Added a fix for issue #8871

IPython/core/pylabtools.py

@@ -123,6 +123,10 b" def print_figure(fig, fmt='png', bbox_inches='tight', **kwargs):"
 def retina_figure(fig, **kwargs):
     """format a figure as a pixel-doubled (retina) PNG"""
     pngdata = print_figure(fig, fmt='retina', **kwargs)
+    # Make sure that retina_figure acts just like print_figure and returns
+    # None when the figure is empty.
+    if pngdata is None:
+        return
     w, h = _pngxy(pngdata)
     metadata = dict(width=w//2, height=h//2)
     return pngdata, metadata

IPython/core/tests/test_pylabtools.py

@@ -66,6 +66,11 b' def test_figure_to_jpeg():'
     assert jpeg.startswith(_JPEG)
 
 def test_retina_figure():
+    # simple empty-figure test
+    fig = plt.figure()
+    nt.assert_equal(pt.retina_figure(fig), None)
+    plt.close('all')
+
     fig = plt.figure()
     ax = fig.add_subplot(1,1,1)
     ax.plot([1,2,3])