Merge branch 'jc/remove-treesame-parent-in-simplify-merges'
authorJunio C Hamano <gitster@pobox.com>
Thu, 28 Mar 2013 21:37:53 +0000 (14:37 -0700)
committerJunio C Hamano <gitster@pobox.com>
Thu, 28 Mar 2013 21:37:53 +0000 (14:37 -0700)
The --simplify-merges logic did not cull irrelevant parents from a
merge that is otherwise not interesting with respect to the paths
we are following.

This touches a fairly core part of the revision traversal
infrastructure; even though I think this change is correct, please
report immediately if you find any unintended side effect.

* jc/remove-treesame-parent-in-simplify-merges:
simplify-merges: drop merge from irrelevant side branch

1  2 
revision.c
t/t6012-rev-list-simplify.sh
diff --combined revision.c
index ef6020541282770b9edc4c921cadb7ab1506da56,3536635a887c3c6c43cdc5c6d280a98d174b4a81..78397d6486203a6b7242c8ea866780979876e685
  #include "reflog-walk.h"
  #include "patch-ids.h"
  #include "decorate.h"
 +#include "log-tree.h"
 +#include "string-list.h"
 +#include "mailmap.h"
  
  volatile show_early_output_fn_t show_early_output;
  
 -static char *path_name(struct name_path *path, const char *name)
 +char *path_name(const struct name_path *path, const char *name)
  {
 -      struct name_path *p;
 +      const struct name_path *p;
        char *n, *m;
        int nlen = strlen(name);
        int len = nlen + 1;
        return n;
  }
  
 +static int show_path_component_truncated(FILE *out, const char *name, int len)
 +{
 +      int cnt;
 +      for (cnt = 0; cnt < len; cnt++) {
 +              int ch = name[cnt];
 +              if (!ch || ch == '\n')
 +                      return -1;
 +              fputc(ch, out);
 +      }
 +      return len;
 +}
 +
 +static int show_path_truncated(FILE *out, const struct name_path *path)
 +{
 +      int emitted, ours;
 +
 +      if (!path)
 +              return 0;
 +      emitted = show_path_truncated(out, path->up);
 +      if (emitted < 0)
 +              return emitted;
 +      if (emitted)
 +              fputc('/', out);
 +      ours = show_path_component_truncated(out, path->elem, path->elem_len);
 +      if (ours < 0)
 +              return ours;
 +      return ours || emitted;
 +}
 +
 +void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
 +{
 +      struct name_path leaf;
 +      leaf.up = (struct name_path *)path;
 +      leaf.elem = component;
 +      leaf.elem_len = strlen(component);
 +
 +      fprintf(out, "%s ", sha1_to_hex(obj->sha1));
 +      show_path_truncated(out, &leaf);
 +      fputc('\n', out);
 +}
 +
  void add_object(struct object *obj,
                struct object_array *p,
                struct name_path *path,
@@@ -140,32 -96,11 +140,32 @@@ void mark_tree_uninteresting(struct tre
  
  void mark_parents_uninteresting(struct commit *commit)
  {
 -      struct commit_list *parents = commit->parents;
 +      struct commit_list *parents = NULL, *l;
 +
 +      for (l = commit->parents; l; l = l->next)
 +              commit_list_insert(l->item, &parents);
  
        while (parents) {
                struct commit *commit = parents->item;
 -              if (!(commit->object.flags & UNINTERESTING)) {
 +              l = parents;
 +              parents = parents->next;
 +              free(l);
 +
 +              while (commit) {
 +                      /*
 +                       * A missing commit is ok iff its parent is marked
 +                       * uninteresting.
 +                       *
 +                       * We just mark such a thing parsed, so that when
 +                       * it is popped next time around, we won't be trying
 +                       * to parse it and get an error.
 +                       */
 +                      if (!has_sha1_file(commit->object.sha1))
 +                              commit->object.parsed = 1;
 +
 +                      if (commit->object.flags & UNINTERESTING)
 +                              break;
 +
                        commit->object.flags |= UNINTERESTING;
  
                        /*
                         * wasn't uninteresting), in which case we need
                         * to mark its parents recursively too..
                         */
 -                      if (commit->parents)
 -                              mark_parents_uninteresting(commit);
 -              }
 +                      if (!commit->parents)
 +                              break;
  
 -              /*
 -               * A missing commit is ok iff its parent is marked
 -               * uninteresting.
 -               *
 -               * We just mark such a thing parsed, so that when
 -               * it is popped next time around, we won't be trying
 -               * to parse it and get an error.
 -               */
 -              if (!has_sha1_file(commit->object.sha1))
 -                      commit->object.parsed = 1;
 -              parents = parents->next;
 +                      for (l = commit->parents->next; l; l = l->next)
 +                              commit_list_insert(l->item, &parents);
 +                      commit = commit->parents->item;
 +              }
        }
  }
  
  static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
  {
 -      if (revs->no_walk && (obj->flags & UNINTERESTING))
 -              die("object ranges do not make sense when not walking revisions");
 -      if (revs->reflog_info && obj->type == OBJ_COMMIT &&
 -                      add_reflog_for_walk(revs->reflog_info,
 -                              (struct commit *)obj, name))
 +      if (!obj)
                return;
 +      if (revs->no_walk && (obj->flags & UNINTERESTING))
 +              revs->no_walk = 0;
 +      if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 +              struct strbuf buf = STRBUF_INIT;
 +              int len = interpret_branch_name(name, &buf);
 +              int st;
 +
 +              if (0 < len && name[len] && buf.len)
 +                      strbuf_addstr(&buf, name + len);
 +              st = add_reflog_for_walk(revs->reflog_info,
 +                                       (struct commit *)obj,
 +                                       buf.buf[0] ? buf.buf: name);
 +              strbuf_release(&buf);
 +              if (st)
 +                      return;
 +      }
        add_object_array_with_mode(obj, name, &revs->pending, mode);
  }
  
@@@ -231,22 -162,12 +231,22 @@@ static struct object *get_reference(str
        struct object *object;
  
        object = parse_object(sha1);
 -      if (!object)
 +      if (!object) {
 +              if (revs->ignore_missing)
 +                      return object;
                die("bad object %s", name);
 +      }
        object->flags |= flags;
        return object;
  }
  
 +void add_pending_sha1(struct rev_info *revs, const char *name,
 +                    const unsigned char *sha1, unsigned int flags)
 +{
 +      struct object *object = get_reference(revs, name, sha1, flags);
 +      add_pending_object(revs, object, name);
 +}
 +
  static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
  {
        unsigned long flags = object->flags;
                if (!tag->tagged)
                        die("bad tag");
                object = parse_object(tag->tagged->sha1);
 -              if (!object)
 +              if (!object) {
 +                      if (flags & UNINTERESTING)
 +                              return NULL;
                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 +              }
        }
  
        /*
                        mark_parents_uninteresting(commit);
                        revs->limited = 1;
                }
 +              if (revs->show_source && !commit->util)
 +                      commit->util = (void *) name;
                return commit;
        }
  
        /*
 -       * Tree object? Either mark it uniniteresting, or add it
 +       * Tree object? Either mark it uninteresting, or add it
         * to the list of objects to look at later..
         */
        if (object->type == OBJ_TREE) {
@@@ -334,24 -250,34 +334,24 @@@ static int everybody_uninteresting(stru
  
  /*
   * The goal is to get REV_TREE_NEW as the result only if the
 - * diff consists of all '+' (and no other changes), and
 - * REV_TREE_DIFFERENT otherwise (of course if the trees are
 - * the same we want REV_TREE_SAME).  That means that once we
 - * get to REV_TREE_DIFFERENT, we do not have to look any further.
 + * diff consists of all '+' (and no other changes), REV_TREE_OLD
 + * if the whole diff is removal of old data, and otherwise
 + * REV_TREE_DIFFERENT (of course if the trees are the same we
 + * want REV_TREE_SAME).
 + * That means that once we get to REV_TREE_DIFFERENT, we do not
 + * have to look any further.
   */
  static int tree_difference = REV_TREE_SAME;
  
  static void file_add_remove(struct diff_options *options,
                    int addremove, unsigned mode,
                    const unsigned char *sha1,
 -                  const char *fullpath)
 +                  int sha1_valid,
 +                  const char *fullpath, unsigned dirty_submodule)
  {
 -      int diff = REV_TREE_DIFFERENT;
 +      int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
  
 -      /*
 -       * Is it an add of a new file? It means that the old tree
 -       * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 -       * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 -       * (and if it already was "REV_TREE_NEW", we'll keep it
 -       * "REV_TREE_NEW" of course).
 -       */
 -      if (addremove == '+') {
 -              diff = tree_difference;
 -              if (diff != REV_TREE_SAME)
 -                      return;
 -              diff = REV_TREE_NEW;
 -      }
 -      tree_difference = diff;
 +      tree_difference |= diff;
        if (tree_difference == REV_TREE_DIFFERENT)
                DIFF_OPT_SET(options, HAS_CHANGES);
  }
@@@ -360,42 -286,18 +360,42 @@@ static void file_change(struct diff_opt
                 unsigned old_mode, unsigned new_mode,
                 const unsigned char *old_sha1,
                 const unsigned char *new_sha1,
 -               const char *fullpath)
 +               int old_sha1_valid, int new_sha1_valid,
 +               const char *fullpath,
 +               unsigned old_dirty_submodule, unsigned new_dirty_submodule)
  {
        tree_difference = REV_TREE_DIFFERENT;
        DIFF_OPT_SET(options, HAS_CHANGES);
  }
  
