galetahub/simple-captcha — pull request #41 by bootleq (2013-09-06 04:22:11+00:00)
Title: Change tmp_path default value to Dir::tmpdir.

The default value of `tmp_path` config option is `/tmp`, as describe in README.
However, current default is set to `nil`, which causes RuntimeError (cannot generate tempfile "") since `Tempfile#new` can not use nil as second argument.

Solution: set the default value to `Dif::tmpdir`.