git-debrebase: insist that breakwater merges are merges

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

diff --git a/git-debrebase b/git-debrebase
index 28cbc8891ba1400aff860309af1db841ac189d09..6d8091e63bfb880b42a56aa1387d8d0b1a0aacfd 100755 (executable)
--- 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));