 -static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 +static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
  {
 +      struct tree *t1 = parent->tree;
 +      struct tree *t2 = commit->tree;
 +
        if (!t1)
                return REV_TREE_NEW;
        if (!t2)
 -              return REV_TREE_DIFFERENT;
 +              return REV_TREE_OLD;
 +
 +      if (revs->simplify_by_decoration) {
 +              /*
 +               * If we are simplifying by decoration, then the commit
 +               * is worth showing if it has a tag pointing at it.
 +               */
 +              if (lookup_decoration(&name_decoration, &commit->object))
 +                      return REV_TREE_DIFFERENT;
 +              /*
 +               * A commit that is not pointed by a tag is uninteresting
 +               * if we are not limited by path.  This means that you will
 +               * see the usual "commits that touch the paths" plus any
 +               * tagged commit by specifying both --simplify-by-decoration
 +               * and pathspec.
 +               */
 +              if (!revs->prune_data.nr)
 +                      return REV_TREE_SAME;
 +      }
 +
        tree_difference = REV_TREE_SAME;
        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
        return tree_difference;
  }
  
 -static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 +static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
  {
        int retval;
        void *tree;
        unsigned long size;
        struct tree_desc empty, real;
 +      struct tree *t1 = commit->tree;
  
        if (!t1)
                return 0;
  static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
  {
        struct commit_list **pp, *parent;
 -      int tree_changed = 0, tree_same = 0;
 +      int tree_changed = 0, tree_same = 0, nth_parent = 0;
  
        /*
         * If we don't do pruning, everything is interesting
                return;
  
        if (!commit->parents) {
 -              if (rev_same_tree_as_empty(revs, commit->tree))
 +              if (rev_same_tree_as_empty(revs, commit))
                        commit->object.flags |= TREESAME;
                return;
        }
        while ((parent = *pp) != NULL) {
                struct commit *p = parent->item;
  
 +              /*
 +               * Do not compare with later parents when we care only about
 +               * the first parent chain, in order to avoid derailing the
 +               * traversal to follow a side branch that brought everything
 +               * in the path we are limited to by the pathspec.
 +               */
 +              if (revs->first_parent_only && nth_parent++)
 +                      break;
                if (parse_commit(p) < 0)
                        die("cannot simplify commit %s (because of %s)",
                            sha1_to_hex(commit->object.sha1),
                            sha1_to_hex(p->object.sha1));
 -              switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 +              switch (rev_compare_tree(revs, p, commit)) {
                case REV_TREE_SAME:
                        tree_same = 1;
                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
  
                case REV_TREE_NEW:
                        if (revs->remove_empty_trees &&
 -                          rev_same_tree_as_empty(revs, p->tree)) {
 +                          rev_same_tree_as_empty(revs, p)) {
                                /* We are adding all the specified
                                 * paths from this parent, so the
                                 * history beyond this parent is not
                                p->parents = NULL;
                        }
                /* fallthrough */
 +              case REV_TREE_OLD:
                case REV_TREE_DIFFERENT:
                        tree_changed = 1;
                        pp = &parent->next;
        commit->object.flags |= TREESAME;
  }
  
 -static void insert_by_date_cached(struct commit *p, struct commit_list **head,
 +static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
                    struct commit_list *cached_base, struct commit_list **cache)
  {
        struct commit_list *new_entry;
  
        if (cached_base && p->date < cached_base->item->date)
 -              new_entry = insert_by_date(p, &cached_base->next);
 +              new_entry = commit_list_insert_by_date(p, &cached_base->next);
        else
 -              new_entry = insert_by_date(p, head);
 +              new_entry = commit_list_insert_by_date(p, head);
  
        if (cache && (!*cache || p->date < (*cache)->item->date))
                *cache = new_entry;
@@@ -562,16 -454,15 +562,16 @@@ static int add_parents_to_list(struct r
                while (parent) {
                        struct commit *p = parent->item;
                        parent = parent->next;
 +                      if (p)
 +                              p->object.flags |= UNINTERESTING;
                        if (parse_commit(p) < 0)
 -                              return -1;
 -                      p->object.flags |= UNINTERESTING;
 +                              continue;
                        if (p->parents)
                                mark_parents_uninteresting(p);
                        if (p->object.flags & SEEN)
                                continue;
                        p->object.flags |= SEEN;
 -                      insert_by_date_cached(p, list, cached_base, cache_ptr);
 +                      commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
                }
                return 0;
        }
  
                if (parse_commit(p) < 0)
                        return -1;
 +              if (revs->show_source && !p->util)
 +                      p->util = commit->util;
                p->object.flags |= left_flag;
                if (!(p->object.flags & SEEN)) {
                        p->object.flags |= SEEN;
 -                      insert_by_date_cached(p, list, cached_base, cache_ptr);
 +                      commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
                }
                if (revs->first_parent_only)
                        break;
@@@ -612,7 -501,6 +612,7 @@@ static void cherry_pick_list(struct com
        int left_count = 0, right_count = 0;
        int left_first;
        struct patch_ids ids;
 +      unsigned cherry_flag;
  
        /* First count the commits on the left and on the right */
        for (p = list; p; p = p->next) {
                        right_count++;
        }
  
 +      if (!left_count || !right_count)
 +              return;
 +
        left_first = left_count < right_count;
        init_patch_ids(&ids);
 -      if (revs->diffopt.nr_paths) {
 -              ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 -              ids.diffopts.paths = revs->diffopt.paths;
 -              ids.diffopts.pathlens = revs->diffopt.pathlens;
 -      }
 +      ids.diffopts.pathspec = revs->diffopt.pathspec;
  
        /* Compute patch-ids for one side */
        for (p = list; p; p = p->next) {
                commit->util = add_commit_patch_id(commit, &ids);
        }
  
 +      /* either cherry_mark or cherry_pick are true */
 +      cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 +
        /* Check the other side */
        for (p = list; p; p = p->next) {
                struct commit *commit = p->item;
                if (!id)
                        continue;
                id->seen = 1;
 -              commit->object.flags |= SHOWN;
 +              commit->object.flags |= cherry_flag;
        }
  
        /* Now check the original side for seen ones */
                if (!ent)
                        continue;
                if (ent->seen)
 -                      commit->object.flags |= SHOWN;
 +                      commit->object.flags |= cherry_flag;
                commit->util = NULL;
        }
  
@@@ -723,114 -609,6 +723,114 @@@ static int still_interesting(struct com
        return slop-1;
  }
  
 +/*
 + * "rev-list --ancestry-path A..B" computes commits that are ancestors
 + * of B but not ancestors of A but further limits the result to those
 + * that are descendants of A.  This takes the list of bottom commits and
 + * the result of "A..B" without --ancestry-path, and limits the latter
 + * further to the ones that can reach one of the commits in "bottom".
 + */
 +static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 +{
 +      struct commit_list *p;
 +      struct commit_list *rlist = NULL;
 +      int made_progress;
 +
 +      /*
 +       * Reverse the list so that it will be likely that we would
 +       * process parents before children.
 +       */
 +      for (p = list; p; p = p->next)
 +              commit_list_insert(p->item, &rlist);
 +
 +      for (p = bottom; p; p = p->next)
 +              p->item->object.flags |= TMP_MARK;
 +
 +      /*
 +       * Mark the ones that can reach bottom commits in "list",
 +       * in a bottom-up fashion.
 +       */
 +      do {
 +              made_progress = 0;
 +              for (p = rlist; p; p = p->next) {
 +                      struct commit *c = p->item;
 +                      struct commit_list *parents;
 +                      if (c->object.flags & (TMP_MARK | UNINTERESTING))
 +                              continue;
 +                      for (parents = c->parents;
 +                           parents;
 +                           parents = parents->next) {
 +                              if (!(parents->item->object.flags & TMP_MARK))
 +                                      continue;
 +                              c->object.flags |= TMP_MARK;
 +                              made_progress = 1;
 +                              break;
 +                      }
 +              }
 +      } while (made_progress);
 +
 +      /*
 +       * NEEDSWORK: decide if we want to remove parents that are
 +       * not marked with TMP_MARK from commit->parents for commits
 +       * in the resulting list.  We may not want to do that, though.
 +       */
 +
 +      /*
 +       * The ones that are not marked with TMP_MARK are uninteresting
 +       */
 +      for (p = list; p; p = p->next) {
 +              struct commit *c = p->item;
 +              if (c->object.flags & TMP_MARK)
 +                      continue;
 +              c->object.flags |= UNINTERESTING;
 +      }
 +
 +      /* We are done with the TMP_MARK */
 +      for (p = list; p; p = p->next)
 +              p->item->object.flags &= ~TMP_MARK;
 +      for (p = bottom; p; p = p->next)
 +              p->item->object.flags &= ~TMP_MARK;
 +      free_commit_list(rlist);
 +}
 +
 +/*
 + * Before walking the history, keep the set of "negative" refs the
 + * caller has asked to exclude.
 + *
 + * This is used to compute "rev-list --ancestry-path A..B", as we need
 + * to filter the result of "A..B" further to the ones that can actually
 + * reach A.
 + */
 +static struct commit_list *collect_bottom_commits(struct rev_info *revs)
 +{
 +      struct commit_list *bottom = NULL;
 +      int i;
 +      for (i = 0; i < revs->cmdline.nr; i++) {
 +              struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
 +              if ((elem->flags & UNINTERESTING) &&
 +                  elem->item->type == OBJ_COMMIT)
 +                      commit_list_insert((struct commit *)elem->item, &bottom);
 +      }
 +      return bottom;
 +}
 +
 +/* Assumes either left_only or right_only is set */
 +static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 +{
 +      struct commit_list *p;
 +
 +      for (p = list; p; p = p->next) {
 +              struct commit *commit = p->item;
 +
 +              if (revs->right_only) {
 +                      if (commit->object.flags & SYMMETRIC_LEFT)
 +                              commit->object.flags |= SHOWN;
 +              } else  /* revs->left_only is set */
 +                      if (!(commit->object.flags & SYMMETRIC_LEFT))
 +                              commit->object.flags |= SHOWN;
 +      }
 +}
 +
  static int limit_list(struct rev_info *revs)
  {
        int slop = SLOP;
        struct commit_list *list = revs->commits;
        struct commit_list *newlist = NULL;
        struct commit_list **p = &newlist;
 +      struct commit_list *bottom = NULL;
 +
 +      if (revs->ancestry_path) {
 +              bottom = collect_bottom_commits(revs);
 +              if (!bottom)
 +                      die("--ancestry-path given but there are no bottom commits");
 +      }
  
