it looks like it could be. I will investigate
I fixed it in 2.4 and 2.2, thanks for the report.
Thanks for your quick reply. Actually I didn't expect such quick response, so I fixed it at my side and was planning to submit a patch. Anyway, I tested the fixes and it works very well.
Just a quick question, in the PortletRequestImpl.isPortletModeAllowed(PortletMode), there is a null test on the argument. I think the same should be applied to the method PortletRequestImpl.isWindowStateAllowed(WindowState).