Make Path.__deepcopy__ interact better with subclasses, e.g. TextPath.

Author: anntzer

lib/matplotlib/path.py

@@ -272,13 +272,10 @@ def __deepcopy__(self, memo=None):
         Return a deepcopy of the `Path`.  The `Path` will not be
         readonly, even if the source `Path` is.
         """
-        try:
-            codes = self.codes.copy()
-        except AttributeError:
-            codes = None
-        return self.__class__(
-            self.vertices.copy(), codes,
-            _interpolation_steps=self._interpolation_steps)
+        # Deepcopying arrays (vertices, codes) strips the writeable=False flag.
+        p = copy.deepcopy(super(), memo)
+        p._readonly = False
+        return p
 
     deepcopy = __deepcopy__
 

lib/matplotlib/tests/test_textpath.py

@@ -0,0 +1,10 @@
+import copy
+
+from matplotlib.textpath import TextPath
+
+
+def test_copy():
+    tp = TextPath((0, 0), ".")
+    assert copy.deepcopy(tp).vertices is not tp.vertices
+    assert (copy.deepcopy(tp).vertices == tp.vertices).all()
+    assert copy.copy(tp).vertices is tp.vertices