git-debrebase: convert-to-gbp: Handle no-patches case better

In this case it's very like git-debrebase forget-was-debrebase.

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

1 files changed, 12 insertions, 7 deletions

diff --git a/git-debrebase b/git-debrebase
index 353b405..a67008f 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -2635,13 +2635,18 @@ sub cmd_convert_to_gbp () {
     my (undef, undef, undef, $ffq, $gdrlast) = ffq_prev_branchinfo();
     my ($anchor, $breakwater) = keycommits $head, 0;
     my $out = $breakwater;
-    make_patches_staged $head;
-    in_workarea sub {
-	$out = make_commit [$out], [
-            'Commit patch queue (converted from git-debrebase format)',
-            '[git-debrebase convert-to-gbp: commit patches]',
-        ];
-    };
+    my $any = make_patches_staged $head;
+    if ($any) {
+	in_workarea sub {
+	    $out = make_commit [$out], [
+		'Commit patch queue (converted from git-debrebase format)',
+		'[git-debrebase convert-to-gbp: commit patches]',
+	    ];
+	};
+    } else {
+	# in this case, it can be fast forward
+	$out = $head;
+    }
     if (defined $ffq) {
 	push @deferred_updates, "delete $ffq";
 	push @deferred_updates, "delete $gdrlast";