don't negate undef in Slice/FetchFirst

diff --git a/lib/Data/Query/Renderer/SQL/Slice/FetchFirst.pm b/lib/Data/Query/Renderer/SQL/Slice/FetchFirst.pm
index 0bb96e0..f2741d6 100644 (file)
--- a/lib/Data/Query/Renderer/SQL/Slice/FetchFirst.pm
+++ b/lib/Data/Query/Renderer/SQL/Slice/FetchFirst.pm
@@ -72,7 +72,7 @@ sub _render_slice {
               : (),
           ],
           compose {
-            Order($b->{by}, !$b->{reverse}, -$b->{nulls}, $a)
+            Order($b->{by}, !$b->{reverse}, -($b->{nulls}||0), $a)
           } (
             @outside_order,
             Alias(