Bug report

On my machine using master I can reliably get segfaults using QT5Agg by resizing the window a bunch of times (say order 20). There is no segfault on v2.2.2 Suspect #11712 and/or #8951. (Sorry, not quite sure how to revert those locally to test).

python3.6_2018-07-21-150850_JMKMBP.crash.zip

import matplotlib.pyplot as plt
fig, ax = plt.subplots()
plt.show()

Matplotlib version

• Operating system: macOS 10.13.6
• Matplotlib version: master as of this AM.
• Matplotlib backend (print(matplotlib.get_backend())): Qt5Agg
• Python version: 3.6.3