URL-encoded hrefs

Hi,

I have an RPM repository that includes packages with characters in the
file name that shouldn't be used in a URL e.g. the '+' in
libjpeg8-8d+1.2.1-r2.armv7a_vfp_neon.rpm.  I'm hosting the repository
on web space (specifically Amazon S3) that urlencodes any forbidden
characters so the URL I (and zypper) expect

http://package-cache.gumstix.org/armv7a_vfp_neon/libjpeg8-8d+1.2.1-r2.armv7a_vfp_neon.rpm

doesn't work because of the '+' sign.  The actual URL turns out to be

http://package-cache.gumstix.org/armv7a_vfp_neon/libjpeg8-8d%2B1.2.1-r2.armv7a_vfp_neon.rpm

Is there a flag or setting for createrepo that allows it to generate
urlencoded hrefs?  If not, would the project be open to a patch that
made this option available?

Thanks,
Ash