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 "grep.h"
  10 #include "reflog-walk.h"
  11 #include "patch-ids.h"
  12
  13 volatile show_early_output_fn_t show_early_output;
  14
  15 static char *path_name(struct name_path *path, const char *name)
  16 {
  17         struct name_path *p;
  18         char *n, *m;
  19         int nlen = strlen(name);
  20         int len = nlen + 1;
  21
  22         for (p = path; p; p = p->up) {
  23                 if (p->elem_len)
  24                         len += p->elem_len + 1;
  25         }
  26         n = xmalloc(len);
  27         m = n + len - (nlen + 1);
  28         strcpy(m, name);
  29         for (p = path; p; p = p->up) {
  30                 if (p->elem_len) {
  31                         m -= p->elem_len + 1;
  32                         memcpy(m, p->elem, p->elem_len);
  33                         m[p->elem_len] = '/';
  34                 }
  35         }
  36         return n;
  37 }
  38
  39 void add_object(struct object *obj,
  40                 struct object_array *p,
  41                 struct name_path *path,
  42                 const char *name)
  43 {
  44         add_object_array(obj, path_name(path, name), p);
  45 }
  46
  47 static void mark_blob_uninteresting(struct blob *blob)
  48 {
  49         if (blob->object.flags & UNINTERESTING)
  50                 return;
  51         blob->object.flags |= UNINTERESTING;
  52 }
  53
  54 void mark_tree_uninteresting(struct tree *tree)
  55 {
  56         struct tree_desc desc;
  57         struct name_entry entry;
  58         struct object *obj = &tree->object;
  59
  60         if (obj->flags & UNINTERESTING)
  61                 return;
  62         obj->flags |= UNINTERESTING;
  63         if (!has_sha1_file(obj->sha1))
  64                 return;
  65         if (parse_tree(tree) < 0)
  66                 die("bad tree %s", sha1_to_hex(obj->sha1));
  67
  68         init_tree_desc(&desc, tree->buffer, tree->size);
  69         while (tree_entry(&desc, &entry)) {
  70                 switch (object_type(entry.mode)) {
  71                 case OBJ_TREE:
  72                         mark_tree_uninteresting(lookup_tree(entry.sha1));
  73                         break;
  74                 case OBJ_BLOB:
  75                         mark_blob_uninteresting(lookup_blob(entry.sha1));
  76                         break;
  77                 default:
  78                         /* Subproject commit - not in this repository */
  79                         break;
  80                 }
  81         }
  82
  83         /*
  84          * We don't care about the tree any more
  85          * after it has been marked uninteresting.
  86          */
  87         free(tree->buffer);
  88         tree->buffer = NULL;
  89 }
  90
  91 void mark_parents_uninteresting(struct commit *commit)
  92 {
  93         struct commit_list *parents = commit->parents;
  94
  95         while (parents) {
  96                 struct commit *commit = parents->item;
  97                 if (!(commit->object.flags & UNINTERESTING)) {
  98                         commit->object.flags |= UNINTERESTING;
  99
 100                         /*
 101                          * Normally we haven't parsed the parent
 102                          * yet, so we won't have a parent of a parent
 103                          * here. However, it may turn out that we've
 104                          * reached this commit some other way (where it
 105                          * wasn't uninteresting), in which case we need
 106                          * to mark its parents recursively too..
 107                          */
 108                         if (commit->parents)
 109                                 mark_parents_uninteresting(commit);
 110                 }
 111
 112                 /*
 113                  * A missing commit is ok iff its parent is marked
 114                  * uninteresting.
 115                  *
 116                  * We just mark such a thing parsed, so that when
 117                  * it is popped next time around, we won't be trying
 118                  * to parse it and get an error.
 119                  */
 120                 if (!has_sha1_file(commit->object.sha1))
 121                         commit->object.parsed = 1;
 122                 parents = parents->next;
 123         }
 124 }
 125
 126 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 127 {
 128         if (revs->no_walk && (obj->flags & UNINTERESTING))
 129                 die("object ranges do not make sense when not walking revisions");
 130         if (revs->reflog_info && obj->type == OBJ_COMMIT &&
 131                         add_reflog_for_walk(revs->reflog_info,
 132                                 (struct commit *)obj, name))
 133                 return;
 134         add_object_array_with_mode(obj, name, &revs->pending, mode);
 135 }
 136
 137 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 138 {
 139         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 140 }
 141
 142 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 143 {
 144         struct object *object;
 145
 146         object = parse_object(sha1);
 147         if (!object)
 148                 die("bad object %s", name);
 149         object->flags |= flags;
 150         return object;
 151 }
 152
 153 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 154 {
 155         unsigned long flags = object->flags;
 156
 157         /*
 158          * Tag object? Look what it points to..
 159          */
 160         while (object->type == OBJ_TAG) {
 161                 struct tag *tag = (struct tag *) object;
 162                 if (revs->tag_objects && !(flags & UNINTERESTING))
 163                         add_pending_object(revs, object, tag->tag);
 164                 object = parse_object(tag->tagged->sha1);
 165                 if (!object)
 166                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 167         }
 168
 169         /*
 170          * Commit object? Just return it, we'll do all the complex
 171          * reachability crud.
 172          */
 173         if (object->type == OBJ_COMMIT) {
 174                 struct commit *commit = (struct commit *)object;
 175                 if (parse_commit(commit) < 0)
 176                         die("unable to parse commit %s", name);
 177                 if (flags & UNINTERESTING) {
 178                         commit->object.flags |= UNINTERESTING;
 179                         mark_parents_uninteresting(commit);
 180                         revs->limited = 1;
 181                 }
 182                 return commit;
 183         }
 184
 185         /*
 186          * Tree object? Either mark it uniniteresting, or add it
 187          * to the list of objects to look at later..
 188          */
 189         if (object->type == OBJ_TREE) {
 190                 struct tree *tree = (struct tree *)object;
 191                 if (!revs->tree_objects)
 192                         return NULL;
 193                 if (flags & UNINTERESTING) {
 194                         mark_tree_uninteresting(tree);
 195                         return NULL;
 196                 }
 197                 add_pending_object(revs, object, "");
 198                 return NULL;
 199         }
 200
 201         /*
 202          * Blob object? You know the drill by now..
