Support for instance method references

Support_for_String_&toUpperCase_method_closures.patch

Index: src/main/org/codehaus/groovy/runtime/MethodClosure.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/main/org/codehaus/groovy/runtime/MethodClosure.java	(revision Local version)
+++ src/main/org/codehaus/groovy/runtime/MethodClosure.java	(revision Shelved version)
@@ -19,8 +19,8 @@
 package org.codehaus.groovy.runtime;
 
 import groovy.lang.Closure;
+import groovy.lang.MetaClass;
 import groovy.lang.MetaMethod;
-
 import java.util.List;
 
 
@@ -31,24 +31,31 @@
  * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
  */
 public class MethodClosure extends Closure {
+    private final static Class[] EMPTY_CLASS_ARRAY = new Class[0];
 
     public static boolean ALLOW_RESOLVE = false;
 
     private static final Class[] EMPTY_CLASS_ARRAY = new Class[0];
-    private String method;
+    private final Object owner;
+    private final String method;
+    private final boolean classReceiver;
 
     public MethodClosure(Object owner, String method) {
         super(owner);
         this.method = method;
+        this.owner = owner;
 
-        final Class clazz = owner.getClass()==Class.class?(Class) owner:owner.getClass();
+        classReceiver = owner.getClass() == Class.class;
+        Class clazz = classReceiver ?(Class) owner:owner.getClass();
         
         maximumNumberOfParameters = 0;
         parameterTypes = EMPTY_CLASS_ARRAY;
 
-        List<MetaMethod> methods = InvokerHelper.getMetaClass(clazz).respondsTo(owner, method);
+        MetaClass ownerMetaClass = InvokerHelper.getMetaClass(clazz);
+        List<MetaMethod> methods = ownerMetaClass.respondsTo(owner, method);
         
         for(MetaMethod m : methods) {
+            if (classReceiver && !m.isStatic()) continue;
             if (m.getParameterTypes().length > maximumNumberOfParameters) {
                 Class[] pt = m.getNativeParameterTypes();
                 maximumNumberOfParameters = pt.length;
@@ -56,13 +63,27 @@
             }
         }
     }
-    
+
     public String getMethod() {
         return method;
     }
 
     protected Object doCall(Object arguments) {
-        return InvokerHelper.invokeMethod(getOwner(), method, arguments);
+        return InvokerHelper.invokeMethod(owner, method, arguments);
+    }
+
+    @Override
+    public Object call(final Object... args) {
+        if (parameterTypes == EMPTY_CLASS_ARRAY && classReceiver && args.length > 0 && args[0].getClass() == owner) {
+            // support String.&toUpperCase style method closures
+            // This implementation is limited to unambiguous cases in order to avoid relying on catching a
+            // MissingMethodException then potentially rethrowing it
+            Object instanceReceiver = args[0];
+            Object[] argsLeft = new Object[args.length - 1];
+            System.arraycopy(args, 1, argsLeft, 0, argsLeft.length);
+            return InvokerHelper.invokeMethod(instanceReceiver, method, argsLeft);
+        }
+        return super.call(args);
     }
 
     private Object readResolve() {
@@ -71,7 +92,7 @@
         }
         throw new UnsupportedOperationException();
     }
-    
+
     public Object getProperty(String property) {
         if ("method".equals(property)) {
             return getMethod();