X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=revision.c;h=28b5f2eacebf637323fa0af112ea568beb95c7f3;hb=6fb73e442a7dc3e4b296b409a6f30145d85750e9;hp=b84c066cbac33bb8b4103e8be0de5959a02a643c;hpb=25a0b20c742985f31a4694f2f98e8e0059765726;p=git.git

diff --git a/revision.c b/revision.c
index b84c066cb..28b5f2eac 100644
--- a/revision.c
+++ b/revision.c
@@ -8,6 +8,7 @@
 #include "revision.h"
 #include "grep.h"
 #include "reflog-walk.h"
+#include "patch-ids.h"
 
 static char *path_name(struct name_path *path, const char *name)
 {
@@ -62,8 +63,7 @@ void mark_tree_uninteresting(struct tree *tree)
 	if (parse_tree(tree) < 0)
 		die("bad tree %s", sha1_to_hex(obj->sha1));
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 	while (tree_entry(&desc, &entry)) {
 		if (S_ISDIR(entry.mode))
 			mark_tree_uninteresting(lookup_tree(entry.sha1));
@@ -114,16 +114,21 @@ void mark_parents_uninteresting(struct commit *commit)
 	}
 }
 
-void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
+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");
-	add_object_array(obj, name, &revs->pending);
+	add_object_array_with_mode(obj, name, &revs->pending, mode);
 	if (revs->reflog_info && obj->type == OBJ_COMMIT)
 		add_reflog_for_walk(revs->reflog_info,
 				(struct commit *)obj, name);
 }
 
+void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
+{
+	add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
+}
+
 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 {
 	struct object *object;
@@ -213,6 +218,13 @@ static int everybody_uninteresting(struct commit_list *orig)
 	return 1;
 }
 
+/*
+ * 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.
+ */
 static int tree_difference = REV_TREE_SAME;
 
 static void file_add_remove(struct diff_options *options,
@@ -236,6 +248,8 @@ static void file_add_remove(struct diff_options *options,
 		diff = REV_TREE_NEW;
 	}
 	tree_difference = diff;
+	if (tree_difference == REV_TREE_DIFFERENT)
+		options->has_changes = 1;
 }
 
 static void file_change(struct diff_options *options,
@@ -245,43 +259,45 @@ static void file_change(struct diff_options *options,
 		 const char *base, const char *path)
 {
 	tree_difference = REV_TREE_DIFFERENT;
+	options->has_changes = 1;
 }
 
-int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
+static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 {
 	if (!t1)
 		return REV_TREE_NEW;
 	if (!t2)
 		return REV_TREE_DIFFERENT;
 	tree_difference = REV_TREE_SAME;
+	revs->pruning.has_changes = 0;
 	if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 			   &revs->pruning) < 0)
 		return REV_TREE_DIFFERENT;
 	return tree_difference;
 }
 
-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 tree *t1)
 {
 	int retval;
 	void *tree;
+	unsigned long size;
 	struct tree_desc empty, real;
 
 	if (!t1)
 		return 0;
 
-	tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
+	tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 	if (!tree)
 		return 0;
-	real.buf = tree;
-
-	empty.buf = "";
-	empty.size = 0;
+	init_tree_desc(&real, tree, size);
+	init_tree_desc(&empty, "", 0);
 
-	tree_difference = 0;
+	tree_difference = REV_TREE_SAME;
+	revs->pruning.has_changes = 0;
 	retval = diff_tree(&empty, &real, "", &revs->pruning);
 	free(tree);
 
-	return retval >= 0 && !tree_difference;
+	return retval >= 0 && (tree_difference == REV_TREE_SAME);
 }
 
 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
@@ -302,7 +318,10 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 	while ((parent = *pp) != NULL) {
 		struct commit *p = parent->item;
 
-		parse_commit(p);
+		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)) {
 		case REV_TREE_SAME:
 			tree_same = 1;
@@ -331,7 +350,10 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 				 * IOW, we pretend this parent is a
 				 * "root" commit.
 				 */
-				parse_commit(p);
+				if (parse_commit(p) < 0)
+					die("cannot simplify commit %s (invalid %s)",
+					    sha1_to_hex(commit->object.sha1),
+					    sha1_to_hex(p->object.sha1));
 				p->parents = NULL;
 			}
 		/* fallthrough */
@@ -346,13 +368,14 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 		commit->object.flags |= TREECHANGE;
 }
 
