Merge pull request matplotlib#21490 from vladistan/line2dfix_fix

Make Line2D copy its inputs

Author: QuLogic

examples/units/basic_units.py

@@ -132,6 +132,9 @@ def __init__(self, value, unit):
         self.unit = unit
         self.proxy_target = self.value
 
+    def __copy__(self):
+        return TaggedValue(self.value, self.unit)
+
     def __getattribute__(self, name):
         if name.startswith('__'):
             return object.__getattribute__(self, name)

lib/matplotlib/lines.py

@@ -2,6 +2,8 @@
 2D lines with support for a variety of line styles, markers, colors, etc.
 """
 
+import copy
+
 from numbers import Integral, Number, Real
 import logging
 
@@ -1230,7 +1232,7 @@ def set_xdata(self, x):
         ----------
         x : 1D array
         """
-        self._xorig = x
+        self._xorig = copy.copy(x)
         self._invalidx = True
         self.stale = True
 
@@ -1242,7 +1244,7 @@ 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")

lib/matplotlib/tests/test_units.py

@@ -26,6 +26,9 @@ def to(self, new_units):
         else:
             return Quantity(self.magnitude, self.units)
 
+    def __copy__(self):
+        return Quantity(self.magnitude, self.units)
+
     def __getattr__(self, attr):
         return getattr(self.magnitude, attr)