Merge pull request #18663 from andrzejnovak/stickies

timhoffm · web-flow · commit c3e96c50c61b · 2020-10-12T23:57:09.000+02:00
fix: keep baseline scale to baseline 0 even if set to None
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -6800,8 +6800,10 @@ def stairs(self, values, edges=None, *,
             baseline = 0
         if orientation == 'vertical':
             patch.sticky_edges.y.append(np.min(baseline))
+            self.update_datalim([(edges[0], np.min(baseline))])
         else:
             patch.sticky_edges.x.append(np.min(baseline))
+            self.update_datalim([(np.min(baseline), edges[0])])
         self._request_autoscale_view()
         return patch
 
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -1908,6 +1908,19 @@ def test_stairs_update(fig_test, fig_ref):
     ref_ax.set_ylim(ylim)
 
 
+@check_figures_equal(extensions=['png'])
+def test_stairs_baseline_0(fig_test, fig_ref):
+    # Test
+    test_ax = fig_test.add_subplot()
+    test_ax.stairs([5, 6, 7], baseline=None)
+
+    # Ref
+    ref_ax = fig_ref.add_subplot()
+    style = {'solid_joinstyle': 'miter', 'solid_capstyle': 'butt'}
+    ref_ax.plot(range(4), [5, 6, 7, 7], drawstyle='steps-post', **style)
+    ref_ax.set_ylim(0, None)
+
+
 def test_stairs_invalid_nan():
     with pytest.raises(ValueError, match='Nan values in "edges"'):
         plt.stairs([1, 2], [0, np.nan, 1])
