Fix: close polygon if requested, even if input array is already closed

Author: cgohlke

lib/matplotlib/patches.py

@@ -768,7 +768,10 @@ def __init__(self, xy, closed=True, **kwargs):
         Patch.__init__(self, **kwargs)
         xy = np.asarray(xy, np.float_)
         self._path = Path(xy)
-        self.set_closed(closed)
+        self._closed = closed
+        if closed and len(xy):
+            xy = np.concatenate([xy, [xy[0]]])
+        self._set_xy(xy)
 
     def get_path(self):
         return self._path