        } else if (!prefixcmp(arg, "--abbrev=")) {
1564                revs->abbrev = strtoul(arg + 9, NULL, 10);
1565                if (revs->abbrev < MINIMUM_ABBREV)
1566                        revs->abbrev = MINIMUM_ABBREV;
1567                else if (revs->abbrev > 40)
1568                        revs->abbrev = 40;
1569        } else if (!strcmp(arg, "--abbrev-commit")) {
1570                revs->abbrev_commit = 1;
1571                revs->abbrev_commit_given = 1;
1572        } else if (!strcmp(arg, "--no-abbrev-commit")) {
1573                revs->abbrev_commit = 0;
1574        } else if (!strcmp(arg, "--full-diff")) {
1575                revs->diff = 1;
1576                revs->full_diff = 1;
1577        } else if (!strcmp(arg, "--full-history")) {
1578                revs->simplify_history = 0;
1579        } else if (!strcmp(arg, "--relative-date")) {
1580                revs->date_mode = DATE_RELATIVE;
1581                revs->date_mode_explicit = 1;
1582        } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1583                revs->date_mode = parse_date_format(optarg);
1584                revs->date_mode_explicit = 1;
1585                return argcount;
1586        } else if (!strcmp(arg, "--log-size")) {
1587                revs->show_log_size = 1;
1588        }
1589        /*
1590         * Grepping the commit log
1591         */
1592        else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1593                add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1594                return argcount;
1595        } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1596                add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1597                return argcount;
1598        } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1599                add_message_grep(revs, optarg);
1600                return argcount;
1601        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1602                revs->grep_filter.regflags |= REG_EXTENDED;
1603        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1604                revs->grep_filter.regflags |= REG_ICASE;
1605                DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1606        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1607                revs->grep_filter.fixed = 1;
1608        } else if (!strcmp(arg, "--all-match")) {
1609                revs->grep_filter.all_match = 1;
1610        } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1611                if (strcmp(optarg, "none"))
1612                        git_log_output_encoding = xstrdup(optarg);
1613                else
1614                        git_log_output_encoding = "";
1615                return argcount;
1616        } else if (!strcmp(arg, "--reverse")) {
1617                revs->reverse ^= 1;
1618        } else if (!strcmp(arg, "--children")) {
1619                revs->children.name = "children";
1620                revs->limited = 1;
1621        } else if (!strcmp(arg, "--ignore-missing")) {
1622                revs->ignore_missing = 1;
1623        } else {
1624                int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1625                if (!opts)
1626                        unkv[(*unkc)++] = arg;
1627                return opts;
1628        }
1629
1630        return 1;
1631}
1632
1633void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1634                        const struct option *options,
1635                        const char * const usagestr[])
1636{
1637        int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1638                                    &ctx->cpidx, ctx->out);
1639        if (n <= 0) {
1640                error("unknown option `%s'", ctx->argv[0]);
1641                usage_with_options(usagestr, options);
1642        }
1643        ctx->argv += n;
1644        ctx->argc -= n;
1645}
1646
1647static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1648{
1649        return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1650}
1651
1652static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1653{
1654        return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1655}
1656
1657static int handle_revision_pseudo_opt(const char *submodule,
1658                                struct rev_info *revs,
1659                                int argc, const char **argv, int *flags)
1660{
1661        const char *arg = argv[0];
1662        const char *optarg;
1663        int argcount;
1664
1665        /*
1666         * NOTE!
1667         *
1668         * Commands like "git shortlog" will not accept the options below
1669         * unless parse_revision_opt queues them (as opposed to erroring
1670         * out).
1671         *
1672         * When implementing your new pseudo-option, remember to
1673         * register it in the list at the top of handle_revision_opt.
