1. open LYX
2. CRTL-N
3. CRTL-D hold D --> crash
Graph must be thread save to fix this.
And for sure, we need a mutex also later.
Mutex is a simple wrapper around QMutex, with
pseudo-value semantic.
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@37222 a592a061-630c-0410-9148-cb99ea01b6c8