-static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
+static int add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 {
 	struct commit_list *parent = commit->parents;
 	unsigned left_flag;
+	int add, rest;
 
 	if (commit->object.flags & ADDED)
-		return;
+		return 0;
 	commit->object.flags |= ADDED;
 
 	/*
@@ -371,7 +394,8 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
 		while (parent) {
 			struct commit *p = parent->item;
 			parent = parent->next;
-			parse_commit(p);
+			if (parse_commit(p) < 0)
+				return -1;
 			p->object.flags |= UNINTERESTING;
 			if (p->parents)
 				mark_parents_uninteresting(p);
@@ -380,7 +404,7 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
 			p->object.flags |= SEEN;
 			insert_by_date(p, list);
 		}
-		return;
+		return 0;
 	}
 
 	/*
@@ -392,25 +416,113 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
 		revs->prune_fn(revs, commit);
 
 	if (revs->no_walk)
-		return;
+		return 0;
 
 	left_flag = (commit->object.flags & SYMMETRIC_LEFT);
-	parent = commit->parents;
-	while (parent) {
+
+	rest = !revs->first_parent_only;
+	for (parent = commit->parents, add = 1; parent; add = rest) {
 		struct commit *p = parent->item;
 
 		parent = parent->next;
-
-		parse_commit(p);
+		if (parse_commit(p) < 0)
+			return -1;
 		p->object.flags |= left_flag;
 		if (p->object.flags & SEEN)
 			continue;
 		p->object.flags |= SEEN;
-		insert_by_date(p, list);
+		if (add)
+			insert_by_date(p, list);
+	}
+	return 0;
+}
+
+static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
+{
+	struct commit_list *p;
+	int left_count = 0, right_count = 0;
+	int left_first;
+	struct patch_ids ids;
+
+	/* First count the commits on the left and on the right */
+	for (p = list; p; p = p->next) {
+		struct commit *commit = p->item;
+		unsigned flags = commit->object.flags;
+		if (flags & BOUNDARY)
+			;
+		else if (flags & SYMMETRIC_LEFT)
+			left_count++;
+		else
+			right_count++;
+	}
+
+	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;
+	}
+
+	/* Compute patch-ids for one side */
+	for (p = list; p; p = p->next) {
+		struct commit *commit = p->item;
+		unsigned flags = commit->object.flags;
+
+		if (flags & BOUNDARY)
+			continue;
+		/*
+		 * If we have fewer left, left_first is set and we omit
+		 * commits on the right branch in this loop.  If we have
+		 * fewer right, we skip the left ones.
+		 */
+		if (left_first != !!(flags & SYMMETRIC_LEFT))
+			continue;
+		commit->util = add_commit_patch_id(commit, &ids);
+	}
+
+	/* Check the other side */
+	for (p = list; p; p = p->next) {
+		struct commit *commit = p->item;
+		struct patch_id *id;
+		unsigned flags = commit->object.flags;
+
+		if (flags & BOUNDARY)
+			continue;
+		/*
+		 * If we have fewer left, left_first is set and we omit
+		 * commits on the left branch in this loop.
+		 */
+		if (left_first == !!(flags & SYMMETRIC_LEFT))
+			continue;
+
+		/*
+		 * Have we seen the same patch id?
+		 */
+		id = has_commit_patch_id(commit, &ids);
+		if (!id)
+			continue;
+		id->seen = 1;
+		commit->object.flags |= SHOWN;
 	}
+
+	/* Now check the original side for seen ones */
+	for (p = list; p; p = p->next) {
+		struct commit *commit = p->item;
+		struct patch_id *ent;
+
+		ent = commit->util;
+		if (!ent)
+			continue;
+		if (ent->seen)
+			commit->object.flags |= SHOWN;
+		commit->util = NULL;
+	}
+
+	free_patch_ids(&ids);
 }
 