 203          */
 204         if (object->type == OBJ_BLOB) {
 205                 struct blob *blob = (struct blob *)object;
 206                 if (!revs->blob_objects)
 207                         return NULL;
 208                 if (flags & UNINTERESTING) {
 209                         mark_blob_uninteresting(blob);
 210                         return NULL;
 211                 }
 212                 add_pending_object(revs, object, "");
 213                 return NULL;
 214         }
 215         die("%s is unknown object", name);
 216 }
 217
 218 static int everybody_uninteresting(struct commit_list *orig)
 219 {
 220         struct commit_list *list = orig;
 221         while (list) {
 222                 struct commit *commit = list->item;
 223                 list = list->next;
 224                 if (commit->object.flags & UNINTERESTING)
 225                         continue;
 226                 return 0;
 227         }
 228         return 1;
 229 }
 230
 231 /*
 232  * The goal is to get REV_TREE_NEW as the result only if the
 233  * diff consists of all '+' (and no other changes), and
 234  * REV_TREE_DIFFERENT otherwise (of course if the trees are
 235  * the same we want REV_TREE_SAME).  That means that once we
 236  * get to REV_TREE_DIFFERENT, we do not have to look any further.
 237  */
 238 static int tree_difference = REV_TREE_SAME;
 239
 240 static void file_add_remove(struct diff_options *options,
 241                     int addremove, unsigned mode,
 242                     const unsigned char *sha1,
 243                     const char *base, const char *path)
 244 {
 245         int diff = REV_TREE_DIFFERENT;
 246
 247         /*
 248          * Is it an add of a new file? It means that the old tree
 249          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 250          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 251          * (and if it already was "REV_TREE_NEW", we'll keep it
 252          * "REV_TREE_NEW" of course).
 253          */
 254         if (addremove == '+') {
 255                 diff = tree_difference;
 256                 if (diff != REV_TREE_SAME)
 257                         return;
 258                 diff = REV_TREE_NEW;
 259         }
 260         tree_difference = diff;
 261         if (tree_difference == REV_TREE_DIFFERENT)
 262                 DIFF_OPT_SET(options, HAS_CHANGES);
 263 }
 264
 265 static void file_change(struct diff_options *options,
 266                  unsigned old_mode, unsigned new_mode,
 267                  const unsigned char *old_sha1,
 268                  const unsigned char *new_sha1,
 269                  const char *base, const char *path)
 270 {
 271         tree_difference = REV_TREE_DIFFERENT;
 272         DIFF_OPT_SET(options, HAS_CHANGES);
 273 }
 274
 275 static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 276 {
 277         if (!t1)
 278                 return REV_TREE_NEW;
 279         if (!t2)
 280                 return REV_TREE_DIFFERENT;
 281         tree_difference = REV_TREE_SAME;
 282         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 283         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 284                            &revs->pruning) < 0)
 285                 return REV_TREE_DIFFERENT;
 286         return tree_difference;
 287 }
 288
 289 static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 290 {
 291         int retval;
 292         void *tree;
 293         unsigned long size;
 294         struct tree_desc empty, real;
 295
 296         if (!t1)
 297                 return 0;
 298
 299         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 300         if (!tree)
 301                 return 0;
 302         init_tree_desc(&real, tree, size);
 303         init_tree_desc(&empty, "", 0);
 304
 305         tree_difference = REV_TREE_SAME;
 306         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 307         retval = diff_tree(&empty, &real, "", &revs->pruning);
 308         free(tree);
 309
 310         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 311 }
 312
 313 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 314 {
 315         struct commit_list **pp, *parent;
 316         int tree_changed = 0, tree_same = 0;
 317
 318         /*
 319          * If we don't do pruning, everything is interesting
 320          */
 321         if (!revs->prune)
 322                 return;
 323
 324         if (!commit->tree)
 325                 return;
 326
 327         if (!commit->parents) {
 328                 if (rev_same_tree_as_empty(revs, commit->tree))
 329                         commit->object.flags |= TREESAME;
 330                 return;
 331         }
 332
 333         /*
 334          * Normal non-merge commit? If we don't want to make the
 335          * history dense, we consider it always to be a change..
 336          */
 337         if (!revs->dense && !commit->parents->next)
 338                 return;
 339
 340         pp = &commit->parents;
 341         while ((parent = *pp) != NULL) {
 342                 struct commit *p = parent->item;
 343
 344                 if (parse_commit(p) < 0)
 345                         die("cannot simplify commit %s (because of %s)",
 346                             sha1_to_hex(commit->object.sha1),
 347                             sha1_to_hex(p->object.sha1));
 348                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 349                 case REV_TREE_SAME:
 350                         tree_same = 1;
 351                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 352                                 /* Even if a merge with an uninteresting
 353                                  * side branch brought the entire change
 354                                  * we are interested in, we do not want
 355                                  * to lose the other branches of this
 356                                  * merge, so we just keep going.
 357                                  */
 358                                 pp = &parent->next;
 359                                 continue;
 360                         }
 361                         parent->next = NULL;
 362                         commit->parents = parent;
 363                         commit->object.flags |= TREESAME;
 364                         return;
 365
 366                 case REV_TREE_NEW:
 367                         if (revs->remove_empty_trees &&
 368                             rev_same_tree_as_empty(revs, p->tree)) {
 369                                 /* We are adding all the specified
 370                                  * paths from this parent, so the
 371                                  * history beyond this parent is not
 372                                  * interesting.  Remove its parents
 373                                  * (they are grandparents for us).
 374                                  * IOW, we pretend this parent is a
 375                                  * "root" commit.
 376                                  */
 377                                 if (parse_commit(p) < 0)
 378                                         die("cannot simplify commit %s (invalid %s)",
 379                                             sha1_to_hex(commit->object.sha1),
 380                                             sha1_to_hex(p->object.sha1));
 381                                 p->parents = NULL;
 382                         }
 383                 /* fallthrough */
 384                 case REV_TREE_DIFFERENT:
 385                         tree_changed = 1;
 386                         pp = &parent->next;
 387                         continue;
 388                 }
 389                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 390         }
 391         if (tree_changed && !tree_same)
 392                 return;
 393         commit->object.flags |= TREESAME;
 394 }
 395
 396 static int add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 397 {
 398         struct commit_list *parent = commit->parents;
 399         unsigned left_flag;
 400         int add, rest;
 401
 402         if (commit->object.flags & ADDED)
 403                 return 0;
 404         commit->object.flags |= ADDED;
 405
 406         /*
 407          * If the commit is uninteresting, don't try to
 408          * prune parents - we want the maximal uninteresting
 409          * set.
 410          *
 411          * Normally we haven't parsed the parent
 412          * yet, so we won't have a parent of a parent
 413          * here. However, it may turn out that we've
 414          * reached this commit some other way (where it
 415          * wasn't uninteresting), in which case we need
 416          * to mark its parents recursively too..
