revision.c

   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 #include "mailmap.h"
  17
  18 volatile show_early_output_fn_t show_early_output;
  19
  20 char *path_name(const struct name_path *path, const char *name)
  21 {
  22         const struct name_path *p;
  23         char *n, *m;
  24         int nlen = strlen(name);
  25         int len = nlen + 1;
  26
  27         for (p = path; p; p = p->up) {
  28                 if (p->elem_len)
  29                         len += p->elem_len + 1;
  30         }
  31         n = xmalloc(len);
  32         m = n + len - (nlen + 1);
  33         strcpy(m, name);
  34         for (p = path; p; p = p->up) {
  35                 if (p->elem_len) {
  36                         m -= p->elem_len + 1;
  37                         memcpy(m, p->elem, p->elem_len);
  38                         m[p->elem_len] = '/';
  39                 }
  40         }
  41         return n;
  42 }
  43
  44 static int show_path_component_truncated(FILE *out, const char *name, int len)
  45 {
  46         int cnt;
  47         for (cnt = 0; cnt < len; cnt++) {
  48                 int ch = name[cnt];
  49                 if (!ch || ch == '\n')
  50                         return -1;
  51                 fputc(ch, out);
  52         }
  53         return len;
  54 }
  55
  56 static int show_path_truncated(FILE *out, const struct name_path *path)
  57 {
  58         int emitted, ours;
  59
  60         if (!path)
  61                 return 0;
  62         emitted = show_path_truncated(out, path->up);
  63         if (emitted < 0)
  64                 return emitted;
  65         if (emitted)
  66                 fputc('/', out);
  67         ours = show_path_component_truncated(out, path->elem, path->elem_len);
  68         if (ours < 0)
  69                 return ours;
  70         return ours || emitted;
  71 }
  72
  73 void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
  74 {
  75         struct name_path leaf;
  76         leaf.up = (struct name_path *)path;
  77         leaf.elem = component;
  78         leaf.elem_len = strlen(component);
  79
  80         fprintf(out, "%s ", sha1_to_hex(obj->sha1));
  81         show_path_truncated(out, &leaf);
  82         fputc('\n', out);
  83 }
  84
  85 void add_object(struct object *obj,
  86                 struct object_array *p,
  87                 struct name_path *path,
  88                 const char *name)
  89 {
  90         add_object_array(obj, path_name(path, name), p);
  91 }
  92
  93 static void mark_blob_uninteresting(struct blob *blob)
  94 {
  95         if (!blob)
  96                 return;
  97         if (blob->object.flags & UNINTERESTING)
  98                 return;
  99         blob->object.flags |= UNINTERESTING;
 100 }
 101
 102 void mark_tree_uninteresting(struct tree *tree)
 103 {
 104         struct tree_desc desc;
 105         struct name_entry entry;
 106         struct object *obj = &tree->object;
 107
 108         if (!tree)
 109                 return;
 110         if (obj->flags & UNINTERESTING)
 111                 return;
 112         obj->flags |= UNINTERESTING;
 113         if (!has_sha1_file(obj->sha1))
 114                 return;
 115         if (parse_tree(tree) < 0)
 116                 die("bad tree %s", sha1_to_hex(obj->sha1));
 117
 118         init_tree_desc(&desc, tree->buffer, tree->size);
 119         while (tree_entry(&desc, &entry)) {
 120                 switch (object_type(entry.mode)) {
 121                 case OBJ_TREE:
 122                         mark_tree_uninteresting(lookup_tree(entry.sha1));
 123                         break;
 124                 case OBJ_BLOB:
 125                         mark_blob_uninteresting(lookup_blob(entry.sha1));
 126                         break;
 127                 default:
 128                         /* Subproject commit - not in this repository */
 129                         break;
 130                 }
 131         }
 132
 133         /*
 134          * We don't care about the tree any more
 135          * after it has been marked uninteresting.
 136          */
 137         free(tree->buffer);
 138         tree->buffer = NULL;
 139 }
 140
 141 void mark_parents_uninteresting(struct commit *commit)
 142 {
 143         struct commit_list *parents = NULL, *l;
 144
 145         for (l = commit->parents; l; l = l->next)
 146                 commit_list_insert(l->item, &parents);
 147
 148         while (parents) {
 149                 struct commit *commit = parents->item;
 150                 l = parents;
 151                 parents = parents->next;
 152                 free(l);
 153
 154                 while (commit) {
 155                         /*
 156                          * A missing commit is ok iff its parent is marked
 157                          * uninteresting.
 158                          *
 159                          * We just mark such a thing parsed, so that when
 160                          * it is popped next time around, we won't be trying
 161                          * to parse it and get an error.
 162                          */
 163                         if (!has_sha1_file(commit->object.sha1))
 164                                 commit->object.parsed = 1;
 165
 166                         if (commit->object.flags & UNINTERESTING)
 167                                 break;
 168
 169                         commit->object.flags |= UNINTERESTING;
 170
 171                         /*
 172                          * Normally we haven't parsed the parent
 173                          * yet, so we won't have a parent of a parent
 174                          * here. However, it may turn out that we've
 175                          * reached this commit some other way (where it
 176                          * wasn't uninteresting), in which case we need
 177                          * to mark its parents recursively too..
 178                          */
 179                         if (!commit->parents)
 180                                 break;
 181
 182                         for (l = commit->parents->next; l; l = l->next)
 183                                 commit_list_insert(l->item, &parents);
 184                         commit = commit->parents->item;
 185                 }
 186         }
 187 }
 188
 189 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 190 {
 191         if (!obj)
 192                 return;
 193         if (revs->no_walk && (obj->flags & UNINTERESTING))
 194                 revs->no_walk = 0;
 195         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 196                 struct strbuf buf = STRBUF_INIT;
 197                 int len = interpret_branch_name(name, &buf);
 198                 int st;
 199
 200                 if (0 < len && name[len] && buf.len)
 201                         strbuf_addstr(&buf, name + len);
 202                 st = add_reflog_for_walk(revs->reflog_info,
 203                                          (struct commit *)obj,
 204                                          buf.buf[0] ? buf.buf: name);
 205                 strbuf_release(&buf);
 206                 if (st)
 207                         return;
 208         }
 209         add_object_array_with_mode(obj, name, &revs->pending, mode);
 210 }
 211
 212 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 213 {
 214         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 215 }
 216
 217 void add_head_to_pending(struct rev_info *revs)
 218 {
 219         unsigned char sha1[20];
 220         struct object *obj;
 221         if (get_sha1("HEAD", sha1))
 222                 return;
 223         obj = parse_object(sha1);
 224         if (!obj)
 225                 return;
 226         add_pending_object(revs, obj, "HEAD");
 227 }
 228
 229 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 230 {
 231         struct object *object;
 232
 233         object = parse_object(sha1);
 234         if (!object) {
 235                 if (revs->ignore_missing)
 236                         return object;
 237                 die("bad object %s", name);
 238         }
 239         object->flags |= flags;
 240         return object;
 241 }
 242
 243 void add_pending_sha1(struct rev_info *revs, const char *name,
 244                       const unsigned char *sha1, unsigned int flags)
 245 {
 246         struct object *object = get_reference(revs, name, sha1, flags);
 247         add_pending_object(revs, object, name);
 248 }
 249
 250 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 251 {
 252         unsigned long flags = object->flags;
 253
 254         /*
 255          * Tag object? Look what it points to..
 256          */
 257         while (object->type == OBJ_TAG) {
 258                 struct tag *tag = (struct tag *) object;
 259                 if (revs->tag_objects && !(flags & UNINTERESTING))
 260                         add_pending_object(revs, object, tag->tag);
 261                 if (!tag->tagged)
 262                         die("bad tag");
 263                 object = parse_object(tag->tagged->sha1);
 264                 if (!object) {
 265                         if (flags & UNINTERESTING)
 266                                 return NULL;
 267                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 268                 }
 269         }
 270
 271         /*
 272          * Commit object? Just return it, we'll do all the complex
 273          * reachability crud.
 274          */
 275         if (object->type == OBJ_COMMIT) {
 276                 struct commit *commit = (struct commit *)object;
 277                 if (parse_commit(commit) < 0)
 278                         die("unable to parse commit %s", name);
 279                 if (flags & UNINTERESTING) {
 280                         commit->object.flags |= UNINTERESTING;
 281                         mark_parents_uninteresting(commit);
 282                         revs->limited = 1;
 283                 }
 284                 if (revs->show_source && !commit->util)
 285                         commit->util = (void *) name;
 286                 return commit;
 287         }
 288
 289         /*
 290          * Tree object? Either mark it uninteresting, or add it
 291          * to the list of objects to look at later..
 292          */
 293         if (object->type == OBJ_TREE) {
 294                 struct tree *tree = (struct tree *)object;
 295                 if (!revs->tree_objects)
 296                         return NULL;
 297                 if (flags & UNINTERESTING) {
 298                         mark_tree_uninteresting(tree);
 299                         return NULL;
 300                 }
 301                 add_pending_object(revs, object, "");
 302                 return NULL;
 303         }
 304
 305         /*
 306          * Blob object? You know the drill by now..
 307          */
 308         if (object->type == OBJ_BLOB) {
 309                 struct blob *blob = (struct blob *)object;
 310                 if (!revs->blob_objects)
 311                         return NULL;
 312                 if (flags & UNINTERESTING) {
 313                         mark_blob_uninteresting(blob);
 314                         return NULL;
 315                 }
 316                 add_pending_object(revs, object, "");
 317                 return NULL;
 318         }
 319         die("%s is unknown object", name);
 320 }
 321
 322 static int everybody_uninteresting(struct commit_list *orig)
 323 {
 324         struct commit_list *list = orig;
 325         while (list) {
 326                 struct commit *commit = list->item;
 327                 list = list->next;
 328                 if (commit->object.flags & UNINTERESTING)
 329                         continue;
 330                 return 0;
 331         }
 332         return 1;
 333 }
 334
 335 /*
 336  * The goal is to get REV_TREE_NEW as the result only if the
 337  * diff consists of all '+' (and no other changes), REV_TREE_OLD
 338  * if the whole diff is removal of old data, and otherwise
 339  * REV_TREE_DIFFERENT (of course if the trees are the same we
 340  * want REV_TREE_SAME).
 341  * That means that once we get to REV_TREE_DIFFERENT, we do not
 342  * have to look any further.
