rails/rails — pull request #12740 by gaurish (2013-11-02 01:43:17+00:00)
Title: Improve Errors when Controller Name or Action isn't specfied

These errors occur when, there routes are wrongly defined.

example, the following line would cause a missing :action error

root "welcomeindex"

Mostly beginners are expected to hit these errors, so lets improve the error message a bit to make their learning experience bit better.