X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=blobdiff_plain;f=git-debrebase;h=771410ef1350443ee703f45434e86fd8ae2c6e74;hp=1e8de52941e10f68a80dc244642925ac0169cbd4;hb=1d38a8e35e08d9a37393a809f8de4492759f4be3;hpb=3522f98a237df1650a2361f3545e36396bc6c797

diff --git a/git-debrebase b/git-debrebase
index 1e8de529..771410ef 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -1235,12 +1235,22 @@ sub walk ($;$$$) {
 	    # breakwater merge base as an ancestor.
 
 	    my @ibs =
-		grep { is_fast_fwd $bwb, $_ }
 		grep /./,
 		split /\n/,
 		cmdoutput @ibcmd;
-	    my ($ib) = @ibs
-		or $nomerge->("no suitable interchange merge base");
+
+            @ibs or confess 'internal error, expected anchor at least ?';
+
+	    my $ib;
+	    foreach my $tibix (0..$#ibs) {
+		my $tib = $ibs[$tibix];
+		my $ff = is_fast_fwd $bwb, $tib;
+		next unless $ff;
+		next if $ib;
+		$ib = $tib;
+	    }
+
+	    $ib or $nomerge->("no suitable interchange merge base");
 
 	    $prline->("  VanillaMerge Base");
 	    $prprdelim->();
@@ -1254,6 +1264,7 @@ sub walk ($;$$$) {
 		or $nomerge->("interchange merge-base ($ib)'s".
 			      " breakwater ($bbw)".
 			      " != breakwaters' merge-base ($bwb)");
+
 	    grep { $_->{Anchor} eq $ibinfo->{Anchor} } @$ps
 		 or $nomerge->("interchange merge-base ($ib)'s".
 			       " anchor ($ibinfo->{SeriesBase})".
@@ -1261,7 +1272,6 @@ sub walk ($;$$$) {
 			       (join ' ', map { $_->{Anchor} } @$ps).
 			       ")");
 
-
 	    $cl->{MergeInterchangeBaseInfo} = $ibinfo;
 	    $cl->{MergeBestAnchor} = $best_anchor;
 	    push @brw_cl, {