Pileus Git - ~andy/git/blob - 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 "line-log.h"
  17 #include "mailmap.h"
  18
  19 volatile show_early_output_fn_t show_early_output;
  20
  21 char *path_name(const struct name_path *path, const char *name)
  22 {
  23         const struct name_path *p;
  24         char *n, *m;
  25         int nlen = strlen(name);
  26         int len = nlen + 1;
  27
  28         for (p = path; p; p = p->up) {
  29                 if (p->elem_len)
  30                         len += p->elem_len + 1;
  31         }
  32         n = xmalloc(len);
  33         m = n + len - (nlen + 1);
  34         strcpy(m, name);
  35         for (p = path; p; p = p->up) {
  36                 if (p->elem_len) {
  37                         m -= p->elem_len + 1;
  38                         memcpy(m, p->elem, p->elem_len);
  39                         m[p->elem_len] = '/';
  40                 }
  41         }
  42         return n;
  43 }
  44
  45 static int show_path_component_truncated(FILE *out, const char *name, int len)
  46 {
  47         int cnt;
  48         for (cnt = 0; cnt < len; cnt++) {
  49                 int ch = name[cnt];
  50                 if (!ch || ch == '\n')
  51                         return -1;
  52                 fputc(ch, out);
  53         }
  54         return len;
  55 }
  56
  57 static int show_path_truncated(FILE *out, const struct name_path *path)
  58 {
  59         int emitted, ours;
  60
  61         if (!path)
  62                 return 0;
  63         emitted = show_path_truncated(out, path->up);
  64         if (emitted < 0)
  65                 return emitted;
  66         if (emitted)
  67                 fputc('/', out);
  68         ours = show_path_component_truncated(out, path->elem, path->elem_len);
  69         if (ours < 0)
  70                 return ours;
  71         return ours || emitted;
  72 }
  73
  74 void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
  75 {
  76         struct name_path leaf;
  77         leaf.up = (struct name_path *)path;
  78         leaf.elem = component;
  79         leaf.elem_len = strlen(component);
  80
  81         fprintf(out, "%s ", sha1_to_hex(obj->sha1));
  82         show_path_truncated(out, &leaf);
  83         fputc('\n', out);
  84 }
  85
  86 void add_object(struct object *obj,
  87                 struct object_array *p,
  88                 struct name_path *path,
  89                 const char *name)
  90 {
  91         add_object_array(obj, path_name(path, name), p);
  92 }
  93
  94 static void mark_blob_uninteresting(struct blob *blob)
  95 {
  96         if (!blob)
  97                 return;
  98         if (blob->object.flags & UNINTERESTING)
  99                 return;
 100         blob->object.flags |= UNINTERESTING;
 101 }
 102
 103 void mark_tree_uninteresting(struct tree *tree)
 104 {
 105         struct tree_desc desc;
 106         struct name_entry entry;
 107         struct object *obj = &tree->object;
 108
 109         if (!tree)
 110                 return;
 111         if (obj->flags & UNINTERESTING)
 112                 return;
 113         obj->flags |= UNINTERESTING;
 114         if (!has_sha1_file(obj->sha1))
 115                 return;
 116         if (parse_tree(tree) < 0)
 117                 die("bad tree %s", sha1_to_hex(obj->sha1));
 118
 119         init_tree_desc(&desc, tree->buffer, tree->size);
 120         while (tree_entry(&desc, &entry)) {
 121                 switch (object_type(entry.mode)) {
 122                 case OBJ_TREE:
 123                         mark_tree_uninteresting(lookup_tree(entry.sha1));
 124                         break;
 125                 case OBJ_BLOB:
 126                         mark_blob_uninteresting(lookup_blob(entry.sha1));
 127                         break;
 128                 default:
 129                         /* Subproject commit - not in this repository */
 130                         break;
 131                 }
 132         }
 133
 134         /*
 135          * We don't care about the tree any more
 136          * after it has been marked uninteresting.
 137          */
 138         free(tree->buffer);
 139         tree->buffer = NULL;
 140 }
 141
 142 void mark_parents_uninteresting(struct commit *commit)
 143 {
 144         struct commit_list *parents = NULL, *l;
 145
 146         for (l = commit->parents; l; l = l->next)
 147                 commit_list_insert(l->item, &parents);
 148
 149         while (parents) {
 150                 struct commit *commit = parents->item;
 151                 l = parents;
 152                 parents = parents->next;
 153                 free(l);
 154
 155                 while (commit) {
 156                         /*
 157                          * A missing commit is ok iff its parent is marked
 158                          * uninteresting.
 159                          *
 160                          * We just mark such a thing parsed, so that when
 161                          * it is popped next time around, we won't be trying
 162                          * to parse it and get an error.
 163                          */
 164                         if (!has_sha1_file(commit->object.sha1))
 165                                 commit->object.parsed = 1;
 166
 167                         if (commit->object.flags & UNINTERESTING)
 168                                 break;
 169
 170                         commit->object.flags |= UNINTERESTING;
 171
 172                         /*
 173                          * Normally we haven't parsed the parent
 174                          * yet, so we won't have a parent of a parent
 175                          * here. However, it may turn out that we've
 176                          * reached this commit some other way (where it
 177                          * wasn't uninteresting), in which case we need
 178                          * to mark its parents recursively too..
 179                          */
 180                         if (!commit->parents)
 181                                 break;
 182
 183                         for (l = commit->parents->next; l; l = l->next)
 184                                 commit_list_insert(l->item, &parents);
 185                         commit = commit->parents->item;
 186                 }
 187         }
 188 }
 189
 190 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 191 {
 192         if (!obj)
 193                 return;
 194         if (revs->no_walk && (obj->flags & UNINTERESTING))
 195                 revs->no_walk = 0;
 196         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 197                 struct strbuf buf = STRBUF_INIT;
 198                 int len = interpret_branch_name(name, &buf);
 199                 int st;
 200
 201                 if (0 < len && name[len] && buf.len)
 202                         strbuf_addstr(&buf, name + len);
 203                 st = add_reflog_for_walk(revs->reflog_info,
 204                                          (struct commit *)obj,
 205                                          buf.buf[0] ? buf.buf: name);
 206                 strbuf_release(&buf);
 207                 if (st)
 208                         return;
 209         }
 210         add_object_array_with_mode(obj, name, &revs->pending, mode);
 211 }
 212
 213 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 214 {
 215         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 216 }
 217
 218 void add_head_to_pending(struct rev_info *revs)
 219 {
 220         unsigned char sha1[20];
 221         struct object *obj;
 222         if (get_sha1("HEAD", sha1))
 223                 return;
 224         obj = parse_object(sha1);
 225         if (!obj)
 226                 return;
 227         add_pending_object(revs, obj, "HEAD");
 228 }
 229
 230 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 231 {
 232         struct object *object;
 233
 234         object = parse_object(sha1);
 235         if (!object) {
 236                 if (revs->ignore_missing)
 237                         return object;
 238                 die("bad object %s", name);
 239         }
 240         object->flags |= flags;
 241         return object;
 242 }
 243
 244 void add_pending_sha1(struct rev_info *revs, const char *name,
 245                       const unsigned char *sha1, unsigned int flags)
 246 {
 247         struct object *object = get_reference(revs, name, sha1, flags);
 248         add_pending_object(revs, object, name);
 249 }
 250
 251 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 252 {
 253         unsigned long flags = object->flags;
 254
 255         /*
 256          * Tag object? Look what it points to..
 257          */
 258         while (object->type == OBJ_TAG) {
 259                 struct tag *tag = (struct tag *) object;
 260                 if (revs->tag_objects && !(flags & UNINTERESTING))
 261                         add_pending_object(revs, object, tag->tag);
 262                 if (!tag->tagged)
 263                         die("bad tag");
 264                 object = parse_object(tag->tagged->sha1);
 265                 if (!object) {
 266                         if (flags & UNINTERESTING)
 267                                 return NULL;
 268                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 269                 }
 270         }
 271
 272         /*
 273          * Commit object? Just return it, we'll do all the complex
 274          * reachability crud.
 275          */
 276         if (object->type == OBJ_COMMIT) {
 277                 struct commit *commit = (struct commit *)object;
 278                 if (parse_commit(commit) < 0)
 279                         die("unable to parse commit %s", name);
 280                 if (flags & UNINTERESTING) {
 281                         commit->object.flags |= UNINTERESTING;
 282                         mark_parents_uninteresting(commit);
 283                         revs->limited = 1;
 284                 }
 285                 if (revs->show_source && !commit->util)
 286                         commit->util = (void *) name;
 287                 return commit;
 288         }
 289
 290         /*
 291          * Tree object? Either mark it uninteresting, or add it
 292          * to the list of objects to look at later..
 293          */
 294         if (object->type == OBJ_TREE) {
 295                 struct tree *tree = (struct tree *)object;
 296                 if (!revs->tree_objects)
 297                         return NULL;
 298                 if (flags & UNINTERESTING) {
 299                         mark_tree_uninteresting(tree);
 300                         return NULL;
 301                 }
 302                 add_pending_object(revs, object, "");
 303                 return NULL;
 304         }
 305
 306         /*
 307          * Blob object? You know the drill by now..
 308          */
 309         if (object->type == OBJ_BLOB) {
 310                 struct blob *blob = (struct blob *)object;
 311                 if (!revs->blob_objects)
 312                         return NULL;
 313                 if (flags & UNINTERESTING) {
 314                         mark_blob_uninteresting(blob);
 315                         return NULL;
 316                 }
 317                 add_pending_object(revs, object, "");
 318                 return NULL;
 319         }
 320         die("%s is unknown object", name);
 321 }
 322
 323 static int everybody_uninteresting(struct commit_list *orig)
 324 {
 325         struct commit_list *list = orig;
 326         while (list) {
 327                 struct commit *commit = list->item;
 328                 list = list->next;
 329                 if (commit->object.flags & UNINTERESTING)
 330                         continue;
 331                 return 0;
 332         }
 333         return 1;
 334 }
 335
 336 /*
 337  * The goal is to get REV_TREE_NEW as the result only if the
 338  * diff consists of all '+' (and no other changes), REV_TREE_OLD
 339  * if the whole diff is removal of old data, and otherwise
 340  * REV_TREE_DIFFERENT (of course if the trees are the same we
 341  * want REV_TREE_SAME).
 342  * That means that once we get to REV_TREE_DIFFERENT, we do not
 343  * have to look any further.