-static void limit_list(struct rev_info *revs)
+static int limit_list(struct rev_info *revs)
 {
 	struct commit_list *list = revs->commits;
 	struct commit_list *newlist = NULL;
@@ -426,7 +538,8 @@ static void limit_list(struct rev_info *revs)
 
 		if (revs->max_age != -1 && (commit->date < revs->max_age))
 			obj->flags |= UNINTERESTING;
-		add_parents_to_list(revs, commit, &list);
+		if (add_parents_to_list(revs, commit, &list) < 0)
+			return -1;
 		if (obj->flags & UNINTERESTING) {
 			mark_parents_uninteresting(commit);
 			if (everybody_uninteresting(list))
@@ -437,37 +550,11 @@ static void limit_list(struct rev_info *revs)
 			continue;
 		p = &commit_list_insert(commit, p)->next;
 	}
-	if (revs->boundary) {
-		/* mark the ones that are on the result list first */
-		for (list = newlist; list; list = list->next) {
-			struct commit *commit = list->item;
-			commit->object.flags |= TMP_MARK;
-		}
-		for (list = newlist; list; list = list->next) {
-			struct commit *commit = list->item;
-			struct object *obj = &commit->object;
-			struct commit_list *parent;
-			if (obj->flags & UNINTERESTING)
-				continue;
-			for (parent = commit->parents;
-			     parent;
-			     parent = parent->next) {
-				struct commit *pcommit = parent->item;
-				if (!(pcommit->object.flags & UNINTERESTING))
-					continue;
-				pcommit->object.flags |= BOUNDARY;
-				if (pcommit->object.flags & TMP_MARK)
-					continue;
-				pcommit->object.flags |= TMP_MARK;
-				p = &commit_list_insert(pcommit, p)->next;
-			}
-		}
-		for (list = newlist; list; list = list->next) {
-			struct commit *commit = list->item;
-			commit->object.flags &= ~TMP_MARK;
-		}
-	}
+	if (revs->cherry_pick)
+		cherry_pick_list(newlist, revs);
+
 	revs->commits = newlist;
+	return 0;
 }
 
 struct all_refs_cb {
@@ -482,7 +569,7 @@ static int handle_one_ref(const char *path, const unsigned char *sha1, int flag,
 	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, "");
+	add_pending_object(cb->all_revs, object, path);
 	return 0;
 }
 
@@ -504,7 +591,7 @@ static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 			add_pending_object(cb->all_revs, o, "");
 		}
 		else if (!cb->warned_bad_reflog) {
-			warn("reflog of '%s' references pruned commits",
+			warning("reflog of '%s' references pruned commits",
 				cb->name_for_errormsg);
 			cb->warned_bad_reflog = 1;
 		}
@@ -575,6 +662,7 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->ignore_merges = 1;
 	revs->simplify_history = 1;
 	revs->pruning.recursive = 1;
+	revs->pruning.quiet = 1;
 	revs->pruning.add_remove = file_add_remove;
 	revs->pruning.change = file_change;
 	revs->lifo = 1;
@@ -655,6 +743,7 @@ int handle_revision_arg(const char *arg, struct rev_info *revs,
 			int flags,
 			int cant_be_filename)
 {
+	unsigned mode;
 	char *dotdot;
 	struct object *object;
 	unsigned char sha1[20];
@@ -728,12 +817,12 @@ int handle_revision_arg(const char *arg, struct rev_info *revs,
 		local_flags = UNINTERESTING;
 		arg++;
 	}
-	if (get_sha1(arg, sha1))
+	if (get_sha1_with_mode(arg, sha1, &mode))
 		return -1;
 	if (!cant_be_filename)
 		verify_non_filename(revs->prefix, arg);
 	object = get_reference(revs, arg, sha1, flags ^ local_flags);
-	add_pending_object(revs, object, arg);
+	add_pending_object_with_mode(revs, object, arg, mode);
 	return 0;
 }
 
@@ -796,6 +885,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 	const char **unrecognized = argv + 1;
 	int left = 1;
 	int all_match = 0;
+	int regflags = 0;
 
