Redmine

We observed this behavior at Planio when invalid markdown syntax was input by the user, which caused an exception in the link callback declared in source:trunk/lib/redmine/wiki_formatting/markdown/formatter.rb because content was nil.

This exception seems to make the formatter instance unusable - the next time the formatter was used it crashed the whole ruby process. This seems to be related to this redcarpet issue.

The patch contains a test case and the (trivial) fix to take care of content==nil in #link.