        while (list) {
                struct commit_list *entry = list;
                show(revs, newlist);
                show_early_output = NULL;
        }
 -      if (revs->cherry_pick)
 +      if (revs->cherry_pick || revs->cherry_mark)
                cherry_pick_list(newlist, revs);
  
 +      if (revs->left_only || revs->right_only)
 +              limit_left_right(newlist, revs);
 +
 +      if (bottom) {
 +              limit_to_ancestry(bottom, newlist);
 +              free_commit_list(bottom);
 +      }
 +
        revs->commits = newlist;
        return 0;
  }
  
 +static void add_rev_cmdline(struct rev_info *revs,
 +                          struct object *item,
 +                          const char *name,
 +                          int whence,
 +                          unsigned flags)
 +{
 +      struct rev_cmdline_info *info = &revs->cmdline;
 +      int nr = info->nr;
 +
 +      ALLOC_GROW(info->rev, nr + 1, info->alloc);
 +      info->rev[nr].item = item;
 +      info->rev[nr].name = name;
 +      info->rev[nr].whence = whence;
 +      info->rev[nr].flags = flags;
 +      info->nr++;
 +}
 +
  struct all_refs_cb {
        int all_flags;
        int warned_bad_reflog;
@@@ -927,24 -673,17 +927,24 @@@ static int handle_one_ref(const char *p
        struct all_refs_cb *cb = cb_data;
        struct object *object = get_reference(cb->all_revs, path, sha1,
                                              cb->all_flags);
 -      add_pending_object(cb->all_revs, object, path);
 +      add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
 +      add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
        return 0;
  }
  
 -static void handle_refs(struct rev_info *revs, unsigned flags,
 -              int (*for_each)(each_ref_fn, void *))
 +static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 +      unsigned flags)
 +{
 +      cb->all_revs = revs;
 +      cb->all_flags = flags;
 +}
 +
 +static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
 +              int (*for_each)(const char *, each_ref_fn, void *))
  {
        struct all_refs_cb cb;
 -      cb.all_revs = revs;
 -      cb.all_flags = flags;
 -      for_each(handle_one_ref, &cb);
 +      init_all_refs_cb(&cb, revs, flags);
 +      for_each(submodule, handle_one_ref, &cb);
  }
  
  static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
                struct object *o = parse_object(sha1);
                if (o) {
                        o->flags |= cb->all_flags;
 +                      /* ??? CMDLINEFLAGS ??? */
                        add_pending_object(cb->all_revs, o, "");
                }
                else if (!cb->warned_bad_reflog) {
@@@ -991,24 -729,21 +991,24 @@@ static void handle_reflog(struct rev_in
        for_each_reflog(handle_one_reflog, &cb);
  }
  
 -static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 +static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
  {
        unsigned char sha1[20];
        struct object *it;
        struct commit *commit;
        struct commit_list *parents;
 +      const char *arg = arg_;
  
        if (*arg == '^') {
                flags ^= UNINTERESTING;
                arg++;
        }
 -      if (get_sha1(arg, sha1))
 +      if (get_sha1_committish(arg, sha1))
                return 0;
        while (1) {
                it = get_reference(revs, arg, sha1, 0);
 +              if (!it && revs->ignore_missing)
 +                      return 0;
                if (it->type != OBJ_TAG)
                        break;
                if (!((struct tag*)it)->tagged)
        for (parents = commit->parents; parents; parents = parents->next) {
                it = &parents->item->object;
                it->flags |= flags;
 +              add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
                add_pending_object(revs, it, arg);
        }
        return 1;
@@@ -1035,7 -769,7 +1035,7 @@@ void init_revisions(struct rev_info *re
        revs->ignore_merges = 1;
        revs->simplify_history = 1;
        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 -      DIFF_OPT_SET(&revs->pruning, QUIET);
 +      DIFF_OPT_SET(&revs->pruning, QUICK);
        revs->pruning.add_remove = file_add_remove;
        revs->pruning.change = file_change;
        revs->lifo = 1;
        revs->min_age = -1;
        revs->skip_count = -1;
        revs->max_count = -1;
 +      revs->max_parents = -1;
  
        revs->commit_format = CMIT_FMT_DEFAULT;
  
 +      init_grep_defaults();
 +      grep_init(&revs->grep_filter, prefix);
 +      revs->grep_filter.status_only = 1;
 +      revs->grep_filter.regflags = REG_NEWLINE;
 +
        diff_setup(&revs->diffopt);
        if (prefix && !revs->diffopt.prefix) {
                revs->diffopt.prefix = prefix;
                revs->diffopt.prefix_length = strlen(prefix);
        }
 +
 +      revs->notes_opt.use_default_notes = -1;
  }
  
  static void add_pending_commit_list(struct rev_info *revs,
@@@ -1083,12 -809,10 +1083,12 @@@ static void prepare_show_merge(struct r
        const char **prune = NULL;
        int i, prune_num = 1; /* counting terminating NULL */
  
 -      if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 +      if (get_sha1("HEAD", sha1))
                die("--merge without HEAD?");
 -      if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 +      head = lookup_commit_or_die(sha1, "HEAD");
 +      if (get_sha1("MERGE_HEAD", sha1))
                die("--merge without MERGE_HEAD?");
 +      other = lookup_commit_or_die(sha1, "MERGE_HEAD");
        add_pending_object(revs, &head->object, "HEAD");
        add_pending_object(revs, &other->object, "MERGE_HEAD");
        bases = get_merge_bases(head, other, 1);
                struct cache_entry *ce = active_cache[i];
                if (!ce_stage(ce))
                        continue;
 -              if (ce_path_match(ce, revs->prune_data)) {
 +              if (ce_path_match(ce, &revs->prune_data)) {
                        prune_num++;
                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
                        prune[prune_num-2] = ce->name;
                       ce_same_name(ce, active_cache[i+1]))
                        i++;
        }
 -      revs->prune_data = prune;
 +      free_pathspec(&revs->prune_data);
 +      init_pathspec(&revs->prune_data, prune);
        revs->limited = 1;
  }
  
 -int handle_revision_arg(const char *arg, struct rev_info *revs,
 -                      int flags,
 -                      int cant_be_filename)
 +int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
  {
 -      unsigned mode;
 +      struct object_context oc;
        char *dotdot;
        struct object *object;
        unsigned char sha1[20];
        int local_flags;
 +      const char *arg = arg_;
 +      int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
 +      unsigned get_sha1_flags = 0;
  
        dotdot = strstr(arg, "..");
        if (dotdot) {
                const char *this = arg;
                int symmetric = *next == '.';
                unsigned int flags_exclude = flags ^ UNINTERESTING;
 +              static const char head_by_default[] = "HEAD";
 +              unsigned int a_flags;
  
                *dotdot = 0;
                next += symmetric;
  
                if (!*next)
 -                      next = "HEAD";
 +                      next = head_by_default;
                if (dotdot == arg)
 -                      this = "HEAD";
 -              if (!get_sha1(this, from_sha1) &&
 -                  !get_sha1(next, sha1)) {
 +                      this = head_by_default;
 +              if (this == head_by_default && next == head_by_default &&
 +                  !symmetric) {
 +                      /*
 +                       * Just ".."?  That is not a range but the
 +                       * pathspec for the parent directory.
 +                       */
 +                      if (!cant_be_filename) {
 +                              *dotdot = '.';
 +                              return -1;
 +                      }
 +              }
 +              if (!get_sha1_committish(this, from_sha1) &&
 +                  !get_sha1_committish(next, sha1)) {
                        struct commit *a, *b;
                        struct commit_list *exclude;
  
