PyQt4 backend delete the widow in C++ but not in Python

Community matplotlib-users
1

This is the BUG:

https://sourceforge.net/tracker/?func=detail&aid=2927619&group_id=80706&atid=560720

If you close the window clicking on the right cross to close the
window the window closes properly. If you then try to create a new
widow (with the same index) you hit a RunTimeError.

Expect:

The window should be created normally.

It seems that the pyQt4 backend doesn't delete the window in the
python world but it does delete it in the C++.

Any ideas hot to fix it?