D15835: avoid that the main context can be #poped

[Christoph Cullmann]

cullmann added reviewers: vkrause, nibags.

REPOSITORY
  R216 Syntax Highlighting

REVISION DETAIL
  https://phabricator.kde.org/D15835

To: cullmann, dhaumann, vkrause, nibags
Cc: kwrite-devel, kde-frameworks-devel, michaelh, ngraham, bruns, demsking, 
cullmann, sars, dhaumann