compiler: no-on for `AIsaExpr` without a valid `cast_type`

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/compiler/abstract_compiler.nit b/src/compiler/abstract_compiler.nit
index 221e628..8fae169 100644 (file)
--- a/src/compiler/abstract_compiler.nit
+++ b/src/compiler/abstract_compiler.nit
@@ -3044,7 +3044,9 @@ redef class AIsaExpr
        redef fun expr(v)
        do
                var i = v.expr(self.n_expr, null)
-               return v.type_test(i, self.cast_type.as(not null), "isa")
+               var cast_type = self.cast_type
+               if cast_type == null then return null # no-no on broken node
+               return v.type_test(i, cast_type, "isa")
        end
 end