Workaround dubious casting between CXFA_Object and void* in FXJSE

This is just a crock to get things working until we fix the
underlying issue.

When there's single-inheritance, it may often work in practice
to C-style (reinterpret) cast a Derived* ptr to void* and then
back to a Base* ptr.  One place where this blows up is if
Derived has virtual functions but Base does not, in which case
the world will be offset by the size of a vtable ptr.

Because of the use of void* types in FXJSE, the above was happening
when setting a CXFA_ThisProxy (Derived, virtual) to be a global
object (void*). This would then be cast back to a CFXA_Object
(Base, non-virtual) and chaos is ensured.

Not sure how far back this goes.

Along the way, pick up some tidying which was necessary for
simplicity while tracking this down.

BUG=613607

Review-Url: https://codereview.chromium.org/2015143005

1 files changed, 2 insertions, 2 deletions

diff --git a/xfa/fxjse/include/fxjse.h b/xfa/fxjse/include/fxjse.h
index d2d0bd9014..e278935657 100644
--- a/xfa/fxjse/include/fxjse.h
+++ b/xfa/fxjse/include/fxjse.h
@@ -72,8 +72,8 @@ void FXJSE_Runtime_Release(v8::Isolate* pIsolate, bool bOwnedRuntime);
 
 CFXJSE_Context* FXJSE_Context_Create(
     v8::Isolate* pIsolate,
-    const FXJSE_CLASS_DESCRIPTOR* lpGlobalClass = nullptr,
-    void* lpGlobalObject = nullptr);
+    const FXJSE_CLASS_DESCRIPTOR* lpGlobalClass,
+    void* lpGlobalObject);
 void FXJSE_Context_Release(CFXJSE_Context* pContext);
 CFXJSE_Value* FXJSE_Context_GetGlobalObject(CFXJSE_Context* pContext);