matplotlib · KonradAdamczyk · Feb 23, 2018 · Mar 14, 2018 · Mar 14, 2018 · Mar 14, 2018
diff --git a/lib/matplotlib/patches.py b/lib/matplotlib/patches.py
@@ -167,8 +167,8 @@ def update_from(self, other):
         # For some properties we don't need or don't want to go through the
         # getters/setters, so we just copy them directly.
         self._edgecolor = other._edgecolor
-        self._facecolor = other._facecolor
         self._original_edgecolor = other._original_edgecolor
+        self._facecolor = other._facecolor
         self._original_facecolor = other._original_facecolor
         self._fill = other._fill
         self._hatch = other._hatch

diff --git a/lib/matplotlib/tests/test_patches.py b/lib/matplotlib/tests/test_patches.py
@@ -444,6 +444,29 @@ def test_contains_points():
     assert np.all(result == expected)
 
 
+def test_when_update_from_and_set_alpha_then_only_alpha_changes():
+    # given
+    source_facecolor = (0.234, 0.123, 0.135, 0.322)
+    source_edgecolor = (0.728, 0.682, 0.945, 0.268)
+    source = mpatches.Rectangle((0, 0), 1., 1.,
+                                facecolor=source_facecolor,
+                                edgecolor=source_edgecolor)
+    updated = mpatches.Rectangle((1., 0), 1., 1.,
+                                 facecolor='pink', edgecolor="green")
+    # when
+    updated.update_from(source)
+    # then
+    assert updated.get_facecolor() == source_facecolor
+    assert updated.get_edgecolor() == source_edgecolor
+    # when
+    updated.set_alpha(0.777)
+    # then
+    expected_facecolor = source_facecolor[0:3] + (0.777,)
+    expected_edgecolor = source_edgecolor[0:3] + (0.777,)
+    assert updated.get_facecolor() == expected_facecolor
+    assert updated.get_edgecolor() == expected_edgecolor
+
+
 # Currently fails with pdf/svg, probably because some parts assume a dpi of 72.
 @check_figures_equal(extensions=["png"])
 def test_shadow(fig_test, fig_ref):