 343  */
 344 static int tree_difference = REV_TREE_SAME;
 345
 346 static void file_add_remove(struct diff_options *options,
 347                     int addremove, unsigned mode,
 348                     const unsigned char *sha1,
 349                     int sha1_valid,
 350                     const char *fullpath, unsigned dirty_submodule)
 351 {
 352         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 353
 354         tree_difference |= diff;
 355         if (tree_difference == REV_TREE_DIFFERENT)
 356                 DIFF_OPT_SET(options, HAS_CHANGES);
 357 }
 358
 359 static void file_change(struct diff_options *options,
 360                  unsigned old_mode, unsigned new_mode,
 361                  const unsigned char *old_sha1,
 362                  const unsigned char *new_sha1,
 363                  int old_sha1_valid, int new_sha1_valid,
 364                  const char *fullpath,
 365                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 366 {
 367         tree_difference = REV_TREE_DIFFERENT;
 368         DIFF_OPT_SET(options, HAS_CHANGES);
 369 }
 370
 371 static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 372 {
 373         struct tree *t1 = parent->tree;
 374         struct tree *t2 = commit->tree;
 375
 376         if (!t1)
 377                 return REV_TREE_NEW;
 378         if (!t2)
 379                 return REV_TREE_OLD;
 380
 381         if (revs->simplify_by_decoration) {
 382                 /*
 383                  * If we are simplifying by decoration, then the commit
 384                  * is worth showing if it has a tag pointing at it.
 385                  */
 386                 if (lookup_decoration(&name_decoration, &commit->object))
 387                         return REV_TREE_DIFFERENT;
 388                 /*
 389                  * A commit that is not pointed by a tag is uninteresting
 390                  * if we are not limited by path.  This means that you will
 391                  * see the usual "commits that touch the paths" plus any
 392                  * tagged commit by specifying both --simplify-by-decoration
 393                  * and pathspec.
 394                  */
 395                 if (!revs->prune_data.nr)
 396                         return REV_TREE_SAME;
 397         }
 398
 399         tree_difference = REV_TREE_SAME;
 400         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 401         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 402                            &revs->pruning) < 0)
 403                 return REV_TREE_DIFFERENT;
 404         return tree_difference;
 405 }
 406
 407 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 408 {
 409         int retval;
 410         void *tree;
 411         unsigned long size;
 412         struct tree_desc empty, real;
 413         struct tree *t1 = commit->tree;
 414
 415         if (!t1)
 416                 return 0;
 417
 418         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 419         if (!tree)
 420                 return 0;
 421         init_tree_desc(&real, tree, size);
 422         init_tree_desc(&empty, "", 0);
 423
 424         tree_difference = REV_TREE_SAME;
 425         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 426         retval = diff_tree(&empty, &real, "", &revs->pruning);
 427         free(tree);
 428
 429         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 430 }
 431
 432 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 433 {
 434         struct commit_list **pp, *parent;
 435         int tree_changed = 0, tree_same = 0, nth_parent = 0;
 436
 437         /*
 438          * If we don't do pruning, everything is interesting
 439          */
 440         if (!revs->prune)
 441                 return;
 442
 443         if (!commit->tree)
 444                 return;
 445
 446         if (!commit->parents) {
 447                 if (rev_same_tree_as_empty(revs, commit))
 448                         commit->object.flags |= TREESAME;
 449                 return;
 450         }
 451
 452         /*
 453          * Normal non-merge commit? If we don't want to make the
 454          * history dense, we consider it always to be a change..
 455          */
 456         if (!revs->dense && !commit->parents->next)
 457                 return;
 458
 459         pp = &commit->parents;
 460         while ((parent = *pp) != NULL) {
 461                 struct commit *p = parent->item;
 462
 463                 /*
 464                  * Do not compare with later parents when we care only about
 465                  * the first parent chain, in order to avoid derailing the
 466                  * traversal to follow a side branch that brought everything
 467                  * in the path we are limited to by the pathspec.
 468                  */
 469                 if (revs->first_parent_only && nth_parent++)
 470                         break;
 471                 if (parse_commit(p) < 0)
 472                         die("cannot simplify commit %s (because of %s)",
 473                             sha1_to_hex(commit->object.sha1),
 474                             sha1_to_hex(p->object.sha1));
 475                 switch (rev_compare_tree(revs, p, commit)) {
 476                 case REV_TREE_SAME:
 477                         tree_same = 1;
 478                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 479                                 /* Even if a merge with an uninteresting
 480                                  * side branch brought the entire change
 481                                  * we are interested in, we do not want
 482                                  * to lose the other branches of this
 483                                  * merge, so we just keep going.
 484                                  */
 485                                 pp = &parent->next;
 486                                 continue;
 487                         }
 488                         parent->next = NULL;
 489                         commit->parents = parent;
 490                         commit->object.flags |= TREESAME;
 491                         return;
 492
 493                 case REV_TREE_NEW:
 494                         if (revs->remove_empty_trees &&
 495                             rev_same_tree_as_empty(revs, p)) {
 496                                 /* We are adding all the specified
 497                                  * paths from this parent, so the
 498                                  * history beyond this parent is not
 499                                  * interesting.  Remove its parents
 500                                  * (they are grandparents for us).
 501                                  * IOW, we pretend this parent is a
 502                                  * "root" commit.
 503                                  */
 504                                 if (parse_commit(p) < 0)
 505                                         die("cannot simplify commit %s (invalid %s)",
 506                                             sha1_to_hex(commit->object.sha1),
 507                                             sha1_to_hex(p->object.sha1));
 508                                 p->parents = NULL;
 509                         }
 510                 /* fallthrough */
 511                 case REV_TREE_OLD:
 512                 case REV_TREE_DIFFERENT:
 513                         tree_changed = 1;
 514                         pp = &parent->next;
 515                         continue;
 516                 }
 517                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 518         }
 519         if (tree_changed && !tree_same)
 520                 return;
 521         commit->object.flags |= TREESAME;
 522 }
 523
 524 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 525                     struct commit_list *cached_base, struct commit_list **cache)
 526 {
 527         struct commit_list *new_entry;
 528
 529         if (cached_base && p->date < cached_base->item->date)
 530                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
 531         else
 532                 new_entry = commit_list_insert_by_date(p, head);
 533
 534         if (cache && (!*cache || p->date < (*cache)->item->date))
 535                 *cache = new_entry;
 536 }
 537
 538 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 539                     struct commit_list **list, struct commit_list **cache_ptr)
 540 {
 541         struct commit_list *parent = commit->parents;
 542         unsigned left_flag;
 543         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 544
 545         if (commit->object.flags & ADDED)
 546                 return 0;
 547         commit->object.flags |= ADDED;
 548
 549         /*
 550          * If the commit is uninteresting, don't try to
 551          * prune parents - we want the maximal uninteresting
 552          * set.
 553          *
 554          * Normally we haven't parsed the parent
 555          * yet, so we won't have a parent of a parent
 556          * here. However, it may turn out that we've
 557          * reached this commit some other way (where it
 558          * wasn't uninteresting), in which case we need
 559          * to mark its parents recursively too..
 560          */
 561         if (commit->object.flags & UNINTERESTING) {
 562                 while (parent) {
 563                         struct commit *p = parent->item;
 564                         parent = parent->next;
 565                         if (p)
 566                                 p->object.flags |= UNINTERESTING;
 567                         if (parse_commit(p) < 0)
 568                                 continue;
 569                         if (p->parents)
 570                                 mark_parents_uninteresting(p);
 571                         if (p->object.flags & SEEN)
 572                                 continue;
 573                         p->object.flags |= SEEN;
 574                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 575                 }
 576                 return 0;
 577         }
 578
 579         /*
 580          * Ok, the commit wasn't uninteresting. Try to
 581          * simplify the commit history and find the parent
 582          * that has no differences in the path set if one exists.
 583          */
 584         try_to_simplify_commit(revs, commit);
 585
 586         if (revs->no_walk)
 587                 return 0;
 588
 589         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 590
 591         for (parent = commit->parents; parent; parent = parent->next) {
 592                 struct commit *p = parent->item;
 593
 594                 if (parse_commit(p) < 0)
 595                         return -1;
 596                 if (revs->show_source && !p->util)
 597                         p->util = commit->util;
 598                 p->object.flags |= left_flag;
 599                 if (!(p->object.flags & SEEN)) {
 600                         p->object.flags |= SEEN;
 601                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 602                 }
 603                 if (revs->first_parent_only)
 604                         break;
 605         }
 606         return 0;
 607 }
 608
 609 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 610 {
 611         struct commit_list *p;
 612         int left_count = 0, right_count = 0;
 613         int left_first;
 614         struct patch_ids ids;
 615         unsigned cherry_flag;
 616
 617         /* First count the commits on the left and on the right */
 618         for (p = list; p; p = p->next) {
 619                 struct commit *commit = p->item;
 620                 unsigned flags = commit->object.flags;
 621                 if (flags & BOUNDARY)
 622                         ;
 623                 else if (flags & SYMMETRIC_LEFT)
 624                         left_count++;
 625                 else
 626                         right_count++;
 627         }
 628
 629         if (!left_count || !right_count)
 630                 return;
 631
 632         left_first = left_count < right_count;
 633         init_patch_ids(&ids);
 634         ids.diffopts.pathspec = revs->diffopt.pathspec;
 635
 636         /* Compute patch-ids for one side */
 637         for (p = list; p; p = p->next) {
 638                 struct commit *commit = p->item;
 639                 unsigned flags = commit->object.flags;
 640
 641                 if (flags & BOUNDARY)
 642                         continue;
 643                 /*
 644                  * If we have fewer left, left_first is set and we omit
 645                  * commits on the right branch in this loop.  If we have
 646                  * fewer right, we skip the left ones.
 647                  */
 648                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 649                         continue;
 650                 commit->util = add_commit_patch_id(commit, &ids);
 651         }
 652
 653         /* either cherry_mark or cherry_pick are true */
 654         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 655
 656         /* Check the other side */
 657         for (p = list; p; p = p->next) {
 658                 struct commit *commit = p->item;
 659                 struct patch_id *id;
 660                 unsigned flags = commit->object.flags;
 661
 662                 if (flags & BOUNDARY)
 663                         continue;
 664                 /*
 665                  * If we have fewer left, left_first is set and we omit
 666                  * commits on the left branch in this loop.
 667                  */
 668                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 669                         continue;
 670
 671                 /*
 672                  * Have we seen the same patch id?
 673                  */
 674                 id = has_commit_patch_id(commit, &ids);
 675                 if (!id)
 676                         continue;
 677                 id->seen = 1;
 678                 commit->object.flags |= cherry_flag;
 679         }
 680
 681         /* Now check the original side for seen ones */
 682         for (p = list; p; p = p->next) {
 683                 struct commit *commit = p->item;
 684                 struct patch_id *ent;
 685
 686                 ent = commit->util;
 687                 if (!ent)
 688                         continue;
 689                 if (ent->seen)
 690                         commit->object.flags |= cherry_flag;
 691                 commit->util = NULL;
 692         }
 693
 694         free_patch_ids(&ids);
 695 }
 696
 697 /* How many extra uninteresting commits we want to see.. */
 698 #define SLOP 5
 699
 700 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 701 {
 702         /*
 703          * No source list at all? We're definitely done..