 344  */
 345 static int tree_difference = REV_TREE_SAME;
 346
 347 static void file_add_remove(struct diff_options *options,
 348                     int addremove, unsigned mode,
 349                     const unsigned char *sha1,
 350                     int sha1_valid,
 351                     const char *fullpath, unsigned dirty_submodule)
 352 {
 353         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 354
 355         tree_difference |= diff;
 356         if (tree_difference == REV_TREE_DIFFERENT)
 357                 DIFF_OPT_SET(options, HAS_CHANGES);
 358 }
 359
 360 static void file_change(struct diff_options *options,
 361                  unsigned old_mode, unsigned new_mode,
 362                  const unsigned char *old_sha1,
 363                  const unsigned char *new_sha1,
 364                  int old_sha1_valid, int new_sha1_valid,
 365                  const char *fullpath,
 366                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 367 {
 368         tree_difference = REV_TREE_DIFFERENT;
 369         DIFF_OPT_SET(options, HAS_CHANGES);
 370 }
 371
 372 static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 373 {
 374         struct tree *t1 = parent->tree;
 375         struct tree *t2 = commit->tree;
 376
 377         if (!t1)
 378                 return REV_TREE_NEW;
 379         if (!t2)
 380                 return REV_TREE_OLD;
 381
 382         if (revs->simplify_by_decoration) {
 383                 /*
 384                  * If we are simplifying by decoration, then the commit
 385                  * is worth showing if it has a tag pointing at it.
 386                  */
 387                 if (lookup_decoration(&name_decoration, &commit->object))
 388                         return REV_TREE_DIFFERENT;
 389                 /*
 390                  * A commit that is not pointed by a tag is uninteresting
 391                  * if we are not limited by path.  This means that you will
 392                  * see the usual "commits that touch the paths" plus any
 393                  * tagged commit by specifying both --simplify-by-decoration
 394                  * and pathspec.
 395                  */
 396                 if (!revs->prune_data.nr)
 397                         return REV_TREE_SAME;
 398         }
 399
 400         tree_difference = REV_TREE_SAME;
 401         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 402         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 403                            &revs->pruning) < 0)
 404                 return REV_TREE_DIFFERENT;
 405         return tree_difference;
 406 }
 407
 408 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 409 {
 410         int retval;
 411         void *tree;
 412         unsigned long size;
 413         struct tree_desc empty, real;
 414         struct tree *t1 = commit->tree;
 415
 416         if (!t1)
 417                 return 0;
 418
 419         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 420         if (!tree)
 421                 return 0;
 422         init_tree_desc(&real, tree, size);
 423         init_tree_desc(&empty, "", 0);
 424
 425         tree_difference = REV_TREE_SAME;
 426         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 427         retval = diff_tree(&empty, &real, "", &revs->pruning);
 428         free(tree);
 429
 430         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 431 }
 432
 433 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 434 {
 435         struct commit_list **pp, *parent;
 436         int tree_changed = 0, tree_same = 0, nth_parent = 0;
 437
 438         /*
 439          * If we don't do pruning, everything is interesting
 440          */
 441         if (!revs->prune)
 442                 return;
 443
 444         if (!commit->tree)
 445                 return;
 446
 447         if (!commit->parents) {
 448                 if (rev_same_tree_as_empty(revs, commit))
 449                         commit->object.flags |= TREESAME;
 450                 return;
 451         }
 452
 453         /*
 454          * Normal non-merge commit? If we don't want to make the
 455          * history dense, we consider it always to be a change..
 456          */
 457         if (!revs->dense && !commit->parents->next)
 458                 return;
 459
 460         pp = &commit->parents;
 461         while ((parent = *pp) != NULL) {
 462                 struct commit *p = parent->item;
 463
 464                 /*
 465                  * Do not compare with later parents when we care only about
 466                  * the first parent chain, in order to avoid derailing the
 467                  * traversal to follow a side branch that brought everything
 468                  * in the path we are limited to by the pathspec.
 469                  */
 470                 if (revs->first_parent_only && nth_parent++)
 471                         break;
 472                 if (parse_commit(p) < 0)
 473                         die("cannot simplify commit %s (because of %s)",
 474                             sha1_to_hex(commit->object.sha1),
 475                             sha1_to_hex(p->object.sha1));
 476                 switch (rev_compare_tree(revs, p, commit)) {
 477                 case REV_TREE_SAME:
 478                         tree_same = 1;
 479                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 480                                 /* Even if a merge with an uninteresting
 481                                  * side branch brought the entire change
 482                                  * we are interested in, we do not want
 483                                  * to lose the other branches of this
 484                                  * merge, so we just keep going.
 485                                  */
 486                                 pp = &parent->next;
 487                                 continue;
 488                         }
 489                         parent->next = NULL;
 490                         commit->parents = parent;
 491                         commit->object.flags |= TREESAME;
 492                         return;
 493
 494                 case REV_TREE_NEW:
 495                         if (revs->remove_empty_trees &&
 496                             rev_same_tree_as_empty(revs, p)) {
 497                                 /* We are adding all the specified
 498                                  * paths from this parent, so the
 499                                  * history beyond this parent is not
 500                                  * interesting.  Remove its parents
 501                                  * (they are grandparents for us).
 502                                  * IOW, we pretend this parent is a
 503                                  * "root" commit.
 504                                  */
 505                                 if (parse_commit(p) < 0)
 506                                         die("cannot simplify commit %s (invalid %s)",
 507                                             sha1_to_hex(commit->object.sha1),
 508                                             sha1_to_hex(p->object.sha1));
 509                                 p->parents = NULL;
 510                         }
 511                 /* fallthrough */
 512                 case REV_TREE_OLD:
 513                 case REV_TREE_DIFFERENT:
 514                         tree_changed = 1;
 515                         pp = &parent->next;
 516                         continue;
 517                 }
 518                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 519         }
 520         if (tree_changed && !tree_same)
 521                 return;
 522         commit->object.flags |= TREESAME;
 523 }
 524
 525 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 526                     struct commit_list *cached_base, struct commit_list **cache)
 527 {
 528         struct commit_list *new_entry;
 529
 530         if (cached_base && p->date < cached_base->item->date)
 531                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
 532         else
 533                 new_entry = commit_list_insert_by_date(p, head);
 534
 535         if (cache && (!*cache || p->date < (*cache)->item->date))
 536                 *cache = new_entry;
 537 }
 538
 539 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 540                     struct commit_list **list, struct commit_list **cache_ptr)
 541 {
 542         struct commit_list *parent = commit->parents;
 543         unsigned left_flag;
 544         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 545
 546         if (commit->object.flags & ADDED)
 547                 return 0;
 548         commit->object.flags |= ADDED;
 549
 550         /*
 551          * If the commit is uninteresting, don't try to
 552          * prune parents - we want the maximal uninteresting
 553          * set.
 554          *
 555          * Normally we haven't parsed the parent
 556          * yet, so we won't have a parent of a parent
 557          * here. However, it may turn out that we've
 558          * reached this commit some other way (where it
 559          * wasn't uninteresting), in which case we need
 560          * to mark its parents recursively too..
 561          */
 562         if (commit->object.flags & UNINTERESTING) {
 563                 while (parent) {
 564                         struct commit *p = parent->item;
 565                         parent = parent->next;
 566                         if (p)
 567                                 p->object.flags |= UNINTERESTING;
 568                         if (parse_commit(p) < 0)
 569                                 continue;
 570                         if (p->parents)
 571                                 mark_parents_uninteresting(p);
 572                         if (p->object.flags & SEEN)
 573                                 continue;
 574                         p->object.flags |= SEEN;
 575                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 576                 }
 577                 return 0;
 578         }
 579
 580         /*
 581          * Ok, the commit wasn't uninteresting. Try to
 582          * simplify the commit history and find the parent
 583          * that has no differences in the path set if one exists.
 584          */
 585         try_to_simplify_commit(revs, commit);
 586
 587         if (revs->no_walk)
 588                 return 0;
 589
 590         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 591
 592         for (parent = commit->parents; parent; parent = parent->next) {
 593                 struct commit *p = parent->item;
 594
 595                 if (parse_commit(p) < 0)
 596                         return -1;
 597                 if (revs->show_source && !p->util)
 598                         p->util = commit->util;
 599                 p->object.flags |= left_flag;
 600                 if (!(p->object.flags & SEEN)) {
 601                         p->object.flags |= SEEN;
 602                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 603                 }
 604                 if (revs->first_parent_only)
 605                         break;
 606         }
 607         return 0;
 608 }
 609
 610 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 611 {
 612         struct commit_list *p;
 613         int left_count = 0, right_count = 0;
 614         int left_first;
 615         struct patch_ids ids;
 616         unsigned cherry_flag;
 617
 618         /* First count the commits on the left and on the right */
 619         for (p = list; p; p = p->next) {
 620                 struct commit *commit = p->item;
 621                 unsigned flags = commit->object.flags;
 622                 if (flags & BOUNDARY)
 623                         ;
 624                 else if (flags & SYMMETRIC_LEFT)
 625                         left_count++;
 626                 else
 627                         right_count++;
 628         }
 629
 630         if (!left_count || !right_count)
 631                 return;
 632
 633         left_first = left_count < right_count;
 634         init_patch_ids(&ids);
 635         ids.diffopts.pathspec = revs->diffopt.pathspec;
 636
 637         /* Compute patch-ids for one side */
 638         for (p = list; p; p = p->next) {
 639                 struct commit *commit = p->item;
 640                 unsigned flags = commit->object.flags;
 641
 642                 if (flags & BOUNDARY)
 643                         continue;
 644                 /*
 645                  * If we have fewer left, left_first is set and we omit
 646                  * commits on the right branch in this loop.  If we have
 647                  * fewer right, we skip the left ones.
 648                  */
 649                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 650                         continue;
 651                 commit->util = add_commit_patch_id(commit, &ids);
 652         }
 653
 654         /* either cherry_mark or cherry_pick are true */
 655         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 656
 657         /* Check the other side */
 658         for (p = list; p; p = p->next) {
 659                 struct commit *commit = p->item;
 660                 struct patch_id *id;
 661                 unsigned flags = commit->object.flags;
 662
 663                 if (flags & BOUNDARY)
 664                         continue;
 665                 /*
 666                  * If we have fewer left, left_first is set and we omit
 667                  * commits on the left branch in this loop.
 668                  */
 669                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 670                         continue;
 671
 672                 /*
 673                  * Have we seen the same patch id?
 674                  */
 675                 id = has_commit_patch_id(commit, &ids);
 676                 if (!id)
 677                         continue;
 678                 id->seen = 1;
 679                 commit->object.flags |= cherry_flag;
 680         }
 681
 682         /* Now check the original side for seen ones */
 683         for (p = list; p; p = p->next) {
 684                 struct commit *commit = p->item;
 685                 struct patch_id *ent;
 686
 687                 ent = commit->util;
 688                 if (!ent)
 689                         continue;
 690                 if (ent->seen)
 691                         commit->object.flags |= cherry_flag;
 692                 commit->util = NULL;
 693         }
 694
 695         free_patch_ids(&ids);
 696 }
 697
 698 /* How many extra uninteresting commits we want to see.. */
 699 #define SLOP 5
 700
 701 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 702 {
 703         /*
 704          * No source list at all? We're definitely done..
 705          */
 706         if (!src)
 707                 return 0;
 708
 709         /*
 710          * Does the destination list contain entries with a date
 711          * before the source list? Definitely _not_ done.