1674         */
1675        if (!strcmp(arg, "--all")) {
1676                handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1677                handle_refs(submodule, revs, *flags, head_ref_submodule);
1678        } else if (!strcmp(arg, "--branches")) {
1679                handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1680        } else if (!strcmp(arg, "--bisect")) {
1681                handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1682                handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
1683                revs->bisect = 1;
1684        } else if (!strcmp(arg, "--tags")) {
1685                handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1686        } else if (!strcmp(arg, "--remotes")) {
1687                handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1688        } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1689                struct all_refs_cb cb;
1690                init_all_refs_cb(&cb, revs, *flags);
1691                for_each_glob_ref(handle_one_ref, optarg, &cb);
1692                return argcount;
1693        } else if (!prefixcmp(arg, "--branches=")) {
1694                struct all_refs_cb cb;
1695                init_all_refs_cb(&cb, revs, *flags);
1696                for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1697        } else if (!prefixcmp(arg, "--tags=")) {
1698                struct all_refs_cb cb;
1699                init_all_refs_cb(&cb, revs, *flags);
1700                for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1701        } else if (!prefixcmp(arg, "--remotes=")) {
1702                struct all_refs_cb cb;
1703                init_all_refs_cb(&cb, revs, *flags);
1704                for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1705        } else if (!strcmp(arg, "--reflog")) {
1706                handle_reflog(revs, *flags);
1707        } else if (!strcmp(arg, "--not")) {
1708                *flags ^= UNINTERESTING;
1709        } else if (!strcmp(arg, "--no-walk")) {
1710                revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
1711        } else if (!prefixcmp(arg, "--no-walk=")) {
1712                /*
1713                 * Detached form ("--no-walk X" as opposed to "--no-walk=X")
1714                 * not allowed, since the argument is optional.
1715                 */
1716                if (!strcmp(arg + 10, "sorted"))
1717                        revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
1718                else if (!strcmp(arg + 10, "unsorted"))
1719                        revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
1720                else
1721                        return error("invalid argument to --no-walk");
1722        } else if (!strcmp(arg, "--do-walk")) {
1723                revs->no_walk = 0;
1724        } else {
1725                return 0;
1726        }
1727
1728        return 1;
1729}
1730
1731/*
1732 * Parse revision information, filling in the "rev_info" structure,
1733 * and removing the used arguments from the argument list.
1734 *
1735 * Returns the number of arguments left that weren't recognized
1736 * (which are also moved to the head of the argument list)
1737 */
1738int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1739{
1740        int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
1741        struct cmdline_pathspec prune_data;
1742        const char *submodule = NULL;
1743
1744        memset(&prune_data, 0, sizeof(prune_data));
1745        if (opt)
1746                submodule = opt->submodule;
1747
1748        /* First, search for "--" */
1749        if (opt && opt->assume_dashdash) {
1750                seen_dashdash = 1;
1751        } else {
1752                seen_dashdash = 0;
1753                for (i = 1; i < argc; i++) {
1754                        const char *arg = argv[i];
1755                        if (strcmp(arg, "--"))
1756                                continue;
1757                        argv[i] = NULL;
1758                        argc = i;
1759                        if (argv[i + 1])
1760                                append_prune_data(&prune_data, argv + i + 1);
1761                        seen_dashdash = 1;
1762                        break;
1763                }
1764        }
1765
1766        /* Second, deal with arguments and options */
1767        flags = 0;
1768        revarg_opt = opt ? opt->revarg_opt : 0;
1769        if (seen_dashdash)
1770                revarg_opt |= REVARG_CANNOT_BE_FILENAME;
1771        read_from_stdin = 0;
1772        for (left = i = 1; i < argc; i++) {
1773                const char *arg = argv[i];
1774                if (*arg == '-') {
1775                        int opts;
1776
1777                        opts = handle_revision_pseudo_opt(submodule,
1778                                                revs, argc - i, argv + i,
1779                                                &flags);
1780                        if (opts > 0) {
1781                                i += opts - 1;
1782                                continue;
1783                        }
1784
1785                        if (!strcmp(arg, "--stdin")) {
1786                                if (revs->disable_stdin) {
1787                                        argv[left++] = arg;
1788                                        continue;
1789                                }
1790                                if (read_from_stdin++)
1791                                        die("--stdin given twice?");
1792                                read_revisions_from_stdin(revs, &prune_data);
1793                                continue;
1794                        }
1795
1796                        opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1797                        if (opts > 0) {
1798                                i += opts - 1;
1799                                continue;
1800                        }
1801                        if (opts < 0)
1802                                exit(128);
1803                        continue;
1804                }
1805
1806
1807                if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
1808                        int j;
1809                        if (seen_dashdash || *arg == '^')
1810                                die("bad revision '%s'", arg);
1811
1812                        /* If we didn't have a "--":
1813                         * (1) all filenames must exist;
1814                         * (2) all rev-args must not be interpretable
1815                         *     as a valid filename.
1816                         * but the latter we have checked in the main loop.
