GROOVY-10499

Author: eric-milles

base-test/org.eclipse.jdt.groovy.core.tests.compiler/src/org/eclipse/jdt/groovy/core/tests/xform/TypeCheckedTests.java

@@ -5231,6 +5231,34 @@ public void testTypeChecked10482b() {
         runConformTest(sources);
     }
 
+    @Test
+    public void testTypeChecked10499() {
+        for (String bounds : new String[] {"?", "Y", "? extends Y"}) {
+            //@formatter:off
+            String[] sources = {
+                "Main.groovy",
+                "class C<X> {\n" +
+                "  C(X x) {\n" +
+                "  }\n" +
+                "}\n" +
+                "class D<Y> {\n" +
+                "  D(C<" + bounds + "> c, Y y) {\n" +
+                "  }\n" +
+                "  Y m(Y y) {\n" +
+                "  }\n" +
+                "}\n" +
+                "@groovy.transform.TypeChecked\n" +
+                "def <Z> void test(Z z = null) {\n" +
+                "  new D<>(new C<Z>(z), z).m(z)\n" + // Cannot find matching method D#m(Z)
+                "}\n" +
+                "test()\n",
+            };
+            //@formatter:on
+
+            runConformTest(sources);
+        }
+    }
+
     @Test
     public void testTypeChecked10525() {
         //@formatter:off

base/org.codehaus.groovy40/src/org/codehaus/groovy/transform/stc/StaticTypeCheckingSupport.java

@@ -1926,10 +1926,13 @@ static ClassNode getCombinedBoundType(final GenericsType genericsType) {
         return genericsType.getType();
     }
 
-    static GenericsType getCombinedGenericsType(final GenericsType gt1, final GenericsType gt2) {
+    static GenericsType getCombinedGenericsType(GenericsType gt1, GenericsType gt2) {
+        // GROOVY-9998, GROOVY-10499: unpack "?" that is from "? extends T"
+        if (isUnboundedWildcard(gt1)) gt1 = gt1.getType().asGenericsType();
+        if (isUnboundedWildcard(gt2)) gt2 = gt2.getType().asGenericsType();
         ClassNode cn1 = GenericsUtils.makeClassSafe0(CLASS_Type, gt1);
         ClassNode cn2 = GenericsUtils.makeClassSafe0(CLASS_Type, gt2);
-        ClassNode lub = lowestUpperBound(cn1,cn2);
+        ClassNode lub = lowestUpperBound(cn1, cn2);
         return lub.getGenericsTypes()[0];
     }