 704          */
 705         if (!src)
 706                 return 0;
 707
 708         /*
 709          * Does the destination list contain entries with a date
 710          * before the source list? Definitely _not_ done.
 711          */
 712         if (date < src->item->date)
 713                 return SLOP;
 714
 715         /*
 716          * Does the source list still have interesting commits in
 717          * it? Definitely not done..
 718          */
 719         if (!everybody_uninteresting(src))
 720                 return SLOP;
 721
 722         /* Ok, we're closing in.. */
 723         return slop-1;
 724 }
 725
 726 /*
 727  * "rev-list --ancestry-path A..B" computes commits that are ancestors
 728  * of B but not ancestors of A but further limits the result to those
 729  * that are descendants of A.  This takes the list of bottom commits and
 730  * the result of "A..B" without --ancestry-path, and limits the latter
 731  * further to the ones that can reach one of the commits in "bottom".
 732  */
 733 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 734 {
 735         struct commit_list *p;
 736         struct commit_list *rlist = NULL;
 737         int made_progress;
 738
 739         /*
 740          * Reverse the list so that it will be likely that we would
 741          * process parents before children.
 742          */
 743         for (p = list; p; p = p->next)
 744                 commit_list_insert(p->item, &rlist);
 745
 746         for (p = bottom; p; p = p->next)
 747                 p->item->object.flags |= TMP_MARK;
 748
 749         /*
 750          * Mark the ones that can reach bottom commits in "list",
 751          * in a bottom-up fashion.
 752          */
 753         do {
 754                 made_progress = 0;
 755                 for (p = rlist; p; p = p->next) {
 756                         struct commit *c = p->item;
 757                         struct commit_list *parents;
 758                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
 759                                 continue;
 760                         for (parents = c->parents;
 761                              parents;
 762                              parents = parents->next) {
 763                                 if (!(parents->item->object.flags & TMP_MARK))
 764                                         continue;
 765                                 c->object.flags |= TMP_MARK;
 766                                 made_progress = 1;
 767                                 break;
 768                         }
 769                 }
 770         } while (made_progress);
 771
 772         /*
 773          * NEEDSWORK: decide if we want to remove parents that are
 774          * not marked with TMP_MARK from commit->parents for commits
 775          * in the resulting list.  We may not want to do that, though.
 776          */
 777
 778         /*
 779          * The ones that are not marked with TMP_MARK are uninteresting
 780          */
 781         for (p = list; p; p = p->next) {
 782                 struct commit *c = p->item;
 783                 if (c->object.flags & TMP_MARK)
 784                         continue;
 785                 c->object.flags |= UNINTERESTING;
 786         }
 787
 788         /* We are done with the TMP_MARK */
 789         for (p = list; p; p = p->next)
 790                 p->item->object.flags &= ~TMP_MARK;
 791         for (p = bottom; p; p = p->next)
 792                 p->item->object.flags &= ~TMP_MARK;
 793         free_commit_list(rlist);
 794 }
 795
 796 /*
 797  * Before walking the history, keep the set of "negative" refs the
 798  * caller has asked to exclude.
 799  *
 800  * This is used to compute "rev-list --ancestry-path A..B", as we need
 801  * to filter the result of "A..B" further to the ones that can actually
 802  * reach A.
 803  */
 804 static struct commit_list *collect_bottom_commits(struct rev_info *revs)
 805 {
 806         struct commit_list *bottom = NULL;
 807         int i;
 808         for (i = 0; i < revs->cmdline.nr; i++) {
 809                 struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
 810                 if ((elem->flags & UNINTERESTING) &&
 811                     elem->item->type == OBJ_COMMIT)
 812                         commit_list_insert((struct commit *)elem->item, &bottom);
 813         }
 814         return bottom;
 815 }
 816
 817 /* Assumes either left_only or right_only is set */
 818 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 819 {
 820         struct commit_list *p;
 821
 822         for (p = list; p; p = p->next) {
 823                 struct commit *commit = p->item;
 824
 825                 if (revs->right_only) {
 826                         if (commit->object.flags & SYMMETRIC_LEFT)
 827                                 commit->object.flags |= SHOWN;
 828                 } else  /* revs->left_only is set */
 829                         if (!(commit->object.flags & SYMMETRIC_LEFT))
 830                                 commit->object.flags |= SHOWN;
 831         }
 832 }
 833
 834 static int limit_list(struct rev_info *revs)
 835 {
 836         int slop = SLOP;
 837         unsigned long date = ~0ul;
 838         struct commit_list *list = revs->commits;
 839         struct commit_list *newlist = NULL;
 840         struct commit_list **p = &newlist;
 841         struct commit_list *bottom = NULL;
 842
 843         if (revs->ancestry_path) {
 844                 bottom = collect_bottom_commits(revs);
 845                 if (!bottom)
 846                         die("--ancestry-path given but there are no bottom commits");
 847         }
 848
 849         while (list) {
 850                 struct commit_list *entry = list;
 851                 struct commit *commit = list->item;
 852                 struct object *obj = &commit->object;
 853                 show_early_output_fn_t show;
 854
 855                 list = list->next;
 856                 free(entry);
 857
 858                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 859                         obj->flags |= UNINTERESTING;
 860                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 861                         return -1;
 862                 if (obj->flags & UNINTERESTING) {
 863                         mark_parents_uninteresting(commit);
 864                         if (revs->show_all)
 865                                 p = &commit_list_insert(commit, p)->next;
 866                         slop = still_interesting(list, date, slop);
 867                         if (slop)
 868                                 continue;
 869                         /* If showing all, add the whole pending list to the end */
 870                         if (revs->show_all)
 871                                 *p = list;
 872                         break;
 873                 }
 874                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 875                         continue;
 876                 date = commit->date;
 877                 p = &commit_list_insert(commit, p)->next;
 878
 879                 show = show_early_output;
 880                 if (!show)
 881                         continue;
 882
 883                 show(revs, newlist);
 884                 show_early_output = NULL;
 885         }
 886         if (revs->cherry_pick || revs->cherry_mark)
 887                 cherry_pick_list(newlist, revs);
 888
 889         if (revs->left_only || revs->right_only)
 890                 limit_left_right(newlist, revs);
 891
 892         if (bottom) {
 893                 limit_to_ancestry(bottom, newlist);
 894                 free_commit_list(bottom);
 895         }
 896
 897         revs->commits = newlist;
 898         return 0;
 899 }
 900
 901 static void add_rev_cmdline(struct rev_info *revs,
 902                             struct object *item,
 903                             const char *name,
 904                             int whence,
 905                             unsigned flags)
 906 {
 907         struct rev_cmdline_info *info = &revs->cmdline;
 908         int nr = info->nr;
 909
 910         ALLOC_GROW(info->rev, nr + 1, info->alloc);
 911         info->rev[nr].item = item;
 912         info->rev[nr].name = name;
 913         info->rev[nr].whence = whence;
 914         info->rev[nr].flags = flags;
 915         info->nr++;
 916 }
 917
 918 struct all_refs_cb {
 919         int all_flags;
 920         int warned_bad_reflog;
 921         struct rev_info *all_revs;
 922         const char *name_for_errormsg;
 923 };
 924
 925 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 926 {
 927         struct all_refs_cb *cb = cb_data;
 928         struct object *object = get_reference(cb->all_revs, path, sha1,
 929                                               cb->all_flags);
 930         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
 931         add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
 932         return 0;
 933 }
 934
 935 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 936         unsigned flags)
 937 {
 938         cb->all_revs = revs;
 939         cb->all_flags = flags;
 940 }
 941
 942 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
 943                 int (*for_each)(const char *, each_ref_fn, void *))
 944 {
 945         struct all_refs_cb cb;
 946         init_all_refs_cb(&cb, revs, flags);
 947         for_each(submodule, handle_one_ref, &cb);
 948 }
 949
 950 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 951 {
 952         struct all_refs_cb *cb = cb_data;
 953         if (!is_null_sha1(sha1)) {
 954                 struct object *o = parse_object(sha1);
 955                 if (o) {
 956                         o->flags |= cb->all_flags;
 957                         /* ??? CMDLINEFLAGS ??? */
 958                         add_pending_object(cb->all_revs, o, "");
 959                 }
 960                 else if (!cb->warned_bad_reflog) {
 961                         warning("reflog of '%s' references pruned commits",
 962                                 cb->name_for_errormsg);
 963                         cb->warned_bad_reflog = 1;
 964                 }
 965         }
 966 }
 967
 968 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 969                 const char *email, unsigned long timestamp, int tz,
 970                 const char *message, void *cb_data)
 971 {
 972         handle_one_reflog_commit(osha1, cb_data);
 973         handle_one_reflog_commit(nsha1, cb_data);
 974         return 0;
 975 }
 976
 977 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 978 {
 979         struct all_refs_cb *cb = cb_data;
 980         cb->warned_bad_reflog = 0;
 981         cb->name_for_errormsg = path;
 982         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 983         return 0;
 984 }
 985
 986 static void handle_reflog(struct rev_info *revs, unsigned flags)
 987 {
 988         struct all_refs_cb cb;
 989         cb.all_revs = revs;
 990         cb.all_flags = flags;
 991         for_each_reflog(handle_one_reflog, &cb);
 992 }
 993
 994 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
 995 {
 996         unsigned char sha1[20];
 997         struct object *it;
 998         struct commit *commit;
 999         struct commit_list *parents;
1000         const char *arg = arg_;
1001
1002         if (*arg == '^') {
1003                 flags ^= UNINTERESTING;
1004                 arg++;
1005         }
1006         if (get_sha1_committish(arg, sha1))
1007                 return 0;
1008         while (1) {
1009                 it = get_reference(revs, arg, sha1, 0);
1010                 if (!it && revs->ignore_missing)
1011                         return 0;
1012                 if (it->type != OBJ_TAG)
1013                         break;
1014                 if (!((struct tag*)it)->tagged)
1015                         return 0;
1016                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1017         }
1018         if (it->type != OBJ_COMMIT)
1019                 return 0;
1020         commit = (struct commit *)it;
1021         for (parents = commit->parents; parents; parents = parents->next) {
1022                 it = &parents->item->object;
1023                 it->flags |= flags;
1024                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1025                 add_pending_object(revs, it, arg);
1026         }
1027         return 1;
1028 }
1029
1030 void init_revisions(struct rev_info *revs, const char *prefix)
1031 {
1032         memset(revs, 0, sizeof(*revs));
1033
1034         revs->abbrev = DEFAULT_ABBREV;
1035         revs->ignore_merges = 1;
1036         revs->simplify_history = 1;
1037         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1038         DIFF_OPT_SET(&revs->pruning, QUICK);
1039         revs->pruning.add_remove = file_add_remove;
1040         revs->pruning.change = file_change;
1041         revs->lifo = 1;
1042         revs->dense = 1;
1043         revs->prefix = prefix;
1044         revs->max_age = -1;
1045         revs->min_age = -1;
1046         revs->skip_count = -1;
1047         revs->max_count = -1;
1048         revs->max_parents = -1;
1049
1050         revs->commit_format = CMIT_FMT_DEFAULT;
1051
1052         init_grep_defaults();
1053         grep_init(&revs->grep_filter, prefix);
1054         revs->grep_filter.status_only = 1;
1055         revs->grep_filter.regflags = REG_NEWLINE;
1056
1057         diff_setup(&revs->diffopt);
1058         if (prefix && !revs->diffopt.prefix) {
1059                 revs->diffopt.prefix = prefix;
1060                 revs->diffopt.prefix_length = strlen(prefix);
1061         }
1062
1063         revs->notes_opt.use_default_notes = -1;
1064 }
1065
1066 static void add_pending_commit_list(struct rev_info *revs,
1067                                     struct commit_list *commit_list,
1068                                     unsigned int flags)
1069 {
1070         while (commit_list) {
