zendframework/zf2 — pull request #4608 by gwis (2013-06-08 08:03:27+00:00)
Title: Allow the 'gc_probability' option to be set to zero.

This is valid because PHP divides gc_divisor into gc_probability - it would only
be invalid to set gc_divisor to 0 (divide-by-zero), so this commit leaves the
same test for that option alone.