git-debrebase: merge: Avoid needlessly walking MergedBreakwaters

We will not ever need to rewrite one of these, so we can just ask
keycommits for its anchor.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 5 insertions, 4 deletions

diff --git a/git-debrebase b/git-debrebase
index 9c44419..35b75cd 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -1130,7 +1130,11 @@ sub walk ($;$$$) {
 		return $bomb->();
 	    }
 	    die "$ty ?";
-	} elsif ($ty eq 'VanillaMerge' or $ty eq 'MergedBreakwaters') {
+	} elsif ($ty eq 'MergedBreakwaters') {
+	    $last_anchor = mergedbreakwaters_anchor $cl;
+	    $build_start->(' MergedBreakwaters', $cur);
+	    last;
+	} elsif ($ty eq 'VanillaMerge') {
 	    # User may have merged unstitched branch(es).  We will
 	    # have now lost what ffq-prev was then (since the later
 	    # pseudomerge may introduce further changes).  The effect
@@ -1166,9 +1170,6 @@ sub walk ($;$$$) {
 
 	    printdebug "*** MERGE\n";
 
-	    # xxx avoid calling walk without nogenerate when
-	    # we have a MergedBreakwater; instead call keycommits ?
-
 	    my @bwbcmd = (@git, qw(merge-base));
 	    my @ibcmd = (@git, qw(merge-base --all));
 	    my $might_be_in_bw = 1;