 712          */
 713         if (date <= src->item->date)
 714                 return SLOP;
 715
 716         /*
 717          * Does the source list still have interesting commits in
 718          * it? Definitely not done..
 719          */
 720         if (!everybody_uninteresting(src))
 721                 return SLOP;
 722
 723         /* Ok, we're closing in.. */
 724         return slop-1;
 725 }
 726
 727 /*
 728  * "rev-list --ancestry-path A..B" computes commits that are ancestors
 729  * of B but not ancestors of A but further limits the result to those
 730  * that are descendants of A.  This takes the list of bottom commits and
 731  * the result of "A..B" without --ancestry-path, and limits the latter
 732  * further to the ones that can reach one of the commits in "bottom".
 733  */
 734 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 735 {
 736         struct commit_list *p;
 737         struct commit_list *rlist = NULL;
 738         int made_progress;
 739
 740         /*
 741          * Reverse the list so that it will be likely that we would
 742          * process parents before children.
 743          */
 744         for (p = list; p; p = p->next)
 745                 commit_list_insert(p->item, &rlist);
 746
 747         for (p = bottom; p; p = p->next)
 748                 p->item->object.flags |= TMP_MARK;
 749
 750         /*
 751          * Mark the ones that can reach bottom commits in "list",
 752          * in a bottom-up fashion.
 753          */
 754         do {
 755                 made_progress = 0;
 756                 for (p = rlist; p; p = p->next) {
 757                         struct commit *c = p->item;
 758                         struct commit_list *parents;
 759                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
 760                                 continue;
 761                         for (parents = c->parents;
 762                              parents;
 763                              parents = parents->next) {
 764                                 if (!(parents->item->object.flags & TMP_MARK))
 765                                         continue;
 766                                 c->object.flags |= TMP_MARK;
 767                                 made_progress = 1;
 768                                 break;
 769                         }
 770                 }
 771         } while (made_progress);
 772
 773         /*
 774          * NEEDSWORK: decide if we want to remove parents that are
 775          * not marked with TMP_MARK from commit->parents for commits
 776          * in the resulting list.  We may not want to do that, though.
 777          */
 778
 779         /*
 780          * The ones that are not marked with TMP_MARK are uninteresting
 781          */
 782         for (p = list; p; p = p->next) {
 783                 struct commit *c = p->item;
 784                 if (c->object.flags & TMP_MARK)
 785                         continue;
 786                 c->object.flags |= UNINTERESTING;
 787         }
 788
 789         /* We are done with the TMP_MARK */
 790         for (p = list; p; p = p->next)
 791                 p->item->object.flags &= ~TMP_MARK;
 792         for (p = bottom; p; p = p->next)
 793                 p->item->object.flags &= ~TMP_MARK;
 794         free_commit_list(rlist);
 795 }
 796
 797 /*
 798  * Before walking the history, keep the set of "negative" refs the
 799  * caller has asked to exclude.
 800  *
 801  * This is used to compute "rev-list --ancestry-path A..B", as we need
 802  * to filter the result of "A..B" further to the ones that can actually
 803  * reach A.
 804  */
 805 static struct commit_list *collect_bottom_commits(struct rev_info *revs)
 806 {
 807         struct commit_list *bottom = NULL;
 808         int i;
 809         for (i = 0; i < revs->cmdline.nr; i++) {
 810                 struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
 811                 if ((elem->flags & UNINTERESTING) &&
 812                     elem->item->type == OBJ_COMMIT)
 813                         commit_list_insert((struct commit *)elem->item, &bottom);
 814         }
 815         return bottom;
 816 }
 817
 818 /* Assumes either left_only or right_only is set */
 819 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 820 {
 821         struct commit_list *p;
 822
 823         for (p = list; p; p = p->next) {
 824                 struct commit *commit = p->item;
 825
 826                 if (revs->right_only) {
 827                         if (commit->object.flags & SYMMETRIC_LEFT)
 828                                 commit->object.flags |= SHOWN;
 829                 } else  /* revs->left_only is set */
 830                         if (!(commit->object.flags & SYMMETRIC_LEFT))
 831                                 commit->object.flags |= SHOWN;
 832         }
 833 }
 834
 835 static int limit_list(struct rev_info *revs)
 836 {
 837         int slop = SLOP;
 838         unsigned long date = ~0ul;
 839         struct commit_list *list = revs->commits;
 840         struct commit_list *newlist = NULL;
 841         struct commit_list **p = &newlist;
 842         struct commit_list *bottom = NULL;
 843
 844         if (revs->ancestry_path) {
 845                 bottom = collect_bottom_commits(revs);
 846                 if (!bottom)
 847                         die("--ancestry-path given but there are no bottom commits");
 848         }
 849
 850         while (list) {
 851                 struct commit_list *entry = list;
 852                 struct commit *commit = list->item;
 853                 struct object *obj = &commit->object;
 854                 show_early_output_fn_t show;
 855
 856                 list = list->next;
 857                 free(entry);
 858
 859                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 860                         obj->flags |= UNINTERESTING;
 861                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 862                         return -1;
 863                 if (obj->flags & UNINTERESTING) {
 864                         mark_parents_uninteresting(commit);
 865                         if (revs->show_all)
 866                                 p = &commit_list_insert(commit, p)->next;
 867                         slop = still_interesting(list, date, slop);
 868                         if (slop)
 869                                 continue;
 870                         /* If showing all, add the whole pending list to the end */
 871                         if (revs->show_all)
 872                                 *p = list;
 873                         break;
 874                 }
 875                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 876                         continue;
 877                 date = commit->date;
 878                 p = &commit_list_insert(commit, p)->next;
 879
 880                 show = show_early_output;
 881                 if (!show)
 882                         continue;
 883
 884                 show(revs, newlist);
 885                 show_early_output = NULL;
 886         }
 887         if (revs->cherry_pick || revs->cherry_mark)
 888                 cherry_pick_list(newlist, revs);
 889
 890         if (revs->left_only || revs->right_only)
 891                 limit_left_right(newlist, revs);
 892
 893         if (bottom) {
 894                 limit_to_ancestry(bottom, newlist);
 895                 free_commit_list(bottom);
 896         }
 897
 898         revs->commits = newlist;
 899         return 0;
 900 }
 901
 902 static void add_rev_cmdline(struct rev_info *revs,
 903                             struct object *item,
 904                             const char *name,
 905                             int whence,
 906                             unsigned flags)
 907 {
 908         struct rev_cmdline_info *info = &revs->cmdline;
 909         int nr = info->nr;
 910
 911         ALLOC_GROW(info->rev, nr + 1, info->alloc);
 912         info->rev[nr].item = item;
 913         info->rev[nr].name = name;
 914         info->rev[nr].whence = whence;
 915         info->rev[nr].flags = flags;
 916         info->nr++;
 917 }
 918
 919 static void add_rev_cmdline_list(struct rev_info *revs,
 920                                  struct commit_list *commit_list,
 921                                  int whence,
 922                                  unsigned flags)
 923 {
 924         while (commit_list) {
 925                 struct object *object = &commit_list->item->object;
 926                 add_rev_cmdline(revs, object, sha1_to_hex(object->sha1),
 927                                 whence, flags);
 928                 commit_list = commit_list->next;
 929         }
 930 }
 931
 932 struct all_refs_cb {
 933         int all_flags;
 934         int warned_bad_reflog;
 935         struct rev_info *all_revs;
 936         const char *name_for_errormsg;
 937 };
 938
 939 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 940 {
 941         struct all_refs_cb *cb = cb_data;
 942         struct object *object = get_reference(cb->all_revs, path, sha1,
 943                                               cb->all_flags);
 944         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
 945         add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
 946         return 0;
 947 }
 948
 949 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 950         unsigned flags)
 951 {
 952         cb->all_revs = revs;
 953         cb->all_flags = flags;
 954 }
 955
 956 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
 957                 int (*for_each)(const char *, each_ref_fn, void *))
 958 {
 959         struct all_refs_cb cb;
 960         init_all_refs_cb(&cb, revs, flags);
 961         for_each(submodule, handle_one_ref, &cb);
 962 }
 963
 964 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 965 {
 966         struct all_refs_cb *cb = cb_data;
 967         if (!is_null_sha1(sha1)) {
 968                 struct object *o = parse_object(sha1);
 969                 if (o) {
 970                         o->flags |= cb->all_flags;
 971                         /* ??? CMDLINEFLAGS ??? */
 972                         add_pending_object(cb->all_revs, o, "");
 973                 }
 974                 else if (!cb->warned_bad_reflog) {
 975                         warning("reflog of '%s' references pruned commits",
 976                                 cb->name_for_errormsg);
 977                         cb->warned_bad_reflog = 1;
 978                 }
 979         }
 980 }
 981
 982 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 983                 const char *email, unsigned long timestamp, int tz,
 984                 const char *message, void *cb_data)
 985 {
 986         handle_one_reflog_commit(osha1, cb_data);
 987         handle_one_reflog_commit(nsha1, cb_data);
 988         return 0;
 989 }
 990
 991 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 992 {
 993         struct all_refs_cb *cb = cb_data;
 994         cb->warned_bad_reflog = 0;
 995         cb->name_for_errormsg = path;
 996         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 997         return 0;
 998 }
 999
1000 static void handle_reflog(struct rev_info *revs, unsigned flags)
1001 {
1002         struct all_refs_cb cb;
1003         cb.all_revs = revs;
1004         cb.all_flags = flags;
1005         for_each_reflog(handle_one_reflog, &cb);
1006 }
1007
1008 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
1009 {
1010         unsigned char sha1[20];
1011         struct object *it;
1012         struct commit *commit;
1013         struct commit_list *parents;
1014         const char *arg = arg_;
1015
1016         if (*arg == '^') {
1017                 flags ^= UNINTERESTING;
1018                 arg++;
1019         }
1020         if (get_sha1_committish(arg, sha1))
1021                 return 0;
1022         while (1) {
1023                 it = get_reference(revs, arg, sha1, 0);
1024                 if (!it && revs->ignore_missing)
1025                         return 0;
1026                 if (it->type != OBJ_TAG)
1027                         break;
1028                 if (!((struct tag*)it)->tagged)
1029                         return 0;
1030                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1031         }
1032         if (it->type != OBJ_COMMIT)
1033                 return 0;
1034         commit = (struct commit *)it;
1035         for (parents = commit->parents; parents; parents = parents->next) {
1036                 it = &parents->item->object;
1037                 it->flags |= flags;
1038                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1039                 add_pending_object(revs, it, arg);
1040         }
1041         return 1;
1042 }
1043
1044 void init_revisions(struct rev_info *revs, const char *prefix)
1045 {
1046         memset(revs, 0, sizeof(*revs));
1047
1048         revs->abbrev = DEFAULT_ABBREV;
1049         revs->ignore_merges = 1;
1050         revs->simplify_history = 1;
1051         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1052         DIFF_OPT_SET(&revs->pruning, QUICK);
1053         revs->pruning.add_remove = file_add_remove;
1054         revs->pruning.change = file_change;
1055         revs->lifo = 1;
1056         revs->dense = 1;
1057         revs->prefix = prefix;
1058         revs->max_age = -1;
1059         revs->min_age = -1;
1060         revs->skip_count = -1;
1061         revs->max_count = -1;
1062         revs->max_parents = -1;
1063
1064         revs->commit_format = CMIT_FMT_DEFAULT;
1065
1066         init_grep_defaults();
1067         grep_init(&revs->grep_filter, prefix);
1068         revs->grep_filter.status_only = 1;
1069         revs->grep_filter.regflags = REG_NEWLINE;
1070
1071         diff_setup(&revs->diffopt);
1072         if (prefix && !revs->diffopt.prefix) {
1073                 revs->diffopt.prefix = prefix;
1074                 revs->diffopt.prefix_length = strlen(prefix);
1075         }
1076
1077         revs->notes_opt.use_default_notes = -1;
1078 }
1079
1080 static void add_pending_commit_list(struct rev_info *revs,
1081                                     struct commit_list *commit_list,
