[vala/0.50] codegen: Fix access to captured generics in async method of interfaces

[Rico Tzschichholz <ricotz src gnome org>]

commit b98cb63f2716b7ddad026bcfc73e5601daf67fa3
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue Mar 9 09:51:21 2021 +0100

    codegen: Fix access to captured generics in async method of interfaces
    
    Fixes https://gitlab.gnome.org/GNOME/vala/issues/537

 codegen/valaccodebasemodule.vala                    |  8 ++++----
 tests/Makefile.am                                   |  1 +
 tests/objects/interface-async-captured-generic.vala | 15 +++++++++++++++
 3 files changed, 20 insertions(+), 4 deletions(-)
---
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 539630901..c712467b8 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -2861,9 +2861,9 @@ 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;
                        }
 
@@ -3488,9 +3488,9 @@ 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 2c0724e38..8e2e49b3b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -449,6 +449,7 @@ 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");
+}