--- a/tests/test-push-warn
+++ b/tests/test-push-warn
@@ -54,4 +54,9 @@ hg push -r 3 -r 4 ../c; echo $?
hg push -f -r 3 -r 4 ../c; echo $?
hg push -r 5 ../c; echo $?
+# issue 450
+hg init ../e
+hg push -r 0 ../e ; echo $?
+hg push -r 1 ../e ; echo $?
+
exit 0