1817                         */
1818                        for (j = i; j < argc; j++)
1819                                verify_filename(revs->prefix, argv[j], j == i);
1820
1821                        append_prune_data(&prune_data, argv + i);
1822                        break;
1823                }
1824                else
1825                        got_rev_arg = 1;
1826        }
1827
1828        if (prune_data.nr) {
1829                /*
1830                 * If we need to introduce the magic "a lone ':' means no
1831                 * pathspec whatsoever", here is the place to do so.
1832                 *
1833                 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1834                 *      prune_data.nr = 0;
1835                 *      prune_data.alloc = 0;
1836                 *      free(prune_data.path);
1837                 *      prune_data.path = NULL;
1838                 * } else {
1839                 *      terminate prune_data.alloc with NULL and
1840                 *      call init_pathspec() to set revs->prune_data here.
1841                 * }
1842                 */
1843                ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1844                prune_data.path[prune_data.nr++] = NULL;
1845                init_pathspec(&revs->prune_data,
1846                              get_pathspec(revs->prefix, prune_data.path));
1847        }
1848
1849        if (revs->def == NULL)
1850                revs->def = opt ? opt->def : NULL;
1851        if (opt && opt->tweak)
1852                opt->tweak(revs, opt);
1853        if (revs->show_merge)
1854                prepare_show_merge(revs);
1855        if (revs->def && !revs->pending.nr && !got_rev_arg) {
1856                unsigned char sha1[20];
1857                struct object *object;
1858                struct object_context oc;
1859                if (get_sha1_with_context(revs->def, 0, sha1, &oc))
1860                        die("bad default revision '%s'", revs->def);
1861                object = get_reference(revs, revs->def, sha1, 0);
1862                add_pending_object_with_mode(revs, object, revs->def, oc.mode);
1863        }
1864
1865        /* Did the user ask for any diff output? Run the diff! */
1866        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1867                revs->diff = 1;
1868
1869        /* Pickaxe, diff-filter and rename following need diffs */
1870        if (revs->diffopt.pickaxe ||
1871            revs->diffopt.filter ||
1872            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1873                revs->diff = 1;
1874
1875        if (revs->topo_order)
1876                revs->limited = 1;
1877
1878        if (revs->prune_data.nr) {
1879                diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1880                /* Can't prune commits with rename following: the paths change.. */
1881                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1882                        revs->prune = 1;
1883                if (!revs->full_diff)
1884                        diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1885        }
1886        if (revs->combine_merges)
1887                revs->ignore_merges = 0;
1888        revs->diffopt.abbrev = revs->abbrev;
1889        diff_setup_done(&revs->diffopt);
1890
1891        compile_grep_patterns(&revs->grep_filter);
1892
1893        if (revs->reverse && revs->reflog_info)
1894                die("cannot combine --reverse with --walk-reflogs");
1895        if (revs->rewrite_parents && revs->children.name)
1896                die("cannot combine --parents and --children");
1897
1898        /*
1899         * Limitations on the graph functionality
1900         */
1901        if (revs->reverse && revs->graph)
1902                die("cannot combine --reverse with --graph");
1903
1904        if (revs->reflog_info && revs->graph)
1905                die("cannot combine --walk-reflogs with --graph");
1906
1907        return left;
1908}
1909
1910static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1911{
1912        struct commit_list *l = xcalloc(1, sizeof(*l));
1913
1914        l->item = child;
1915        l->next = add_decoration(&revs->children, &parent->object, l);
1916}
1917
1918static int remove_duplicate_parents(struct commit *commit)
1919{
1920        struct commit_list **pp, *p;
1921        int surviving_parents;
1922
1923        /* Examine existing parents while marking ones we have seen... */
1924        pp = &commit->parents;
1925        while ((p = *pp) != NULL) {
1926                struct commit *parent = p->item;
1927                if (parent->object.flags & TMP_MARK) {
1928                        *pp = p->next;
1929                        continue;
1930                }
1931                parent->object.flags |= TMP_MARK;
1932                pp = &p->next;
1933        }
1934        /* count them while clearing the temporary mark */
1935        surviving_parents = 0;
1936        for (p = commit->parents; p; p = p->next) {
1937                p->item->object.flags &= ~TMP_MARK;
1938                surviving_parents++;
1939        }
1940        return surviving_parents;
1941}
1942
1943struct merge_simplify_state {
1944        struct commit *simplified;
1945};
1946
1947static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1948{
1949        struct merge_simplify_state *st;
1950
1951        st = lookup_decoration(&revs->merge_simplification, &commit->object);
1952        if (!st) {
1953                st = xcalloc(1, sizeof(*st));
1954                add_decoration(&revs->merge_simplification, &commit->object, st);
1955        }
1956        return st;
1957}
1958
1959static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1960{
1961        struct commit_list *p;
1962        struct merge_simplify_state *st, *pst;
1963        int cnt;
1964
1965        st = locate_simplify_state(revs, commit);
1966
1967        /*
1968         * Have we handled this one?
