treat __new__ specially when addressing it as tp_new

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/cext/DynamicObjectNativeWrapper.java

@@ -102,6 +102,7 @@
 import com.oracle.graal.python.builtins.objects.memoryview.PBuffer;
 import com.oracle.graal.python.builtins.objects.memoryview.PMemoryView;
 import com.oracle.graal.python.builtins.objects.method.PBuiltinMethod;
+import com.oracle.graal.python.builtins.objects.method.PDecoratedMethod;
 import com.oracle.graal.python.builtins.objects.method.PMethod;
 import com.oracle.graal.python.builtins.objects.mmap.PMMap;
 import com.oracle.graal.python.builtins.objects.module.PythonModule;
@@ -462,9 +463,15 @@ static Object doTpAsMapping(PythonManagedClass object, @SuppressWarnings("unused
 
         @Specialization(guards = "eq(TP_NEW, key)")
         static Object doTpNew(PythonManagedClass object, @SuppressWarnings("unused") PythonNativeWrapper nativeWrapper, @SuppressWarnings("unused") String key,
+                        @Cached ConditionProfile profileNewType,
                         @Cached LookupAttributeInMRONode.Dynamic getAttrNode,
                         @Cached PCallCapiFunction callGetNewfuncTypeidNode) {
-            return ManagedMethodWrappers.createKeywords(getAttrNode.execute(object, __NEW__), callGetNewfuncTypeidNode.call(NativeCAPISymbols.FUN_GET_NEWFUNC_TYPE_ID));
+            // __new__ is magically a staticmethod for Python types. The tp_new slot lookup expects to get the function
+            Object newFunction = getAttrNode.execute(object, __NEW__);
+            if (profileNewType.profile(newFunction instanceof PDecoratedMethod)) {
+                newFunction = ((PDecoratedMethod) newFunction).getCallable();
+            }
+            return ManagedMethodWrappers.createKeywords(newFunction, callGetNewfuncTypeidNode.call(NativeCAPISymbols.FUN_GET_NEWFUNC_TYPE_ID));
         }
 
         @Specialization(guards = "eq(TP_HASH, key)")