matplotlib/matplotlib — pull request #566 by leejjoon (2011-11-03 11:52:30+00:00)
Title: fix fancy-style annotation causing an exception when the connecting path 

This issue is originally reported by brenbarn@brenbarn.net on the user mailing list.

http://www.mail-archive.com/matplotlib-users@lists.sourceforge.net/msg22443.html

This happens when the connecting path is too short compared to the arrow head length.
The patch fixes this problem.