1071                 struct object *object = &commit_list->item->object;
1072                 object->flags |= flags;
1073                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
1074                 commit_list = commit_list->next;
1075         }
1076 }
1077
1078 static void prepare_show_merge(struct rev_info *revs)
1079 {
1080         struct commit_list *bases;
1081         struct commit *head, *other;
1082         unsigned char sha1[20];
1083         const char **prune = NULL;
1084         int i, prune_num = 1; /* counting terminating NULL */
1085
1086         if (get_sha1("HEAD", sha1))
1087                 die("--merge without HEAD?");
1088         head = lookup_commit_or_die(sha1, "HEAD");
1089         if (get_sha1("MERGE_HEAD", sha1))
1090                 die("--merge without MERGE_HEAD?");
1091         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1092         add_pending_object(revs, &head->object, "HEAD");
1093         add_pending_object(revs, &other->object, "MERGE_HEAD");
1094         bases = get_merge_bases(head, other, 1);
1095         add_pending_commit_list(revs, bases, UNINTERESTING);
1096         free_commit_list(bases);
1097         head->object.flags |= SYMMETRIC_LEFT;
1098
1099         if (!active_nr)
1100                 read_cache();
1101         for (i = 0; i < active_nr; i++) {
1102                 struct cache_entry *ce = active_cache[i];
1103                 if (!ce_stage(ce))
1104                         continue;
1105                 if (ce_path_match(ce, &revs->prune_data)) {
1106                         prune_num++;
1107                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
1108                         prune[prune_num-2] = ce->name;
1109                         prune[prune_num-1] = NULL;
1110                 }
1111                 while ((i+1 < active_nr) &&
1112                        ce_same_name(ce, active_cache[i+1]))
1113                         i++;
1114         }
1115         free_pathspec(&revs->prune_data);
1116         init_pathspec(&revs->prune_data, prune);
1117         revs->limited = 1;
1118 }
1119
1120 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1121 {
1122         struct object_context oc;
1123         char *dotdot;
1124         struct object *object;
1125         unsigned char sha1[20];
1126         int local_flags;
1127         const char *arg = arg_;
1128         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1129         unsigned get_sha1_flags = 0;
1130
1131         dotdot = strstr(arg, "..");
1132         if (dotdot) {
1133                 unsigned char from_sha1[20];
1134                 const char *next = dotdot + 2;
1135                 const char *this = arg;
1136                 int symmetric = *next == '.';
1137                 unsigned int flags_exclude = flags ^ UNINTERESTING;
1138                 static const char head_by_default[] = "HEAD";
1139                 unsigned int a_flags;
1140
1141                 *dotdot = 0;
1142                 next += symmetric;
1143
1144                 if (!*next)
1145                         next = head_by_default;
1146                 if (dotdot == arg)
1147                         this = head_by_default;
1148                 if (this == head_by_default && next == head_by_default &&
1149                     !symmetric) {
1150                         /*
1151                          * Just ".."?  That is not a range but the
1152                          * pathspec for the parent directory.
1153                          */
1154                         if (!cant_be_filename) {
1155                                 *dotdot = '.';
1156                                 return -1;
1157                         }
1158                 }
1159                 if (!get_sha1_committish(this, from_sha1) &&
1160                     !get_sha1_committish(next, sha1)) {
1161                         struct commit *a, *b;
1162                         struct commit_list *exclude;
1163
1164                         a = lookup_commit_reference(from_sha1);
1165                         b = lookup_commit_reference(sha1);
1166                         if (!a || !b) {
1167                                 if (revs->ignore_missing)
1168                                         return 0;
1169                                 die(symmetric ?
1170                                     "Invalid symmetric difference expression %s...%s" :
1171                                     "Invalid revision range %s..%s",
1172                                     arg, next);
1173                         }
1174
1175                         if (!cant_be_filename) {
1176                                 *dotdot = '.';
1177                                 verify_non_filename(revs->prefix, arg);
1178                         }
1179
1180                         if (symmetric) {
1181                                 exclude = get_merge_bases(a, b, 1);
1182                                 add_pending_commit_list(revs, exclude,
1183                                                         flags_exclude);
1184                                 free_commit_list(exclude);
1185                                 a_flags = flags | SYMMETRIC_LEFT;
1186                         } else
1187                                 a_flags = flags_exclude;
1188                         a->object.flags |= a_flags;
1189                         b->object.flags |= flags;
1190                         add_rev_cmdline(revs, &a->object, this,
1191                                         REV_CMD_LEFT, a_flags);
1192                         add_rev_cmdline(revs, &b->object, next,
1193                                         REV_CMD_RIGHT, flags);
1194                         add_pending_object(revs, &a->object, this);
1195                         add_pending_object(revs, &b->object, next);
1196                         return 0;
1197                 }
1198                 *dotdot = '.';
1199         }
1200         dotdot = strstr(arg, "^@");
1201         if (dotdot && !dotdot[2]) {
1202                 *dotdot = 0;
1203                 if (add_parents_only(revs, arg, flags))
1204                         return 0;
1205                 *dotdot = '^';
1206         }
1207         dotdot = strstr(arg, "^!");
1208         if (dotdot && !dotdot[2]) {
1209                 *dotdot = 0;
1210                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1211                         *dotdot = '^';
1212         }
1213
1214         local_flags = 0;
1215         if (*arg == '^') {
1216                 local_flags = UNINTERESTING;
1217                 arg++;
1218         }
1219
1220         if (revarg_opt & REVARG_COMMITTISH)
1221                 get_sha1_flags = GET_SHA1_COMMITTISH;
1222
1223         if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1224                 return revs->ignore_missing ? 0 : -1;
1225         if (!cant_be_filename)
1226                 verify_non_filename(revs->prefix, arg);
1227         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1228         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1229         add_pending_object_with_mode(revs, object, arg, oc.mode);
1230         return 0;
1231 }
1232
1233 struct cmdline_pathspec {
1234         int alloc;
1235         int nr;
1236         const char **path;
1237 };
1238
1239 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1240 {
1241         while (*av) {
1242                 ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1243                 prune->path[prune->nr++] = *(av++);
1244         }
1245 }
1246
1247 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1248                                      struct cmdline_pathspec *prune)
1249 {
1250         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1251                 int len = sb->len;
1252                 if (len && sb->buf[len - 1] == '\n')
1253                         sb->buf[--len] = '\0';
1254                 ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1255                 prune->path[prune->nr++] = xstrdup(sb->buf);
1256         }
1257 }
1258
1259 static void read_revisions_from_stdin(struct rev_info *revs,
1260                                       struct cmdline_pathspec *prune)
1261 {
1262         struct strbuf sb;
1263         int seen_dashdash = 0;
1264
1265         strbuf_init(&sb, 1000);
1266         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1267                 int len = sb.len;
1268                 if (len && sb.buf[len - 1] == '\n')
1269                         sb.buf[--len] = '\0';
1270                 if (!len)
1271                         break;
1272                 if (sb.buf[0] == '-') {
1273                         if (len == 2 && sb.buf[1] == '-') {
1274                                 seen_dashdash = 1;
1275                                 break;
1276                         }
1277                         die("options not supported in --stdin mode");
1278                 }
1279                 if (handle_revision_arg(sb.buf, revs, 0, REVARG_CANNOT_BE_FILENAME))
1280                         die("bad revision '%s'", sb.buf);
1281         }
1282         if (seen_dashdash)
1283                 read_pathspec_from_stdin(revs, &sb, prune);
1284         strbuf_release(&sb);
1285 }
1286
1287 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1288 {
1289         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1290 }
1291
1292 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1293 {
1294         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1295 }
1296
1297 static void add_message_grep(struct rev_info *revs, const char *pattern)
1298 {
1299         add_grep(revs, pattern, GREP_PATTERN_BODY);
1300 }
1301
1302 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1303                                int *unkc, const char **unkv)
1304 {
1305         const char *arg = argv[0];
1306         const char *optarg;
1307         int argcount;
1308
1309         /* pseudo revision arguments */
1310         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1311             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1312             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1313             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1314             !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1315             !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1316             !prefixcmp(arg, "--remotes=") || !prefixcmp(arg, "--no-walk="))
1317         {
1318                 unkv[(*unkc)++] = arg;
1319                 return 1;
1320         }
1321
1322         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1323                 revs->max_count = atoi(optarg);
1324                 revs->no_walk = 0;
1325                 return argcount;
1326         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1327                 revs->skip_count = atoi(optarg);
1328                 return argcount;
1329         } else if ((*arg == '-') && isdigit(arg[1])) {
1330         /* accept -<digit>, like traditional "head" */
1331                 revs->max_count = atoi(arg + 1);
1332                 revs->no_walk = 0;
1333         } else if (!strcmp(arg, "-n")) {
1334                 if (argc <= 1)
1335                         return error("-n requires an argument");
1336                 revs->max_count = atoi(argv[1]);
1337                 revs->no_walk = 0;
1338                 return 2;
1339         } else if (!prefixcmp(arg, "-n")) {
1340                 revs->max_count = atoi(arg + 2);
1341                 revs->no_walk = 0;
1342         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1343                 revs->max_age = atoi(optarg);
1344                 return argcount;
1345         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1346                 revs->max_age = approxidate(optarg);
1347                 return argcount;
1348         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1349                 revs->max_age = approxidate(optarg);
1350                 return argcount;
1351         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1352                 revs->min_age = atoi(optarg);
1353                 return argcount;
1354         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1355                 revs->min_age = approxidate(optarg);
1356                 return argcount;
1357         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1358                 revs->min_age = approxidate(optarg);
1359                 return argcount;
1360         } else if (!strcmp(arg, "--first-parent")) {
1361                 revs->first_parent_only = 1;
1362         } else if (!strcmp(arg, "--ancestry-path")) {
1363                 revs->ancestry_path = 1;
1364                 revs->simplify_history = 0;
1365                 revs->limited = 1;
1366         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1367                 init_reflog_walk(&revs->reflog_info);
1368         } else if (!strcmp(arg, "--default")) {
1369                 if (argc <= 1)
1370                         return error("bad --default argument");
1371                 revs->def = argv[1];
1372                 return 2;
1373         } else if (!strcmp(arg, "--merge")) {
1374                 revs->show_merge = 1;
1375         } else if (!strcmp(arg, "--topo-order")) {
1376                 revs->lifo = 1;
1377                 revs->topo_order = 1;
1378         } else if (!strcmp(arg, "--simplify-merges")) {
1379                 revs->simplify_merges = 1;
1380                 revs->topo_order = 1;
1381                 revs->rewrite_parents = 1;
1382                 revs->simplify_history = 0;
1383                 revs->limited = 1;
1384         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1385                 revs->simplify_merges = 1;
1386                 revs->topo_order = 1;
1387                 revs->rewrite_parents = 1;
1388                 revs->simplify_history = 0;
1389                 revs->simplify_by_decoration = 1;
1390                 revs->limited = 1;