                        a = lookup_commit_reference(from_sha1);
                        b = lookup_commit_reference(sha1);
                        if (!a || !b) {
 +                              if (revs->ignore_missing)
 +                                      return 0;
                                die(symmetric ?
                                    "Invalid symmetric difference expression %s...%s" :
                                    "Invalid revision range %s..%s",
                                add_pending_commit_list(revs, exclude,
                                                        flags_exclude);
                                free_commit_list(exclude);
 -                              a->object.flags |= flags | SYMMETRIC_LEFT;
 +                              a_flags = flags | SYMMETRIC_LEFT;
                        } else
 -                              a->object.flags |= flags_exclude;
 +                              a_flags = flags_exclude;
 +                      a->object.flags |= a_flags;
                        b->object.flags |= flags;
 +                      add_rev_cmdline(revs, &a->object, this,
 +                                      REV_CMD_LEFT, a_flags);
 +                      add_rev_cmdline(revs, &b->object, next,
 +                                      REV_CMD_RIGHT, flags);
                        add_pending_object(revs, &a->object, this);
                        add_pending_object(revs, &b->object, next);
                        return 0;
                local_flags = UNINTERESTING;
                arg++;
        }
 -      if (get_sha1_with_mode(arg, sha1, &mode))
 -              return -1;
 +
 +      if (revarg_opt & REVARG_COMMITTISH)
 +              get_sha1_flags = GET_SHA1_COMMITTISH;
 +
 +      if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
 +              return revs->ignore_missing ? 0 : -1;
        if (!cant_be_filename)
                verify_non_filename(revs->prefix, arg);
        object = get_reference(revs, arg, sha1, flags ^ local_flags);
 -      add_pending_object_with_mode(revs, object, arg, mode);
 +      add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
 +      add_pending_object_with_mode(revs, object, arg, oc.mode);
        return 0;
  }
  
 -void read_revisions_from_stdin(struct rev_info *revs)
 +struct cmdline_pathspec {
 +      int alloc;
 +      int nr;
 +      const char **path;
 +};
 +
 +static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
  {
 -      char line[1000];
 +      while (*av) {
 +              ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
 +              prune->path[prune->nr++] = *(av++);
 +      }
 +}
 +
 +static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
 +                                   struct cmdline_pathspec *prune)
 +{
 +      while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
 +              int len = sb->len;
 +              if (len && sb->buf[len - 1] == '\n')
 +                      sb->buf[--len] = '\0';
 +              ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
 +              prune->path[prune->nr++] = xstrdup(sb->buf);
 +      }
 +}
  
 -      while (fgets(line, sizeof(line), stdin) != NULL) {
 -              int len = strlen(line);
 -              if (len && line[len - 1] == '\n')
 -                      line[--len] = '\0';
 +static void read_revisions_from_stdin(struct rev_info *revs,
 +                                    struct cmdline_pathspec *prune)
 +{
 +      struct strbuf sb;
 +      int seen_dashdash = 0;
 +
 +      strbuf_init(&sb, 1000);
 +      while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
 +              int len = sb.len;
 +              if (len && sb.buf[len - 1] == '\n')
 +                      sb.buf[--len] = '\0';
                if (!len)
                        break;
 -              if (line[0] == '-')
 +              if (sb.buf[0] == '-') {
 +                      if (len == 2 && sb.buf[1] == '-') {
 +                              seen_dashdash = 1;
 +                              break;
 +                      }
                        die("options not supported in --stdin mode");
 -              if (handle_revision_arg(line, revs, 0, 1))
 -                      die("bad revision '%s'", line);
 +              }
 +              if (handle_revision_arg(sb.buf, revs, 0, REVARG_CANNOT_BE_FILENAME))
 +                      die("bad revision '%s'", sb.buf);
        }
 +      if (seen_dashdash)
 +              read_pathspec_from_stdin(revs, &sb, prune);
 +      strbuf_release(&sb);
  }
  
  static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
  {
 -      if (!revs->grep_filter) {
 -              struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 -              opt->status_only = 1;
 -              opt->pattern_tail = &(opt->pattern_list);
 -              opt->regflags = REG_NEWLINE;
 -              revs->grep_filter = opt;
 -      }
 -      append_grep_pattern(revs->grep_filter, ptn,
 -                          "command line", 0, what);
 +      append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
  }
  
 -static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 +static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
  {
 -      char *pat;
 -      const char *prefix;
 -      int patlen, fldlen;
 -
 -      fldlen = strlen(field);
 -      patlen = strlen(pattern);
 -      pat = xmalloc(patlen + fldlen + 10);
 -      prefix = ".*";
 -      if (*pattern == '^') {
 -              prefix = "";
 -              pattern++;
 -      }
 -      sprintf(pat, "^%s %s%s", field, prefix, pattern);
 -      add_grep(revs, pat, GREP_PATTERN_HEAD);
 +      append_header_grep_pattern(&revs->grep_filter, field, pattern);
  }
  
  static void add_message_grep(struct rev_info *revs, const char *pattern)
        add_grep(revs, pattern, GREP_PATTERN_BODY);
  }
  
 -static void add_ignore_packed(struct rev_info *revs, const char *name)
 -{
 -      int num = ++revs->num_ignore_packed;
 -
 -      revs->ignore_packed = xrealloc(revs->ignore_packed,
 -                                     sizeof(const char **) * (num + 1));
 -      revs->ignore_packed[num-1] = name;
 -      revs->ignore_packed[num] = NULL;
 -}
 -
  static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
                               int *unkc, const char **unkv)
  {
        const char *arg = argv[0];
 +      const char *optarg;
 +      int argcount;
  
        /* pseudo revision arguments */
        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
 -          !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk"))
 +          !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
 +          !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
 +          !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
 +          !prefixcmp(arg, "--remotes=") || !prefixcmp(arg, "--no-walk="))
        {
                unkv[(*unkc)++] = arg;
                return 1;
        }
  
