Add missing call to __init__, since Java subclasses' __new__ returns a non-subinstance

Author: timfel

graalpython/com.oracle.graal.python.test/src/tests/test_interop.py

@@ -1423,7 +1423,7 @@ class PythonLevel(Level, new_style=True):
             def __new__(cls, name="default name", level=2):
                 return super().__new__(cls, name, level)
 
-            def __init__(self):
+            def __init__(self, *args, **kwarg):
                 self.misc_value = 42
 
             def getName(self):

graalpython/lib-graalpython/__graalpython__.py

@@ -204,7 +204,9 @@ def __delattr__(self, name):
         polyglot.register_interop_type(JavaClass, MroClass, allow_method_overwrites=True)
 
     # A class to make sure that the returned Python class can be used for
-    # issubclass and isinstance checks with the Java instances
+    # issubclass and isinstance checks with the Java instances, and to wrap all
+    # methods in created subclasses to provide the proper `self` (the Java
+    # instance) and still make `super()` work.
     class JavaSubclassMeta(type):
         @property
         def __bases__(self):
@@ -274,6 +276,7 @@ def __new__(cls, *args, **kwds):
             delegate = object.__new__(cls)
             java_object = polyglot.__new__(JavaClass, *(args + (delegate,)))
             delegate.__this__ = java_object
+            delegate.__init__(*args, **kwds)
             return java_object
 
     return type(name, (DelegateSuperclass,), ns)