git-debrebase: insist that breakwater merges are merges

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

1 files changed, 3 insertions, 0 deletions

diff --git a/git-debrebase b/git-debrebase
index 28cbc88..6d8091e 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -375,6 +375,9 @@ sub classify ($) {
 	$r->{Msg} =~ m{^\[git-debrebase breakwater.*\]$}m;
 
     if (@p == 1) {
+	if ($claims_to_be_breakwater) {
+	    return $unknown->("single-parent git-debrebase breakwater \`merge'");
+	}
 	my $d = $r->{Parents}[0]{Differs};
 	if ($d == D_PAT_ADD) {
 	    return $classify->(qw(AddPatches));