 -      if (!prefixcmp(arg, "--max-count=")) {
 -              revs->max_count = atoi(arg + 12);
 -      } else if (!prefixcmp(arg, "--skip=")) {
 -              revs->skip_count = atoi(arg + 7);
 +      if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
 +              revs->max_count = atoi(optarg);
 +              revs->no_walk = 0;
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
 +              revs->skip_count = atoi(optarg);
 +              return argcount;
        } else if ((*arg == '-') && isdigit(arg[1])) {
        /* accept -<digit>, like traditional "head" */
                revs->max_count = atoi(arg + 1);
 +              revs->no_walk = 0;
        } else if (!strcmp(arg, "-n")) {
                if (argc <= 1)
                        return error("-n requires an argument");
                revs->max_count = atoi(argv[1]);
 +              revs->no_walk = 0;
                return 2;
        } else if (!prefixcmp(arg, "-n")) {
                revs->max_count = atoi(arg + 2);
 -      } else if (!prefixcmp(arg, "--max-age=")) {
 -              revs->max_age = atoi(arg + 10);
 -      } else if (!prefixcmp(arg, "--since=")) {
 -              revs->max_age = approxidate(arg + 8);
 -      } else if (!prefixcmp(arg, "--after=")) {
 -              revs->max_age = approxidate(arg + 8);
 -      } else if (!prefixcmp(arg, "--min-age=")) {
 -              revs->min_age = atoi(arg + 10);
 -      } else if (!prefixcmp(arg, "--before=")) {
 -              revs->min_age = approxidate(arg + 9);
 -      } else if (!prefixcmp(arg, "--until=")) {
 -              revs->min_age = approxidate(arg + 8);
 +              revs->no_walk = 0;
 +      } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
 +              revs->max_age = atoi(optarg);
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
 +              revs->max_age = approxidate(optarg);
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
 +              revs->max_age = approxidate(optarg);
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
 +              revs->min_age = atoi(optarg);
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
 +              revs->min_age = approxidate(optarg);
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
 +              revs->min_age = approxidate(optarg);
 +              return argcount;
        } else if (!strcmp(arg, "--first-parent")) {
                revs->first_parent_only = 1;
 +      } else if (!strcmp(arg, "--ancestry-path")) {
 +              revs->ancestry_path = 1;
 +              revs->simplify_history = 0;
 +              revs->limited = 1;
        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
                init_reflog_walk(&revs->reflog_info);
        } else if (!strcmp(arg, "--default")) {
                revs->topo_order = 1;
        } else if (!strcmp(arg, "--simplify-merges")) {
                revs->simplify_merges = 1;
 +              revs->topo_order = 1;
 +              revs->rewrite_parents = 1;
 +              revs->simplify_history = 0;
 +              revs->limited = 1;
 +      } else if (!strcmp(arg, "--simplify-by-decoration")) {
 +              revs->simplify_merges = 1;
 +              revs->topo_order = 1;
                revs->rewrite_parents = 1;
                revs->simplify_history = 0;
 +              revs->simplify_by_decoration = 1;
                revs->limited = 1;
 +              revs->prune = 1;
 +              load_ref_decorations(DECORATE_SHORT_REFS);
        } else if (!strcmp(arg, "--date-order")) {
                revs->lifo = 0;
                revs->topo_order = 1;
                revs->show_all = 1;
        } else if (!strcmp(arg, "--remove-empty")) {
                revs->remove_empty_trees = 1;
 +      } else if (!strcmp(arg, "--merges")) {
 +              revs->min_parents = 2;
        } else if (!strcmp(arg, "--no-merges")) {
 -              revs->no_merges = 1;
 +              revs->max_parents = 1;
 +      } else if (!prefixcmp(arg, "--min-parents=")) {
 +              revs->min_parents = atoi(arg+14);
 +      } else if (!prefixcmp(arg, "--no-min-parents")) {
 +              revs->min_parents = 0;
 +      } else if (!prefixcmp(arg, "--max-parents=")) {
 +              revs->max_parents = atoi(arg+14);
 +      } else if (!prefixcmp(arg, "--no-max-parents")) {
 +              revs->max_parents = -1;
        } else if (!strcmp(arg, "--boundary")) {
                revs->boundary = 1;
        } else if (!strcmp(arg, "--left-right")) {
                revs->left_right = 1;
 +      } else if (!strcmp(arg, "--left-only")) {
 +              if (revs->right_only)
 +                      die("--left-only is incompatible with --right-only"
 +                          " or --cherry");
 +              revs->left_only = 1;
 +      } else if (!strcmp(arg, "--right-only")) {
 +              if (revs->left_only)
 +                      die("--right-only is incompatible with --left-only");
 +              revs->right_only = 1;
 +      } else if (!strcmp(arg, "--cherry")) {
 +              if (revs->left_only)
 +                      die("--cherry is incompatible with --left-only");
 +              revs->cherry_mark = 1;
 +              revs->right_only = 1;
 +              revs->max_parents = 1;
 +              revs->limited = 1;
 +      } else if (!strcmp(arg, "--count")) {
 +              revs->count = 1;
 +      } else if (!strcmp(arg, "--cherry-mark")) {
 +              if (revs->cherry_pick)
 +                      die("--cherry-mark is incompatible with --cherry-pick");
 +              revs->cherry_mark = 1;
 +              revs->limited = 1; /* needs limit_list() */
        } else if (!strcmp(arg, "--cherry-pick")) {
 +              if (revs->cherry_mark)
 +                      die("--cherry-pick is incompatible with --cherry-mark");
                revs->cherry_pick = 1;
                revs->limited = 1;
        } else if (!strcmp(arg, "--objects")) {
                revs->tree_objects = 1;
                revs->blob_objects = 1;
                revs->edge_hint = 1;
 +      } else if (!strcmp(arg, "--verify-objects")) {
 +              revs->tag_objects = 1;
 +              revs->tree_objects = 1;
 +              revs->blob_objects = 1;
 +              revs->verify_objects = 1;
        } else if (!strcmp(arg, "--unpacked")) {
                revs->unpacked = 1;
 -              free(revs->ignore_packed);
 -              revs->ignore_packed = NULL;
 -              revs->num_ignore_packed = 0;
        } else if (!prefixcmp(arg, "--unpacked=")) {
 -              revs->unpacked = 1;
 -              add_ignore_packed(revs, arg+11);
 +              die("--unpacked=<packfile> no longer supported.");
        } else if (!strcmp(arg, "-r")) {
                revs->diff = 1;
                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
                revs->verbose_header = 1;
        } else if (!strcmp(arg, "--pretty")) {
                revs->verbose_header = 1;
 +              revs->pretty_given = 1;
                get_commit_format(arg+8, revs);
 -      } else if (!prefixcmp(arg, "--pretty=")) {
 +      } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
 +              /*
 +               * Detached form ("--pretty X" as opposed to "--pretty=X")
 +               * not allowed, since the argument is optional.
 +               */
                revs->verbose_header = 1;
 +              revs->pretty_given = 1;
                get_commit_format(arg+9, revs);
 +      } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 +              revs->show_notes = 1;
 +              revs->show_notes_given = 1;
 +              revs->notes_opt.use_default_notes = 1;
 +      } else if (!strcmp(arg, "--show-signature")) {
 +              revs->show_signature = 1;
 +      } else if (!prefixcmp(arg, "--show-notes=") ||
 +                 !prefixcmp(arg, "--notes=")) {
 +              struct strbuf buf = STRBUF_INIT;
 +              revs->show_notes = 1;
 +              revs->show_notes_given = 1;
 +              if (!prefixcmp(arg, "--show-notes")) {
 +                      if (revs->notes_opt.use_default_notes < 0)
 +                              revs->notes_opt.use_default_notes = 1;
 +                      strbuf_addstr(&buf, arg+13);
 +              }
 +              else
 +                      strbuf_addstr(&buf, arg+8);
 +              expand_notes_ref(&buf);
 +              string_list_append(&revs->notes_opt.extra_notes_refs,
 +                                 strbuf_detach(&buf, NULL));
 +      } else if (!strcmp(arg, "--no-notes")) {
 +              revs->show_notes = 0;
 +              revs->show_notes_given = 1;
 +              revs->notes_opt.use_default_notes = -1;
 +              /* we have been strdup'ing ourselves, so trick
 +               * string_list into free()ing strings */
 +              revs->notes_opt.extra_notes_refs.strdup_strings = 1;
 +              string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
 +              revs->notes_opt.extra_notes_refs.strdup_strings = 0;
 +      } else if (!strcmp(arg, "--standard-notes")) {
 +              revs->show_notes_given = 1;
 +              revs->notes_opt.use_default_notes = 1;
 +      } else if (!strcmp(arg, "--no-standard-notes")) {
 +              revs->notes_opt.use_default_notes = 0;
 +      } else if (!strcmp(arg, "--oneline")) {
 +              revs->verbose_header = 1;
 +              get_commit_format("oneline", revs);
 +              revs->pretty_given = 1;
 +              revs->abbrev_commit = 1;
        } else if (!strcmp(arg, "--graph")) {
                revs->topo_order = 1;
                revs->rewrite_parents = 1;
                        revs->abbrev = 40;
        } else if (!strcmp(arg, "--abbrev-commit")) {
                revs->abbrev_commit = 1;
 +              revs->abbrev_commit_given = 1;
 +      } else if (!strcmp(arg, "--no-abbrev-commit")) {
 +              revs->abbrev_commit = 0;
        } else if (!strcmp(arg, "--full-diff")) {
                revs->diff = 1;
                revs->full_diff = 1;
                revs->simplify_history = 0;
        } else if (!strcmp(arg, "--relative-date")) {
                revs->date_mode = DATE_RELATIVE;
 -      } else if (!strncmp(arg, "--date=", 7)) {
 -              revs->date_mode = parse_date_format(arg + 7);
 +              revs->date_mode_explicit = 1;
 +      } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
 +              revs->date_mode = parse_date_format(optarg);
 +              revs->date_mode_explicit = 1;
 +              return argcount;
        } else if (!strcmp(arg, "--log-size")) {
                revs->show_log_size = 1;
        }
        /*
         * Grepping the commit log
         */
 -      else if (!prefixcmp(arg, "--author=")) {
 -              add_header_grep(revs, "author", arg+9);
 -      } else if (!prefixcmp(arg, "--committer=")) {
 -              add_header_grep(revs, "committer", arg+12);
 -      } else if (!prefixcmp(arg, "--grep=")) {
 -              add_message_grep(revs, arg+7);
 +      else if ((argcount = parse_long_opt("author", argv, &optarg))) {
 +              add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
 +              add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
 +              add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
 +              return argcount;
 +      } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
 +              add_message_grep(revs, optarg);
 +              return argcount;
 +      } else if (!strcmp(arg, "--grep-debug")) {
 +              revs->grep_filter.debug = 1;
 +      } else if (!strcmp(arg, "--basic-regexp")) {
 +              grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
 -              if (revs->grep_filter)
 -                      revs->grep_filter->regflags |= REG_EXTENDED;
 +              grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
 -              if (revs->grep_filter)
 -                      revs->grep_filter->regflags |= REG_ICASE;
 +              revs->grep_filter.regflags |= REG_ICASE;
 +              DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
 -              if (revs->grep_filter)
 -                      revs->grep_filter->fixed = 1;
 +              grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
 +      } else if (!strcmp(arg, "--perl-regexp")) {
 +              grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
        } else if (!strcmp(arg, "--all-match")) {
 -              if (revs->grep_filter)
 -                      revs->grep_filter->all_match = 1;
 -      } else if (!prefixcmp(arg, "--encoding=")) {
 -              arg += 11;
 -              if (strcmp(arg, "none"))
 -                      git_log_output_encoding = xstrdup(arg);
 +              revs->grep_filter.all_match = 1;
 +      } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
 +              if (strcmp(optarg, "none"))
 +                      git_log_output_encoding = xstrdup(optarg);
                else
                        git_log_output_encoding = "";
 +              return argcount;
        } else if (!strcmp(arg, "--reverse")) {
                revs->reverse ^= 1;
        } else if (!strcmp(arg, "--children")) {
                revs->children.name = "children";
                revs->limited = 1;
 +      } else if (!strcmp(arg, "--ignore-missing")) {
 +              revs->ignore_missing = 1;
        } else {
                int opts = diff_opt_parse(&revs->diffopt, argv, argc);
                if (!opts)
@@@ -1654,90 -1215,6 +1654,90 @@@ void parse_revision_opt(struct rev_inf
        ctx->argc -= n;
  }
  