 417          */
 418         if (commit->object.flags & UNINTERESTING) {
 419                 while (parent) {
 420                         struct commit *p = parent->item;
 421                         parent = parent->next;
 422                         if (parse_commit(p) < 0)
 423                                 return -1;
 424                         p->object.flags |= UNINTERESTING;
 425                         if (p->parents)
 426                                 mark_parents_uninteresting(p);
 427                         if (p->object.flags & SEEN)
 428                                 continue;
 429                         p->object.flags |= SEEN;
 430                         insert_by_date(p, list);
 431                 }
 432                 return 0;
 433         }
 434
 435         /*
 436          * Ok, the commit wasn't uninteresting. Try to
 437          * simplify the commit history and find the parent
 438          * that has no differences in the path set if one exists.
 439          */
 440         try_to_simplify_commit(revs, commit);
 441
 442         if (revs->no_walk)
 443                 return 0;
 444
 445         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 446
 447         rest = !revs->first_parent_only;
 448         for (parent = commit->parents, add = 1; parent; add = rest) {
 449                 struct commit *p = parent->item;
 450
 451                 parent = parent->next;
 452                 if (parse_commit(p) < 0)
 453                         return -1;
 454                 p->object.flags |= left_flag;
 455                 if (p->object.flags & SEEN)
 456                         continue;
 457                 p->object.flags |= SEEN;
 458                 if (add)
 459                         insert_by_date(p, list);
 460         }
 461         return 0;
 462 }
 463
 464 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 465 {
 466         struct commit_list *p;
 467         int left_count = 0, right_count = 0;
 468         int left_first;
 469         struct patch_ids ids;
 470
 471         /* First count the commits on the left and on the right */
 472         for (p = list; p; p = p->next) {
 473                 struct commit *commit = p->item;
 474                 unsigned flags = commit->object.flags;
 475                 if (flags & BOUNDARY)
 476                         ;
 477                 else if (flags & SYMMETRIC_LEFT)
 478                         left_count++;
 479                 else
 480                         right_count++;
 481         }
 482
 483         left_first = left_count < right_count;
 484         init_patch_ids(&ids);
 485         if (revs->diffopt.nr_paths) {
 486                 ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 487                 ids.diffopts.paths = revs->diffopt.paths;
 488                 ids.diffopts.pathlens = revs->diffopt.pathlens;
 489         }
 490
 491         /* Compute patch-ids for one side */
 492         for (p = list; p; p = p->next) {
 493                 struct commit *commit = p->item;
 494                 unsigned flags = commit->object.flags;
 495
 496                 if (flags & BOUNDARY)
 497                         continue;
 498                 /*
 499                  * If we have fewer left, left_first is set and we omit
 500                  * commits on the right branch in this loop.  If we have
 501                  * fewer right, we skip the left ones.
 502                  */
 503                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 504                         continue;
 505                 commit->util = add_commit_patch_id(commit, &ids);
 506         }
 507
 508         /* Check the other side */
 509         for (p = list; p; p = p->next) {
 510                 struct commit *commit = p->item;
 511                 struct patch_id *id;
 512                 unsigned flags = commit->object.flags;
 513
 514                 if (flags & BOUNDARY)
 515                         continue;
 516                 /*
 517                  * If we have fewer left, left_first is set and we omit
 518                  * commits on the left branch in this loop.
 519                  */
 520                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 521                         continue;
 522
 523                 /*
 524                  * Have we seen the same patch id?
 525                  */
 526                 id = has_commit_patch_id(commit, &ids);
 527                 if (!id)
 528                         continue;
 529                 id->seen = 1;
 530                 commit->object.flags |= SHOWN;
 531         }
 532
 533         /* Now check the original side for seen ones */
 534         for (p = list; p; p = p->next) {
 535                 struct commit *commit = p->item;
 536                 struct patch_id *ent;
 537
 538                 ent = commit->util;
 539                 if (!ent)
 540                         continue;
 541                 if (ent->seen)
 542                         commit->object.flags |= SHOWN;
 543                 commit->util = NULL;
 544         }
 545
 546         free_patch_ids(&ids);
 547 }
 548
 549 static int limit_list(struct rev_info *revs)
 550 {
 551         struct commit_list *list = revs->commits;
 552         struct commit_list *newlist = NULL;
 553         struct commit_list **p = &newlist;
 554
 555         while (list) {
 556                 struct commit_list *entry = list;
 557                 struct commit *commit = list->item;
 558                 struct object *obj = &commit->object;
 559                 show_early_output_fn_t show;
 560
 561                 list = list->next;
 562                 free(entry);
 563
 564                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 565                         obj->flags |= UNINTERESTING;
 566                 if (add_parents_to_list(revs, commit, &list) < 0)
 567                         return -1;
 568                 if (obj->flags & UNINTERESTING) {
 569                         mark_parents_uninteresting(commit);
 570                         if (everybody_uninteresting(list))
 571                                 break;
 572                         continue;
 573                 }
 574                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 575                         continue;
 576                 p = &commit_list_insert(commit, p)->next;
 577
 578                 show = show_early_output;
 579                 if (!show)
 580                         continue;
 581
 582                 show(revs, newlist);
 583                 show_early_output = NULL;
 584         }
 585         if (revs->cherry_pick)
 586                 cherry_pick_list(newlist, revs);
 587
 588         revs->commits = newlist;
 589         return 0;
 590 }
 591
 592 struct all_refs_cb {
 593         int all_flags;
 594         int warned_bad_reflog;
 595         struct rev_info *all_revs;
 596         const char *name_for_errormsg;
 597 };
 598
 599 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 600 {
 601         struct all_refs_cb *cb = cb_data;
 602         struct object *object = get_reference(cb->all_revs, path, sha1,
 603                                               cb->all_flags);
 604         add_pending_object(cb->all_revs, object, path);
 605         return 0;
 606 }
 607
