Re: rerere fails to record resolution if file doesn't exist in merge base

[Junio C Hamano <gitster@pobox.com>]

Uwe Kleine-König  <ukleinek@informatik.uni-freiburg.de> writes:

> Anyhow, the failure still exists, even though the original report was
> sent when rerere was still a perl script ...
>
> 	zeisberg@cassiopeia:/tmp/rerere$ git init
> 	Initialized empty Git repository in .git/
> 	zeisberg@cassiopeia:/tmp/rerere$ mkdir .git/rerere

This should be creating .git/rr-cache, but what you said in your
message is correct regardless.

> In my eyes the last command should have recorded the resolution for
> lolo, shouldn't it?

I think two-file merge (ancestor did not have it, and you and he
added the path differently) is rare enough that it was dropped
outside of the radar.  A fix would probably be a trivial change
to builtin-rerere.c::find_conflict(), I think.  While it would
still be sane to insist that we do not do rerere for symlinks,
and require to have stages #2 and #3, we should be able to drop
the requirement to have stage #1.  rerere does not use
information from there anyway.

Not even compile tested, but something like this should do.

 builtin-rerere.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/builtin-rerere.c b/builtin-rerere.c
index c25b3d5..6ffc43d 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -168,19 +168,16 @@ static int find_conflict(struct path_list *conflict)
 	int i;
 	if (read_cache() < 0)
 		return error("Could not read index");
-	for (i = 0; i + 2 < active_nr; i++) {
-		struct cache_entry *e1 = active_cache[i];
-		struct cache_entry *e2 = active_cache[i+1];
-		struct cache_entry *e3 = active_cache[i+2];
-		if (ce_stage(e1) == 1 &&
-		    ce_stage(e2) == 2 &&
+	for (i = 0; i+1 < active_nr; i++) {
+		struct cache_entry *e2 = active_cache[i];
+		struct cache_entry *e3 = active_cache[i+1];
+		if (ce_stage(e2) == 2 &&
 		    ce_stage(e3) == 3 &&
-		    ce_same_name(e1, e2) && ce_same_name(e1, e3) &&
-		    S_ISREG(ntohl(e1->ce_mode)) &&
+		    ce_same_name(e2, e3) &&
 		    S_ISREG(ntohl(e2->ce_mode)) &&
 		    S_ISREG(ntohl(e3->ce_mode))) {
-			path_list_insert((const char *)e1->name, conflict);
-			i += 2;
+			path_list_insert((const char *)e2->name, conflict);
+			i++; /* skip over both #2 and #3 */
 		}
 	}
 	return 0;