 +static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
 +{
 +      return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
 +}
 +
 +static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
 +{
 +      return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
 +}
 +
 +static int handle_revision_pseudo_opt(const char *submodule,
 +                              struct rev_info *revs,
 +                              int argc, const char **argv, int *flags)
 +{
 +      const char *arg = argv[0];
 +      const char *optarg;
 +      int argcount;
 +
 +      /*
 +       * NOTE!
 +       *
 +       * Commands like "git shortlog" will not accept the options below
 +       * unless parse_revision_opt queues them (as opposed to erroring
 +       * out).
 +       *
 +       * When implementing your new pseudo-option, remember to
 +       * register it in the list at the top of handle_revision_opt.
 +       */
 +      if (!strcmp(arg, "--all")) {
 +              handle_refs(submodule, revs, *flags, for_each_ref_submodule);
 +              handle_refs(submodule, revs, *flags, head_ref_submodule);
 +      } else if (!strcmp(arg, "--branches")) {
 +              handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
 +      } else if (!strcmp(arg, "--bisect")) {
 +              handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
 +              handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
 +              revs->bisect = 1;
 +      } else if (!strcmp(arg, "--tags")) {
 +              handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
 +      } else if (!strcmp(arg, "--remotes")) {
 +              handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
 +      } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
 +              struct all_refs_cb cb;
 +              init_all_refs_cb(&cb, revs, *flags);
 +              for_each_glob_ref(handle_one_ref, optarg, &cb);
 +              return argcount;
 +      } else if (!prefixcmp(arg, "--branches=")) {
 +              struct all_refs_cb cb;
 +              init_all_refs_cb(&cb, revs, *flags);
 +              for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
 +      } else if (!prefixcmp(arg, "--tags=")) {
 +              struct all_refs_cb cb;
 +              init_all_refs_cb(&cb, revs, *flags);
 +              for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
 +      } else if (!prefixcmp(arg, "--remotes=")) {
 +              struct all_refs_cb cb;
 +              init_all_refs_cb(&cb, revs, *flags);
 +              for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
 +      } else if (!strcmp(arg, "--reflog")) {
 +              handle_reflog(revs, *flags);
 +      } else if (!strcmp(arg, "--not")) {
 +              *flags ^= UNINTERESTING;
 +      } else if (!strcmp(arg, "--no-walk")) {
 +              revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
 +      } else if (!prefixcmp(arg, "--no-walk=")) {
 +              /*
 +               * Detached form ("--no-walk X" as opposed to "--no-walk=X")
 +               * not allowed, since the argument is optional.
 +               */
 +              if (!strcmp(arg + 10, "sorted"))
 +                      revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
 +              else if (!strcmp(arg + 10, "unsorted"))
 +                      revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
 +              else
 +                      return error("invalid argument to --no-walk");
 +      } else if (!strcmp(arg, "--do-walk")) {
 +              revs->no_walk = 0;
 +      } else {
 +              return 0;
 +      }
 +
 +      return 1;
 +}
 +
  /*
   * Parse revision information, filling in the "rev_info" structure,
   * and removing the used arguments from the argument list.
   * Returns the number of arguments left that weren't recognized
   * (which are also moved to the head of the argument list)
   */
 -int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 +int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
  {
 -      int i, flags, left, seen_dashdash;
 +      int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
 +      struct cmdline_pathspec prune_data;
 +      const char *submodule = NULL;
 +
 +      memset(&prune_data, 0, sizeof(prune_data));
 +      if (opt)
 +              submodule = opt->submodule;
  
        /* First, search for "--" */
 -      seen_dashdash = 0;
 -      for (i = 1; i < argc; i++) {
 -              const char *arg = argv[i];
 -              if (strcmp(arg, "--"))
 -                      continue;
 -              argv[i] = NULL;
 -              argc = i;
 -              if (argv[i + 1])
 -                      revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 +      if (opt && opt->assume_dashdash) {
                seen_dashdash = 1;
 -              break;
 +      } else {
 +              seen_dashdash = 0;
 +              for (i = 1; i < argc; i++) {
 +                      const char *arg = argv[i];
 +                      if (strcmp(arg, "--"))
 +                              continue;
 +                      argv[i] = NULL;
 +                      argc = i;
 +                      if (argv[i + 1])
 +                              append_prune_data(&prune_data, argv + i + 1);
 +                      seen_dashdash = 1;
 +                      break;
 +              }
        }
  
        /* Second, deal with arguments and options */
        flags = 0;
 +      revarg_opt = opt ? opt->revarg_opt : 0;
 +      if (seen_dashdash)
 +              revarg_opt |= REVARG_CANNOT_BE_FILENAME;
 +      read_from_stdin = 0;
        for (left = i = 1; i < argc; i++) {
                const char *arg = argv[i];
                if (*arg == '-') {
                        int opts;
  
 -                      if (!strcmp(arg, "--all")) {
 -                              handle_refs(revs, flags, for_each_ref);
 -                              continue;
 -                      }
 -                      if (!strcmp(arg, "--branches")) {
 -                              handle_refs(revs, flags, for_each_branch_ref);
 -                              continue;
 -                      }
 -                      if (!strcmp(arg, "--tags")) {
 -                              handle_refs(revs, flags, for_each_tag_ref);
 -                              continue;
 -                      }
 -                      if (!strcmp(arg, "--remotes")) {
 -                              handle_refs(revs, flags, for_each_remote_ref);
 -                              continue;
 -                      }
 -                      if (!strcmp(arg, "--reflog")) {
 -                              handle_reflog(revs, flags);
 -                              continue;
 -                      }
 -                      if (!strcmp(arg, "--not")) {
 -                              flags ^= UNINTERESTING;
 -                              continue;
 -                      }
 -                      if (!strcmp(arg, "--no-walk")) {
 -                              revs->no_walk = 1;
 +                      opts = handle_revision_pseudo_opt(submodule,
 +                                              revs, argc - i, argv + i,
 +                                              &flags);
 +                      if (opts > 0) {
 +                              i += opts - 1;
                                continue;
                        }
 -                      if (!strcmp(arg, "--do-walk")) {
 -                              revs->no_walk = 0;
 +
 +                      if (!strcmp(arg, "--stdin")) {
 +                              if (revs->disable_stdin) {
 +                                      argv[left++] = arg;
 +                                      continue;
 +                              }
 +                              if (read_from_stdin++)
 +                                      die("--stdin given twice?");
 +                              read_revisions_from_stdin(revs, &prune_data);
                                continue;
                        }
  
                        continue;
                }
  
 -              if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
 +
 +              if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
                        int j;
                        if (seen_dashdash || *arg == '^')
                                die("bad revision '%s'", arg);
                         * but the latter we have checked in the main loop.
                         */
                        for (j = i; j < argc; j++)
 -                              verify_filename(revs->prefix, argv[j]);
 +                              verify_filename(revs->prefix, argv[j], j == i);
  
 -                      revs->prune_data = get_pathspec(revs->prefix,
 -                                                      argv + i);
 +                      append_prune_data(&prune_data, argv + i);
                        break;
                }
 +              else
 +                      got_rev_arg = 1;
 +      }
 +
 +      if (prune_data.nr) {
 +              /*
 +               * If we need to introduce the magic "a lone ':' means no
 +               * pathspec whatsoever", here is the place to do so.
 +               *
 +               * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
 +               *      prune_data.nr = 0;
 +               *      prune_data.alloc = 0;
 +               *      free(prune_data.path);
 +               *      prune_data.path = NULL;
 +               * } else {
 +               *      terminate prune_data.alloc with NULL and
 +               *      call init_pathspec() to set revs->prune_data here.
 +               * }
 +               */
 +              ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
 +              prune_data.path[prune_data.nr++] = NULL;
 +              init_pathspec(&revs->prune_data,
 +                            get_pathspec(revs->prefix, prune_data.path));
        }
  
        if (revs->def == NULL)
 -              revs->def = def;
 +              revs->def = opt ? opt->def : NULL;
 +      if (opt && opt->tweak)
 +              opt->tweak(revs, opt);
        if (revs->show_merge)
                prepare_show_merge(revs);
 -      if (revs->def && !revs->pending.nr) {
 +      if (revs->def && !revs->pending.nr && !got_rev_arg) {
                unsigned char sha1[20];
                struct object *object;
 -              unsigned mode;
 -              if (get_sha1_with_mode(revs->def, sha1, &mode))
 +              struct object_context oc;
 +              if (get_sha1_with_context(revs->def, 0, sha1, &oc))
                        die("bad default revision '%s'", revs->def);
                object = get_reference(revs, revs->def, sha1, 0);
 -              add_pending_object_with_mode(revs, object, revs->def, mode);
 +              add_pending_object_with_mode(revs, object, revs->def, oc.mode);
        }
  