1082                                     unsigned int flags)
1083 {
1084         while (commit_list) {
1085                 struct object *object = &commit_list->item->object;
1086                 object->flags |= flags;
1087                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
1088                 commit_list = commit_list->next;
1089         }
1090 }
1091
1092 static void prepare_show_merge(struct rev_info *revs)
1093 {
1094         struct commit_list *bases;
1095         struct commit *head, *other;
1096         unsigned char sha1[20];
1097         const char **prune = NULL;
1098         int i, prune_num = 1; /* counting terminating NULL */
1099
1100         if (get_sha1("HEAD", sha1))
1101                 die("--merge without HEAD?");
1102         head = lookup_commit_or_die(sha1, "HEAD");
1103         if (get_sha1("MERGE_HEAD", sha1))
1104                 die("--merge without MERGE_HEAD?");
1105         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1106         add_pending_object(revs, &head->object, "HEAD");
1107         add_pending_object(revs, &other->object, "MERGE_HEAD");
1108         bases = get_merge_bases(head, other, 1);
1109         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING);
1110         add_pending_commit_list(revs, bases, UNINTERESTING);
1111         free_commit_list(bases);
1112         head->object.flags |= SYMMETRIC_LEFT;
1113
1114         if (!active_nr)
1115                 read_cache();
1116         for (i = 0; i < active_nr; i++) {
1117                 struct cache_entry *ce = active_cache[i];
1118                 if (!ce_stage(ce))
1119                         continue;
1120                 if (ce_path_match(ce, &revs->prune_data)) {
1121                         prune_num++;
1122                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
1123                         prune[prune_num-2] = ce->name;
1124                         prune[prune_num-1] = NULL;
1125                 }
1126                 while ((i+1 < active_nr) &&
1127                        ce_same_name(ce, active_cache[i+1]))
1128                         i++;
1129         }
1130         free_pathspec(&revs->prune_data);
1131         init_pathspec(&revs->prune_data, prune);
1132         revs->limited = 1;
1133 }
1134
1135 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1136 {
1137         struct object_context oc;
1138         char *dotdot;
1139         struct object *object;
1140         unsigned char sha1[20];
1141         int local_flags;
1142         const char *arg = arg_;
1143         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1144         unsigned get_sha1_flags = 0;
1145
1146         dotdot = strstr(arg, "..");
1147         if (dotdot) {
1148                 unsigned char from_sha1[20];
1149                 const char *next = dotdot + 2;
1150                 const char *this = arg;
1151                 int symmetric = *next == '.';
1152                 unsigned int flags_exclude = flags ^ UNINTERESTING;
1153                 static const char head_by_default[] = "HEAD";
1154                 unsigned int a_flags;
1155
1156                 *dotdot = 0;
1157                 next += symmetric;
1158
1159                 if (!*next)
1160                         next = head_by_default;
1161                 if (dotdot == arg)
1162                         this = head_by_default;
1163                 if (this == head_by_default && next == head_by_default &&
1164                     !symmetric) {
1165                         /*
1166                          * Just ".."?  That is not a range but the
1167                          * pathspec for the parent directory.
1168                          */
1169                         if (!cant_be_filename) {
1170                                 *dotdot = '.';
1171                                 return -1;
1172                         }
1173                 }
1174                 if (!get_sha1_committish(this, from_sha1) &&
1175                     !get_sha1_committish(next, sha1)) {
1176                         struct commit *a, *b;
1177                         struct commit_list *exclude;
1178
1179                         a = lookup_commit_reference(from_sha1);
1180                         b = lookup_commit_reference(sha1);
1181                         if (!a || !b) {
1182                                 if (revs->ignore_missing)
1183                                         return 0;
1184                                 die(symmetric ?
1185                                     "Invalid symmetric difference expression %s...%s" :
1186                                     "Invalid revision range %s..%s",
1187                                     arg, next);
1188                         }
1189
1190                         if (!cant_be_filename) {
1191                                 *dotdot = '.';
1192                                 verify_non_filename(revs->prefix, arg);
1193                         }
1194
1195                         if (symmetric) {
1196                                 exclude = get_merge_bases(a, b, 1);
1197                                 add_rev_cmdline_list(revs, exclude,
1198                                                      REV_CMD_MERGE_BASE,
1199                                                      flags_exclude);
1200                                 add_pending_commit_list(revs, exclude,
1201                                                         flags_exclude);
1202                                 free_commit_list(exclude);
1203                                 a_flags = flags | SYMMETRIC_LEFT;
1204                         } else
1205                                 a_flags = flags_exclude;
1206                         a->object.flags |= a_flags;
1207                         b->object.flags |= flags;
1208                         add_rev_cmdline(revs, &a->object, this,
1209                                         REV_CMD_LEFT, a_flags);
1210                         add_rev_cmdline(revs, &b->object, next,
1211                                         REV_CMD_RIGHT, flags);
1212                         add_pending_object(revs, &a->object, this);
1213                         add_pending_object(revs, &b->object, next);
1214                         return 0;
1215                 }
1216                 *dotdot = '.';
1217         }
1218         dotdot = strstr(arg, "^@");
1219         if (dotdot && !dotdot[2]) {
1220                 *dotdot = 0;
1221                 if (add_parents_only(revs, arg, flags))
1222                         return 0;
1223                 *dotdot = '^';
1224         }
1225         dotdot = strstr(arg, "^!");
1226         if (dotdot && !dotdot[2]) {
1227                 *dotdot = 0;
1228                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1229                         *dotdot = '^';
1230         }
1231
1232         local_flags = 0;
1233         if (*arg == '^') {
1234                 local_flags = UNINTERESTING;
1235                 arg++;
1236         }
1237
1238         if (revarg_opt & REVARG_COMMITTISH)
1239                 get_sha1_flags = GET_SHA1_COMMITTISH;
1240
1241         if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1242                 return revs->ignore_missing ? 0 : -1;
1243         if (!cant_be_filename)
1244                 verify_non_filename(revs->prefix, arg);
1245         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1246         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1247         add_pending_object_with_mode(revs, object, arg, oc.mode);
1248         return 0;
1249 }
1250
1251 struct cmdline_pathspec {
1252         int alloc;
1253         int nr;
1254         const char **path;
1255 };
1256
1257 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1258 {
1259         while (*av) {
1260                 ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1261                 prune->path[prune->nr++] = *(av++);
1262         }
1263 }
1264
1265 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1266                                      struct cmdline_pathspec *prune)
1267 {
1268         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1269                 int len = sb->len;
1270                 if (len && sb->buf[len - 1] == '\n')
1271                         sb->buf[--len] = '\0';
1272                 ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1273                 prune->path[prune->nr++] = xstrdup(sb->buf);
1274         }
1275 }
1276
1277 static void read_revisions_from_stdin(struct rev_info *revs,
1278                                       struct cmdline_pathspec *prune)
1279 {
1280         struct strbuf sb;
1281         int seen_dashdash = 0;
1282
1283         strbuf_init(&sb, 1000);
1284         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1285                 int len = sb.len;
1286                 if (len && sb.buf[len - 1] == '\n')
1287                         sb.buf[--len] = '\0';
1288                 if (!len)
1289                         break;
1290                 if (sb.buf[0] == '-') {
1291                         if (len == 2 && sb.buf[1] == '-') {
1292                                 seen_dashdash = 1;
1293                                 break;
1294                         }
1295                         die("options not supported in --stdin mode");
1296                 }
1297                 if (handle_revision_arg(xstrdup(sb.buf), revs, 0,
1298                                         REVARG_CANNOT_BE_FILENAME))
1299                         die("bad revision '%s'", sb.buf);
1300         }
1301         if (seen_dashdash)
1302                 read_pathspec_from_stdin(revs, &sb, prune);
1303         strbuf_release(&sb);
1304 }
1305
1306 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1307 {
1308         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1309 }
1310
1311 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1312 {
1313         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1314 }
1315
1316 static void add_message_grep(struct rev_info *revs, const char *pattern)
1317 {
1318         add_grep(revs, pattern, GREP_PATTERN_BODY);
1319 }
1320
1321 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1322                                int *unkc, const char **unkv)
1323 {
1324         const char *arg = argv[0];
1325         const char *optarg;
1326         int argcount;
1327
1328         /* pseudo revision arguments */
1329         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1330             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1331             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1332             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1333             !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1334             !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1335             !prefixcmp(arg, "--remotes=") || !prefixcmp(arg, "--no-walk="))
1336         {
1337                 unkv[(*unkc)++] = arg;
1338                 return 1;
1339         }
1340
1341         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1342                 revs->max_count = atoi(optarg);
1343                 revs->no_walk = 0;
1344                 return argcount;
1345         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1346                 revs->skip_count = atoi(optarg);
1347                 return argcount;
1348         } else if ((*arg == '-') && isdigit(arg[1])) {
1349         /* accept -<digit>, like traditional "head" */
1350                 revs->max_count = atoi(arg + 1);
1351                 revs->no_walk = 0;
1352         } else if (!strcmp(arg, "-n")) {
1353                 if (argc <= 1)
1354                         return error("-n requires an argument");
1355                 revs->max_count = atoi(argv[1]);
1356                 revs->no_walk = 0;
1357                 return 2;
1358         } else if (!prefixcmp(arg, "-n")) {
1359                 revs->max_count = atoi(arg + 2);
1360                 revs->no_walk = 0;
1361         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1362                 revs->max_age = atoi(optarg);
1363                 return argcount;
1364         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1365                 revs->max_age = approxidate(optarg);
1366                 return argcount;
1367         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1368                 revs->max_age = approxidate(optarg);
1369                 return argcount;
1370         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1371                 revs->min_age = atoi(optarg);
1372                 return argcount;
1373         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1374                 revs->min_age = approxidate(optarg);
1375                 return argcount;
1376         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1377                 revs->min_age = approxidate(optarg);
1378                 return argcount;
1379         } else if (!strcmp(arg, "--first-parent")) {
1380                 revs->first_parent_only = 1;
1381         } else if (!strcmp(arg, "--ancestry-path")) {
1382                 revs->ancestry_path = 1;
1383                 revs->simplify_history = 0;
1384                 revs->limited = 1;
1385         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1386                 init_reflog_walk(&revs->reflog_info);
1387         } else if (!strcmp(arg, "--default")) {
1388                 if (argc <= 1)
1389                         return error("bad --default argument");
1390                 revs->def = argv[1];
1391                 return 2;
1392         } else if (!strcmp(arg, "--merge")) {
1393                 revs->show_merge = 1;
1394         } else if (!strcmp(arg, "--topo-order")) {
1395                 revs->lifo = 1;
1396                 revs->topo_order = 1;
1397         } else if (!strcmp(arg, "--simplify-merges")) {
1398                 revs->simplify_merges = 1;
1399                 revs->topo_order = 1;
1400                 revs->rewrite_parents = 1;
1401                 revs->simplify_history = 0;
1402                 revs->limited = 1;
1403         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1404                 revs->simplify_merges = 1;
1405                 revs->topo_order = 1;
