matplotlib/matplotlib — pull request #1929 by pelson (2013-04-22 08:01:01+00:00)
Title: Fixed failing bbox_inches='tight' case when a contour collection is empty

Identified on the ipython-dev mailinglist: http://python.6.x6.nabble.com/Maptlotlib-Contour-Issue-Bug-with-IPython-Notebook-td5014995.html