1391                 revs->prune = 1;
1392                 load_ref_decorations(DECORATE_SHORT_REFS);
1393         } else if (!strcmp(arg, "--date-order")) {
1394                 revs->lifo = 0;
1395                 revs->topo_order = 1;
1396         } else if (!prefixcmp(arg, "--early-output")) {
1397                 int count = 100;
1398                 switch (arg[14]) {
1399                 case '=':
1400                         count = atoi(arg+15);
1401                         /* Fallthrough */
1402                 case 0:
1403                         revs->topo_order = 1;
1404                        revs->early_output = count;
1405                 }
1406         } else if (!strcmp(arg, "--parents")) {
1407                 revs->rewrite_parents = 1;
1408                 revs->print_parents = 1;
1409         } else if (!strcmp(arg, "--dense")) {
1410                 revs->dense = 1;
1411         } else if (!strcmp(arg, "--sparse")) {
1412                 revs->dense = 0;
1413         } else if (!strcmp(arg, "--show-all")) {
1414                 revs->show_all = 1;
1415         } else if (!strcmp(arg, "--remove-empty")) {
1416                 revs->remove_empty_trees = 1;
1417         } else if (!strcmp(arg, "--merges")) {
1418                 revs->min_parents = 2;
1419         } else if (!strcmp(arg, "--no-merges")) {
1420                 revs->max_parents = 1;
1421         } else if (!prefixcmp(arg, "--min-parents=")) {
1422                 revs->min_parents = atoi(arg+14);
1423         } else if (!prefixcmp(arg, "--no-min-parents")) {
1424                 revs->min_parents = 0;
1425         } else if (!prefixcmp(arg, "--max-parents=")) {
1426                 revs->max_parents = atoi(arg+14);
1427         } else if (!prefixcmp(arg, "--no-max-parents")) {
1428                 revs->max_parents = -1;
1429         } else if (!strcmp(arg, "--boundary")) {
1430                 revs->boundary = 1;
1431         } else if (!strcmp(arg, "--left-right")) {
1432                 revs->left_right = 1;
1433         } else if (!strcmp(arg, "--left-only")) {
1434                 if (revs->right_only)
1435                         die("--left-only is incompatible with --right-only"
1436                             " or --cherry");
1437                 revs->left_only = 1;
1438         } else if (!strcmp(arg, "--right-only")) {
1439                 if (revs->left_only)
1440                         die("--right-only is incompatible with --left-only");
1441                 revs->right_only = 1;
1442         } else if (!strcmp(arg, "--cherry")) {
1443                 if (revs->left_only)
1444                         die("--cherry is incompatible with --left-only");
1445                 revs->cherry_mark = 1;
1446                 revs->right_only = 1;
1447                 revs->max_parents = 1;
1448                 revs->limited = 1;
1449         } else if (!strcmp(arg, "--count")) {
1450                 revs->count = 1;
1451         } else if (!strcmp(arg, "--cherry-mark")) {
1452                 if (revs->cherry_pick)
1453                         die("--cherry-mark is incompatible with --cherry-pick");
1454                 revs->cherry_mark = 1;
1455                 revs->limited = 1; /* needs limit_list() */
1456         } else if (!strcmp(arg, "--cherry-pick")) {
1457                 if (revs->cherry_mark)
1458                         die("--cherry-pick is incompatible with --cherry-mark");
1459                 revs->cherry_pick = 1;
1460                 revs->limited = 1;
1461         } else if (!strcmp(arg, "--objects")) {
1462                 revs->tag_objects = 1;
1463                 revs->tree_objects = 1;
1464                 revs->blob_objects = 1;
1465         } else if (!strcmp(arg, "--objects-edge")) {
1466                 revs->tag_objects = 1;
1467                 revs->tree_objects = 1;
1468                 revs->blob_objects = 1;
1469                 revs->edge_hint = 1;
1470         } else if (!strcmp(arg, "--verify-objects")) {
1471                 revs->tag_objects = 1;
1472                 revs->tree_objects = 1;
1473                 revs->blob_objects = 1;
1474                 revs->verify_objects = 1;
1475         } else if (!strcmp(arg, "--unpacked")) {
1476                 revs->unpacked = 1;
1477         } else if (!prefixcmp(arg, "--unpacked=")) {
1478                 die("--unpacked=<packfile> no longer supported.");
1479         } else if (!strcmp(arg, "-r")) {
1480                 revs->diff = 1;
1481                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1482         } else if (!strcmp(arg, "-t")) {
1483                 revs->diff = 1;
1484                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1485                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1486         } else if (!strcmp(arg, "-m")) {
1487                 revs->ignore_merges = 0;
1488         } else if (!strcmp(arg, "-c")) {
1489                 revs->diff = 1;
1490                 revs->dense_combined_merges = 0;
1491                 revs->combine_merges = 1;
1492         } else if (!strcmp(arg, "--cc")) {
1493                 revs->diff = 1;
1494                 revs->dense_combined_merges = 1;
1495                 revs->combine_merges = 1;
1496         } else if (!strcmp(arg, "-v")) {
1497                 revs->verbose_header = 1;
1498         } else if (!strcmp(arg, "--pretty")) {
1499                 revs->verbose_header = 1;
1500                 revs->pretty_given = 1;
1501                 get_commit_format(arg+8, revs);
1502         } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1503                 /*
1504                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1505                  * not allowed, since the argument is optional.
1506                  */
1507                 revs->verbose_header = 1;
1508                 revs->pretty_given = 1;
1509                 get_commit_format(arg+9, revs);
1510         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1511                 revs->show_notes = 1;
1512                 revs->show_notes_given = 1;
1513                 revs->notes_opt.use_default_notes = 1;
1514         } else if (!strcmp(arg, "--show-signature")) {
1515                 revs->show_signature = 1;
1516         } else if (!prefixcmp(arg, "--show-notes=") ||
1517                    !prefixcmp(arg, "--notes=")) {
1518                 struct strbuf buf = STRBUF_INIT;
1519                 revs->show_notes = 1;
1520                 revs->show_notes_given = 1;
1521                 if (!prefixcmp(arg, "--show-notes")) {
1522                         if (revs->notes_opt.use_default_notes < 0)
1523                                 revs->notes_opt.use_default_notes = 1;
1524                         strbuf_addstr(&buf, arg+13);
1525                 }
1526                 else
1527                         strbuf_addstr(&buf, arg+8);
1528                 expand_notes_ref(&buf);
1529                 string_list_append(&revs->notes_opt.extra_notes_refs,
1530                                    strbuf_detach(&buf, NULL));
1531         } else if (!strcmp(arg, "--no-notes")) {
1532                 revs->show_notes = 0;
1533                 revs->show_notes_given = 1;
1534                 revs->notes_opt.use_default_notes = -1;
1535                 /* we have been strdup'ing ourselves, so trick
1536                  * string_list into free()ing strings */
1537                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1538                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1539                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1540         } else if (!strcmp(arg, "--standard-notes")) {
1541                 revs->show_notes_given = 1;
1542                 revs->notes_opt.use_default_notes = 1;
1543         } else if (!strcmp(arg, "--no-standard-notes")) {
1544                 revs->notes_opt.use_default_notes = 0;
1545         } else if (!strcmp(arg, "--oneline")) {
1546                 revs->verbose_header = 1;
1547                 get_commit_format("oneline", revs);
1548                 revs->pretty_given = 1;
1549                 revs->abbrev_commit = 1;
1550         } else if (!strcmp(arg, "--graph")) {
1551                 revs->topo_order = 1;
1552                 revs->rewrite_parents = 1;
1553                 revs->graph = graph_init(revs);
1554         } else if (!strcmp(arg, "--root")) {
1555                 revs->show_root_diff = 1;
1556         } else if (!strcmp(arg, "--no-commit-id")) {
1557                 revs->no_commit_id = 1;
1558         } else if (!strcmp(arg, "--always")) {
1559                 revs->always_show_header = 1;
1560         } else if (!strcmp(arg, "--no-abbrev")) {
1561                 revs->abbrev = 0;
1562         } else if (!strcmp(arg, "--abbrev")) {
1563                 revs->abbrev = DEFAULT_ABBREV;
1564         } else if (!prefixcmp(arg, "--abbrev=")) {
1565                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1566                 if (revs->abbrev < MINIMUM_ABBREV)
1567                         revs->abbrev = MINIMUM_ABBREV;
1568                 else if (revs->abbrev > 40)
1569                         revs->abbrev = 40;
1570         } else if (!strcmp(arg, "--abbrev-commit")) {
1571                 revs->abbrev_commit = 1;
1572                 revs->abbrev_commit_given = 1;
1573         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1574                 revs->abbrev_commit = 0;
1575         } else if (!strcmp(arg, "--full-diff")) {
1576                 revs->diff = 1;
1577                 revs->full_diff = 1;
1578         } else if (!strcmp(arg, "--full-history")) {
1579                 revs->simplify_history = 0;
1580         } else if (!strcmp(arg, "--relative-date")) {
1581                 revs->date_mode = DATE_RELATIVE;
1582                 revs->date_mode_explicit = 1;
1583         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1584                 revs->date_mode = parse_date_format(optarg);
1585                 revs->date_mode_explicit = 1;
1586                 return argcount;
1587         } else if (!strcmp(arg, "--log-size")) {
1588                 revs->show_log_size = 1;
1589         }
1590         /*
1591          * Grepping the commit log
1592          */
1593         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1594                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1595                 return argcount;
1596         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1597                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1598                 return argcount;
1599         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
1600                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
1601                 return argcount;
1602         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1603                 add_message_grep(revs, optarg);
1604                 return argcount;
1605         } else if (!strcmp(arg, "--grep-debug")) {
1606                 revs->grep_filter.debug = 1;
1607         } else if (!strcmp(arg, "--basic-regexp")) {
1608                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
1609         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1610                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
1611         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1612                 revs->grep_filter.regflags |= REG_ICASE;
1613                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1614         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1615                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
1616         } else if (!strcmp(arg, "--perl-regexp")) {
1617                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
1618         } else if (!strcmp(arg, "--all-match")) {
1619                 revs->grep_filter.all_match = 1;
1620         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1621                 if (strcmp(optarg, "none"))
1622                         git_log_output_encoding = xstrdup(optarg);
1623                 else
1624                         git_log_output_encoding = "";
1625                 return argcount;
1626         } else if (!strcmp(arg, "--reverse")) {
1627                 revs->reverse ^= 1;
1628         } else if (!strcmp(arg, "--children")) {
1629                 revs->children.name = "children";
1630                 revs->limited = 1;
1631         } else if (!strcmp(arg, "--ignore-missing")) {
1632                 revs->ignore_missing = 1;
1633         } else {
1634                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1635                 if (!opts)
1636                         unkv[(*unkc)++] = arg;
1637                 return opts;
1638         }
1639
1640         return 1;
1641 }
1642
1643 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1644                         const struct option *options,
1645                         const char * const usagestr[])
1646 {
1647         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1648                                     &ctx->cpidx, ctx->out);
1649         if (n <= 0) {
1650                 error("unknown option `%s'", ctx->argv[0]);
1651                 usage_with_options(usagestr, options);
1652         }
1653         ctx->argv += n;
1654         ctx->argc -= n;
1655 }
1656
1657 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1658 {
1659         return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1660 }
1661
1662 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1663 {
1664         return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1665 }
1666
1667 static int handle_revision_pseudo_opt(const char *submodule,
1668                                 struct rev_info *revs,
1669                                 int argc, const char **argv, int *flags)
1670 {
1671         const char *arg = argv[0];
1672         const char *optarg;
1673         int argcount;
1674
1675         /*
1676          * NOTE!
