Closing dockable pane closes other dockable windows

[PhillipM]

Closing my custom Dockable pane closes other dockable windows untill there is none left.  Has any one seen this before?

https://db.tt/PRtL3OGR

Regards

Phillip Miller

[Aaron.Lu]

I think it should be by design.
it will close the whole tab unless you drag your dockable dialog out and close it seperately, or, you can double click the tab header, it will be close and leave the remaining.