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

anntzer · anntzer · commit 64647945adb9 · 2021-10-05T10:19:36.000+02:00
diff --git a/lib/matplotlib/path.py b/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__
 
diff --git a/lib/matplotlib/tests/test_textpath.py b/lib/matplotlib/tests/test_textpath.py
@@ -0,0 +1,9 @@
+import copy
+
+from matplotlib.textpath import TextPath
+
+
+def test_copy():
+    path = TextPath((0, 0), ".")
+    copy.copy(path)  # no error
+    copy.deepcopy(path)  # no error
