Savefig shrinks image #8805

Bug report

Bug summary

When I save a figure my canvas is smaller as before. As I need to extract images from an interactive pyplot I cannot align them anymore afterwards.

Code for reproduction

import matplotlib.pyplot as plt
f = plt.Figure()
plt.plot([1,2,3])
f.savefig('test.png')

Actual outcome

Figure gets saved, figure shrinks. Subsequent figure is then a tiny bit smaller

Expected outcome

The figure gets saved, the canvas or figure size stays untouched.

Matplotlib version

• Operating System: Win10 64
• Matplotlib Version: 2.0.2
• Python Version: 3.5.2
• Spyder 3 using Qt5