 	/* First, search for "--" */
 	seen_dashdash = 0;
@@ -866,6 +956,10 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				handle_all(revs, flags);
 				continue;
 			}
+			if (!strcmp(arg, "--first-parent")) {
+				revs->first_parent_only = 1;
+				continue;
+			}
 			if (!strcmp(arg, "--reflog")) {
 				handle_reflog(revs, flags);
 				continue;
@@ -926,6 +1020,10 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				revs->left_right = 1;
 				continue;
 			}
+			if (!strcmp(arg, "--cherry-pick")) {
+				revs->cherry_pick = 1;
+				continue;
+			}
 			if (!strcmp(arg, "--objects")) {
 				revs->tag_objects = 1;
 				revs->tree_objects = 1;
@@ -1029,7 +1127,26 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				continue;
 			}
 			if (!strcmp(arg, "--relative-date")) {
-				revs->relative_date = 1;
+				revs->date_mode = DATE_RELATIVE;
+				continue;
+			}
+			if (!strncmp(arg, "--date=", 7)) {
+				if (!strcmp(arg + 7, "relative"))
+					revs->date_mode = DATE_RELATIVE;
+				else if (!strcmp(arg + 7, "iso8601") ||
+					 !strcmp(arg + 7, "iso"))
+					revs->date_mode = DATE_ISO8601;
+				else if (!strcmp(arg + 7, "rfc2822") ||
+					 !strcmp(arg + 7, "rfc"))
+					revs->date_mode = DATE_RFC2822;
+				else if (!strcmp(arg + 7, "short"))
+					revs->date_mode = DATE_SHORT;
+				else if (!strcmp(arg + 7, "local"))
+					revs->date_mode = DATE_LOCAL;
+				else if (!strcmp(arg + 7, "default"))
+					revs->date_mode = DATE_NORMAL;
+				else
+					die("unknown date format %s", arg);
 				continue;
 			}
 
@@ -1048,6 +1165,14 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				add_message_grep(revs, arg+7);
 				continue;
 			}
+			if (!prefixcmp(arg, "--extended-regexp")) {
+				regflags |= REG_EXTENDED;
+				continue;
+			}
+			if (!prefixcmp(arg, "--regexp-ignore-case")) {
+				regflags |= REG_ICASE;
+				continue;
+			}
 			if (!strcmp(arg, "--all-match")) {
 				all_match = 1;
 				continue;
@@ -1055,7 +1180,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 			if (!prefixcmp(arg, "--encoding=")) {
 				arg += 11;
 				if (strcmp(arg, "none"))
-					git_log_output_encoding = strdup(arg);
+					git_log_output_encoding = xstrdup(arg);
 				else
 					git_log_output_encoding = "";
 				continue;
@@ -1067,7 +1192,8 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 
 			opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
 			if (opts > 0) {
-				revs->diff = 1;
+				if (strcmp(argv[i], "-z"))
+					revs->diff = 1;
 				i += opts - 1;
 				continue;
 			}
@@ -1096,15 +1222,19 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 		}
 	}
 
+	if (revs->grep_filter)
+		revs->grep_filter->regflags |= regflags;
+
 	if (show_merge)
 		prepare_show_merge(revs);
 	if (def && !revs->pending.nr) {
 		unsigned char sha1[20];
 		struct object *object;
-		if (get_sha1(def, sha1))
+		unsigned mode;
+		if (get_sha1_with_mode(def, sha1, &mode))
 			die("bad default revision '%s'", def);
 		object = get_reference(revs, def, sha1, 0);
-		add_pending_object(revs, object, def);
+		add_pending_object_with_mode(revs, object, def, mode);
 	}
 
 	if (revs->topo_order)
@@ -1112,7 +1242,9 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 
 	if (revs->prune_data) {
 		diff_tree_setup_paths(revs->prune_data, &revs->pruning);
-		revs->prune_fn = try_to_simplify_commit;
+		/* Can't prune commits with rename following: the paths change.. */
+		if (!revs->diffopt.follow_renames)
+			revs->prune_fn = try_to_simplify_commit;
 		if (!revs->full_diff)
 			diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
 	}
@@ -1133,7 +1265,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 	return left;
 }
 
-void prepare_revision_walk(struct rev_info *revs)
+int prepare_revision_walk(struct rev_info *revs)
 {
 	int nr = revs->pending.nr;
 	struct object_array_entry *e, *list;
@@ -1155,53 +1287,77 @@ void prepare_revision_walk(struct rev_info *revs)
 	free(list);
 
 	if (revs->no_walk)
-		return;
+		return 0;
 	if (revs->limited)
-		limit_list(revs);
+		if (limit_list(revs) < 0)
+			return -1;
 	if (revs->topo_order)
 		sort_in_topological_order_fn(&revs->commits, revs->lifo,
 					     revs->topo_setter,
 					     revs->topo_getter);
+	return 0;
 }
 
