oox: GrabBagStack: add method isStackEmpty

Change-Id: Iec563762e7be7fb6e2d5501fe5efeb88093793cb

include/oox/helper/grabbagstack.hxx

@@ -47,6 +47,7 @@ public:
     void pop();
     void addInt32(OUString aElementName, sal_Int32 aIntValue);
     void addString(OUString aElementName, OUString aStringValue);
+    bool isStackEmpty();
 };
 
 } // namespace oox

oox/source/helper/grabbagstack.cxx

@@ -30,6 +30,11 @@ OUString GrabBagStack::getCurrentName()
     return mCurrentElement.maName;
 }
 
+bool GrabBagStack::isStackEmpty()
+{
+    return mStack.empty();
+}
+
 PropertyValue GrabBagStack::getRootProperty()
 {
     while(!mStack.empty())