Bug summary

Calling tricontourf from PolarAxes and adding in the kwarg extend='both' does not extend the colormap to cover patches outside of the colormap.

Code for reproduction

import matplotlib.pyplot as plt
fig = plt.figure()
ax = fig.add_subplot(1,1,1, polar=True)
ax.tricontourf(angle, radius, data, extend='both')

Actual outcome

Expected outcome

No white patches in the plot, all replaced by the minimum color.

Additional information

No response

Operating system

Windows

Matplotlib Version

3.7.2

Matplotlib Backend

Qt5Agg

Python version

3.11.3

Jupyter version

No response

Installation

pip