-static int rewrite_one(struct rev_info *revs, struct commit **pp)
+enum rewrite_result {
+	rewrite_one_ok,
+	rewrite_one_noparents,
+	rewrite_one_error,
+};
+
+static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
 {
 	for (;;) {
 		struct commit *p = *pp;
 		if (!revs->limited)
-			add_parents_to_list(revs, p, &revs->commits);
+			if (add_parents_to_list(revs, p, &revs->commits) < 0)
+				return rewrite_one_error;
 		if (p->parents && p->parents->next)
-			return 0;
+			return rewrite_one_ok;
 		if (p->object.flags & (TREECHANGE | UNINTERESTING))
-			return 0;
+			return rewrite_one_ok;
 		if (!p->parents)
-			return -1;
+			return rewrite_one_noparents;
 		*pp = p->parents->item;
 	}
 }
 
-static void rewrite_parents(struct rev_info *revs, struct commit *commit)
+static void remove_duplicate_parents(struct commit *commit)
+{
+	struct commit_list *p;
+	struct commit_list **pp = &commit->parents;
+
+	/* Examine existing parents while marking ones we have seen... */
+	for (p = commit->parents; p; p = p->next) {
+		struct commit *parent = p->item;
+		if (parent->object.flags & TMP_MARK)
+			continue;
+		parent->object.flags |= TMP_MARK;
+		*pp = p;
+		pp = &p->next;
+	}
+	/* ... and clear the temporary mark */
+	for (p = commit->parents; p; p = p->next)
+		p->item->object.flags &= ~TMP_MARK;
+}
+
+static int rewrite_parents(struct rev_info *revs, struct commit *commit)
 {
 	struct commit_list **pp = &commit->parents;
 	while (*pp) {
 		struct commit_list *parent = *pp;
-		if (rewrite_one(revs, &parent->item) < 0) {
+		switch (rewrite_one(revs, &parent->item)) {
+		case rewrite_one_ok:
+			break;
+		case rewrite_one_noparents:
 			*pp = parent->next;
 			continue;
+		case rewrite_one_error:
+			return -1;
 		}
 		pp = &parent->next;
 	}
-}
-
-static void mark_boundary_to_show(struct commit *commit)
-{
-	struct commit_list *p = commit->parents;
-	while (p) {
-		commit = p->item;
-		p = p->next;
-		if (commit->object.flags & BOUNDARY)
-			commit->object.flags |= BOUNDARY_SHOW;
-	}
+	remove_duplicate_parents(commit);
+	return 0;
 }
 
 static int commit_match(struct commit *commit, struct rev_info *opt)
@@ -1235,15 +1391,10 @@ static struct commit *get_revision_1(struct rev_info *revs)
 		 */
 		if (!revs->limited) {
 			if (revs->max_age != -1 &&
-			    (commit->date < revs->max_age)) {
-				if (revs->boundary)
-					commit->object.flags |=
-						BOUNDARY_SHOW | BOUNDARY;
-				else
-					continue;
-			} else
-				add_parents_to_list(revs, commit,
-						&revs->commits);
+			    (commit->date < revs->max_age))
+				continue;
+			if (add_parents_to_list(revs, commit, &revs->commits) < 0)
+				return NULL;
 		}
 		if (commit->object.flags & SHOWN)
 			continue;
@@ -1252,18 +1403,6 @@ static struct commit *get_revision_1(struct rev_info *revs)
 						    revs->ignore_packed))
 		    continue;
 
-		/* We want to show boundary commits only when their
-		 * children are shown.  When path-limiter is in effect,
-		 * rewrite_parents() drops some commits from getting shown,
-		 * and there is no point showing boundary parents that
-		 * are not shown.  After rewrite_parents() rewrites the
-		 * parents of a commit that is shown, we mark the boundary
-		 * parents with BOUNDARY_SHOW.
-		 */
-		if (commit->object.flags & BOUNDARY_SHOW) {
-			commit->object.flags |= SHOWN;
-			return commit;
-		}
 		if (commit->object.flags & UNINTERESTING)
 			continue;
 		if (revs->min_age != -1 && (commit->date > revs->min_age))
@@ -1283,83 +1422,139 @@ static struct commit *get_revision_1(struct rev_info *revs)
 				if (!commit->parents || !commit->parents->next)
 					continue;
 			}
-			if (revs->parents)
-				rewrite_parents(revs, commit);
+			if (revs->parents && rewrite_parents(revs, commit) < 0)
+				return NULL;
 		}
-		if (revs->boundary)
-			mark_boundary_to_show(commit);
-		commit->object.flags |= SHOWN;
 		return commit;
 	} while (revs->commits);
 	return NULL;
 }
 