1969         */
1970        if (st->simplified)
1971                return tail;
1972
1973        /*
1974         * An UNINTERESTING commit simplifies to itself, so does a
1975         * root commit.  We do not rewrite parents of such commit
1976         * anyway.
1977         */
1978        if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1979                st->simplified = commit;
1980                return tail;
1981        }
1982
1983        /*
1984         * Do we know what commit all of our parents that matter
1985         * should be rewritten to?  Otherwise we are not ready to
1986         * rewrite this one yet.
1987         */
1988        for (cnt = 0, p = commit->parents; p; p = p->next) {
1989                pst = locate_simplify_state(revs, p->item);
1990                if (!pst->simplified) {
1991                        tail = &commit_list_insert(p->item, tail)->next;
1992                        cnt++;
1993                }
1994                if (revs->first_parent_only)
1995                        break;
1996        }
1997        if (cnt) {
1998                tail = &commit_list_insert(commit, tail)->next;
1999                return tail;
2000        }
2001
2002        /*
2003         * Rewrite our list of parents.
2004         */
2005        for (p = commit->parents; p; p = p->next) {
2006                pst = locate_simplify_state(revs, p->item);
2007                p->item = pst->simplified;
2008                if (revs->first_parent_only)
2009                        break;
2010        }
2011        if (!revs->first_parent_only)
2012                cnt = remove_duplicate_parents(commit);
2013        else
2014                cnt = 1;
2015
2016        /*
2017         * It is possible that we are a merge and one side branch
2018         * does not have any commit that touches the given paths;
2019         * in such a case, the immediate parents will be rewritten
2020         * to different commits.
2021         *
2022         *      o----X          X: the commit we are looking at;
2023         *     /    /           o: a commit that touches the paths;
2024         * ---o----'
2025         *
2026         * Further reduce the parents by removing redundant parents.
2027         */
2028        if (1 < cnt) {
2029                struct commit_list *h = reduce_heads(commit->parents);
2030                cnt = commit_list_count(h);
2031                free_commit_list(commit->parents);
2032                commit->parents = h;
2033        }
2034
2035        /*
2036         * A commit simplifies to itself if it is a root, if it is
2037         * UNINTERESTING, if it touches the given paths, or if it is a
2038         * merge and its parents simplifies to more than one commits
2039         * (the first two cases are already handled at the beginning of
2040         * this function).
2041         *
2042         * Otherwise, it simplifies to what its sole parent simplifies to.
2043         */
2044        if (!cnt ||
2045            (commit->object.flags & UNINTERESTING) ||
2046            !(commit->object.flags & TREESAME) ||
2047            (1 < cnt))
2048                st->simplified = commit;
2049        else {
2050                pst = locate_simplify_state(revs, commit->parents->item);
2051                st->simplified = pst->simplified;
2052        }
2053        return tail;
2054}
2055
2056static void simplify_merges(struct rev_info *revs)
2057{
2058        struct commit_list *list, *next;
2059        struct commit_list *yet_to_do, **tail;
2060        struct commit *commit;
2061
2062        if (!revs->prune)
2063                return;
2064
2065        /* feed the list reversed */
2066        yet_to_do = NULL;
2067        for (list = revs->commits; list; list = next) {
2068                commit = list->item;
2069                next = list->next;
2070                /*
2071                 * Do not free(list) here yet; the original list
2072                 * is used later in this function.
