fix bug 36805 - was leaking xptiInterfaceGuts by unconditionally overwriting a union

xpcom/reflect/xptinfo/src/xptiInterfaceInfo.cpp

@@ -82,6 +82,19 @@ xptiInterfaceInfo::~xptiInterfaceInfo()
         delete mInterface;        
 }        
 
+void 
+xptiInterfaceInfo::Invalidate()
+{ 
+    if(IsValid())
+    {
+        // The order of operations here is important!
+        xptiTypelib typelib = GetTypelibRecord();
+        if(HasInterfaceRecord())
+            delete mInterface;        
+        mTypelib = typelib;
+        mName = nsnull;
+    }
+}
 
 PRBool 
 xptiInterfaceInfo::Resolve(xptiWorkingSet* aWorkingSet /* = nsnull */)

xpcom/reflect/xptinfo/src/xptiprivate.h

@@ -487,15 +487,7 @@ public:
     PRBool PartiallyResolveLocked(XPTInterfaceDescriptor*  aDescriptor,
                                   xptiWorkingSet*          aWorkingSet);
 
-    void Invalidate()
-        { 
-            if(IsValid())
-            {
-                xptiTypelib typelib = GetTypelibRecord();
-                mTypelib = typelib;
-                mName = nsnull;
-            }
-        }
+    void Invalidate();
 
 private:
     void CopyName(const char* name,