[QScintilla] QsciLexerCustom crash

[Baz Walter]

hello

i've been experimenting with custom lexers recently and came across this 
bug:

 >>> from PyQt4 import QtCore, QtGui, Qsci
 >>> a = QtGui.QApplication([])
 >>> class X(Qsci.QsciLexerCustom):
...     def description(self, s): return QtCore.QString()
...
 >>> s = Qsci.QsciScintilla()
 >>> x = X()
 >>> s.setLexer(x)
 >>> s.deleteLater()
 >>> s = Qsci.QsciScintilla()
 >>> s.setLexer(x)
Segmentation fault


this is using: gcc 4.3.2, python 2.6.2, qt 4.5.2, sip 4.8.1, pyqt 
4.5.2-snapshot-20090627, qsci 2.4