2073                 */
2074                commit_list_insert(commit, &yet_to_do);
2075        }
2076        while (yet_to_do) {
2077                list = yet_to_do;
2078                yet_to_do = NULL;
2079                tail = &yet_to_do;
2080                while (list) {
2081                        commit = list->item;
2082                        next = list->next;
2083                        free(list);
2084                        list = next;
2085                        tail = simplify_one(revs, commit, tail);
2086                }
2087        }
2088
2089        /* clean up the result, removing the simplified ones */
2090        list = revs->commits;
2091        revs->commits = NULL;
2092        tail = &revs->commits;
2093        while (list) {
2094                struct merge_simplify_state *st;
2095
2096                commit = list->item;
2097                next = list->next;
2098                free(list);
2099                list = next;
2100                st = locate_simplify_state(revs, commit);
2101                if (st->simplified == commit)
2102                        tail = &commit_list_insert(commit, tail)->next;
2103        }
2104}
2105
2106static void set_children(struct rev_info *revs)
2107{
2108        struct commit_list *l;
2109        for (l = revs->commits; l; l = l->next) {
2110                struct commit *commit = l->item;
2111                struct commit_list *p;
2112
2113                for (p = commit->parents; p; p = p->next)
2114                        add_child(revs, p->item, commit);
2115        }
2116}
2117
2118void reset_revision_walk(void)
2119{
2120        clear_object_flags(SEEN | ADDED | SHOWN);
2121}
2122
2123int prepare_revision_walk(struct rev_info *revs)
2124{
2125        int nr = revs->pending.nr;
2126        struct object_array_entry *e, *list;
2127        struct commit_list **next = &revs->commits;
2128
2129        e = list = revs->pending.objects;
2130        revs->pending.nr = 0;
2131        revs->pending.alloc = 0;
2132        revs->pending.objects = NULL;
2133        while (--nr >= 0) {
2134                struct commit *commit = handle_commit(revs, e->item, e->name);
2135                if (commit) {
2136                        if (!(commit->object.flags & SEEN)) {
2137                                commit->object.flags |= SEEN;
2138                                next = commit_list_append(commit, next);
2139                        }
2140                }
2141                e++;
2142        }
2143        if (!revs->leak_pending)
2144                free(list);
2145
2146        if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2147                commit_list_sort_by_date(&revs->commits);
2148        if (revs->no_walk)
2149                return 0;
2150        if (revs->limited)
2151                if (limit_list(revs) < 0)
2152                        return -1;
2153        if (revs->topo_order)
2154                sort_in_topological_order(&revs->commits, revs->lifo);
2155        if (revs->simplify_merges)
2156                simplify_merges(revs);
2157        if (revs->children.name)
2158                set_children(revs);
2159        return 0;
2160}
2161
2162enum rewrite_result {
2163        rewrite_one_ok,
2164        rewrite_one_noparents,
2165        rewrite_one_error
2166};
2167
2168static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2169{
2170        struct commit_list *cache = NULL;
2171
2172        for (;;) {
2173                struct commit *p = *pp;
2174                if (!revs->limited)
2175                        if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2176                                return rewrite_one_error;
2177                if (p->parents && p->parents->next)
2178                        return rewrite_one_ok;
2179                if (p->object.flags & UNINTERESTING)
2180                        return rewrite_one_ok;
2181                if (!(p->object.flags & TREESAME))
2182                        return rewrite_one_ok;
2183                if (!p->parents)
2184                        return rewrite_one_noparents;
2185                *pp = p->parents->item;
2186        }
2187}
2188
2189static int rewrite_parents(struct rev_info *revs, struct commit *commit)
2190{
2191        struct commit_list **pp = &commit->parents;
2192        while (*pp) {
2193                struct commit_list *parent = *pp;
2194                switch (rewrite_one(revs, &parent->item)) {
2195                case rewrite_one_ok:
2196                        break;
2197                case rewrite_one_noparents:
2198                        *pp = parent->next;
2199                        continue;
2200                case rewrite_one_error:
2201                        return -1;
2202                }
2203                pp = &parent->next;
2204        }
2205        remove_duplicate_parents(commit);
2206        return 0;
2207}
2208
2209static int commit_match(struct commit *commit, struct rev_info *opt)
2210{
2211        if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2212                return 1;
2213        return grep_buffer(&opt->grep_filter,
2214                           commit->buffer, strlen(commit->buffer));
2215}
2216
2217static inline int want_ancestry(struct rev_info *revs)
2218{
2219        return (revs->rewrite_parents || revs->children.name);
2220}
2221
2222enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2223{
2224        if (commit->object.flags & SHOWN)
2225                return commit_ignore;
2226        if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2227                return commit_ignore;
2228        if (revs->show_all)
2229                return commit_show;
2230        if (commit->object.flags & UNINTERESTING)
2231                return commit_ignore;
2232        if (revs->min_age != -1 && (commit->date > revs->min_age))
2233                return commit_ignore;
2234        if (revs->min_parents || (revs->max_parents >= 0)) {
2235                int n = 0;
