Bug report

I'm using imshow, and between 3.1.0 and 3.1.1 the behavior of the extents of the plot has changed when using Axes.set_yticks. In 3.1.0, and in 3.1.1 when not calling set_yticks, the plot includes the outer 0.5 bin in the top and bottom rows. This is the desired behavior. But in 3.1.1 when using set_yticks, the outer 0.5 bin in the top and bottom rows is not included in the plot.

Code for reproduction

import matplotlib
import matplotlib.pyplot as plt

xy = [[1, 3], [2, 4]]
fig, ax = matplotlib.pyplot.subplots(1)
ax.imshow(xy)
ax.set_xticks([0, 1])
ax.set_xticklabels(["0", "1"])
ax.set_yticks([0, 1])
ax.set_yticklabels(["0", "1"])
fig.savefig(f"matplotlib-v{matplotlib.__version__}.png")

The behavior changes in 3.1.1 if ax.set_yticks([0, 1]) is commented out.

Desired behavior

Behavior in 3.1.1 with set_yticks

Matplotlib version

• Operating system: Mac OS 10.14.5
• Matplotlib version: 3.1.1
• Matplotlib backend: agg
• Python version: 3.7.3
• Jupyter version (if applicable): N/A
• Other libraries: Fresh conda install of just matplotlib, using conda-forge