1406                 revs->rewrite_parents = 1;
1407                 revs->simplify_history = 0;
1408                 revs->simplify_by_decoration = 1;
1409                 revs->limited = 1;
1410                 revs->prune = 1;
1411                 load_ref_decorations(DECORATE_SHORT_REFS);
1412         } else if (!strcmp(arg, "--date-order")) {
1413                 revs->lifo = 0;
1414                 revs->topo_order = 1;
1415         } else if (!prefixcmp(arg, "--early-output")) {
1416                 int count = 100;
1417                 switch (arg[14]) {
1418                 case '=':
1419                         count = atoi(arg+15);
1420                         /* Fallthrough */
1421                 case 0:
1422                         revs->topo_order = 1;
1423                        revs->early_output = count;
1424                 }
1425         } else if (!strcmp(arg, "--parents")) {
1426                 revs->rewrite_parents = 1;
1427                 revs->print_parents = 1;
1428         } else if (!strcmp(arg, "--dense")) {
1429                 revs->dense = 1;
1430         } else if (!strcmp(arg, "--sparse")) {
1431                 revs->dense = 0;
1432         } else if (!strcmp(arg, "--show-all")) {
1433                 revs->show_all = 1;
1434         } else if (!strcmp(arg, "--remove-empty")) {
1435                 revs->remove_empty_trees = 1;
1436         } else if (!strcmp(arg, "--merges")) {
1437                 revs->min_parents = 2;
1438         } else if (!strcmp(arg, "--no-merges")) {
1439                 revs->max_parents = 1;
1440         } else if (!prefixcmp(arg, "--min-parents=")) {
1441                 revs->min_parents = atoi(arg+14);
1442         } else if (!prefixcmp(arg, "--no-min-parents")) {
1443                 revs->min_parents = 0;
1444         } else if (!prefixcmp(arg, "--max-parents=")) {
1445                 revs->max_parents = atoi(arg+14);
1446         } else if (!prefixcmp(arg, "--no-max-parents")) {
1447                 revs->max_parents = -1;
1448         } else if (!strcmp(arg, "--boundary")) {
1449                 revs->boundary = 1;
1450         } else if (!strcmp(arg, "--left-right")) {
1451                 revs->left_right = 1;
1452         } else if (!strcmp(arg, "--left-only")) {
1453                 if (revs->right_only)
1454                         die("--left-only is incompatible with --right-only"
1455                             " or --cherry");
1456                 revs->left_only = 1;
1457         } else if (!strcmp(arg, "--right-only")) {
1458                 if (revs->left_only)
1459                         die("--right-only is incompatible with --left-only");
1460                 revs->right_only = 1;
1461         } else if (!strcmp(arg, "--cherry")) {
1462                 if (revs->left_only)
1463                         die("--cherry is incompatible with --left-only");
1464                 revs->cherry_mark = 1;
1465                 revs->right_only = 1;
1466                 revs->max_parents = 1;
1467                 revs->limited = 1;
1468         } else if (!strcmp(arg, "--count")) {
1469                 revs->count = 1;
1470         } else if (!strcmp(arg, "--cherry-mark")) {
1471                 if (revs->cherry_pick)
1472                         die("--cherry-mark is incompatible with --cherry-pick");
1473                 revs->cherry_mark = 1;
1474                 revs->limited = 1; /* needs limit_list() */
1475         } else if (!strcmp(arg, "--cherry-pick")) {
1476                 if (revs->cherry_mark)
1477                         die("--cherry-pick is incompatible with --cherry-mark");
1478                 revs->cherry_pick = 1;
1479                 revs->limited = 1;
1480         } else if (!strcmp(arg, "--objects")) {
1481                 revs->tag_objects = 1;
1482                 revs->tree_objects = 1;
1483                 revs->blob_objects = 1;
1484         } else if (!strcmp(arg, "--objects-edge")) {
1485                 revs->tag_objects = 1;
1486                 revs->tree_objects = 1;
1487                 revs->blob_objects = 1;
1488                 revs->edge_hint = 1;
1489         } else if (!strcmp(arg, "--verify-objects")) {
1490                 revs->tag_objects = 1;
1491                 revs->tree_objects = 1;
1492                 revs->blob_objects = 1;
1493                 revs->verify_objects = 1;
1494         } else if (!strcmp(arg, "--unpacked")) {
1495                 revs->unpacked = 1;
1496         } else if (!prefixcmp(arg, "--unpacked=")) {
1497                 die("--unpacked=<packfile> no longer supported.");
1498         } else if (!strcmp(arg, "-r")) {
1499                 revs->diff = 1;
1500                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1501         } else if (!strcmp(arg, "-t")) {
1502                 revs->diff = 1;
1503                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1504                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1505         } else if (!strcmp(arg, "-m")) {
1506                 revs->ignore_merges = 0;
1507         } else if (!strcmp(arg, "-c")) {
1508                 revs->diff = 1;
1509                 revs->dense_combined_merges = 0;
1510                 revs->combine_merges = 1;
1511         } else if (!strcmp(arg, "--cc")) {
1512                 revs->diff = 1;
1513                 revs->dense_combined_merges = 1;
1514                 revs->combine_merges = 1;
1515         } else if (!strcmp(arg, "-v")) {
1516                 revs->verbose_header = 1;
1517         } else if (!strcmp(arg, "--pretty")) {
1518                 revs->verbose_header = 1;
1519                 revs->pretty_given = 1;
1520                 get_commit_format(arg+8, revs);
1521         } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1522                 /*
1523                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1524                  * not allowed, since the argument is optional.
1525                  */
1526                 revs->verbose_header = 1;
1527                 revs->pretty_given = 1;
1528                 get_commit_format(arg+9, revs);
1529         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1530                 revs->show_notes = 1;
1531                 revs->show_notes_given = 1;
1532                 revs->notes_opt.use_default_notes = 1;
1533         } else if (!strcmp(arg, "--show-signature")) {
1534                 revs->show_signature = 1;
1535         } else if (!prefixcmp(arg, "--show-notes=") ||
1536                    !prefixcmp(arg, "--notes=")) {
1537                 struct strbuf buf = STRBUF_INIT;
1538                 revs->show_notes = 1;
1539                 revs->show_notes_given = 1;
1540                 if (!prefixcmp(arg, "--show-notes")) {
1541                         if (revs->notes_opt.use_default_notes < 0)
1542                                 revs->notes_opt.use_default_notes = 1;
1543                         strbuf_addstr(&buf, arg+13);
1544                 }
1545                 else
1546                         strbuf_addstr(&buf, arg+8);
1547                 expand_notes_ref(&buf);
1548                 string_list_append(&revs->notes_opt.extra_notes_refs,
1549                                    strbuf_detach(&buf, NULL));
1550         } else if (!strcmp(arg, "--no-notes")) {
1551                 revs->show_notes = 0;
1552                 revs->show_notes_given = 1;
1553                 revs->notes_opt.use_default_notes = -1;
1554                 /* we have been strdup'ing ourselves, so trick
1555                  * string_list into free()ing strings */
1556                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1557                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1558                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1559         } else if (!strcmp(arg, "--standard-notes")) {
1560                 revs->show_notes_given = 1;
1561                 revs->notes_opt.use_default_notes = 1;
1562         } else if (!strcmp(arg, "--no-standard-notes")) {
1563                 revs->notes_opt.use_default_notes = 0;
1564         } else if (!strcmp(arg, "--oneline")) {
1565                 revs->verbose_header = 1;
1566                 get_commit_format("oneline", revs);
1567                 revs->pretty_given = 1;
1568                 revs->abbrev_commit = 1;
1569         } else if (!strcmp(arg, "--graph")) {
1570                 revs->topo_order = 1;
1571                 revs->rewrite_parents = 1;
1572                 revs->graph = graph_init(revs);
1573         } else if (!strcmp(arg, "--root")) {
1574                 revs->show_root_diff = 1;
1575         } else if (!strcmp(arg, "--no-commit-id")) {
1576                 revs->no_commit_id = 1;
1577         } else if (!strcmp(arg, "--always")) {
1578                 revs->always_show_header = 1;
1579         } else if (!strcmp(arg, "--no-abbrev")) {
1580                 revs->abbrev = 0;
1581         } else if (!strcmp(arg, "--abbrev")) {
1582                 revs->abbrev = DEFAULT_ABBREV;
1583         } else if (!prefixcmp(arg, "--abbrev=")) {
1584                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1585                 if (revs->abbrev < MINIMUM_ABBREV)
1586                         revs->abbrev = MINIMUM_ABBREV;
1587                 else if (revs->abbrev > 40)
1588                         revs->abbrev = 40;
1589         } else if (!strcmp(arg, "--abbrev-commit")) {
1590                 revs->abbrev_commit = 1;
1591                 revs->abbrev_commit_given = 1;
1592         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1593                 revs->abbrev_commit = 0;
1594         } else if (!strcmp(arg, "--full-diff")) {
1595                 revs->diff = 1;
1596                 revs->full_diff = 1;
1597         } else if (!strcmp(arg, "--full-history")) {
1598                 revs->simplify_history = 0;
1599         } else if (!strcmp(arg, "--relative-date")) {
1600                 revs->date_mode = DATE_RELATIVE;
1601                 revs->date_mode_explicit = 1;
1602         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1603                 revs->date_mode = parse_date_format(optarg);
1604                 revs->date_mode_explicit = 1;
1605                 return argcount;
1606         } else if (!strcmp(arg, "--log-size")) {
1607                 revs->show_log_size = 1;
1608         }
1609         /*
1610          * Grepping the commit log
1611          */
1612         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1613                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1614                 return argcount;
1615         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1616                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1617                 return argcount;
1618         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
1619                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
1620                 return argcount;
1621         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1622                 add_message_grep(revs, optarg);
1623                 return argcount;
1624         } else if (!strcmp(arg, "--grep-debug")) {
1625                 revs->grep_filter.debug = 1;
1626         } else if (!strcmp(arg, "--basic-regexp")) {
1627                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
1628         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1629                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
1630         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1631                 revs->grep_filter.regflags |= REG_ICASE;
1632                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1633         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1634                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
1635         } else if (!strcmp(arg, "--perl-regexp")) {
1636                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
1637         } else if (!strcmp(arg, "--all-match")) {
1638                 revs->grep_filter.all_match = 1;
1639         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1640                 if (strcmp(optarg, "none"))
1641                         git_log_output_encoding = xstrdup(optarg);
1642                 else
1643                         git_log_output_encoding = "";
1644                 return argcount;
1645         } else if (!strcmp(arg, "--reverse")) {
1646                 revs->reverse ^= 1;
1647         } else if (!strcmp(arg, "--children")) {
1648                 revs->children.name = "children";
1649                 revs->limited = 1;
1650         } else if (!strcmp(arg, "--ignore-missing")) {
1651                 revs->ignore_missing = 1;
1652         } else {
1653                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1654                 if (!opts)
1655                         unkv[(*unkc)++] = arg;
1656                 return opts;
1657         }
1658
1659         return 1;
1660 }
1661
1662 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1663                         const struct option *options,
1664                         const char * const usagestr[])
1665 {
1666         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1667                                     &ctx->cpidx, ctx->out);
1668         if (n <= 0) {
1669                 error("unknown option `%s'", ctx->argv[0]);
1670                 usage_with_options(usagestr, options);
1671         }
1672         ctx->argv += n;
1673         ctx->argc -= n;
1674 }
1675
1676 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1677 {
1678         return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1679 }
1680
1681 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1682 {
1683         return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1684 }
1685
1686 static int handle_revision_pseudo_opt(const char *submodule,
1687                                 struct rev_info *revs,
1688                                 int argc, const char **argv, int *flags)
1689 {
1690         const char *arg = argv[0];
1691         const char *optarg;
1692         int argcount;
1693
1694         /*
1695          * NOTE!