1677          *
1678          * Commands like "git shortlog" will not accept the options below
1679          * unless parse_revision_opt queues them (as opposed to erroring
1680          * out).
1681          *
1682          * When implementing your new pseudo-option, remember to
1683          * register it in the list at the top of handle_revision_opt.
1684          */
1685         if (!strcmp(arg, "--all")) {
1686                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1687                 handle_refs(submodule, revs, *flags, head_ref_submodule);
1688         } else if (!strcmp(arg, "--branches")) {
1689                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1690         } else if (!strcmp(arg, "--bisect")) {
1691                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1692                 handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
1693                 revs->bisect = 1;
1694         } else if (!strcmp(arg, "--tags")) {
1695                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1696         } else if (!strcmp(arg, "--remotes")) {
1697                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1698         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1699                 struct all_refs_cb cb;
1700                 init_all_refs_cb(&cb, revs, *flags);
1701                 for_each_glob_ref(handle_one_ref, optarg, &cb);
1702                 return argcount;
1703         } else if (!prefixcmp(arg, "--branches=")) {
1704                 struct all_refs_cb cb;
1705                 init_all_refs_cb(&cb, revs, *flags);
1706                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1707         } else if (!prefixcmp(arg, "--tags=")) {
1708                 struct all_refs_cb cb;
1709                 init_all_refs_cb(&cb, revs, *flags);
1710                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1711         } else if (!prefixcmp(arg, "--remotes=")) {
1712                 struct all_refs_cb cb;
1713                 init_all_refs_cb(&cb, revs, *flags);
1714                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1715         } else if (!strcmp(arg, "--reflog")) {
1716                 handle_reflog(revs, *flags);
1717         } else if (!strcmp(arg, "--not")) {
1718                 *flags ^= UNINTERESTING;
1719         } else if (!strcmp(arg, "--no-walk")) {
1720                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
1721         } else if (!prefixcmp(arg, "--no-walk=")) {
1722                 /*
1723                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
1724                  * not allowed, since the argument is optional.
1725                  */
1726                 if (!strcmp(arg + 10, "sorted"))
1727                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
1728                 else if (!strcmp(arg + 10, "unsorted"))
1729                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
1730                 else
1731                         return error("invalid argument to --no-walk");
1732         } else if (!strcmp(arg, "--do-walk")) {
1733                 revs->no_walk = 0;
1734         } else {
1735                 return 0;
1736         }
1737
1738         return 1;
1739 }
1740
1741 /*
1742  * Parse revision information, filling in the "rev_info" structure,
1743  * and removing the used arguments from the argument list.
1744  *
1745  * Returns the number of arguments left that weren't recognized
1746  * (which are also moved to the head of the argument list)
1747  */
1748 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1749 {
1750         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
1751         struct cmdline_pathspec prune_data;
1752         const char *submodule = NULL;
1753
1754         memset(&prune_data, 0, sizeof(prune_data));
1755         if (opt)
1756                 submodule = opt->submodule;
1757
1758         /* First, search for "--" */
1759         if (opt && opt->assume_dashdash) {
1760                 seen_dashdash = 1;
1761         } else {
1762                 seen_dashdash = 0;
1763                 for (i = 1; i < argc; i++) {
1764                         const char *arg = argv[i];
1765                         if (strcmp(arg, "--"))
1766                                 continue;
1767                         argv[i] = NULL;
1768                         argc = i;
1769                         if (argv[i + 1])
1770                                 append_prune_data(&prune_data, argv + i + 1);
1771                         seen_dashdash = 1;
1772                         break;
1773                 }
1774         }
1775
1776         /* Second, deal with arguments and options */
1777         flags = 0;
1778         revarg_opt = opt ? opt->revarg_opt : 0;
1779         if (seen_dashdash)
1780                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
1781         read_from_stdin = 0;
1782         for (left = i = 1; i < argc; i++) {
1783                 const char *arg = argv[i];
1784                 if (*arg == '-') {
1785                         int opts;
1786
1787                         opts = handle_revision_pseudo_opt(submodule,
1788                                                 revs, argc - i, argv + i,
1789                                                 &flags);
1790                         if (opts > 0) {
1791                                 i += opts - 1;
1792                                 continue;
1793                         }
1794
1795                         if (!strcmp(arg, "--stdin")) {
1796                                 if (revs->disable_stdin) {
1797                                         argv[left++] = arg;
1798                                         continue;
1799                                 }
1800                                 if (read_from_stdin++)
1801                                         die("--stdin given twice?");
1802                                 read_revisions_from_stdin(revs, &prune_data);
1803                                 continue;
1804                         }
1805
1806                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1807                         if (opts > 0) {
1808                                 i += opts - 1;
1809                                 continue;
1810                         }
1811                         if (opts < 0)
1812                                 exit(128);
1813                         continue;
1814                 }
1815
1816
1817                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
1818                         int j;
1819                         if (seen_dashdash || *arg == '^')
1820                                 die("bad revision '%s'", arg);
1821
1822                         /* If we didn't have a "--":
1823                          * (1) all filenames must exist;
1824                          * (2) all rev-args must not be interpretable
1825                          *     as a valid filename.
1826                          * but the latter we have checked in the main loop.
1827                          */
1828                         for (j = i; j < argc; j++)
1829                                 verify_filename(revs->prefix, argv[j], j == i);
1830
1831                         append_prune_data(&prune_data, argv + i);
1832                         break;
1833                 }
1834                 else
1835                         got_rev_arg = 1;
1836         }
1837
1838         if (prune_data.nr) {
1839                 /*
1840                  * If we need to introduce the magic "a lone ':' means no
1841                  * pathspec whatsoever", here is the place to do so.
1842                  *
1843                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1844                  *      prune_data.nr = 0;
1845                  *      prune_data.alloc = 0;
1846                  *      free(prune_data.path);
1847                  *      prune_data.path = NULL;
1848                  * } else {
1849                  *      terminate prune_data.alloc with NULL and
1850                  *      call init_pathspec() to set revs->prune_data here.
1851                  * }
1852                  */
1853                 ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1854                 prune_data.path[prune_data.nr++] = NULL;
1855                 init_pathspec(&revs->prune_data,
1856                               get_pathspec(revs->prefix, prune_data.path));
1857         }
1858
1859         if (revs->def == NULL)
1860                 revs->def = opt ? opt->def : NULL;
1861         if (opt && opt->tweak)
1862                 opt->tweak(revs, opt);
1863         if (revs->show_merge)
1864                 prepare_show_merge(revs);
1865         if (revs->def && !revs->pending.nr && !got_rev_arg) {
1866                 unsigned char sha1[20];
1867                 struct object *object;
1868                 struct object_context oc;
1869                 if (get_sha1_with_context(revs->def, 0, sha1, &oc))
1870                         die("bad default revision '%s'", revs->def);
1871                 object = get_reference(revs, revs->def, sha1, 0);
1872                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
1873         }
1874
1875         /* Did the user ask for any diff output? Run the diff! */
1876         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1877                 revs->diff = 1;
1878
1879         /* Pickaxe, diff-filter and rename following need diffs */
1880         if (revs->diffopt.pickaxe ||
1881             revs->diffopt.filter ||
1882             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1883                 revs->diff = 1;
1884
1885         if (revs->topo_order)
1886                 revs->limited = 1;
1887
1888         if (revs->prune_data.nr) {
1889                 diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1890                 /* Can't prune commits with rename following: the paths change.. */
1891                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1892                         revs->prune = 1;
1893                 if (!revs->full_diff)
1894                         diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1895         }
1896         if (revs->combine_merges)
1897                 revs->ignore_merges = 0;
1898         revs->diffopt.abbrev = revs->abbrev;
1899         diff_setup_done(&revs->diffopt);
1900
1901         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
1902                                  &revs->grep_filter);
1903         compile_grep_patterns(&revs->grep_filter);
1904
1905         if (revs->reverse && revs->reflog_info)
1906                 die("cannot combine --reverse with --walk-reflogs");
1907         if (revs->rewrite_parents && revs->children.name)
1908                 die("cannot combine --parents and --children");
1909
1910         /*
1911          * Limitations on the graph functionality
1912          */
1913         if (revs->reverse && revs->graph)
1914                 die("cannot combine --reverse with --graph");
1915
1916         if (revs->reflog_info && revs->graph)
1917                 die("cannot combine --walk-reflogs with --graph");
1918         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
1919                 die("cannot use --grep-reflog without --walk-reflogs");
1920
1921         return left;
1922 }
1923
1924 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1925 {
1926         struct commit_list *l = xcalloc(1, sizeof(*l));
1927
1928         l->item = child;
1929         l->next = add_decoration(&revs->children, &parent->object, l);
1930 }
1931
1932 static int remove_duplicate_parents(struct commit *commit)
1933 {
1934         struct commit_list **pp, *p;
1935         int surviving_parents;
1936
1937         /* Examine existing parents while marking ones we have seen... */
1938         pp = &commit->parents;
1939         while ((p = *pp) != NULL) {
1940                 struct commit *parent = p->item;
1941                 if (parent->object.flags & TMP_MARK) {
1942                         *pp = p->next;
1943                         continue;
1944                 }
1945                 parent->object.flags |= TMP_MARK;
1946                 pp = &p->next;
1947         }
1948         /* count them while clearing the temporary mark */
1949         surviving_parents = 0;
1950         for (p = commit->parents; p; p = p->next) {
1951                 p->item->object.flags &= ~TMP_MARK;
1952                 surviving_parents++;
1953         }
1954         return surviving_parents;
1955 }
1956
1957 struct merge_simplify_state {
1958         struct commit *simplified;
1959 };
1960
1961 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1962 {
1963         struct merge_simplify_state *st;
1964
1965         st = lookup_decoration(&revs->merge_simplification, &commit->object);
1966         if (!st) {
1967                 st = xcalloc(1, sizeof(*st));
1968                 add_decoration(&revs->merge_simplification, &commit->object, st);
1969         }
1970         return st;
1971 }
1972
1973 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1974 {
1975         struct commit_list *p;
1976         struct merge_simplify_state *st, *pst;
1977         int cnt;
1978
1979         st = locate_simplify_state(revs, commit);
1980
1981         /*
1982          * Have we handled this one?