 608 static void handle_all(struct rev_info *revs, unsigned flags)
 609 {
 610         struct all_refs_cb cb;
 611         cb.all_revs = revs;
 612         cb.all_flags = flags;
 613         for_each_ref(handle_one_ref, &cb);
 614 }
 615
 616 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 617 {
 618         struct all_refs_cb *cb = cb_data;
 619         if (!is_null_sha1(sha1)) {
 620                 struct object *o = parse_object(sha1);
 621                 if (o) {
 622                         o->flags |= cb->all_flags;
 623                         add_pending_object(cb->all_revs, o, "");
 624                 }
 625                 else if (!cb->warned_bad_reflog) {
 626                         warning("reflog of '%s' references pruned commits",
 627                                 cb->name_for_errormsg);
 628                         cb->warned_bad_reflog = 1;
 629                 }
 630         }
 631 }
 632
 633 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 634                 const char *email, unsigned long timestamp, int tz,
 635                 const char *message, void *cb_data)
 636 {
 637         handle_one_reflog_commit(osha1, cb_data);
 638         handle_one_reflog_commit(nsha1, cb_data);
 639         return 0;
 640 }
 641
 642 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 643 {
 644         struct all_refs_cb *cb = cb_data;
 645         cb->warned_bad_reflog = 0;
 646         cb->name_for_errormsg = path;
 647         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 648         return 0;
 649 }
 650
 651 static void handle_reflog(struct rev_info *revs, unsigned flags)
 652 {
 653         struct all_refs_cb cb;
 654         cb.all_revs = revs;
 655         cb.all_flags = flags;
 656         for_each_reflog(handle_one_reflog, &cb);
 657 }
 658
 659 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 660 {
 661         unsigned char sha1[20];
 662         struct object *it;
 663         struct commit *commit;
 664         struct commit_list *parents;
 665
 666         if (*arg == '^') {
 667                 flags ^= UNINTERESTING;
 668                 arg++;
 669         }
 670         if (get_sha1(arg, sha1))
 671                 return 0;
 672         while (1) {
 673                 it = get_reference(revs, arg, sha1, 0);
 674                 if (it->type != OBJ_TAG)
 675                         break;
 676                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 677         }
 678         if (it->type != OBJ_COMMIT)
 679                 return 0;
 680         commit = (struct commit *)it;
 681         for (parents = commit->parents; parents; parents = parents->next) {
 682                 it = &parents->item->object;
 683                 it->flags |= flags;
 684                 add_pending_object(revs, it, arg);
 685         }
 686         return 1;
 687 }
 688
 689 void init_revisions(struct rev_info *revs, const char *prefix)
 690 {
 691         memset(revs, 0, sizeof(*revs));
 692
 693         revs->abbrev = DEFAULT_ABBREV;
 694         revs->ignore_merges = 1;
 695         revs->simplify_history = 1;
 696         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 697         DIFF_OPT_SET(&revs->pruning, QUIET);
 698         revs->pruning.add_remove = file_add_remove;
 699         revs->pruning.change = file_change;
 700         revs->lifo = 1;
 701         revs->dense = 1;
 702         revs->prefix = prefix;
 703         revs->max_age = -1;
 704         revs->min_age = -1;
 705         revs->skip_count = -1;
 706         revs->max_count = -1;
 707
 708         revs->commit_format = CMIT_FMT_DEFAULT;
 709
 710         diff_setup(&revs->diffopt);
 711 }
 712
 713 static void add_pending_commit_list(struct rev_info *revs,
 714                                     struct commit_list *commit_list,
 715                                     unsigned int flags)
 716 {
 717         while (commit_list) {
 718                 struct object *object = &commit_list->item->object;
 719                 object->flags |= flags;
 720                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 721                 commit_list = commit_list->next;
 722         }
 723 }
 724
 725 static void prepare_show_merge(struct rev_info *revs)
 726 {
 727         struct commit_list *bases;
 728         struct commit *head, *other;
 729         unsigned char sha1[20];
 730         const char **prune = NULL;
 731         int i, prune_num = 1; /* counting terminating NULL */
 732
 733         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 734                 die("--merge without HEAD?");
 735         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 736                 die("--merge without MERGE_HEAD?");
 737         add_pending_object(revs, &head->object, "HEAD");
 738         add_pending_object(revs, &other->object, "MERGE_HEAD");
 739         bases = get_merge_bases(head, other, 1);
 740         while (bases) {
 741                 struct commit *it = bases->item;
 742                 struct commit_list *n = bases->next;
 743                 free(bases);
 744                 bases = n;
 745                 it->object.flags |= UNINTERESTING;
 746                 add_pending_object(revs, &it->object, "(merge-base)");
 747         }
 748
 749         if (!active_nr)
 750                 read_cache();
 751         for (i = 0; i < active_nr; i++) {
 752                 struct cache_entry *ce = active_cache[i];
 753                 if (!ce_stage(ce))
 754                         continue;
 755                 if (ce_path_match(ce, revs->prune_data)) {
 756                         prune_num++;
 757                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 758                         prune[prune_num-2] = ce->name;
 759                         prune[prune_num-1] = NULL;
 760                 }
 761                 while ((i+1 < active_nr) &&
 762                        ce_same_name(ce, active_cache[i+1]))
 763                         i++;
 764         }
 765         revs->prune_data = prune;
 766 }
 767
 768 int handle_revision_arg(const char *arg, struct rev_info *revs,
 769                         int flags,
 770                         int cant_be_filename)
 771 {
 772         unsigned mode;
 773         char *dotdot;
 774         struct object *object;
 775         unsigned char sha1[20];
 776         int local_flags;
 777
 778         dotdot = strstr(arg, "..");
 779         if (dotdot) {
 780                 unsigned char from_sha1[20];
 781                 const char *next = dotdot + 2;
 782                 const char *this = arg;
 783                 int symmetric = *next == '.';
 784                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 785
 786                 *dotdot = 0;
 787                 next += symmetric;
 788
 789                 if (!*next)
 790                         next = "HEAD";
 791                 if (dotdot == arg)
 792                         this = "HEAD";
 793                 if (!get_sha1(this, from_sha1) &&
 794                     !get_sha1(next, sha1)) {
 795                         struct commit *a, *b;
 796                         struct commit_list *exclude;
 797
 798                         a = lookup_commit_reference(from_sha1);
 799                         b = lookup_commit_reference(sha1);
 800                         if (!a || !b) {
 801                                 die(symmetric ?
