Forward port 532913:
Forward port 532913:

Fix crash when trying to view source while the Message Preview Pane is hidden.

CCBUG: 85175


svn path=/trunk/KDE/kdepim/; revision=532918

lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi