Fix bug in wxAutomationObject introduced by r71574.

Check that we have any arguments, expression oleArgs[0] is invalid otherwise.

Closes #14343.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71578 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/ole/automtn.cpp

@@ -187,7 +187,7 @@ bool wxAutomationObject::Invoke(const wxString& member, int action,
     }
 
     dispparams.rgdispidNamedArgs = &dispIds[0] + 1;
-    dispparams.rgvarg = &oleArgs[0];
+    dispparams.rgvarg = oleArgs.empty() ? NULL : &oleArgs[0];
     dispparams.cArgs = noArgs;
     dispparams.cNamedArgs = namedArgCount;