From: Charles Oliver Nutter <charles.nutter@...>
Date: 2009-02-25T02:38:55+09:00
Subject: [ruby-core:22421] Re: [Bug #1195] String#% does not include prefix before zero value for # versions of numeric formats

Yukihiro Matsumoto wrote:
> Ruby 1.8 uses underlying sprintf() where 1.9 uses its own
> implementation.  So, in short, choose 1.9 behavior.

Given that, I think leaving it specified as a new behavior in 1.9 is 
best. (i.e. 1.8 behavior is not a bug, since it's just default sprintf).

- Charlie