thoughtbot/paperclip — pull request #988 by felipecsl (2012-08-08 21:00:32+00:00)
Title: Replace illegal characters in file extension

We found issues with paperclip when the image file extension contains colon, eg: ``https://p.twimg.com/AzvR1RsCUAEhBhV.jpg:large``

This is very common for twitter images. In our case, it caused an error in ImageMagick identify when checking the image dimensions via ``image.queued_for_write[:original]`` before saving it.

The command was failing since bash was getting confused with the .jpg:large[0].

This replaces any colons in the extension with underscores.