Bug report

Bug summary
I use matplotlib version 3.0.3 and while testing sample code for multicursor, everything is OK and
window opens and multicursor works fine. But if I maximize plotting window, and move mouse cursor on plot, python crashes and exists with code: -1073741819 (0xC0000005)

Code for reproduction

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import MultiCursor

t = np.arange(0.0, 2.0, 0.01)
s1 = np.sin(2*np.pi*t)
s2 = np.sin(4*np.pi*t)
fig, (ax1, ax2) = plt.subplots(2, sharex=True)
ax1.plot(t, s1)
ax2.plot(t, s2)
multi = MultiCursor(fig.canvas, (ax1, ax2), color='r', lw=1)
plt.show()

Process finished with exit code -1073741819 (0xC0000005)

Matplotlib version

• Operating system: Windows 10 (version: 10.0.17763)
• Matplotlib version: 3.0.3
• Matplotlib backend (TkAgg):
• Python version: 3.7
• IDE: PyCharm 2018.3