1983          */
1984         if (st->simplified)
1985                 return tail;
1986
1987         /*
1988          * An UNINTERESTING commit simplifies to itself, so does a
1989          * root commit.  We do not rewrite parents of such commit
1990          * anyway.
1991          */
1992         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1993                 st->simplified = commit;
1994                 return tail;
1995         }
1996
1997         /*
1998          * Do we know what commit all of our parents that matter
1999          * should be rewritten to?  Otherwise we are not ready to
2000          * rewrite this one yet.
2001          */
2002         for (cnt = 0, p = commit->parents; p; p = p->next) {
2003                 pst = locate_simplify_state(revs, p->item);
2004                 if (!pst->simplified) {
2005                         tail = &commit_list_insert(p->item, tail)->next;
2006                         cnt++;
2007                 }
2008                 if (revs->first_parent_only)
2009                         break;
2010         }
2011         if (cnt) {
2012                 tail = &commit_list_insert(commit, tail)->next;
2013                 return tail;
2014         }
2015
2016         /*
2017          * Rewrite our list of parents.
2018          */
2019         for (p = commit->parents; p; p = p->next) {
2020                 pst = locate_simplify_state(revs, p->item);
2021                 p->item = pst->simplified;
2022                 if (revs->first_parent_only)
2023                         break;
2024         }
2025         if (!revs->first_parent_only)
2026                 cnt = remove_duplicate_parents(commit);
2027         else
2028                 cnt = 1;
2029
2030         /*
2031          * It is possible that we are a merge and one side branch
2032          * does not have any commit that touches the given paths;
2033          * in such a case, the immediate parents will be rewritten
2034          * to different commits.
2035          *
2036          *      o----X          X: the commit we are looking at;
2037          *     /    /           o: a commit that touches the paths;
2038          * ---o----'
2039          *
2040          * Further reduce the parents by removing redundant parents.
2041          */
2042         if (1 < cnt) {
2043                 struct commit_list *h = reduce_heads(commit->parents);
2044                 cnt = commit_list_count(h);
2045                 free_commit_list(commit->parents);
2046                 commit->parents = h;
2047         }
2048
2049         /*
2050          * A commit simplifies to itself if it is a root, if it is
2051          * UNINTERESTING, if it touches the given paths, or if it is a
2052          * merge and its parents simplifies to more than one commits
2053          * (the first two cases are already handled at the beginning of
2054          * this function).
2055          *
2056          * Otherwise, it simplifies to what its sole parent simplifies to.
2057          */
2058         if (!cnt ||
2059             (commit->object.flags & UNINTERESTING) ||
2060             !(commit->object.flags & TREESAME) ||
2061             (1 < cnt))
2062                 st->simplified = commit;
2063         else {
2064                 pst = locate_simplify_state(revs, commit->parents->item);
2065                 st->simplified = pst->simplified;
2066         }
2067         return tail;
2068 }
2069
2070 static void simplify_merges(struct rev_info *revs)
2071 {
2072         struct commit_list *list, *next;
2073         struct commit_list *yet_to_do, **tail;
2074         struct commit *commit;
2075
2076         if (!revs->prune)
2077                 return;
2078
2079         /* feed the list reversed */
2080         yet_to_do = NULL;
2081         for (list = revs->commits; list; list = next) {
2082                 commit = list->item;
2083                 next = list->next;
2084                 /*
2085                  * Do not free(list) here yet; the original list
2086                  * is used later in this function.
2087                  */
2088                 commit_list_insert(commit, &yet_to_do);
2089         }
2090         while (yet_to_do) {
2091                 list = yet_to_do;
2092                 yet_to_do = NULL;
2093                 tail = &yet_to_do;
2094                 while (list) {
2095                         commit = list->item;
2096                         next = list->next;
2097                         free(list);
2098                         list = next;
2099                         tail = simplify_one(revs, commit, tail);
2100                 }
2101         }
2102
2103         /* clean up the result, removing the simplified ones */
2104         list = revs->commits;
2105         revs->commits = NULL;
2106         tail = &revs->commits;
2107         while (list) {
2108                 struct merge_simplify_state *st;
2109
2110                 commit = list->item;
2111                 next = list->next;
2112                 free(list);
2113                 list = next;
2114                 st = locate_simplify_state(revs, commit);
2115                 if (st->simplified == commit)
2116                         tail = &commit_list_insert(commit, tail)->next;
2117         }
2118 }
2119
2120 static void set_children(struct rev_info *revs)
2121 {
2122         struct commit_list *l;
2123         for (l = revs->commits; l; l = l->next) {
2124                 struct commit *commit = l->item;
2125                 struct commit_list *p;
2126
2127                 for (p = commit->parents; p; p = p->next)
2128                         add_child(revs, p->item, commit);
2129         }
2130 }
2131
2132 void reset_revision_walk(void)
2133 {
2134         clear_object_flags(SEEN | ADDED | SHOWN);
2135 }
2136
2137 int prepare_revision_walk(struct rev_info *revs)
2138 {
2139         int nr = revs->pending.nr;
2140         struct object_array_entry *e, *list;
2141         struct commit_list **next = &revs->commits;
2142
2143         e = list = revs->pending.objects;
2144         revs->pending.nr = 0;
2145         revs->pending.alloc = 0;
2146         revs->pending.objects = NULL;
2147         while (--nr >= 0) {
2148                 struct commit *commit = handle_commit(revs, e->item, e->name);
2149                 if (commit) {
2150                         if (!(commit->object.flags & SEEN)) {
2151                                 commit->object.flags |= SEEN;
2152                                 next = commit_list_append(commit, next);
2153                         }
2154                 }
2155                 e++;
2156         }
2157         if (!revs->leak_pending)
2158                 free(list);
2159
2160         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2161                 commit_list_sort_by_date(&revs->commits);
2162         if (revs->no_walk)
2163                 return 0;
2164         if (revs->limited)
2165                 if (limit_list(revs) < 0)
2166                         return -1;
2167         if (revs->topo_order)
2168                 sort_in_topological_order(&revs->commits, revs->lifo);
2169         if (revs->simplify_merges)
2170                 simplify_merges(revs);
2171         if (revs->children.name)
2172                 set_children(revs);
2173         return 0;
2174 }
2175
2176 enum rewrite_result {
2177         rewrite_one_ok,
2178         rewrite_one_noparents,
2179         rewrite_one_error
2180 };
2181
2182 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2183 {
2184         struct commit_list *cache = NULL;
2185
2186         for (;;) {
2187                 struct commit *p = *pp;
2188                 if (!revs->limited)
2189                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2190                                 return rewrite_one_error;
2191                 if (p->parents && p->parents->next)
2192                         return rewrite_one_ok;
2193                 if (p->object.flags & UNINTERESTING)
2194                         return rewrite_one_ok;
2195                 if (!(p->object.flags & TREESAME))
2196                         return rewrite_one_ok;
2197                 if (!p->parents)
2198                         return rewrite_one_noparents;
2199                 *pp = p->parents->item;
2200         }
2201 }
2202
2203 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
2204 {
2205         struct commit_list **pp = &commit->parents;
2206         while (*pp) {
2207                 struct commit_list *parent = *pp;
2208                 switch (rewrite_one(revs, &parent->item)) {
2209                 case rewrite_one_ok:
2210                         break;
2211                 case rewrite_one_noparents:
2212                         *pp = parent->next;
2213                         continue;
2214                 case rewrite_one_error:
2215                         return -1;
2216                 }
2217                 pp = &parent->next;
2218         }
2219         remove_duplicate_parents(commit);
2220         return 0;
2221 }
2222
2223 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2224 {
2225         char *person, *endp;
2226         size_t len, namelen, maillen;
2227         const char *name;
2228         const char *mail;
2229         struct ident_split ident;
2230
2231         person = strstr(buf->buf, what);
2232         if (!person)
2233                 return 0;
2234
2235         person += strlen(what);
2236         endp = strchr(person, '\n');
2237         if (!endp)
2238                 return 0;
2239
2240         len = endp - person;
2241
2242         if (split_ident_line(&ident, person, len))
2243                 return 0;
2244
2245         mail = ident.mail_begin;
2246         maillen = ident.mail_end - ident.mail_begin;
2247         name = ident.name_begin;
2248         namelen = ident.name_end - ident.name_begin;
2249
2250         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2251                 struct strbuf namemail = STRBUF_INIT;
2252
2253                 strbuf_addf(&namemail, "%.*s <%.*s>",
2254                             (int)namelen, name, (int)maillen, mail);
2255
2256                 strbuf_splice(buf, ident.name_begin - buf->buf,
2257                               ident.mail_end - ident.name_begin + 1,
2258                               namemail.buf, namemail.len);
2259
2260                 strbuf_release(&namemail);
2261
2262                 return 1;
2263         }
2264
2265         return 0;
2266 }
2267
2268 static int commit_match(struct commit *commit, struct rev_info *opt)
2269 {
2270         int retval;
2271         struct strbuf buf = STRBUF_INIT;
2272         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2273                 return 1;
2274
2275         /* Prepend "fake" headers as needed */
2276         if (opt->grep_filter.use_reflog_filter) {
2277                 strbuf_addstr(&buf, "reflog ");
2278                 get_reflog_message(&buf, opt->reflog_info);
2279                 strbuf_addch(&buf, '\n');
2280         }
2281
2282         /* Copy the commit to temporary if we are using "fake" headers */
2283         if (buf.len)
2284                 strbuf_addstr(&buf, commit->buffer);
2285
2286         if (opt->grep_filter.header_list && opt->mailmap) {
2287                 if (!buf.len)
2288                         strbuf_addstr(&buf, commit->buffer);
2289
2290                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2291                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2292         }
2293
2294         /* Append "fake" message parts as needed */
2295         if (opt->show_notes) {
2296                 if (!buf.len)
2297                         strbuf_addstr(&buf, commit->buffer);
2298                 format_display_notes(commit->object.sha1, &buf,
2299                                      get_log_output_encoding(), 1);
2300         }
2301
2302         /* Find either in the commit object, or in the temporary */
2303         if (buf.len)