 802                                     "Invalid symmetric difference expression %s...%s" :
 803                                     "Invalid revision range %s..%s",
 804                                     arg, next);
 805                         }
 806
 807                         if (!cant_be_filename) {
 808                                 *dotdot = '.';
 809                                 verify_non_filename(revs->prefix, arg);
 810                         }
 811
 812                         if (symmetric) {
 813                                 exclude = get_merge_bases(a, b, 1);
 814                                 add_pending_commit_list(revs, exclude,
 815                                                         flags_exclude);
 816                                 free_commit_list(exclude);
 817                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 818                         } else
 819                                 a->object.flags |= flags_exclude;
 820                         b->object.flags |= flags;
 821                         add_pending_object(revs, &a->object, this);
 822                         add_pending_object(revs, &b->object, next);
 823                         return 0;
 824                 }
 825                 *dotdot = '.';
 826         }
 827         dotdot = strstr(arg, "^@");
 828         if (dotdot && !dotdot[2]) {
 829                 *dotdot = 0;
 830                 if (add_parents_only(revs, arg, flags))
 831                         return 0;
 832                 *dotdot = '^';
 833         }
 834         dotdot = strstr(arg, "^!");
 835         if (dotdot && !dotdot[2]) {
 836                 *dotdot = 0;
 837                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 838                         *dotdot = '^';
 839         }
 840
 841         local_flags = 0;
 842         if (*arg == '^') {
 843                 local_flags = UNINTERESTING;
 844                 arg++;
 845         }
 846         if (get_sha1_with_mode(arg, sha1, &mode))
 847                 return -1;
 848         if (!cant_be_filename)
 849                 verify_non_filename(revs->prefix, arg);
 850         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 851         add_pending_object_with_mode(revs, object, arg, mode);
 852         return 0;
 853 }
 854
 855 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 856 {
 857         if (!revs->grep_filter) {
 858                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 859                 opt->status_only = 1;
 860                 opt->pattern_tail = &(opt->pattern_list);
 861                 opt->regflags = REG_NEWLINE;
 862                 revs->grep_filter = opt;
 863         }
 864         append_grep_pattern(revs->grep_filter, ptn,
 865                             "command line", 0, what);
 866 }
 867
 868 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 869 {
 870         char *pat;
 871         const char *prefix;
 872         int patlen, fldlen;
 873
 874         fldlen = strlen(field);
 875         patlen = strlen(pattern);
 876         pat = xmalloc(patlen + fldlen + 10);
 877         prefix = ".*";
 878         if (*pattern == '^') {
 879                 prefix = "";
 880                 pattern++;
 881         }
 882         sprintf(pat, "^%s %s%s", field, prefix, pattern);
 883         add_grep(revs, pat, GREP_PATTERN_HEAD);
 884 }
 885
 886 static void add_message_grep(struct rev_info *revs, const char *pattern)
 887 {
 888         add_grep(revs, pattern, GREP_PATTERN_BODY);
 889 }
 890
 891 static void add_ignore_packed(struct rev_info *revs, const char *name)
 892 {
 893         int num = ++revs->num_ignore_packed;
 894
 895         revs->ignore_packed = xrealloc(revs->ignore_packed,
 896                                        sizeof(const char **) * (num + 1));
 897         revs->ignore_packed[num-1] = name;
 898         revs->ignore_packed[num] = NULL;
 899 }
 900
 901 /*
 902  * Parse revision information, filling in the "rev_info" structure,
 903  * and removing the used arguments from the argument list.
 904  *
 905  * Returns the number of arguments left that weren't recognized
 906  * (which are also moved to the head of the argument list)
 907  */
 908 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 909 {
 910         int i, flags, seen_dashdash, show_merge;
 911         const char **unrecognized = argv + 1;
 912         int left = 1;
 913         int all_match = 0;
 914         int regflags = 0;
 915
 916         /* First, search for "--" */
 917         seen_dashdash = 0;
 918         for (i = 1; i < argc; i++) {
 919                 const char *arg = argv[i];
 920                 if (strcmp(arg, "--"))
 921                         continue;
 922                 argv[i] = NULL;
 923                 argc = i;
 924                 if (argv[i + 1])
 925                         revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 926                 seen_dashdash = 1;
 927                 break;
 928         }
 929
 930         flags = show_merge = 0;
 931         for (i = 1; i < argc; i++) {
 932                 const char *arg = argv[i];
 933                 if (*arg == '-') {
 934                         int opts;
 935                         if (!prefixcmp(arg, "--max-count=")) {
 936                                 revs->max_count = atoi(arg + 12);
 937                                 continue;
 938                         }
 939                         if (!prefixcmp(arg, "--skip=")) {
 940                                 revs->skip_count = atoi(arg + 7);
 941                                 continue;
 942                         }
 943                         /* accept -<digit>, like traditional "head" */
 944                         if ((*arg == '-') && isdigit(arg[1])) {
 945                                 revs->max_count = atoi(arg + 1);
 946                                 continue;
 947                         }
 948                         if (!strcmp(arg, "-n")) {
 949                                 if (argc <= i + 1)
 950                                         die("-n requires an argument");
 951                                 revs->max_count = atoi(argv[++i]);
 952                                 continue;
 953                         }
 954                         if (!prefixcmp(arg, "-n")) {
 955                                 revs->max_count = atoi(arg + 2);
 956                                 continue;
 957                         }
 958                         if (!prefixcmp(arg, "--max-age=")) {
 959                                 revs->max_age = atoi(arg + 10);
 960                                 continue;
 961                         }
 962                         if (!prefixcmp(arg, "--since=")) {
 963                                 revs->max_age = approxidate(arg + 8);
 964                                 continue;
 965                         }
 966                         if (!prefixcmp(arg, "--after=")) {
 967                                 revs->max_age = approxidate(arg + 8);
 968                                 continue;
 969                         }
 970                         if (!prefixcmp(arg, "--min-age=")) {
 971                                 revs->min_age = atoi(arg + 10);
 972                                 continue;
 973                         }
 974                         if (!prefixcmp(arg, "--before=")) {
 975                                 revs->min_age = approxidate(arg + 9);
 976                                 continue;
 977                         }
 978                         if (!prefixcmp(arg, "--until=")) {
 979                                 revs->min_age = approxidate(arg + 8);
 980                                 continue;
 981                         }
 982                         if (!strcmp(arg, "--all")) {
 983                                 handle_all(revs, flags);
 984                                 continue;
 985                         }
 986                         if (!strcmp(arg, "--first-parent")) {
 987                                 revs->first_parent_only = 1;
 988                                 continue;
 989                         }
 990                         if (!strcmp(arg, "--reflog")) {
 991                                 handle_reflog(revs, flags);
 992                                 continue;
 993                         }
 994                         if (!strcmp(arg, "-g") ||
 995                                         !strcmp(arg, "--walk-reflogs")) {
 996                                 init_reflog_walk(&revs->reflog_info);
 997                                 continue;
 998                         }
 999                         if (!strcmp(arg, "--not")) {
1000                                 flags ^= UNINTERESTING;
1001                                 continue;
1002                         }
1003                         if (!strcmp(arg, "--default")) {
1004                                 if (++i >= argc)
1005                                         die("bad --default argument");
1006                                 def = argv[i];
1007                                 continue;
1008                         }
1009                         if (!strcmp(arg, "--merge")) {
1010                                 show_merge = 1;
1011                                 continue;
1012                         }
1013                         if (!strcmp(arg, "--topo-order")) {
1014                                 revs->topo_order = 1;
1015                                 continue;
1016                         }
1017                         if (!strcmp(arg, "--date-order")) {
1018                                 revs->lifo = 0;
1019                                 revs->topo_order = 1;
1020                                 continue;
1021                         }
1022                         if (!prefixcmp(arg, "--early-output")) {
1023                                 int count = 100;
1024                                 switch (arg[14]) {
1025                                 case '=':
1026                                         count = atoi(arg+15);
1027                                         /* Fallthrough */
1028                                 case 0:
1029                                         revs->topo_order = 1;
1030                                         revs->early_output = count;
1031                                         continue;
1032                                 }
1033                         }
1034                         if (!strcmp(arg, "--parents")) {
1035                                 revs->parents = 1;
1036                                 continue;
1037                         }
1038                         if (!strcmp(arg, "--dense")) {
1039                                 revs->dense = 1;
1040                                 continue;
