Merge pull request matplotlib#11729 from anntzer/pyqt4-pyside2-fix

FIX: Pass 'figure' as kwarg to FigureCanvasQt5Agg super __init__.

Author: tacaswell

lib/matplotlib/backends/backend_qt5agg.py

@@ -15,6 +15,10 @@
 
 class FigureCanvasQTAgg(FigureCanvasAgg, FigureCanvasQT):
 
+    def __init__(self, figure):
+        # Must pass 'figure' as kwarg to Qt base class.
+        super().__init__(figure=figure)
+
     def paintEvent(self, event):
         """Copy the image from the Agg canvas to the qt.drawable.