        /* Did the user ask for any diff output? Run the diff! */
        if (revs->topo_order)
                revs->limited = 1;
  
 -      if (revs->prune_data) {
 -              diff_tree_setup_paths(revs->prune_data, &revs->pruning);
 +      if (revs->prune_data.nr) {
 +              diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
                /* Can't prune commits with rename following: the paths change.. */
                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
                        revs->prune = 1;
                if (!revs->full_diff)
 -                      diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
 +                      diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
        }
 -      if (revs->combine_merges) {
 +      if (revs->combine_merges)
                revs->ignore_merges = 0;
 -              if (revs->dense_combined_merges && !revs->diffopt.output_format)
 -                      revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 -      }
        revs->diffopt.abbrev = revs->abbrev;
 -      if (diff_setup_done(&revs->diffopt) < 0)
 -              die("diff_setup_done failed");
 +      diff_setup_done(&revs->diffopt);
  
 -      if (revs->grep_filter) {
 -              compile_grep_patterns(revs->grep_filter);
 -      }
 +      grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
 +                               &revs->grep_filter);
 +      compile_grep_patterns(&revs->grep_filter);
  
        if (revs->reverse && revs->reflog_info)
                die("cannot combine --reverse with --walk-reflogs");
  
        if (revs->reflog_info && revs->graph)
                die("cannot combine --walk-reflogs with --graph");
 +      if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
 +              die("cannot use --grep-reflog without --walk-reflogs");
  
        return left;
  }
@@@ -1970,6 -1424,22 +1970,22 @@@ static struct merge_simplify_state *loc
        return st;
  }
  
+ static void remove_treesame_parents(struct commit *commit)
+ {
+       struct commit_list **pp, *p;
+       pp = &commit->parents;
+       while ((p = *pp) != NULL) {
+               struct commit *parent = p->item;
+               if (parent->object.flags & TREESAME) {
+                       *pp = p->next;
+                       free(p);
+                       continue;
+               }
+               pp = &p->next;
+       }
+ }
  static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
  {
        struct commit_list *p;
        }
  
        /*
 -       * Do we know what commit all of our parents should be rewritten to?
 -       * Otherwise we are not ready to rewrite this one yet.
 +       * Do we know what commit all of our parents that matter
 +       * should be rewritten to?  Otherwise we are not ready to
 +       * rewrite this one yet.
         */
        for (cnt = 0, p = commit->parents; p; p = p->next) {
                pst = locate_simplify_state(revs, p->item);
                        tail = &commit_list_insert(p->item, tail)->next;
                        cnt++;
                }
 +              if (revs->first_parent_only)
 +                      break;
        }
 -      if (cnt)
 +      if (cnt) {
 +              tail = &commit_list_insert(commit, tail)->next;
                return tail;
 +      }
  
        /*
         * Rewrite our list of parents.
        for (p = commit->parents; p; p = p->next) {
                pst = locate_simplify_state(revs, p->item);
                p->item = pst->simplified;
 +              if (revs->first_parent_only)
 +                      break;
        }
-       if (!revs->first_parent_only)
-               cnt = remove_duplicate_parents(commit);
-       else
 -      /*
 -       * A merge with a tree-same parent is useless
 -       */
 -      if (commit->parents && commit->parents->next)
 -              remove_treesame_parents(commit);
++      if (revs->first_parent_only) {
 +              cnt = 1;
++      } else {
++              /*
++               * A merge with a tree-same parent is useless
++               */
++              if (commit->parents && commit->parents->next)
++                      remove_treesame_parents(commit);
 -      cnt = remove_duplicate_parents(commit);
++              cnt = remove_duplicate_parents(commit);
++      }
  
        /*
         * It is possible that we are a merge and one side branch
  
  static void simplify_merges(struct rev_info *revs)
  {
 -      struct commit_list *list;
 +      struct commit_list *list, *next;
        struct commit_list *yet_to_do, **tail;
 +      struct commit *commit;
  
 -      sort_in_topological_order(&revs->commits, revs->lifo);
 +      if (!revs->prune)
 +              return;
  
        /* feed the list reversed */
        yet_to_do = NULL;
 -      for (list = revs->commits; list; list = list->next)
 -              commit_list_insert(list->item, &yet_to_do);
 +      for (list = revs->commits; list; list = next) {
 +              commit = list->item;
 +              next = list->next;
 +              /*
 +               * Do not free(list) here yet; the original list
 +               * is used later in this function.
 +               */
 +              commit_list_insert(commit, &yet_to_do);
 +      }
        while (yet_to_do) {
                list = yet_to_do;
                yet_to_do = NULL;
                tail = &yet_to_do;
                while (list) {
 -                      struct commit *commit = list->item;
 -                      struct commit_list *next = list->next;
 +                      commit = list->item;
 +                      next = list->next;
                        free(list);
                        list = next;
                        tail = simplify_one(revs, commit, tail);
        revs->commits = NULL;
        tail = &revs->commits;
        while (list) {
 -              struct commit *commit = list->item;
 -              struct commit_list *next = list->next;
                struct merge_simplify_state *st;
 +
 +              commit = list->item;
 +              next = list->next;
                free(list);
                list = next;
                st = locate_simplify_state(revs, commit);
@@@ -2129,16 -1586,10 +2153,16 @@@ static void set_children(struct rev_inf
        }
  }
  
 +void reset_revision_walk(void)
 +{
 +      clear_object_flags(SEEN | ADDED | SHOWN);
 +}
 +
  int prepare_revision_walk(struct rev_info *revs)
  {
        int nr = revs->pending.nr;
        struct object_array_entry *e, *list;
 +      struct commit_list **next = &revs->commits;
  
        e = list = revs->pending.objects;
        revs->pending.nr = 0;
                if (commit) {
                        if (!(commit->object.flags & SEEN)) {
                                commit->object.flags |= SEEN;
 -                              insert_by_date(commit, &revs->commits);
 +                              next = commit_list_append(commit, next);
                        }
                }
                e++;
        }
 -      free(list);
 +      if (!revs->leak_pending)
 +              free(list);
  
 +      if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
 +              commit_list_sort_by_date(&revs->commits);
        if (revs->no_walk)
                return 0;
        if (revs->limited)
  enum rewrite_result {
        rewrite_one_ok,
        rewrite_one_noparents,
 -      rewrite_one_error,
 +      rewrite_one_error
  };
  
  static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
@@@ -2220,106 -1668,13 +2244,106 @@@ static int rewrite_parents(struct rev_i
        return 0;
  }
  
 +static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
 +{
 +      char *person, *endp;
 +      size_t len, namelen, maillen;
 +      const char *name;
 +      const char *mail;
 +      struct ident_split ident;
 +
 +      person = strstr(buf->buf, what);
 +      if (!person)
 +              return 0;
 +
 +      person += strlen(what);
 +      endp = strchr(person, '\n');
 +      if (!endp)
 +              return 0;
 +
 +      len = endp - person;
 +
 +      if (split_ident_line(&ident, person, len))
 +              return 0;
 +
 +      mail = ident.mail_begin;
 +      maillen = ident.mail_end - ident.mail_begin;
 +      name = ident.name_begin;
 +      namelen = ident.name_end - ident.name_begin;
 +
 +      if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
 +              struct strbuf namemail = STRBUF_INIT;
 +
 +              strbuf_addf(&namemail, "%.*s <%.*s>",
 +                          (int)namelen, name, (int)maillen, mail);
 +
 +              strbuf_splice(buf, ident.name_begin - buf->buf,
 +                            ident.mail_end - ident.name_begin + 1,
 +                            namemail.buf, namemail.len);
 +
 +              strbuf_release(&namemail);
 +
 +              return 1;
 +      }
 +
 +      return 0;
 +}
 +
  static int commit_match(struct commit *commit, struct rev_info *opt)
  {
 -      if (!opt->grep_filter)
 +      int retval;
 +      const char *encoding;
 +      char *message;
 +      struct strbuf buf = STRBUF_INIT;
 +
 +      if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
                return 1;
 -      return grep_buffer(opt->grep_filter,
 -                         NULL, /* we say nothing, not even filename */
 -                         commit->buffer, strlen(commit->buffer));
 +
 +      /* Prepend "fake" headers as needed */
 +      if (opt->grep_filter.use_reflog_filter) {
 +              strbuf_addstr(&buf, "reflog ");
 +              get_reflog_message(&buf, opt->reflog_info);
 +              strbuf_addch(&buf, '\n');
 +      }
 +
 +      /*
 +       * We grep in the user's output encoding, under the assumption that it
 +       * is the encoding they are most likely to write their grep pattern
 +       * for. In addition, it means we will match the "notes" encoding below,
 +       * so we will not end up with a buffer that has two different encodings
 +       * in it.
 +       */
 +      encoding = get_log_output_encoding();
 +      message = logmsg_reencode(commit, encoding);
 +
 +      /* Copy the commit to temporary if we are using "fake" headers */
 +      if (buf.len)
 +              strbuf_addstr(&buf, message);
 +
 +      if (opt->grep_filter.header_list && opt->mailmap) {
 +              if (!buf.len)
 +                      strbuf_addstr(&buf, message);
 +
 +              commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
 +              commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
 +      }
 +
 +      /* Append "fake" message parts as needed */
 +      if (opt->show_notes) {
 +              if (!buf.len)
 +                      strbuf_addstr(&buf, message);
 +              format_display_notes(commit->object.sha1, &buf, encoding, 1);
 +      }
 +
 +      /* Find either in the original commit message, or in the temporary */
 +      if (buf.len)
 +              retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
 +      else
 +              retval = grep_buffer(&opt->grep_filter,
 +                                   message, strlen(message));
 +      strbuf_release(&buf);
 +      logmsg_free(message, commit);
 +      return retval;
  }
  
  static inline int want_ancestry(struct rev_info *revs)
        return (revs->rewrite_parents || revs->children.name);
  }
  