1696          *
1697          * Commands like "git shortlog" will not accept the options below
1698          * unless parse_revision_opt queues them (as opposed to erroring
1699          * out).
1700          *
1701          * When implementing your new pseudo-option, remember to
1702          * register it in the list at the top of handle_revision_opt.
1703          */
1704         if (!strcmp(arg, "--all")) {
1705                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1706                 handle_refs(submodule, revs, *flags, head_ref_submodule);
1707         } else if (!strcmp(arg, "--branches")) {
1708                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1709         } else if (!strcmp(arg, "--bisect")) {
1710                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1711                 handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
1712                 revs->bisect = 1;
1713         } else if (!strcmp(arg, "--tags")) {
1714                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1715         } else if (!strcmp(arg, "--remotes")) {
1716                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1717         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1718                 struct all_refs_cb cb;
1719                 init_all_refs_cb(&cb, revs, *flags);
1720                 for_each_glob_ref(handle_one_ref, optarg, &cb);
1721                 return argcount;
1722         } else if (!prefixcmp(arg, "--branches=")) {
1723                 struct all_refs_cb cb;
1724                 init_all_refs_cb(&cb, revs, *flags);
1725                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1726         } else if (!prefixcmp(arg, "--tags=")) {
1727                 struct all_refs_cb cb;
1728                 init_all_refs_cb(&cb, revs, *flags);
1729                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1730         } else if (!prefixcmp(arg, "--remotes=")) {
1731                 struct all_refs_cb cb;
1732                 init_all_refs_cb(&cb, revs, *flags);
1733                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1734         } else if (!strcmp(arg, "--reflog")) {
1735                 handle_reflog(revs, *flags);
1736         } else if (!strcmp(arg, "--not")) {
1737                 *flags ^= UNINTERESTING;
1738         } else if (!strcmp(arg, "--no-walk")) {
1739                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
1740         } else if (!prefixcmp(arg, "--no-walk=")) {
1741                 /*
1742                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
1743                  * not allowed, since the argument is optional.
1744                  */
1745                 if (!strcmp(arg + 10, "sorted"))
1746                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
1747                 else if (!strcmp(arg + 10, "unsorted"))
1748                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
1749                 else
1750                         return error("invalid argument to --no-walk");
1751         } else if (!strcmp(arg, "--do-walk")) {
1752                 revs->no_walk = 0;
1753         } else {
1754                 return 0;
1755         }
1756
1757         return 1;
1758 }
1759
1760 /*
1761  * Parse revision information, filling in the "rev_info" structure,
1762  * and removing the used arguments from the argument list.
1763  *
1764  * Returns the number of arguments left that weren't recognized
1765  * (which are also moved to the head of the argument list)
1766  */
1767 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1768 {
1769         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
1770         struct cmdline_pathspec prune_data;
1771         const char *submodule = NULL;
1772
1773         memset(&prune_data, 0, sizeof(prune_data));
1774         if (opt)
1775                 submodule = opt->submodule;
1776
1777         /* First, search for "--" */
1778         if (opt && opt->assume_dashdash) {
1779                 seen_dashdash = 1;
1780         } else {
1781                 seen_dashdash = 0;
1782                 for (i = 1; i < argc; i++) {
1783                         const char *arg = argv[i];
1784                         if (strcmp(arg, "--"))
1785                                 continue;
1786                         argv[i] = NULL;
1787                         argc = i;
1788                         if (argv[i + 1])
1789                                 append_prune_data(&prune_data, argv + i + 1);
1790                         seen_dashdash = 1;
1791                         break;
1792                 }
1793         }
1794
1795         /* Second, deal with arguments and options */
1796         flags = 0;
1797         revarg_opt = opt ? opt->revarg_opt : 0;
1798         if (seen_dashdash)
1799                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
1800         read_from_stdin = 0;
1801         for (left = i = 1; i < argc; i++) {
1802                 const char *arg = argv[i];
1803                 if (*arg == '-') {
1804                         int opts;
1805
1806                         opts = handle_revision_pseudo_opt(submodule,
1807                                                 revs, argc - i, argv + i,
1808                                                 &flags);
1809                         if (opts > 0) {
1810                                 i += opts - 1;
1811                                 continue;
1812                         }
1813
1814                         if (!strcmp(arg, "--stdin")) {
1815                                 if (revs->disable_stdin) {
1816                                         argv[left++] = arg;
1817                                         continue;
1818                                 }
1819                                 if (read_from_stdin++)
1820                                         die("--stdin given twice?");
1821                                 read_revisions_from_stdin(revs, &prune_data);
1822                                 continue;
1823                         }
1824
1825                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1826                         if (opts > 0) {
1827                                 i += opts - 1;
1828                                 continue;
1829                         }
1830                         if (opts < 0)
1831                                 exit(128);
1832                         continue;
1833                 }
1834
1835
1836                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
1837                         int j;
1838                         if (seen_dashdash || *arg == '^')
1839                                 die("bad revision '%s'", arg);
1840
1841                         /* If we didn't have a "--":
1842                          * (1) all filenames must exist;
1843                          * (2) all rev-args must not be interpretable
1844                          *     as a valid filename.
1845                          * but the latter we have checked in the main loop.
1846                          */
1847                         for (j = i; j < argc; j++)
1848                                 verify_filename(revs->prefix, argv[j], j == i);
1849
1850                         append_prune_data(&prune_data, argv + i);
1851                         break;
1852                 }
1853                 else
1854                         got_rev_arg = 1;
1855         }
1856
1857         if (prune_data.nr) {
1858                 /*
1859                  * If we need to introduce the magic "a lone ':' means no
1860                  * pathspec whatsoever", here is the place to do so.
1861                  *
1862                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1863                  *      prune_data.nr = 0;
1864                  *      prune_data.alloc = 0;
1865                  *      free(prune_data.path);
1866                  *      prune_data.path = NULL;
1867                  * } else {
1868                  *      terminate prune_data.alloc with NULL and
1869                  *      call init_pathspec() to set revs->prune_data here.
1870                  * }
1871                  */
1872                 ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1873                 prune_data.path[prune_data.nr++] = NULL;
1874                 init_pathspec(&revs->prune_data,
1875                               get_pathspec(revs->prefix, prune_data.path));
1876         }
1877
1878         if (revs->def == NULL)
1879                 revs->def = opt ? opt->def : NULL;
1880         if (opt && opt->tweak)
1881                 opt->tweak(revs, opt);
1882         if (revs->show_merge)
1883                 prepare_show_merge(revs);
1884         if (revs->def && !revs->pending.nr && !got_rev_arg) {
1885                 unsigned char sha1[20];
1886                 struct object *object;
1887                 struct object_context oc;
1888                 if (get_sha1_with_context(revs->def, 0, sha1, &oc))
1889                         die("bad default revision '%s'", revs->def);
1890                 object = get_reference(revs, revs->def, sha1, 0);
1891                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
1892         }
1893
1894         /* Did the user ask for any diff output? Run the diff! */
1895         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1896                 revs->diff = 1;
1897
1898         /* Pickaxe, diff-filter and rename following need diffs */
1899         if (revs->diffopt.pickaxe ||
1900             revs->diffopt.filter ||
1901             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1902                 revs->diff = 1;
1903
1904         if (revs->topo_order)
1905                 revs->limited = 1;
1906
1907         if (revs->prune_data.nr) {
1908                 diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1909                 /* Can't prune commits with rename following: the paths change.. */
1910                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1911                         revs->prune = 1;
1912                 if (!revs->full_diff)
1913                         diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1914         }
1915         if (revs->combine_merges)
1916                 revs->ignore_merges = 0;
1917         revs->diffopt.abbrev = revs->abbrev;
1918
1919         if (revs->line_level_traverse) {
1920                 revs->limited = 1;
1921                 revs->topo_order = 1;
1922         }
1923
1924         diff_setup_done(&revs->diffopt);
1925
1926         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
1927                                  &revs->grep_filter);
1928         compile_grep_patterns(&revs->grep_filter);
1929
1930         if (revs->reverse && revs->reflog_info)
1931                 die("cannot combine --reverse with --walk-reflogs");
1932         if (revs->rewrite_parents && revs->children.name)
1933                 die("cannot combine --parents and --children");
1934
1935         /*
1936          * Limitations on the graph functionality
1937          */
1938         if (revs->reverse && revs->graph)
1939                 die("cannot combine --reverse with --graph");
1940
1941         if (revs->reflog_info && revs->graph)
1942                 die("cannot combine --walk-reflogs with --graph");
1943         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
1944                 die("cannot use --grep-reflog without --walk-reflogs");
1945
1946         return left;
1947 }
1948
1949 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1950 {
1951         struct commit_list *l = xcalloc(1, sizeof(*l));
1952
1953         l->item = child;
1954         l->next = add_decoration(&revs->children, &parent->object, l);
1955 }
1956
1957 static int remove_duplicate_parents(struct commit *commit)
1958 {
1959         struct commit_list **pp, *p;
1960         int surviving_parents;
1961
1962         /* Examine existing parents while marking ones we have seen... */
1963         pp = &commit->parents;
1964         while ((p = *pp) != NULL) {
1965                 struct commit *parent = p->item;
1966                 if (parent->object.flags & TMP_MARK) {
1967                         *pp = p->next;
1968                         continue;
1969                 }
1970                 parent->object.flags |= TMP_MARK;
1971                 pp = &p->next;
1972         }
1973         /* count them while clearing the temporary mark */
1974         surviving_parents = 0;
1975         for (p = commit->parents; p; p = p->next) {
1976                 p->item->object.flags &= ~TMP_MARK;
1977                 surviving_parents++;
1978         }
1979         return surviving_parents;
1980 }
1981
1982 struct merge_simplify_state {
1983         struct commit *simplified;
1984 };
1985
1986 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1987 {
1988         struct merge_simplify_state *st;
1989
1990         st = lookup_decoration(&revs->merge_simplification, &commit->object);
1991         if (!st) {
1992                 st = xcalloc(1, sizeof(*st));
1993                 add_decoration(&revs->merge_simplification, &commit->object, st);
1994         }
1995         return st;
1996 }
1997
1998 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1999 {
2000         struct commit_list *p;
2001         struct merge_simplify_state *st, *pst;
2002         int cnt;
2003
2004         st = locate_simplify_state(revs, commit);
2005
2006         /*
2007          * Have we handled this one?
