#55 Crash inside QwtWidgetOverlay::paintEvent.when run with xvfb

[Anonymous]

I have a unit test (using the QtTest library) that crashes if I run the test by doing a "xvfb-run ./mytest" to run the test under a virtual X server.

The crash occurs in QwtWidgetOverlay::paintEvent. It appears that in this case, painter.paintEngine() returns a nullptr. I have a small patch that works around the issue.

I am using Qt 5.4.1 and Qwt 6.1.2. The code is compile using gcc 4.9 on RHEL6. I am using the prebuilt Qt 5.4.0 binaries.

[Uwe Rathmann]

The painter is initialized with "this" a couple of lines before - so the engine has to be valid - otherwise the complete system is in an invalid state.

Guess your test kills the X-Server while the application is still alive ?