[vala/wip/issue548: 1/8] vala: Add GenericType.get_actual_type()

[Rico Tzschichholz <ricotz src gnome org>]

commit 83112b21e245afec5e0d2a2b707d40259589db67
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Dec 5 16:01:13 2018 +0100

    vala: Add GenericType.get_actual_type()

 vala/valadatatype.vala    |  6 +-----
 vala/valagenerictype.vala | 12 ++++++++++++
 2 files changed, 13 insertions(+), 5 deletions(-)
---
diff --git a/vala/valadatatype.vala b/vala/valadatatype.vala
index 09209a7fd..85d8fb87b 100644
--- a/vala/valadatatype.vala
+++ b/vala/valadatatype.vala
@@ -463,11 +463,7 @@ public abstract class Vala.DataType : CodeNode {
                        return result;
                }
 
-               if (result is GenericType) {
-                       result = SemanticAnalyzer.get_actual_type (derived_instance_type, 
method_type_arguments, (GenericType) result, node_reference);
-                       // don't try to resolve type arguments of returned actual type
-                       // they can never be resolved and are not related to the instance type
-               } else if (result.type_argument_list != null) {
+               if (result.type_argument_list != null) {
                        // recursely get actual types for type arguments
                        for (int i = 0; i < result.type_argument_list.size; i++) {
                                result.type_argument_list[i] = result.type_argument_list[i].get_actual_type 
(derived_instance_type, method_type_arguments, node_reference);
diff --git a/vala/valagenerictype.vala b/vala/valagenerictype.vala
index d964ab63a..0a229a43e 100644
--- a/vala/valagenerictype.vala
+++ b/vala/valagenerictype.vala
@@ -47,6 +47,18 @@ public class Vala.GenericType : DataType {
                return result;
        }
 
+       public override DataType get_actual_type (DataType? derived_instance_type, List<DataType>? 
method_type_arguments, CodeNode node_reference) {
+               var result = this.copy ();
+
+               if (derived_instance_type == null && method_type_arguments == null) {
+                       return result;
+               }
+
+               result = SemanticAnalyzer.get_actual_type (derived_instance_type, method_type_arguments, 
(GenericType) result, node_reference);
+
+               return result;
+       }
+
        public override DataType? infer_type_argument (TypeParameter type_param, DataType value_type) {
                if (type_parameter == type_param) {
                        var ret = value_type.copy ();