Make Line2D copy its inputs

Author: kinshukdua

lib/matplotlib/lines.py

@@ -16,6 +16,7 @@
 from .path import Path
 from .transforms import Bbox, BboxTransformTo, TransformedPath
 from ._enums import JoinStyle, CapStyle
+import copy
 
 # Imported here for backward compatibility, even though they don't
 # really belong.
@@ -1230,7 +1231,7 @@ def set_xdata(self, x):
         ----------
         x : 1D array
         """
-        self._xorig = x
+        self._xorig = copy.copy(x)
         self._invalidx = True
         self.stale = True
 
@@ -1242,7 +1243,7 @@ def set_ydata(self, y):
         ----------
         y : 1D array
         """
-        self._yorig = y
+        self._yorig = copy.copy(y)
         self._invalidy = True
         self.stale = True
 

lib/matplotlib/tests/test_lines.py

@@ -332,3 +332,14 @@ def test_picking():
     found, indices = l2.contains(mouse_event)
     assert found
     assert_array_equal(indices['ind'], [0])
+
+
+@check_figures_equal()
+def test_input_copy(fig_test, fig_ref):
+
+    t = np.arange(0, 6, 2)
+    l, = fig_test.add_subplot().plot(t, t, ".-")
+    t[:] = range(3)
+    # Trigger cache invalidation
+    l.set_drawstyle("steps")
+    fig_ref.add_subplot().plot([0, 2, 4], [0, 2, 4], ".-", drawstyle="steps")