correct type substitution for method-closures

plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/impl/types/GrClosureParameterImpl.java

@@ -49,7 +49,7 @@ public class GrClosureParameterImpl implements GrClosureParameter {
   }
 
   public static boolean isParameterOptional(PsiParameter parameter) {
-    return parameter instanceof GrParameter ? ((GrParameter)parameter).isOptional() : false;
+    return parameter instanceof GrParameter && ((GrParameter)parameter).isOptional();
   }
 
   public static boolean isVararg(GrClosureParameter[] closureParams) {

plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/impl/types/GrClosureSignatureUtil.java

@@ -87,7 +87,7 @@ public class GrClosureSignatureUtil {
     return new GrClosureSignatureImpl(method.getParameterList().getParameters(), null, substitutor) {
       @Override
       public PsiType getReturnType() {
-        return PsiUtil.getSmartReturnType(method);
+        return getSubstitutor().substitute(PsiUtil.getSmartReturnType(method));
       }
 
       @Override

plugins/groovy/test/org/jetbrains/plugins/groovy/lang/resolve/TypeInferenceTest.java

@@ -204,4 +204,8 @@ public class TypeInferenceTest extends GroovyResolveTestCase {
   public void testPreferMethodOverloader() {
     assertTypeEquals("java.lang.String", "A.groovy");
   }
+
+  public void testReturnTypeFromMethodClosure() {
+    assertTypeEquals("java.lang.String","A.groovy");
+  }
 }

plugins/groovy/testdata/resolve/inference/returnTypeFromMethodClosure/A.groovy

@@ -0,0 +1,8 @@
+class Test<T> {
+  T foo(T t) {t}
+}
+
+def test=new Test<String>()
+def a = test.&foo
+def res = a("a")
+print re<ref>s