Add image comparison test.

Author: stefmolin

lib/matplotlib/tests/baseline_images/test_axes/test_centered_bar_label_nonlinear.svg

@@ -7749,6 +7749,16 @@ def test_bar_label_location_center():
     assert labels[1].get_va() == 'center'
 
 
+@image_comparison(['test_centered_bar_label_nonlinear.svg'])
+def test_centered_bar_label_nonlinear():
+    _, ax = plt.subplots()
+    bar_container = ax.barh(['c', 'b', 'a'], [1_000, 5_000, 7_000])
+    ax.set_xscale('log')
+    ax.set_xlim(1, None)
+    ax.bar_label(bar_container, label_type='center')
+    ax.set_axis_off()
+
+
 def test_bar_label_location_errorbars():
     ax = plt.gca()
     xs, heights = [1, 2], [3, -4]