Make "--parents" logs also be incremental

The parent rewriting feature caused us to create the whole history in one
go, and then simplify it later, because of how rewrite_parents() had been
written. However, with a little tweaking, it's perfectly possible to do
even that one incrementally.

Right now, this doesn't really much matter, because every user of
"--parents" will probably generally _also_ use "--topo-order", which will
cause the old non-incremental behaviour anyway. However, I'm hopeful that
we could make even the topological sort incremental, or at least
_partially_ so (for example, make it incremental up to the first merge).

In the meantime, this at least moves things in the right direction, and
removes a strange special case.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

http-push.c

@@ -59,12 +59,12 @@ enum XML_Status {
 #define LOCK_TIME 600
 #define LOCK_REFRESH 30
 
-/* bits #0-4 in revision.h */
+/* bits #0-6 in revision.h */
 
-#define LOCAL    (1u << 5)
-#define REMOTE   (1u << 6)
-#define FETCHING (1u << 7)
-#define PUSHING  (1u << 8)
+#define LOCAL    (1u << 7)
+#define REMOTE   (1u << 8)
+#define FETCHING (1u << 9)
+#define PUSHING  (1u << 10)
 
 /* We allow "recursive" symbolic refs. Only within reason, though */
 #define MAXDEPTH 5

rev-list.c

@@ -7,9 +7,9 @@
 #include "tree-walk.h"
 #include "revision.h"
 
-/* bits #0-5 in revision.h */
+/* bits #0-6 in revision.h */
 
-#define COUNTED		(1u<<6)
+#define COUNTED		(1u<<7)
 
 static const char rev_list_usage[] =
 "git-rev-list [OPTION] <commit-id>... [ -- paths... ]\n"

revision.c

@@ -340,6 +340,10 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
 {
 	struct commit_list *parent = commit->parents;
 
+	if (commit->object.flags & ADDED)
+		return;
+	commit->object.flags |= ADDED;
+
 	/*
 	 * If the commit is uninteresting, don't try to
 	 * prune parents - we want the maximal uninteresting
@@ -705,13 +709,6 @@ 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->prune_fn = try_to_simplify_commit;
-
-		/*
-		 * If we fix up parent data, we currently cannot
-		 * do that on-the-fly.
-		 */
-		if (revs->parents)
-			revs->limited = 1;
 	}
 
 	return left;
@@ -728,10 +725,12 @@ void prepare_revision_walk(struct rev_info *revs)
 					     revs->topo_getter);
 }
 
-static int rewrite_one(struct commit **pp)
+static int 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 (p->object.flags & (TREECHANGE | UNINTERESTING))
 			return 0;
 		if (!p->parents)
@@ -740,12 +739,12 @@ static int rewrite_one(struct commit **pp)
 	}
 }
 
-static void rewrite_parents(struct commit *commit)
+static void 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(&parent->item) < 0) {
+		if (rewrite_one(revs, &parent->item) < 0) {
 			*pp = parent->next;
 			continue;
 		}
@@ -802,7 +801,7 @@ struct commit *get_revision(struct rev_info *revs)
 			if (!(commit->object.flags & TREECHANGE))
 				continue;
 			if (revs->parents)
-				rewrite_parents(commit);
+				rewrite_parents(revs, commit);
 		}
 		commit->object.flags |= SHOWN;
 		return commit;

revision.h

@@ -7,6 +7,7 @@
 #define SHOWN		(1u<<3)
 #define TMP_MARK	(1u<<4) /* for isolated cases; clean after use */
 #define BOUNDARY	(1u<<5)
+#define ADDED		(1u<<6)	/* Parents already parsed and added? */
 
 struct rev_info;