Re: A note on merging conflicts..

[Daniel Barkalow <barkalow@iabervon.org>]

On Sat, 1 Jul 2006, Daniel Barkalow wrote:

> Actually, I think that it would work to have object flags "LEFT" and 
> "RIGHT", mark b with left, mark c with right, and mark anything with both 
> LEFT and RIGHT as UNINTERESTING as we go through the revisions. The 
> time-ordering problem with symmetric difference isn't absent with regular 
> difference, and, assuming that b..c works in the tricky cases, the same 
> logic should handle symmetric difference.

That is: (this only has the logic portion, and it's against master, so it 
isn't actually a really working patch or anything; also, it doesn't handle 
"--not a...b" correctly, whatever that should mean)

---

diff --git a/revision.c b/revision.c
index 6a6952c..c21d332 100644
--- a/revision.c
+++ b/revision.c
@@ -351,6 +351,9 @@ static void add_parents_to_list(struct r
 		return;
 	commit->object.flags |= ADDED;
 
+	if (commit->object.flags & LEFT && commit->objects.flags & RIGHT)
+		commit->object.flags |= UNINTERESTING;
+
 	/*
 	 * If the commit is uninteresting, don't try to
 	 * prune parents - we want the maximal uninteresting
@@ -781,8 +784,13 @@ int setup_revisions(int argc, const char
 				struct object *exclude;
 				struct object *include;
 
-				exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
-				include = get_reference(revs, next, sha1, flags);
+				if (symmetric) {
+					exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
+					include = get_reference(revs, next, sha1, flags);
+				} else {
+					exclude = get_reference(revs, this, from_sha1, flags | LEFT_HALF);
+					include = get_reference(revs, next, sha1, flags | RIGHT_HALF);
+				}
 				if (!exclude || !include)
 					die("Invalid revision range %s..%s", arg, next);
 
diff --git a/revision.h b/revision.h
index 7d85b0f..93421e6 100644
--- a/revision.h
+++ b/revision.h
@@ -9,6 +9,8 @@
 #define BOUNDARY	(1u<<5)
 #define BOUNDARY_SHOW	(1u<<6)
 #define ADDED		(1u<<7)	/* Parents already parsed and added? */
+#define LEFT_HALF	(1u<<8) /* Reachable from start of dotdotdot */
+#define RIGHT_HALF	(1u<<9) /* Reachable from end of dotdotdot */
 
 struct rev_info;
 struct log_info;
-- 
1.2.4