codegen: Don't add errornous cast for unknown type_symbol

This causes invalid C code for reference transfer of GenericType.

Regression of 7ae2f115a702439bd94bf09867b38019f39d010f

Fixes https://gitlab.gnome.org/GNOME/vala/issues/1180

1 files changed, 12 insertions, 2 deletions

diff --git a/tests/generics/reference-transfer.vala b/tests/generics/reference-transfer.vala
index da2c1e305..5dc7a666f 100644
--- a/tests/generics/reference-transfer.vala
+++ b/tests/generics/reference-transfer.vala
@@ -19,6 +19,16 @@ void foo<G> (owned G g) {
 }
 
 void main () {
-	foo<string> ("foo");
-	bar<string> (new Bar<string> ("bar"));
+	{
+		foo<string> ("foo");
+	}
+	{
+		bar<string> (new Bar<string> ("bar"));
+	}
+	{
+		var bar = new Bar<string> ("bar");
+		var t = (owned) bar.g;
+		assert (bar.g == null);
+		assert (t == "bar");
+	}
 }