codegen: Fix access to captured generics in async method of interfaces

Fixes https://gitlab.gnome.org/GNOME/vala/issues/537

3 files changed, 20 insertions, 4 deletions

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index fa6f058f8..8c5926fb0 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -2907,9 +2907,9 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 
 				string method_name = "get_%s_type".printf (type_parameter.name.ascii_down ());
 				var cast_self = new CCodeFunctionCall (new CCodeIdentifier (get_ccode_type_get_function (iface)));
-				cast_self.add_argument (new CCodeIdentifier ("self"));
+				cast_self.add_argument (get_this_cexpression ());
 				var function_call = new CCodeFunctionCall (new CCodeMemberAccess.pointer (cast_self, method_name));
-				function_call.add_argument (new CCodeIdentifier ("self"));
+				function_call.add_argument (get_this_cexpression ());
 				return function_call;
 			}
 
@@ -3534,9 +3534,9 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 
 				string method_name = "get_%s_destroy_func".printf (type_parameter.name.ascii_down ());
 				var cast_self = new CCodeFunctionCall (new CCodeIdentifier (get_ccode_type_get_function (iface)));
-				cast_self.add_argument (new CCodeIdentifier ("self"));
+				cast_self.add_argument (get_this_cexpression ());
 				var function_call = new CCodeFunctionCall (new CCodeMemberAccess.pointer (cast_self, method_name));
-				function_call.add_argument (new CCodeIdentifier ("self"));
+				function_call.add_argument (get_this_cexpression ());
 				return function_call;
 			}
 
diff --git a/tests/Makefile.am b/tests/Makefile.am
index eea0131e1..7718adef4 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -451,6 +451,7 @@ TESTS = \
 	objects/interface-inner-types.vala \
 	objects/interfaces.vala \
 	objects/interface-abstract-async-override.vala \
+	objects/interface-async-captured-generic.vala \
 	objects/interface-generics.vala \
 	objects/interface-property-base-access.vala \
 	objects/interface-property-base-impl.vala \
diff --git a/tests/objects/interface-async-captured-generic.vala b/tests/objects/interface-async-captured-generic.vala
new file mode 100644
index 000000000..ae51d676a
--- /dev/null
+++ b/tests/objects/interface-async-captured-generic.vala
@@ -0,0 +1,15 @@
+[GenericAccessors]
+interface IFoo<G> : Object {
+	public async void bar (G g) {
+		assert (typeof (G) == typeof (string));
+		assert (g == "foo");
+	}
+}
+
+class Foo : Object, IFoo<string> {
+}
+
+void main () {
+	var foo = new Foo ();
+	foo.bar.begin ("foo");
+}