IDL: Don't lose nullable flag when "preprocessing" type

Source/bindings/scripts/v8_types.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
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 # modification, are permitted provided that the following conditions are
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@@ skipping 653 matching lines @@
     return idl_type.is_dictionary or idl_type.is_union_type
 
 IdlTypeBase.use_output_parameter_for_result = property(use_output_parameter_for_result)
 
 
 ################################################################################
 # C++ -> V8
 ################################################################################
 
 def preprocess_idl_type(idl_type):
+    if idl_type.is_nullable:
+        return IdlNullableType(idl_type.inner_type.preprocessed_type)
     if idl_type.is_enum:
         # Enumerations are internally DOMStrings
         return IdlType('DOMString')
-    if (idl_type.name in ['Any', 'Object'] or idl_type.is_callback_function):

[Jens Widell, 2015/02/16 14:33:54]

Looking at idl_type.name here was wrong; it would be AnyOrNull/ObjectOrNull for
a nullable type (and was in the case of
WebGLRenderingContextBase.getExtension()'s "object?" return value.)

With the other change in this function this code would now have worked, but I
changed it anyway, since I think it's better to look at base_type in most cases;
using name is equivalent except it invites this kind of error.

+    if idl_type.base_type in ['any', 'object'] or idl_type.is_callback_function:
         return IdlType('ScriptValue')
     return idl_type
 
 IdlTypeBase.preprocessed_type = property(preprocess_idl_type)
 
 
 def preprocess_idl_type_and_value(idl_type, cpp_value, extended_attributes):
     """Returns IDL type and value, with preliminary type conversions applied."""
     idl_type = idl_type.preprocessed_type
     if idl_type.name == 'Promise':
@@ skipping 259 matching lines @@
     number_of_nullable_member_types_union)
 
 
 def includes_nullable_type_union(idl_type):
     # http://heycam.github.io/webidl/#dfn-includes-a-nullable-type
     return idl_type.number_of_nullable_member_types == 1
 
 IdlTypeBase.includes_nullable_type = False
 IdlNullableType.includes_nullable_type = True
 IdlUnionType.includes_nullable_type = property(includes_nullable_type_union)