2008          */
2009         if (st->simplified)
2010                 return tail;
2011
2012         /*
2013          * An UNINTERESTING commit simplifies to itself, so does a
2014          * root commit.  We do not rewrite parents of such commit
2015          * anyway.
2016          */
2017         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2018                 st->simplified = commit;
2019                 return tail;
2020         }
2021
2022         /*
2023          * Do we know what commit all of our parents that matter
2024          * should be rewritten to?  Otherwise we are not ready to
2025          * rewrite this one yet.
2026          */
2027         for (cnt = 0, p = commit->parents; p; p = p->next) {
2028                 pst = locate_simplify_state(revs, p->item);
2029                 if (!pst->simplified) {
2030                         tail = &commit_list_insert(p->item, tail)->next;
2031                         cnt++;
2032                 }
2033                 if (revs->first_parent_only)
2034                         break;
2035         }
2036         if (cnt) {
2037                 tail = &commit_list_insert(commit, tail)->next;
2038                 return tail;
2039         }
2040
2041         /*
2042          * Rewrite our list of parents.
2043          */
2044         for (p = commit->parents; p; p = p->next) {
2045                 pst = locate_simplify_state(revs, p->item);
2046                 p->item = pst->simplified;
2047                 if (revs->first_parent_only)
2048                         break;
2049         }
2050
2051         if (revs->first_parent_only)
2052                 cnt = 1;
2053         else
2054                 cnt = remove_duplicate_parents(commit);
2055
2056         /*
2057          * It is possible that we are a merge and one side branch
2058          * does not have any commit that touches the given paths;
2059          * in such a case, the immediate parents will be rewritten
2060          * to different commits.
2061          *
2062          *      o----X          X: the commit we are looking at;
2063          *     /    /           o: a commit that touches the paths;
2064          * ---o----'
2065          *
2066          * Further reduce the parents by removing redundant parents.
2067          */
2068         if (1 < cnt) {
2069                 struct commit_list *h = reduce_heads(commit->parents);
2070                 cnt = commit_list_count(h);
2071                 free_commit_list(commit->parents);
2072                 commit->parents = h;
2073         }
2074
2075         /*
2076          * A commit simplifies to itself if it is a root, if it is
2077          * UNINTERESTING, if it touches the given paths, or if it is a
2078          * merge and its parents simplifies to more than one commits
2079          * (the first two cases are already handled at the beginning of
2080          * this function).
2081          *
2082          * Otherwise, it simplifies to what its sole parent simplifies to.
2083          */
2084         if (!cnt ||
2085             (commit->object.flags & UNINTERESTING) ||
2086             !(commit->object.flags & TREESAME) ||
2087             (1 < cnt))
2088                 st->simplified = commit;
2089         else {
2090                 pst = locate_simplify_state(revs, commit->parents->item);
2091                 st->simplified = pst->simplified;
2092         }
2093         return tail;
2094 }
2095
2096 static void simplify_merges(struct rev_info *revs)
2097 {
2098         struct commit_list *list, *next;
2099         struct commit_list *yet_to_do, **tail;
2100         struct commit *commit;
2101
2102         if (!revs->prune)
2103                 return;
2104
2105         /* feed the list reversed */
2106         yet_to_do = NULL;
2107         for (list = revs->commits; list; list = next) {
2108                 commit = list->item;
2109                 next = list->next;
2110                 /*
2111                  * Do not free(list) here yet; the original list
2112                  * is used later in this function.
2113                  */
2114                 commit_list_insert(commit, &yet_to_do);
2115         }
2116         while (yet_to_do) {
2117                 list = yet_to_do;
2118                 yet_to_do = NULL;
2119                 tail = &yet_to_do;
2120                 while (list) {
2121                         commit = list->item;
2122                         next = list->next;
2123                         free(list);
2124                         list = next;
2125                         tail = simplify_one(revs, commit, tail);
2126                 }
2127         }
2128
2129         /* clean up the result, removing the simplified ones */
2130         list = revs->commits;
2131         revs->commits = NULL;
2132         tail = &revs->commits;
2133         while (list) {
2134                 struct merge_simplify_state *st;
2135
2136                 commit = list->item;
2137                 next = list->next;
2138                 free(list);
2139                 list = next;
2140                 st = locate_simplify_state(revs, commit);
2141                 if (st->simplified == commit)
2142                         tail = &commit_list_insert(commit, tail)->next;
2143         }
2144 }
2145
2146 static void set_children(struct rev_info *revs)
2147 {
2148         struct commit_list *l;
2149         for (l = revs->commits; l; l = l->next) {
2150                 struct commit *commit = l->item;
2151                 struct commit_list *p;
2152
2153                 for (p = commit->parents; p; p = p->next)
2154                         add_child(revs, p->item, commit);
2155         }
2156 }
2157
2158 void reset_revision_walk(void)
2159 {
2160         clear_object_flags(SEEN | ADDED | SHOWN);
2161 }
2162
2163 int prepare_revision_walk(struct rev_info *revs)
2164 {
2165         int nr = revs->pending.nr;
2166         struct object_array_entry *e, *list;
2167         struct commit_list **next = &revs->commits;
2168
2169         e = list = revs->pending.objects;
2170         revs->pending.nr = 0;
2171         revs->pending.alloc = 0;
2172         revs->pending.objects = NULL;
2173         while (--nr >= 0) {
2174                 struct commit *commit = handle_commit(revs, e->item, e->name);
2175                 if (commit) {
2176                         if (!(commit->object.flags & SEEN)) {
2177                                 commit->object.flags |= SEEN;
2178                                 next = commit_list_append(commit, next);
2179                         }
2180                 }
2181                 e++;
2182         }
2183         if (!revs->leak_pending)
2184                 free(list);
2185
2186         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2187                 commit_list_sort_by_date(&revs->commits);
2188         if (revs->no_walk)
2189                 return 0;
2190         if (revs->limited)
2191                 if (limit_list(revs) < 0)
2192                         return -1;
2193         if (revs->topo_order)
2194                 sort_in_topological_order(&revs->commits, revs->lifo);
2195         if (revs->line_level_traverse)
2196                 line_log_filter(revs);
2197         if (revs->simplify_merges)
2198                 simplify_merges(revs);
2199         if (revs->children.name)
2200                 set_children(revs);
2201         return 0;
2202 }
2203
2204 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2205 {
2206         struct commit_list *cache = NULL;
2207
2208         for (;;) {
2209                 struct commit *p = *pp;
2210                 if (!revs->limited)
2211                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2212                                 return rewrite_one_error;
2213                 if (p->parents && p->parents->next)
2214                         return rewrite_one_ok;
2215                 if (p->object.flags & UNINTERESTING)
2216                         return rewrite_one_ok;
2217                 if (!(p->object.flags & TREESAME))
2218                         return rewrite_one_ok;
2219                 if (!p->parents)
2220                         return rewrite_one_noparents;
2221                 *pp = p->parents->item;
2222         }
2223 }
2224
2225 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2226         rewrite_parent_fn_t rewrite_parent)
2227 {
2228         struct commit_list **pp = &commit->parents;
2229         while (*pp) {
2230                 struct commit_list *parent = *pp;
2231                 switch (rewrite_parent(revs, &parent->item)) {
2232                 case rewrite_one_ok:
2233                         break;
2234                 case rewrite_one_noparents:
2235                         *pp = parent->next;
2236                         continue;
2237                 case rewrite_one_error:
2238                         return -1;
2239                 }
2240                 pp = &parent->next;
2241         }
2242         remove_duplicate_parents(commit);
2243         return 0;
2244 }
2245
2246 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2247 {
2248         char *person, *endp;
2249         size_t len, namelen, maillen;
2250         const char *name;
2251         const char *mail;
2252         struct ident_split ident;
2253
2254         person = strstr(buf->buf, what);
2255         if (!person)
2256                 return 0;
2257
2258         person += strlen(what);
2259         endp = strchr(person, '\n');
2260         if (!endp)
2261                 return 0;
2262
2263         len = endp - person;
2264
2265         if (split_ident_line(&ident, person, len))
2266                 return 0;
2267
2268         mail = ident.mail_begin;
2269         maillen = ident.mail_end - ident.mail_begin;
2270         name = ident.name_begin;
2271         namelen = ident.name_end - ident.name_begin;
2272
2273         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2274                 struct strbuf namemail = STRBUF_INIT;
2275
2276                 strbuf_addf(&namemail, "%.*s <%.*s>",
2277                             (int)namelen, name, (int)maillen, mail);
2278
2279                 strbuf_splice(buf, ident.name_begin - buf->buf,
2280                               ident.mail_end - ident.name_begin + 1,
2281                               namemail.buf, namemail.len);
2282
2283                 strbuf_release(&namemail);
2284
2285                 return 1;
2286         }
2287
2288         return 0;
2289 }
2290
2291 static int commit_match(struct commit *commit, struct rev_info *opt)
2292 {
2293         int retval;
2294         const char *encoding;
2295         char *message;
2296         struct strbuf buf = STRBUF_INIT;
2297
2298         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2299                 return 1;
2300
2301         /* Prepend "fake" headers as needed */
2302         if (opt->grep_filter.use_reflog_filter) {
2303                 strbuf_addstr(&buf, "reflog ");
2304                 get_reflog_message(&buf, opt->reflog_info);
2305                 strbuf_addch(&buf, '\n');
2306         }
2307
2308         /*
2309          * We grep in the user's output encoding, under the assumption that it
2310          * is the encoding they are most likely to write their grep pattern
2311          * for. In addition, it means we will match the "notes" encoding below,
2312          * so we will not end up with a buffer that has two different encodings
2313          * in it.