1041                         }
1042                         if (!strcmp(arg, "--sparse")) {
1043                                 revs->dense = 0;
1044                                 continue;
1045                         }
1046                         if (!strcmp(arg, "--remove-empty")) {
1047                                 revs->remove_empty_trees = 1;
1048                                 continue;
1049                         }
1050                         if (!strcmp(arg, "--no-merges")) {
1051                                 revs->no_merges = 1;
1052                                 continue;
1053                         }
1054                         if (!strcmp(arg, "--boundary")) {
1055                                 revs->boundary = 1;
1056                                 continue;
1057                         }
1058                         if (!strcmp(arg, "--left-right")) {
1059                                 revs->left_right = 1;
1060                                 continue;
1061                         }
1062                         if (!strcmp(arg, "--cherry-pick")) {
1063                                 revs->cherry_pick = 1;
1064                                 revs->limited = 1;
1065                                 continue;
1066                         }
1067                         if (!strcmp(arg, "--objects")) {
1068                                 revs->tag_objects = 1;
1069                                 revs->tree_objects = 1;
1070                                 revs->blob_objects = 1;
1071                                 continue;
1072                         }
1073                         if (!strcmp(arg, "--objects-edge")) {
1074                                 revs->tag_objects = 1;
1075                                 revs->tree_objects = 1;
1076                                 revs->blob_objects = 1;
1077                                 revs->edge_hint = 1;
1078                                 continue;
1079                         }
1080                         if (!strcmp(arg, "--unpacked")) {
1081                                 revs->unpacked = 1;
1082                                 free(revs->ignore_packed);
1083                                 revs->ignore_packed = NULL;
1084                                 revs->num_ignore_packed = 0;
1085                                 continue;
1086                         }
1087                         if (!prefixcmp(arg, "--unpacked=")) {
1088                                 revs->unpacked = 1;
1089                                 add_ignore_packed(revs, arg+11);
1090                                 continue;
1091                         }
1092                         if (!strcmp(arg, "-r")) {
1093                                 revs->diff = 1;
1094                                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1095                                 continue;
1096                         }
1097                         if (!strcmp(arg, "-t")) {
1098                                 revs->diff = 1;
1099                                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1100                                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1101                                 continue;
1102                         }
1103                         if (!strcmp(arg, "-m")) {
1104                                 revs->ignore_merges = 0;
1105                                 continue;
1106                         }
1107                         if (!strcmp(arg, "-c")) {
1108                                 revs->diff = 1;
1109                                 revs->dense_combined_merges = 0;
1110                                 revs->combine_merges = 1;
1111                                 continue;
1112                         }
1113                         if (!strcmp(arg, "--cc")) {
1114                                 revs->diff = 1;
1115                                 revs->dense_combined_merges = 1;
1116                                 revs->combine_merges = 1;
1117                                 continue;
1118                         }
1119                         if (!strcmp(arg, "-v")) {
1120                                 revs->verbose_header = 1;
1121                                 continue;
1122                         }
1123                         if (!prefixcmp(arg, "--pretty")) {
1124                                 revs->verbose_header = 1;
1125                                 revs->commit_format = get_commit_format(arg+8);
1126                                 continue;
1127                         }
1128                         if (!strcmp(arg, "--root")) {
1129                                 revs->show_root_diff = 1;
1130                                 continue;
1131                         }
1132                         if (!strcmp(arg, "--no-commit-id")) {
1133                                 revs->no_commit_id = 1;
1134                                 continue;
1135                         }
1136                         if (!strcmp(arg, "--always")) {
1137                                 revs->always_show_header = 1;
1138                                 continue;
1139                         }
1140                         if (!strcmp(arg, "--no-abbrev")) {
1141                                 revs->abbrev = 0;
1142                                 continue;
1143                         }
1144                         if (!strcmp(arg, "--abbrev")) {
1145                                 revs->abbrev = DEFAULT_ABBREV;
1146                                 continue;
1147                         }
1148                         if (!prefixcmp(arg, "--abbrev=")) {
1149                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1150                                 if (revs->abbrev < MINIMUM_ABBREV)
1151                                         revs->abbrev = MINIMUM_ABBREV;
1152                                 else if (revs->abbrev > 40)
1153                                         revs->abbrev = 40;
1154                                 continue;
1155                         }
1156                         if (!strcmp(arg, "--abbrev-commit")) {
1157                                 revs->abbrev_commit = 1;
1158                                 continue;
1159                         }
1160                         if (!strcmp(arg, "--full-diff")) {
1161                                 revs->diff = 1;
1162                                 revs->full_diff = 1;
1163                                 continue;
1164                         }
1165                         if (!strcmp(arg, "--full-history")) {
1166                                 revs->simplify_history = 0;
1167                                 continue;
1168                         }
1169                         if (!strcmp(arg, "--relative-date")) {
1170                                 revs->date_mode = DATE_RELATIVE;
1171                                 continue;
1172                         }
1173                         if (!strncmp(arg, "--date=", 7)) {
1174                                 revs->date_mode = parse_date_format(arg + 7);
1175                                 continue;
1176                         }
1177                         if (!strcmp(arg, "--log-size")) {
1178                                 revs->show_log_size = 1;
1179                                 continue;
1180                         }
1181
1182                         /*
1183                          * Grepping the commit log
1184                          */
1185                         if (!prefixcmp(arg, "--author=")) {
1186                                 add_header_grep(revs, "author", arg+9);
1187                                 continue;
1188                         }
1189                         if (!prefixcmp(arg, "--committer=")) {
1190                                 add_header_grep(revs, "committer", arg+12);
1191                                 continue;
1192                         }
1193                         if (!prefixcmp(arg, "--grep=")) {
1194                                 add_message_grep(revs, arg+7);
1195                                 continue;
1196                         }
1197                         if (!strcmp(arg, "--extended-regexp") ||
1198                             !strcmp(arg, "-E")) {
1199                                 regflags |= REG_EXTENDED;
1200                                 continue;
1201                         }
1202                         if (!strcmp(arg, "--regexp-ignore-case") ||
1203                             !strcmp(arg, "-i")) {
1204                                 regflags |= REG_ICASE;
1205                                 continue;
1206                         }
1207                         if (!strcmp(arg, "--all-match")) {
1208                                 all_match = 1;
1209                                 continue;
1210                         }
1211                         if (!prefixcmp(arg, "--encoding=")) {
1212                                 arg += 11;
1213                                 if (strcmp(arg, "none"))
1214                                         git_log_output_encoding = xstrdup(arg);
1215                                 else
1216                                         git_log_output_encoding = "";
1217                                 continue;
1218                         }
1219                         if (!strcmp(arg, "--reverse")) {
1220                                 revs->reverse ^= 1;
1221                                 continue;
1222                         }
1223                         if (!strcmp(arg, "--no-walk")) {
1224                                 revs->no_walk = 1;
1225                                 continue;
1226                         }
1227                         if (!strcmp(arg, "--do-walk")) {
1228                                 revs->no_walk = 0;
1229                                 continue;
1230                         }
1231
1232                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1233                         if (opts > 0) {
1234                                 i += opts - 1;
1235                                 continue;
1236                         }
1237                         *unrecognized++ = arg;
1238                         left++;
1239                         continue;
1240                 }
1241
1242                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1243                         int j;
1244                         if (seen_dashdash || *arg == '^')
1245                                 die("bad revision '%s'", arg);
1246
1247                         /* If we didn't have a "--":
1248                          * (1) all filenames must exist;
1249                          * (2) all rev-args must not be interpretable
1250                          *     as a valid filename.
