musescore/MuseScore — pull request #341 by mgavioli (2013-05-09 23:45:15+00:00)
Title: QT5 - On a new installation, "Preferences" crashes

On a new (Linux?) installation, if no sound output is enabled, opening "Preferences" crashes. It happens on my Linux setup where the default output (Jack?, pulseaudio?) is not available; may happen to others.

In mscore/preferences.cpp, seq is accessed but set to 0.

Added some safeguard checks.