[PySide] open/close QMdiArea subwindows

Joel B. Mohler joel at kiwistrawberry.us
Thu Feb 21 23:45:59 CET 2013

TL;DR;  QMdiArea claims to take any QWidget in the addSubWindow method.  
However, in PySide, this appears to work but it will almost certainly 
segfault after many (or few) open/close cycles.

I get a segfault in both windows and linux on the following code. After 
opening and closing the window created in "newkid" 4-50 times.  I simply 
start the program and press Ctrl+F5, Ctrl+W repeatedly activating the 
QAction and using the platform specific close sub-window shortcut.   The 
nondescript newkid widget appears and disappears until on some open I 
get a segfault.

#!/usr/bin/env python

from PySide import QtCore, QtGui

class MainWin(QtGui.QMainWindow):
     def __init__(self, parent=None):
         super(MainWin, self).__init__(parent)


         self.myaction = QtGui.QAction("add win", self)

     def newkid(self):
         w = QtGui.QWidget()
         w.setWindowTitle("hi there")

if __name__ == '__main__':
     app = QtGui.QApplication([])
     w = MainWin()

Both systems are running PySide 1.1.2 and Qt 4.8.x.

Indeed, I've modified the example to make a QMdiSubWindow rather than a 
QWidget and I have yet to have it crash for me after pounding on the F5 
& W keys as described above.  I think I have a fix then for the 
immediate issue, but I guess this is a bug for the bug tracker as well 
since the qmdiarea docs imply this should work.  I think I'm with-in 
bounds for the documentation at 
http://qt-project.org/doc/qt-4.8/qmdiarea.html#addSubWindow .


(Side-note:  this is one of the other things that went wrong in my 
thread about "RuntimeError:  Failed to connect signal" ... the bug hunt 
is wide open I guess and expect I'll find other issues)

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