 -enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
 +enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
  {
        if (commit->object.flags & SHOWN)
                return commit_ignore;
 -      if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
 +      if (revs->unpacked && has_sha1_pack(commit->object.sha1))
                return commit_ignore;
        if (revs->show_all)
                return commit_show;
                return commit_ignore;
        if (revs->min_age != -1 && (commit->date > revs->min_age))
                return commit_ignore;
 -      if (revs->no_merges && commit->parents && commit->parents->next)
 -              return commit_ignore;
 +      if (revs->min_parents || (revs->max_parents >= 0)) {
 +              int n = 0;
 +              struct commit_list *p;
 +              for (p = commit->parents; p; p = p->next)
 +                      n++;
 +              if ((n < revs->min_parents) ||
 +                  ((revs->max_parents >= 0) && (n > revs->max_parents)))
 +                      return commit_ignore;
 +      }
        if (!commit_match(commit, revs))
                return commit_ignore;
        if (revs->prune && revs->dense) {
                        if (!commit->parents || !commit->parents->next)
                                return commit_ignore;
                }
 -              if (want_ancestry(revs) && rewrite_parents(revs, commit) < 0)
 -                      return commit_error;
        }
        return commit_show;
  }
  
 +enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
 +{
 +      enum commit_action action = get_commit_action(revs, commit);
 +
 +      if (action == commit_show &&
 +          !revs->show_all &&
 +          revs->prune && revs->dense && want_ancestry(revs)) {
 +              if (rewrite_parents(revs, commit) < 0)
 +                      return commit_error;
 +      }
 +      return action;
 +}
 +
  static struct commit *get_revision_1(struct rev_info *revs)
  {
        if (!revs->commits)
                revs->commits = entry->next;
                free(entry);
  
 -              if (revs->reflog_info)
 +              if (revs->reflog_info) {
                        fake_reflog_parent(revs->reflog_info, commit);
 +                      commit->object.flags &= ~(ADDED | SEEN | SHOWN);
 +              }
  
                /*
                 * If we haven't done the list limiting, we need to look at
                            (commit->date < revs->max_age))
                                continue;
                        if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
 -                              return NULL;
 +                              die("Failed to traverse parents of commit %s",
 +                                  sha1_to_hex(commit->object.sha1));
                }
  
                switch (simplify_commit(revs, commit)) {
                case commit_ignore:
                        continue;
                case commit_error:
 -                      return NULL;
 +                      die("Failed to simplify parents of commit %s",
 +                          sha1_to_hex(commit->object.sha1));
                default:
                        return commit;
                }
@@@ -2501,29 -1834,50 +2525,29 @@@ static struct commit *get_revision_inte
                return c;
        }
  
 -      if (revs->reverse) {
 -              int limit = -1;
 -
 -              if (0 <= revs->max_count) {
 -                      limit = revs->max_count;
 -                      if (0 < revs->skip_count)
 -                              limit += revs->skip_count;
 -              }
 -              l = NULL;
 -              while ((c = get_revision_1(revs))) {
 -                      commit_list_insert(c, &l);
 -                      if ((0 < limit) && !--limit)
 -                              break;
 -              }
 -              revs->commits = l;
 -              revs->reverse = 0;
 -              revs->max_count = -1;
 -              c = NULL;
 -      }
 -
        /*
 -       * Now pick up what they want to give us
 +       * If our max_count counter has reached zero, then we are done. We
 +       * don't simply return NULL because we still might need to show
 +       * boundary commits. But we want to avoid calling get_revision_1, which
 +       * might do a considerable amount of work finding the next commit only
 +       * for us to throw it away.
 +       *
 +       * If it is non-zero, then either we don't have a max_count at all
 +       * (-1), or it is still counting, in which case we decrement.
         */
 -      c = get_revision_1(revs);
 -      if (c) {
 -              while (0 < revs->skip_count) {
 -                      revs->skip_count--;
 -                      c = get_revision_1(revs);
 -                      if (!c)
 -                              break;
 +      if (revs->max_count) {
 +              c = get_revision_1(revs);
 +              if (c) {
 +                      while (0 < revs->skip_count) {
 +                              revs->skip_count--;
 +                              c = get_revision_1(revs);
 +                              if (!c)
 +                                      break;
 +                      }
                }
 -      }
  
 -      /*
 -       * Check the max_count.
 -       */
 -      switch (revs->max_count) {
 -      case -1:
 -              break;
 -      case 0:
 -              c = NULL;
 -              break;
 -      default:
 -              revs->max_count--;
 +              if (revs->max_count > 0)
 +                      revs->max_count--;
        }
  
        if (c)
  
  struct commit *get_revision(struct rev_info *revs)
  {
 -      struct commit *c = get_revision_internal(revs);
 +      struct commit *c;
 +      struct commit_list *reversed;
 +
 +      if (revs->reverse) {
 +              reversed = NULL;
 +              while ((c = get_revision_internal(revs))) {
 +                      commit_list_insert(c, &reversed);
 +              }
 +              revs->commits = reversed;
 +              revs->reverse = 0;
 +              revs->reverse_output_stage = 1;
 +      }
 +
 +      if (revs->reverse_output_stage)
 +              return pop_commit(&revs->commits);
 +
 +      c = get_revision_internal(revs);
        if (c && revs->graph)
                graph_update(revs->graph, c);
        return c;
  }
 +
 +char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
 +{
 +      if (commit->object.flags & BOUNDARY)
 +              return "-";
 +      else if (commit->object.flags & UNINTERESTING)
 +              return "^";
 +      else if (commit->object.flags & PATCHSAME)
 +              return "=";
 +      else if (!revs || revs->left_right) {
 +              if (commit->object.flags & SYMMETRIC_LEFT)
 +                      return "<";
 +              else
 +                      return ">";
 +      } else if (revs->graph)
 +              return "*";
 +      else if (revs->cherry_mark)
 +              return "+";
 +      return "";
 +}
 +
 +void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
 +{
 +      char *mark = get_revision_mark(revs, commit);
 +      if (!strlen(mark))
 +              return;
 +      fputs(mark, stdout);
 +      putchar(' ');
 +}
index 839ad97b791c6aa757d0b82eea7fc16369ad4586,d6d79c467f70b08541be0254b37d0d63ea7da95d..8e2ff13423ba01095404ec49232760bc66c68978
@@@ -8,6 -8,9 +8,6 @@@ note () 
        git tag "$1"
  }
  
 -_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
 -_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 -
  unnote () {
        git name-rev --tags --stdin | sed -e "s|$_x40 (tags/\([^)]*\)) |\1 |g"
  }
@@@ -56,7 -59,23 +56,23 @@@ test_expect_success setup 
  
        echo "Final change" >file &&
        test_tick && git commit -a -m "Final change" &&
-       note I
+       note I &&
+       git symbolic-ref HEAD refs/heads/unrelated &&
+       git rm -f "*" &&
+       echo "Unrelated branch" >side &&
+       git add side &&
+       test_tick && git commit -m "Side root" &&
+       note J &&
+       git checkout master &&
+       test_tick && git merge -m "Coolest" unrelated &&
+       note K &&
+       echo "Immaterial" >elif &&
+       git add elif &&
+       test_tick && git commit -m "Last" &&
+       note L
  '
  
  FMT='tformat:%P       %H | %s'
@@@ -79,13 -98,12 +95,13 @@@ check_result () 
        '
  }
  
- check_result 'I H G F E D C B A' --full-history
- check_result 'I H E C B A' --full-history -- file
- check_result 'I H E C B A' --full-history --topo-order -- file
- check_result 'I H E C B A' --full-history --date-order -- file
+ check_result 'L K J I H G F E D C B A' --full-history
+ check_result 'I H E C B A' --full-history -- file
+ check_result 'I H E C B A' --full-history --topo-order -- file
+ check_result 'I H E C B A' --full-history --date-order -- file
  check_result 'I E C B A' --simplify-merges -- file
  check_result 'I B A' -- file
  check_result 'I B A' --topo-order -- file
 +check_result 'H' --first-parent -- another-file
  
  test_done