Test that affine2d not decalred valid on access.

djdt · djdt · commit 935f920d50e1 · 2019-08-12T14:57:58.000+10:00
diff --git a/lib/matplotlib/tests/test_transforms.py b/lib/matplotlib/tests/test_transforms.py
@@ -176,6 +176,17 @@ def test_Affine2D_from_values():
     assert_almost_equal(actual, expected)
 
 
+def test_affine_inverted_invalidated():
+    # Ensure that the an affine transform is not declared valid on access
+    point = [1.0, 1.0]
+    t = mtransforms.Affine2D()
+
+    assert_almost_equal(point, t.transform(t.inverted().transform(point)))
+    # Change and access the transform
+    t.translate(1.0, 1.0).get_matrix()
+    assert_almost_equal(point, t.transform(t.inverted().transform(point)))
+
+
 def test_clipping_of_log():
     # issue 804
     M, L, C = Path.MOVETO, Path.LINETO, Path.CLOSEPOLY