2236                struct commit_list *p;
2237                for (p = commit->parents; p; p = p->next)
2238                        n++;
2239                if ((n < revs->min_parents) ||
2240                    ((revs->max_parents >= 0) && (n > revs->max_parents)))
2241                        return commit_ignore;
2242        }
2243        if (!commit_match(commit, revs))
2244                return commit_ignore;
2245        if (revs->prune && revs->dense) {
2246                /* Commit without changes? */
2247                if (commit->object.flags & TREESAME) {
2248                        /* drop merges unless we want parenthood */
2249                        if (!want_ancestry(revs))
2250                                return commit_ignore;
2251                        /* non-merge - always ignore it */
2252                        if (!commit->parents || !commit->parents->next)
2253                                return commit_ignore;
2254                }
2255        }
2256        return commit_show;
2257}
2258
2259enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2260{
2261        enum commit_action action = get_commit_action(revs, commit);
2262
2263        if (action == commit_show &&
2264            !revs->show_all &&
2265            revs->prune && revs->dense && want_ancestry(revs)) {
2266                if (rewrite_parents(revs, commit) < 0)
2267                        return commit_error;
2268        }
2269        return action;
2270}
2271
2272static struct commit *get_revision_1(struct rev_info *revs)
2273{
2274        if (!revs->commits)
2275                return NULL;
2276
2277        do {
2278                struct commit_list *entry = revs->commits;
2279                struct commit *commit = entry->item;
2280
2281                revs->commits = entry->next;
2282                free(entry);
2283
2284                if (revs->reflog_info) {
2285                        fake_reflog_parent(revs->reflog_info, commit);
2286                        commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2287                }
2288
2289                /*
2290                 * If we haven't done the list limiting, we need to look at
2291                 * the parents here. We also need to do the date-based limiting
2292                 * that we'd otherwise have done in limit_list().
2293                 */
2294                if (!revs->limited) {
2295                        if (revs->max_age != -1 &&
2296                            (commit->date < revs->max_age))
2297                                continue;
2298                        if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2299                                die("Failed to traverse parents of commit %s",
2300                                    sha1_to_hex(commit->object.sha1));
2301                }
2302
2303                switch (simplify_commit(revs, commit)) {
2304                case commit_ignore:
2305                        continue;
2306                case commit_error:
2307                        die("Failed to simplify parents of commit %s",
2308                            sha1_to_hex(commit->object.sha1));
2309                default:
2310                        return commit;
2311                }
2312        } while (revs->commits);
2313        return NULL;
2314}
2315
2316static void gc_boundary(struct object_array *array)
2317{
2318        unsigned nr = array->nr;
2319        unsigned alloc = array->alloc;
2320        struct object_array_entry *objects = array->objects;
2321
2322        if (alloc <= nr) {
2323                unsigned i, j;
2324                for (i = j = 0; i < nr; i++) {
2325                        if (objects[i].item->flags & SHOWN)
2326                                continue;
2327                        if (i != j)
2328                                objects[j] = objects[i];
2329                        j++;
2330                }
2331                for (i = j; i < nr; i++)
2332                        objects[i].item = NULL;
2333                array->nr = j;
2334        }
2335}
2336
2337static void create_boundary_commit_list(struct rev_info *revs)
2338{
2339        unsigned i;
2340        struct commit *c;
2341        struct object_array *array = &revs->boundary_commits;
2342        struct object_array_entry *objects = array->objects;
2343
2344        /*
2345         * If revs->commits is non-NULL at this point, an error occurred in
2346         * get_revision_1().  Ignore the error and continue printing the
2347         * boundary commits anyway.  (This is what the code has always
2348         * done.)
2349         */
2350        if (revs->commits) {
2351                free_commit_list(revs->commits);
2352                revs->commits = NULL;
2353        }
2354
2355        /*
2356         * Put all of the actual boundary commits from revs->boundary_commits
2357         * into revs->commits
2358         */
2359        for (i = 0; i < array->nr; i++) {
2360                c = (struct commit *)(objects[i].item);
2361                if (!c)
2362                        continue;
2363                if (!(c->object.flags & CHILD_SHOWN))
2364                        continue;
2365                if (c->object.flags & (SHOWN | BOUNDARY))
2366                        continue;
2367                c->object.flags |= BOUNDARY;
2368                commit_list_insert(c, &revs->commits);
2369        }
2370
2371        /*
2372         * If revs->topo_order is set, sort the boundary commits
2373         * in topological order
2374         */
2375        sort_in_topological_order(&revs->commits, revs->lifo);
2376}
2377
2378static struct commit *get_revision_internal(struct rev_info *revs)
2379{
2380        struct commit *c = NULL;
2381        struct commit_list *l;
2382
2383        if (revs->boundary == 2) {
2384                /*
2385                 * All of the normal commits have already been returned,
2386                 * and we are now returning boundary commits.