1251                          * but the latter we have checked in the main loop.
1252                          */
1253                         for (j = i; j < argc; j++)
1254                                 verify_filename(revs->prefix, argv[j]);
1255
1256                         revs->prune_data = get_pathspec(revs->prefix,
1257                                                         argv + i);
1258                         break;
1259                 }
1260         }
1261
1262         if (revs->grep_filter)
1263                 revs->grep_filter->regflags |= regflags;
1264
1265         if (show_merge)
1266                 prepare_show_merge(revs);
1267         if (def && !revs->pending.nr) {
1268                 unsigned char sha1[20];
1269                 struct object *object;
1270                 unsigned mode;
1271                 if (get_sha1_with_mode(def, sha1, &mode))
1272                         die("bad default revision '%s'", def);
1273                 object = get_reference(revs, def, sha1, 0);
1274                 add_pending_object_with_mode(revs, object, def, mode);
1275         }
1276
1277         /* Did the user ask for any diff output? Run the diff! */
1278         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1279                 revs->diff = 1;
1280
1281         /* Pickaxe and rename following needs diffs */
1282         if (revs->diffopt.pickaxe || DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1283                 revs->diff = 1;
1284
1285         if (revs->topo_order)
1286                 revs->limited = 1;
1287
1288         if (revs->prune_data) {
1289                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1290                 /* Can't prune commits with rename following: the paths change.. */
1291                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1292                         revs->prune = 1;
1293                 if (!revs->full_diff)
1294                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1295         }
1296         if (revs->combine_merges) {
1297                 revs->ignore_merges = 0;
1298                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1299                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1300         }
1301         revs->diffopt.abbrev = revs->abbrev;
1302         if (diff_setup_done(&revs->diffopt) < 0)
1303                 die("diff_setup_done failed");
1304
1305         if (revs->grep_filter) {
1306                 revs->grep_filter->all_match = all_match;
1307                 compile_grep_patterns(revs->grep_filter);
1308         }
1309
1310         if (revs->reverse && revs->reflog_info)
1311                 die("cannot combine --reverse with --walk-reflogs");
1312
1313         return left;
1314 }
1315
1316 int prepare_revision_walk(struct rev_info *revs)
1317 {
1318         int nr = revs->pending.nr;
1319         struct object_array_entry *e, *list;
1320
1321         e = list = revs->pending.objects;
1322         revs->pending.nr = 0;
1323         revs->pending.alloc = 0;
1324         revs->pending.objects = NULL;
1325         while (--nr >= 0) {
1326                 struct commit *commit = handle_commit(revs, e->item, e->name);
1327                 if (commit) {
1328                         if (!(commit->object.flags & SEEN)) {
1329                                 commit->object.flags |= SEEN;
1330                                 insert_by_date(commit, &revs->commits);
1331                         }
1332                 }
1333                 e++;
1334         }
1335         free(list);
1336
1337         if (revs->no_walk)
1338                 return 0;
1339         if (revs->limited)
1340                 if (limit_list(revs) < 0)
1341                         return -1;
1342         if (revs->topo_order)
1343                 sort_in_topological_order(&revs->commits, revs->lifo);
1344         return 0;
1345 }
1346
1347 enum rewrite_result {
1348         rewrite_one_ok,
1349         rewrite_one_noparents,
1350         rewrite_one_error,
1351 };
1352
1353 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1354 {
1355         for (;;) {
1356                 struct commit *p = *pp;
1357                 if (!revs->limited)
1358                         if (add_parents_to_list(revs, p, &revs->commits) < 0)
1359                                 return rewrite_one_error;
1360                 if (p->parents && p->parents->next)
1361                         return rewrite_one_ok;
1362                 if (p->object.flags & UNINTERESTING)
1363                         return rewrite_one_ok;
1364                 if (!(p->object.flags & TREESAME))
1365                         return rewrite_one_ok;
1366                 if (!p->parents)
1367                         return rewrite_one_noparents;
1368                 *pp = p->parents->item;
1369         }
1370 }
1371
1372 static void remove_duplicate_parents(struct commit *commit)
1373 {
1374         struct commit_list **pp, *p;
1375
1376         /* Examine existing parents while marking ones we have seen... */
1377         pp = &commit->parents;
1378         while ((p = *pp) != NULL) {
1379                 struct commit *parent = p->item;
1380                 if (parent->object.flags & TMP_MARK) {
1381                         *pp = p->next;
1382                         continue;
1383                 }
1384                 parent->object.flags |= TMP_MARK;
1385                 pp = &p->next;
1386         }
1387         /* ... and clear the temporary mark */
1388         for (p = commit->parents; p; p = p->next)
1389                 p->item->object.flags &= ~TMP_MARK;
1390 }
1391
1392 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1393 {
1394         struct commit_list **pp = &commit->parents;
1395         while (*pp) {
1396                 struct commit_list *parent = *pp;
1397                 switch (rewrite_one(revs, &parent->item)) {
1398                 case rewrite_one_ok:
1399                         break;
1400                 case rewrite_one_noparents:
1401                         *pp = parent->next;
1402                         continue;
1403                 case rewrite_one_error:
1404                         return -1;
1405                 }
1406                 pp = &parent->next;
1407         }
1408         remove_duplicate_parents(commit);
1409         return 0;
1410 }
1411
1412 static int commit_match(struct commit *commit, struct rev_info *opt)
1413 {
1414         if (!opt->grep_filter)
1415                 return 1;
1416         return grep_buffer(opt->grep_filter,
1417                            NULL, /* we say nothing, not even filename */
1418                            commit->buffer, strlen(commit->buffer));
1419 }
1420
1421 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1422 {
1423         if (commit->object.flags & SHOWN)
1424                 return commit_ignore;
1425         if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1426                 return commit_ignore;
1427         if (commit->object.flags & UNINTERESTING)
1428                 return commit_ignore;
1429         if (revs->min_age != -1 && (commit->date > revs->min_age))
