Description

When using certain projections such as cartopy.crs.AlbersEqualArea or cartopy.crs.Orthographic along with changing the extent such that some of the map is clipped, the spines at one corner do not form a connection or properly align. This is evident if you increase the line width of the spines. The image below shows the result in the affected corner which I have observed to be in both the top right corner as well as the lower left corner. The code below produced the plot this image was taken from.

Code to reproduce

import matplotlib.pyplot as plt
import cartopy.crs as ccrs

fig = plt.figure()
ax = plt.axes(projection=ccrs.Orthographic(0, 0))
ax.set_extent([-10, -11, 10, 11])
ax.spines[:].set_linewidth(3)
plt.savefig("test.pdf")