2304                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2305         else
2306                 retval = grep_buffer(&opt->grep_filter,
2307                                      commit->buffer, strlen(commit->buffer));
2308         strbuf_release(&buf);
2309         return retval;
2310 }
2311
2312 static inline int want_ancestry(struct rev_info *revs)
2313 {
2314         return (revs->rewrite_parents || revs->children.name);
2315 }
2316
2317 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2318 {
2319         if (commit->object.flags & SHOWN)
2320                 return commit_ignore;
2321         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2322                 return commit_ignore;
2323         if (revs->show_all)
2324                 return commit_show;
2325         if (commit->object.flags & UNINTERESTING)
2326                 return commit_ignore;
2327         if (revs->min_age != -1 && (commit->date > revs->min_age))
2328                 return commit_ignore;
2329         if (revs->min_parents || (revs->max_parents >= 0)) {
2330                 int n = 0;
2331                 struct commit_list *p;
2332                 for (p = commit->parents; p; p = p->next)
2333                         n++;
2334                 if ((n < revs->min_parents) ||
2335                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2336                         return commit_ignore;
2337         }
2338         if (!commit_match(commit, revs))
2339                 return commit_ignore;
2340         if (revs->prune && revs->dense) {
2341                 /* Commit without changes? */
2342                 if (commit->object.flags & TREESAME) {
2343                         /* drop merges unless we want parenthood */
2344                         if (!want_ancestry(revs))
2345                                 return commit_ignore;
2346                         /* non-merge - always ignore it */
2347                         if (!commit->parents || !commit->parents->next)
2348                                 return commit_ignore;
2349                 }
2350         }
2351         return commit_show;
2352 }
2353
2354 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2355 {
2356         enum commit_action action = get_commit_action(revs, commit);
2357
2358         if (action == commit_show &&
2359             !revs->show_all &&
2360             revs->prune && revs->dense && want_ancestry(revs)) {
2361                 if (rewrite_parents(revs, commit) < 0)
2362                         return commit_error;
2363         }
2364         return action;
2365 }
2366
2367 static struct commit *get_revision_1(struct rev_info *revs)
2368 {
2369         if (!revs->commits)
2370                 return NULL;
2371
2372         do {
2373                 struct commit_list *entry = revs->commits;
2374                 struct commit *commit = entry->item;
2375
2376                 revs->commits = entry->next;
2377                 free(entry);
2378
2379                 if (revs->reflog_info) {
2380                         fake_reflog_parent(revs->reflog_info, commit);
2381                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2382                 }
2383
2384                 /*
2385                  * If we haven't done the list limiting, we need to look at
2386                  * the parents here. We also need to do the date-based limiting
2387                  * that we'd otherwise have done in limit_list().
2388                  */
2389                 if (!revs->limited) {
2390                         if (revs->max_age != -1 &&
2391                             (commit->date < revs->max_age))
2392                                 continue;
2393                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2394                                 die("Failed to traverse parents of commit %s",
2395                                     sha1_to_hex(commit->object.sha1));
2396                 }
2397
2398                 switch (simplify_commit(revs, commit)) {
2399                 case commit_ignore:
2400                         continue;
2401                 case commit_error:
2402                         die("Failed to simplify parents of commit %s",
2403                             sha1_to_hex(commit->object.sha1));
2404                 default:
2405                         return commit;
2406                 }
2407         } while (revs->commits);
2408         return NULL;
2409 }
2410
2411 static void gc_boundary(struct object_array *array)
2412 {
2413         unsigned nr = array->nr;
2414         unsigned alloc = array->alloc;
2415         struct object_array_entry *objects = array->objects;
2416
2417         if (alloc <= nr) {
2418                 unsigned i, j;
2419                 for (i = j = 0; i < nr; i++) {
2420                         if (objects[i].item->flags & SHOWN)
2421                                 continue;
2422                         if (i != j)
2423                                 objects[j] = objects[i];
2424                         j++;
2425                 }
2426                 for (i = j; i < nr; i++)
2427                         objects[i].item = NULL;
2428                 array->nr = j;
2429         }
2430 }
2431
2432 static void create_boundary_commit_list(struct rev_info *revs)
2433 {
2434         unsigned i;
2435         struct commit *c;
2436         struct object_array *array = &revs->boundary_commits;
2437         struct object_array_entry *objects = array->objects;
2438
2439         /*
2440          * If revs->commits is non-NULL at this point, an error occurred in
2441          * get_revision_1().  Ignore the error and continue printing the
2442          * boundary commits anyway.  (This is what the code has always
2443          * done.)
2444          */
2445         if (revs->commits) {
2446                 free_commit_list(revs->commits);
2447                 revs->commits = NULL;
2448         }
2449
2450         /*
2451          * Put all of the actual boundary commits from revs->boundary_commits
2452          * into revs->commits
2453          */
2454         for (i = 0; i < array->nr; i++) {
2455                 c = (struct commit *)(objects[i].item);
2456                 if (!c)
2457                         continue;
2458                 if (!(c->object.flags & CHILD_SHOWN))
2459                         continue;
2460                 if (c->object.flags & (SHOWN | BOUNDARY))
2461                         continue;
2462                 c->object.flags |= BOUNDARY;
2463                 commit_list_insert(c, &revs->commits);
2464         }
2465
2466         /*
2467          * If revs->topo_order is set, sort the boundary commits
2468          * in topological order
2469          */
2470         sort_in_topological_order(&revs->commits, revs->lifo);
2471 }
2472
2473 static struct commit *get_revision_internal(struct rev_info *revs)
2474 {
2475         struct commit *c = NULL;
2476         struct commit_list *l;
2477
2478         if (revs->boundary == 2) {
2479                 /*
2480                  * All of the normal commits have already been returned,
2481                  * and we are now returning boundary commits.
2482                  * create_boundary_commit_list() has populated
2483                  * revs->commits with the remaining commits to return.
2484                  */
2485                 c = pop_commit(&revs->commits);
2486                 if (c)
2487                         c->object.flags |= SHOWN;
2488                 return c;
2489         }
2490
2491         /*
2492          * If our max_count counter has reached zero, then we are done. We
2493          * don't simply return NULL because we still might need to show
2494          * boundary commits. But we want to avoid calling get_revision_1, which
2495          * might do a considerable amount of work finding the next commit only
2496          * for us to throw it away.
2497          *
2498          * If it is non-zero, then either we don't have a max_count at all
2499          * (-1), or it is still counting, in which case we decrement.
2500          */
2501         if (revs->max_count) {
2502                 c = get_revision_1(revs);
2503                 if (c) {
2504                         while (0 < revs->skip_count) {
2505                                 revs->skip_count--;
2506                                 c = get_revision_1(revs);
2507                                 if (!c)
2508                                         break;
2509                         }
2510                 }
2511
2512                 if (revs->max_count > 0)
2513                         revs->max_count--;
2514         }
2515
2516         if (c)
2517                 c->object.flags |= SHOWN;
2518
2519         if (!revs->boundary) {
2520                 return c;
2521         }
2522
2523         if (!c) {
2524                 /*
2525                  * get_revision_1() runs out the commits, and
2526                  * we are done computing the boundaries.
2527                  * switch to boundary commits output mode.
2528                  */
2529                 revs->boundary = 2;
2530
2531                 /*
2532                  * Update revs->commits to contain the list of
2533                  * boundary commits.
2534                  */
2535                 create_boundary_commit_list(revs);
2536
2537                 return get_revision_internal(revs);
2538         }
2539
2540         /*
2541          * boundary commits are the commits that are parents of the
2542          * ones we got from get_revision_1() but they themselves are
2543          * not returned from get_revision_1().  Before returning
2544          * 'c', we need to mark its parents that they could be boundaries.
2545          */
2546
2547         for (l = c->parents; l; l = l->next) {
2548                 struct object *p;
2549                 p = &(l->item->object);
2550                 if (p->flags & (CHILD_SHOWN | SHOWN))
2551                         continue;
2552                 p->flags |= CHILD_SHOWN;
2553                 gc_boundary(&revs->boundary_commits);
2554                 add_object_array(p, NULL, &revs->boundary_commits);
2555         }
2556
2557         return c;
2558 }
2559
2560 struct commit *get_revision(struct rev_info *revs)
2561 {
2562         struct commit *c;
2563         struct commit_list *reversed;
2564
2565         if (revs->reverse) {
2566                 reversed = NULL;
2567                 while ((c = get_revision_internal(revs))) {
2568                         commit_list_insert(c, &reversed);
2569                 }
2570                 revs->commits = reversed;
2571                 revs->reverse = 0;
2572                 revs->reverse_output_stage = 1;
2573         }
2574
2575         if (revs->reverse_output_stage)
2576                 return pop_commit(&revs->commits);
2577
2578         c = get_revision_internal(revs);
2579         if (c && revs->graph)
2580                 graph_update(revs->graph, c);
2581         return c;
2582 }
2583
2584 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2585 {
2586         if (commit->object.flags & BOUNDARY)
2587                 return "-";
2588         else if (commit->object.flags & UNINTERESTING)
2589                 return "^";
2590         else if (commit->object.flags & PATCHSAME)
2591                 return "=";
2592         else if (!revs || revs->left_right) {
2593                 if (commit->object.flags & SYMMETRIC_LEFT)
2594                         return "<";
2595                 else
2596                         return ">";
2597         } else if (revs->graph)
2598                 return "*";
2599         else if (revs->cherry_mark)
2600                 return "+";
2601         return "";
2602 }
2603
2604 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2605 {
2606         char *mark = get_revision_mark(revs, commit);
2607         if (!strlen(mark))
2608                 return;
2609         fputs(mark, stdout);
2610         putchar(' ');
2611 }