Merge pull request #15208 from tacaswell/auto-backport-of-pr-15206-on-v2.2.x

tacaswell · web-flow · commit 50407d0860e6 · 2019-10-15T15:23:40.000-04:00
Backport PR #15206: FIX: be more forgiving about expecting internal s…
diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
@@ -506,7 +506,8 @@ def draw_idle(self):
         # current event loop in order to ensure thread affinity and to
         # accumulate multiple draw requests from event handling.
         # TODO: queued signal connection might be safer than singleShot
-        if not (self._draw_pending or self._is_drawing):
+        if not (getattr(self, '_draw_pending', False) or
+                getattr(self, '._is_drawing', False)):
             self._draw_pending = True
             QtCore.QTimer.singleShot(0, self._draw_idle)
 
