kmail: open tabs lost when changing layout settings

Project:Linux software
Component:Documentation
Category:bug report
Priority:normal
Assigned:Unassigned
Status:active
Related pages:#263: kmail
Description

kmail: open tabs lost when changing layout settings:

Open a few tabs showing different folders.
Go to kmail > settings > appearence > layout > change 'show message preview pane below / next to the message list'.
After applying the change, all opened tabs are lost. Only an empty tab remains. The user must reopen the tabs manually.