EllisLab/CodeIgniter — pull request #2599 by sv3tli0 (2013-08-12 09:00:49+00:00)
Title: Issue with empty posts and min_length rules

If user set at validation that field is not required but he sets min_length there is problem.
Validation is successful even if min_length check is not valid, when string is empty.
After that the validation data has this empty (not valid) field..