Fix log scale for pcolor

Author: dstansby

lib/matplotlib/axes/_axes.py

@@ -6252,8 +6252,7 @@ def pcolor(self, *args, shading=None, alpha=None, norm=None, cmap=None,
         maxy = np.max(y)
         collection.sticky_edges.x[:] = [minx, maxx]
         collection.sticky_edges.y[:] = [miny, maxy]
-        corners = (minx, miny), (maxx, maxy)
-        self.update_datalim(corners)
+        self.update_datalim(coords.reshape(-1, 2))
         self._request_autoscale_view()
         return collection
 

lib/matplotlib/tests/test_axes.py

@@ -1571,6 +1571,25 @@ def test_pcolor_datetime_axis():
             label.set_rotation(30)
 
 
+@check_figures_equal(extensions=["png"])
+def test_pcolor_log_scale(fig_test, fig_ref):
+    """
+    Check that setting a log scale sets good default axis limits
+    when using pcolor.
+    """
+    x = np.linspace(0, 1, 11)
+    y = np.linspace(1, 2, 5)
+    X, Y = np.meshgrid(x, y)
+    C = X[:-1, :-1] + Y[:-1, :-1]
+
+    ax = fig_test.subplots()
+    ax.pcolor(X, Y, C)
+    ax.set_xscale('log')
+
+    ax = fig_ref.subplots()
+    ax.pcolor(X, Y, C)
+    ax.set_xlim(1e-1, 1e0)
+    ax.set_xscale('log')
 
 
 def test_pcolorargs():