1430                 return commit_ignore;
1431         if (revs->no_merges && commit->parents && commit->parents->next)
1432                 return commit_ignore;
1433         if (!commit_match(commit, revs))
1434                 return commit_ignore;
1435         if (revs->prune && revs->dense) {
1436                 /* Commit without changes? */
1437                 if (commit->object.flags & TREESAME) {
1438                         /* drop merges unless we want parenthood */
1439                         if (!revs->parents)
1440                                 return commit_ignore;
1441                         /* non-merge - always ignore it */
1442                         if (!commit->parents || !commit->parents->next)
1443                                 return commit_ignore;
1444                 }
1445                 if (revs->parents && rewrite_parents(revs, commit) < 0)
1446                         return commit_error;
1447         }
1448         return commit_show;
1449 }
1450
1451 static struct commit *get_revision_1(struct rev_info *revs)
1452 {
1453         if (!revs->commits)
1454                 return NULL;
1455
1456         do {
1457                 struct commit_list *entry = revs->commits;
1458                 struct commit *commit = entry->item;
1459
1460                 revs->commits = entry->next;
1461                 free(entry);
1462
1463                 if (revs->reflog_info)
1464                         fake_reflog_parent(revs->reflog_info, commit);
1465
1466                 /*
1467                  * If we haven't done the list limiting, we need to look at
1468                  * the parents here. We also need to do the date-based limiting
1469                  * that we'd otherwise have done in limit_list().
1470                  */
1471                 if (!revs->limited) {
1472                         if (revs->max_age != -1 &&
1473                             (commit->date < revs->max_age))
1474                                 continue;
1475                         if (add_parents_to_list(revs, commit, &revs->commits) < 0)
1476                                 return NULL;
1477                 }
1478
1479                 switch (simplify_commit(revs, commit)) {
1480                 case commit_ignore:
1481                         continue;
1482                 case commit_error:
1483                         return NULL;
1484                 default:
1485                         return commit;
1486                 }
1487         } while (revs->commits);
1488         return NULL;
1489 }
1490
1491 static void gc_boundary(struct object_array *array)
1492 {
1493         unsigned nr = array->nr;
1494         unsigned alloc = array->alloc;
1495         struct object_array_entry *objects = array->objects;
1496
1497         if (alloc <= nr) {
1498                 unsigned i, j;
1499                 for (i = j = 0; i < nr; i++) {
1500                         if (objects[i].item->flags & SHOWN)
1501                                 continue;
1502                         if (i != j)
1503                                 objects[j] = objects[i];
1504                         j++;
1505                 }
1506                 for (i = j; i < nr; i++)
1507                         objects[i].item = NULL;
1508                 array->nr = j;
1509         }
1510 }
1511
1512 struct commit *get_revision(struct rev_info *revs)
1513 {
1514         struct commit *c = NULL;
1515         struct commit_list *l;
1516
1517         if (revs->boundary == 2) {
1518                 unsigned i;
1519                 struct object_array *array = &revs->boundary_commits;
1520                 struct object_array_entry *objects = array->objects;
1521                 for (i = 0; i < array->nr; i++) {
1522                         c = (struct commit *)(objects[i].item);
1523                         if (!c)
1524                                 continue;
1525                         if (!(c->object.flags & CHILD_SHOWN))
1526                                 continue;
1527                         if (!(c->object.flags & SHOWN))
1528                                 break;
1529                 }
1530                 if (array->nr <= i)
1531                         return NULL;
1532
1533                 c->object.flags |= SHOWN | BOUNDARY;
1534                 return c;
1535         }
1536
1537         if (revs->reverse) {
1538                 int limit = -1;
1539
1540                 if (0 <= revs->max_count) {
1541                         limit = revs->max_count;
1542                         if (0 < revs->skip_count)
1543                                 limit += revs->skip_count;
1544                 }
1545                 l = NULL;
1546                 while ((c = get_revision_1(revs))) {
1547                         commit_list_insert(c, &l);
1548                         if ((0 < limit) && !--limit)
1549                                 break;
1550                 }
1551                 revs->commits = l;
1552                 revs->reverse = 0;
1553                 revs->max_count = -1;
1554                 c = NULL;
1555         }
1556
1557         /*
1558          * Now pick up what they want to give us
1559          */
1560         c = get_revision_1(revs);
1561         if (c) {
1562                 while (0 < revs->skip_count) {
1563                         revs->skip_count--;
1564                         c = get_revision_1(revs);
1565                         if (!c)
1566                                 break;
1567                 }
1568         }
1569
1570         /*
1571          * Check the max_count.
1572          */
1573         switch (revs->max_count) {
1574         case -1:
1575                 break;
1576         case 0:
1577                 c = NULL;
1578                 break;
1579         default:
1580                 revs->max_count--;
1581         }
1582
1583         if (c)
1584                 c->object.flags |= SHOWN;
1585
1586         if (!revs->boundary) {
1587                 return c;
1588         }
1589
1590         if (!c) {
1591                 /*
1592                  * get_revision_1() runs out the commits, and
1593                  * we are done computing the boundaries.
1594                  * switch to boundary commits output mode.
1595                  */
1596                 revs->boundary = 2;
1597                 return get_revision(revs);
1598         }
1599
1600         /*
1601          * boundary commits are the commits that are parents of the
1602          * ones we got from get_revision_1() but they themselves are
1603          * not returned from get_revision_1().  Before returning
1604          * 'c', we need to mark its parents that they could be boundaries.
1605          */
1606
1607         for (l = c->parents; l; l = l->next) {
1608                 struct object *p;
1609                 p = &(l->item->object);
1610                 if (p->flags & (CHILD_SHOWN | SHOWN))
1611                         continue;
1612                 p->flags |= CHILD_SHOWN;
1613                 gc_boundary(&revs->boundary_commits);
1614                 add_object_array(p, NULL, &revs->boundary_commits);
1615         }
1616
1617         return c;
1618 }