2314          */
2315         encoding = get_log_output_encoding();
2316         message = logmsg_reencode(commit, NULL, encoding);
2317
2318         /* Copy the commit to temporary if we are using "fake" headers */
2319         if (buf.len)
2320                 strbuf_addstr(&buf, message);
2321
2322         if (opt->grep_filter.header_list && opt->mailmap) {
2323                 if (!buf.len)
2324                         strbuf_addstr(&buf, message);
2325
2326                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2327                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2328         }
2329
2330         /* Append "fake" message parts as needed */
2331         if (opt->show_notes) {
2332                 if (!buf.len)
2333                         strbuf_addstr(&buf, message);
2334                 format_display_notes(commit->object.sha1, &buf, encoding, 1);
2335         }
2336
2337         /* Find either in the original commit message, or in the temporary */
2338         if (buf.len)
2339                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2340         else
2341                 retval = grep_buffer(&opt->grep_filter,
2342                                      message, strlen(message));
2343         strbuf_release(&buf);
2344         logmsg_free(message, commit);
2345         return retval;
2346 }
2347
2348 static inline int want_ancestry(struct rev_info *revs)
2349 {
2350         return (revs->rewrite_parents || revs->children.name);
2351 }
2352
2353 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2354 {
2355         if (commit->object.flags & SHOWN)
2356                 return commit_ignore;
2357         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2358                 return commit_ignore;
2359         if (revs->show_all)
2360                 return commit_show;
2361         if (commit->object.flags & UNINTERESTING)
2362                 return commit_ignore;
2363         if (revs->min_age != -1 && (commit->date > revs->min_age))
2364                 return commit_ignore;
2365         if (revs->min_parents || (revs->max_parents >= 0)) {
2366                 int n = 0;
2367                 struct commit_list *p;
2368                 for (p = commit->parents; p; p = p->next)
2369                         n++;
2370                 if ((n < revs->min_parents) ||
2371                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2372                         return commit_ignore;
2373         }
2374         if (!commit_match(commit, revs))
2375                 return commit_ignore;
2376         if (revs->prune && revs->dense) {
2377                 /* Commit without changes? */
2378                 if (commit->object.flags & TREESAME) {
2379                         /* drop merges unless we want parenthood */
2380                         if (!want_ancestry(revs))
2381                                 return commit_ignore;
2382                         /* non-merge - always ignore it */
2383                         if (!commit->parents || !commit->parents->next)
2384                                 return commit_ignore;
2385                 }
2386         }
2387         return commit_show;
2388 }
2389
2390 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2391 {
2392         enum commit_action action = get_commit_action(revs, commit);
2393
2394         if (action == commit_show &&
2395             !revs->show_all &&
2396             revs->prune && revs->dense && want_ancestry(revs)) {
2397                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
2398                         return commit_error;
2399         }
2400         return action;
2401 }
2402
2403 static struct commit *get_revision_1(struct rev_info *revs)
2404 {
2405         if (!revs->commits)
2406                 return NULL;
2407
2408         do {
2409                 struct commit_list *entry = revs->commits;
2410                 struct commit *commit = entry->item;
2411
2412                 revs->commits = entry->next;
2413                 free(entry);
2414
2415                 if (revs->reflog_info) {
2416                         fake_reflog_parent(revs->reflog_info, commit);
2417                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2418                 }
2419
2420                 /*
2421                  * If we haven't done the list limiting, we need to look at
2422                  * the parents here. We also need to do the date-based limiting
2423                  * that we'd otherwise have done in limit_list().
2424                  */
2425                 if (!revs->limited) {
2426                         if (revs->max_age != -1 &&
2427                             (commit->date < revs->max_age))
2428                                 continue;
2429                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2430                                 die("Failed to traverse parents of commit %s",
2431                                     sha1_to_hex(commit->object.sha1));
2432                 }
2433
2434                 switch (simplify_commit(revs, commit)) {
2435                 case commit_ignore:
2436                         continue;
2437                 case commit_error:
2438                         die("Failed to simplify parents of commit %s",
2439                             sha1_to_hex(commit->object.sha1));
2440                 default:
2441                         return commit;
2442                 }
2443         } while (revs->commits);
2444         return NULL;
2445 }
2446
2447 static void gc_boundary(struct object_array *array)
2448 {
2449         unsigned nr = array->nr;
2450         unsigned alloc = array->alloc;
2451         struct object_array_entry *objects = array->objects;
2452
2453         if (alloc <= nr) {
2454                 unsigned i, j;
2455                 for (i = j = 0; i < nr; i++) {
2456                         if (objects[i].item->flags & SHOWN)
2457                                 continue;
2458                         if (i != j)
2459                                 objects[j] = objects[i];
2460                         j++;
2461                 }
2462                 for (i = j; i < nr; i++)
2463                         objects[i].item = NULL;
2464                 array->nr = j;
2465         }
2466 }
2467
2468 static void create_boundary_commit_list(struct rev_info *revs)
2469 {
2470         unsigned i;
2471         struct commit *c;
2472         struct object_array *array = &revs->boundary_commits;
2473         struct object_array_entry *objects = array->objects;
2474
2475         /*
2476          * If revs->commits is non-NULL at this point, an error occurred in
2477          * get_revision_1().  Ignore the error and continue printing the
2478          * boundary commits anyway.  (This is what the code has always
2479          * done.)
2480          */
2481         if (revs->commits) {
2482                 free_commit_list(revs->commits);
2483                 revs->commits = NULL;
2484         }
2485
2486         /*
2487          * Put all of the actual boundary commits from revs->boundary_commits
2488          * into revs->commits
2489          */
2490         for (i = 0; i < array->nr; i++) {
2491                 c = (struct commit *)(objects[i].item);
2492                 if (!c)
2493                         continue;
2494                 if (!(c->object.flags & CHILD_SHOWN))
2495                         continue;
2496                 if (c->object.flags & (SHOWN | BOUNDARY))
2497                         continue;
2498                 c->object.flags |= BOUNDARY;
2499                 commit_list_insert(c, &revs->commits);
2500         }
2501
2502         /*
2503          * If revs->topo_order is set, sort the boundary commits
2504          * in topological order
2505          */
2506         sort_in_topological_order(&revs->commits, revs->lifo);
2507 }
2508
2509 static struct commit *get_revision_internal(struct rev_info *revs)
2510 {
2511         struct commit *c = NULL;
2512         struct commit_list *l;
2513
2514         if (revs->boundary == 2) {
2515                 /*
2516                  * All of the normal commits have already been returned,
2517                  * and we are now returning boundary commits.
2518                  * create_boundary_commit_list() has populated
2519                  * revs->commits with the remaining commits to return.
2520                  */
2521                 c = pop_commit(&revs->commits);
2522                 if (c)
2523                         c->object.flags |= SHOWN;
2524                 return c;
2525         }
2526
2527         /*
2528          * If our max_count counter has reached zero, then we are done. We
2529          * don't simply return NULL because we still might need to show
2530          * boundary commits. But we want to avoid calling get_revision_1, which
2531          * might do a considerable amount of work finding the next commit only
2532          * for us to throw it away.
2533          *
2534          * If it is non-zero, then either we don't have a max_count at all
2535          * (-1), or it is still counting, in which case we decrement.
2536          */
2537         if (revs->max_count) {
2538                 c = get_revision_1(revs);
2539                 if (c) {
2540                         while (0 < revs->skip_count) {
2541                                 revs->skip_count--;
2542                                 c = get_revision_1(revs);
2543                                 if (!c)
2544                                         break;
2545                         }
2546                 }
2547
2548                 if (revs->max_count > 0)
2549                         revs->max_count--;
2550         }
2551
2552         if (c)
2553                 c->object.flags |= SHOWN;
2554
2555         if (!revs->boundary) {
2556                 return c;
2557         }
2558
2559         if (!c) {
2560                 /*
2561                  * get_revision_1() runs out the commits, and
2562                  * we are done computing the boundaries.
2563                  * switch to boundary commits output mode.
2564                  */
2565                 revs->boundary = 2;
2566
2567                 /*
2568                  * Update revs->commits to contain the list of
2569                  * boundary commits.
2570                  */
2571                 create_boundary_commit_list(revs);
2572
2573                 return get_revision_internal(revs);
2574         }
2575
2576         /*
2577          * boundary commits are the commits that are parents of the
2578          * ones we got from get_revision_1() but they themselves are
2579          * not returned from get_revision_1().  Before returning
2580          * 'c', we need to mark its parents that they could be boundaries.
2581          */
2582
2583         for (l = c->parents; l; l = l->next) {
2584                 struct object *p;
2585                 p = &(l->item->object);
2586                 if (p->flags & (CHILD_SHOWN | SHOWN))
2587                         continue;
2588                 p->flags |= CHILD_SHOWN;
2589                 gc_boundary(&revs->boundary_commits);
2590                 add_object_array(p, NULL, &revs->boundary_commits);
2591         }
2592
2593         return c;
2594 }
2595
2596 struct commit *get_revision(struct rev_info *revs)
2597 {
2598         struct commit *c;
2599         struct commit_list *reversed;
2600
2601         if (revs->reverse) {
2602                 reversed = NULL;
2603                 while ((c = get_revision_internal(revs))) {
2604                         commit_list_insert(c, &reversed);
2605                 }
2606                 revs->commits = reversed;
2607                 revs->reverse = 0;
2608                 revs->reverse_output_stage = 1;
2609         }
2610
2611         if (revs->reverse_output_stage)
2612                 return pop_commit(&revs->commits);
2613
2614         c = get_revision_internal(revs);
2615         if (c && revs->graph)
2616                 graph_update(revs->graph, c);
2617         return c;
2618 }
2619
2620 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2621 {
2622         if (commit->object.flags & BOUNDARY)
2623                 return "-";
2624         else if (commit->object.flags & UNINTERESTING)
2625                 return "^";
2626         else if (commit->object.flags & PATCHSAME)
2627                 return "=";
2628         else if (!revs || revs->left_right) {
2629                 if (commit->object.flags & SYMMETRIC_LEFT)
2630                         return "<";
2631                 else
2632                         return ">";
2633         } else if (revs->graph)
2634                 return "*";
2635         else if (revs->cherry_mark)
2636                 return "+";
2637         return "";
2638 }
2639
2640 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2641 {
2642         char *mark = get_revision_mark(revs, commit);
2643         if (!strlen(mark))
2644                 return;
2645         fputs(mark, stdout);
2646         putchar(' ');
2647 }