If you redefined the AUTO_LINK_RE to support protocols other than HTTP, bad links are generated. In the auto_link_urls code it checks if there is an http in the generated href and if there isn’t it prepends one. If you’re using auto_link_urls on, for example, ftp:// links, instead of ftp://example.com , you get ftp://example.com. This patch adds a test and changes the code to check for any protocol instead of just http before prepending the default.
This patch is against the 2-3-stable branch.
Lighthouse ticket: https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/3494-patch-autolinking-non-http-protocols-doesnt-work
-Zach Brock