2387                 * create_boundary_commit_list() has populated
2388                 * revs->commits with the remaining commits to return.
2389                 */
2390                c = pop_commit(&revs->commits);
2391                if (c)
2392                        c->object.flags |= SHOWN;
2393                return c;
2394        }
2395
2396        /*
2397         * If our max_count counter has reached zero, then we are done. We
2398         * don't simply return NULL because we still might need to show
2399         * boundary commits. But we want to avoid calling get_revision_1, which
2400         * might do a considerable amount of work finding the next commit only
2401         * for us to throw it away.
2402         *
2403         * If it is non-zero, then either we don't have a max_count at all
2404         * (-1), or it is still counting, in which case we decrement.
2405         */
2406        if (revs->max_count) {
2407                c = get_revision_1(revs);
2408                if (c) {
2409                        while (0 < revs->skip_count) {
2410                                revs->skip_count--;
2411                                c = get_revision_1(revs);
2412                                if (!c)
2413                                        break;
2414                        }
2415                }
2416
2417                if (revs->max_count > 0)
2418                        revs->max_count--;
2419        }
2420
2421        if (c)
2422                c->object.flags |= SHOWN;
2423
2424        if (!revs->boundary) {
2425                return c;
2426        }
2427
2428        if (!c) {
2429                /*
2430                 * get_revision_1() runs out the commits, and
2431                 * we are done computing the boundaries.
2432                 * switch to boundary commits output mode.
2433                 */
2434                revs->boundary = 2;
2435
2436                /*
2437                 * Update revs->commits to contain the list of
2438                 * boundary commits.
2439                 */
2440                create_boundary_commit_list(revs);
2441
2442                return get_revision_internal(revs);
2443        }
2444
2445        /*
2446         * boundary commits are the commits that are parents of the
2447         * ones we got from get_revision_1() but they themselves are
2448         * not returned from get_revision_1().  Before returning
2449         * 'c', we need to mark its parents that they could be boundaries.
2450         */
2451
2452        for (l = c->parents; l; l = l->next) {
2453                struct object *p;
2454                p = &(l->item->object);
2455                if (p->flags & (CHILD_SHOWN | SHOWN))
2456                        continue;
2457                p->flags |= CHILD_SHOWN;
2458                gc_boundary(&revs->boundary_commits);
2459                add_object_array(p, NULL, &revs->boundary_commits);
2460        }
2461
2462        return c;
2463}
2464
2465struct commit *get_revision(struct rev_info *revs)
2466{
2467        struct commit *c;
2468        struct commit_list *reversed;
2469
2470        if (revs->reverse) {
2471                reversed = NULL;
2472                while ((c = get_revision_internal(revs))) {
2473                        commit_list_insert(c, &reversed);
2474                }
2475                revs->commits = reversed;
2476                revs->reverse = 0;
2477                revs->reverse_output_stage = 1;
2478        }
2479
2480        if (revs->reverse_output_stage)
2481                return pop_commit(&revs->commits);
2482
2483        c = get_revision_internal(revs);
2484        if (c && revs->graph)
2485                graph_update(revs->graph, c);
2486        return c;
2487}
2488
2489char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2490{
2491        if (commit->object.flags & BOUNDARY)
2492                return "-";
2493        else if (commit->object.flags & UNINTERESTING)
2494                return "^";
2495        else if (commit->object.flags & PATCHSAME)
2496                return "=";
2497        else if (!revs || revs->left_right) {
2498                if (commit->object.flags & SYMMETRIC_LEFT)
2499                        return "<";
2500                else
2501                        return ">";
2502        } else if (revs->graph)
2503                return "*";
2504        else if (revs->cherry_mark)
2505                return "+";
2506        return "";
2507}
2508
2509void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2510{
2511        char *mark = get_revision_mark(revs, commit);
2512        if (!strlen(mark))
2513                return;
2514        fputs(mark, stdout);
2515        putchar(' ');
2516}