+static void gc_boundary(struct object_array *array)
+{
+	unsigned nr = array->nr;
+	unsigned alloc = array->alloc;
+	struct object_array_entry *objects = array->objects;
+
+	if (alloc <= nr) {
+		unsigned i, j;
+		for (i = j = 0; i < nr; i++) {
+			if (objects[i].item->flags & SHOWN)
+				continue;
+			if (i != j)
+				objects[j] = objects[i];
+			j++;
+		}
+		for (i = j; i < nr; i++)
+			objects[i].item = NULL;
+		array->nr = j;
+	}
+}
+
 struct commit *get_revision(struct rev_info *revs)
 {
 	struct commit *c = NULL;
+	struct commit_list *l;
+
+	if (revs->boundary == 2) {
+		unsigned i;
+		struct object_array *array = &revs->boundary_commits;
+		struct object_array_entry *objects = array->objects;
+		for (i = 0; i < array->nr; i++) {
+			c = (struct commit *)(objects[i].item);
+			if (!c)
+				continue;
+			if (!(c->object.flags & CHILD_SHOWN))
+				continue;
+			if (!(c->object.flags & SHOWN))
+				break;
+		}
+		if (array->nr <= i)
+			return NULL;
 
-	if (revs->reverse) {
-		struct commit_list *list;
+		c->object.flags |= SHOWN | BOUNDARY;
+		return c;
+	}
 
-		/*
-		 * rev_info.reverse is used to note the fact that we
-		 * want to output the list of revisions in reverse
-		 * order.  To accomplish this goal, reverse can have
-		 * different values:
-		 *
-		 *  0  do nothing
-		 *  1  reverse the list
-		 *  2  internal use:  we have already obtained and
-		 *     reversed the list, now we only need to yield
-		 *     its items.
-		 */
+	if (revs->reverse) {
+		int limit = -1;
 
-		if (revs->reverse == 1) {
-			revs->reverse = 0;
-			list = NULL;
-			while ((c = get_revision(revs)))
-				commit_list_insert(c, &list);
-			revs->commits = list;
-			revs->reverse = 2;
+		if (0 <= revs->max_count) {
+			limit = revs->max_count;
+			if (0 < revs->skip_count)
+				limit += revs->skip_count;
 		}
-
-		if (!revs->commits)
-			return NULL;
-		c = revs->commits->item;
-		list = revs->commits->next;
-		free(revs->commits);
-		revs->commits = list;
-		return c;
+		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;
 	}
 
-	if (0 < revs->skip_count) {
-		while ((c = get_revision_1(revs)) != NULL) {
-			if (revs->skip_count-- <= 0)
+	/*
+	 * Now pick up what they want to give us
+	 */
+	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 ... */
+	/*
+	 * Check the max_count.
+	 */
 	switch (revs->max_count) {
 	case -1:
 		break;
 	case 0:
-		if (revs->boundary) {
-			struct commit_list *list = revs->commits;
-			while (list) {
-				list->item->object.flags |=
-					BOUNDARY_SHOW | BOUNDARY;
-				list = list->next;
-			}
-			/* all remaining commits are boundary commits */
-			revs->max_count = -1;
-			revs->limited = 1;
-		} else
-			return NULL;
+		c = NULL;
+		break;
 	default:
 		revs->max_count--;
 	}
+
 	if (c)
+		c->object.flags |= SHOWN;
+
+	if (!revs->boundary) {
 		return c;
-	return get_revision_1(revs);
+	}
+
+	if (!c) {
+		/*
+		 * get_revision_1() runs out the commits, and
+		 * we are done computing the boundaries.
+		 * switch to boundary commits output mode.
+		 */
+		revs->boundary = 2;
+		return get_revision(revs);
+	}
+
+	/*
+	 * boundary commits are the commits that are parents of the
+	 * ones we got from get_revision_1() but they themselves are
+	 * not returned from get_revision_1().  Before returning
+	 * 'c', we need to mark its parents that they could be boundaries.
+	 */
+
+	for (l = c->parents; l; l = l->next) {
+		struct object *p;
+		p = &(l->item->object);
+		if (p->flags & (CHILD_SHOWN | SHOWN))
+			continue;
+		p->flags |= CHILD_SHOWN;
+		gc_boundary(&revs->boundary_commits);
+		add_object_array(p, NULL, &revs->boundary_commits);
+	}
+
+	return c;
 }