model: really implement precondition of lookup_first_definition

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

diff --git a/src/model/model.nit b/src/model/model.nit
index f493353..11bdce3 100644 (file)
--- a/src/model/model.nit
+++ b/src/model/model.nit
@@ -1680,6 +1680,7 @@ abstract class MProperty
        # REQUIRE: `mtype.has_mproperty(mmodule, self)`
        fun lookup_first_definition(mmodule: MModule, mtype: MType): MPROPDEF
        do
+               assert mtype.has_mproperty(mmodule, self)
                return lookup_all_definitions(mmodule, mtype).first
        end