Per debian 473204: http://bugs.debian.org/473204, mhash exports #defines that are customarily autotools-private. This results in warnings when other packages attempt to use mhash's headers.
Created attachment 152625 [details, diff] mhash-0.9.9-autotools-namespace-stomping.patch Fixes the problem. Adapted from the patch on the Debian bug, though they missed a spot; VERSION was still exported. Fixed that.
Created attachment 152627 [details, diff] mhash-0.9.9-r1--0.9.9-r2.ebuild.patch Ebuild patch to use the patch. Also added a QA bonus; die on dodoc cause you forgot to remove doc/*.txt.
InCVS.