Avoid RuntimeError at wx exit.

anntzer · anntzer · commit 443dd47337a5 · 2019-11-12T22:40:47.000+01:00
diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -1080,7 +1080,10 @@ def Destroy(self, *args, **kwargs):
             # Rationale for line above: see issue 2941338.
         except AttributeError:
             pass  # classic toolbar lacks the attribute
-        if not self.IsBeingDeleted():
+        # The "if self" check avoids a "wrapped C/C++ object has been deleted"
+        # RuntimeError at exit with e.g.
+        # MPLBACKEND=wxagg python -c 'from pylab import *; plot()'.
+        if self and not self.IsBeingDeleted():
             wx.Frame.Destroy(self, *args, **kwargs)
             if self.toolbar is not None:
                 self.toolbar.Destroy()
