add tests

Author: Yi Wei

lib/matplotlib/tests/test_axes.py

@@ -1478,6 +1478,20 @@ def test_pcolorargs():
                       match='are not monotonically increasing or decreasing'):
         ax.pcolormesh(X, Y, Z, shading='auto')
 
+    # GH 26093
+    x = np.arange(6).reshape(2, 3)
+    mask = np.broadcast_to([False, True, False], x.shape)  # read-only array
+    masked_x = np.ma.array(x, mask=mask)
+    plt.pcolormesh(masked_x)
+
+    x = np.linspace(0, 1, 10)
+    y = np.linspace(0, 1, 10)
+    X, Y = np.meshgrid(x, y)
+    Z = np.sin(2 * np.pi * X) * np.cos(2 * np.pi * Y)
+    Zmask = np.broadcast_to([True, False]*5, Z.shape)
+    masked_Z = np.ma.array(Z, mask = Zmask)
+    plt.pcolormesh(X, Y, masked_Z)
+
 
 @check_figures_equal(extensions=["png"])
 def test_pcolornearest(fig_test, fig_ref):