The patch in summary is touching both Makefile.in and Makefile.am, probably to avoid autotools rebuild.
This treatment is usually reserved for a few selected system packages that cannot have their autotool scripts rebuilt.
This _could_ cause maintainermode-driven rebuild (see http://blog.flameeyes.eu/articles/2008/06/13/maintaner-mode ), which is something we should be avoiding as much as possible.
Please just patch Makefile.am and/or configure.in/.ac and rebuild autotools, unless you have very good reasons not to.
Moving to maintainer-needed since compnerd left Gentoo (#71985).
Fixed in aa117088bc193683a5708b8b6345ab76523d7f90 for sys-auth/nss-mdns-0.10-r1 at kde-overlay.
Keywords += InOverlay
Created attachment 262349 [details, diff]
Please review if this matches your suggestion
+*nss-mdns-0.10-r1 (11 Feb 2012)
+ 11 Feb 2012; Pacho Ramos <email@example.com>
+ +files/nss-mdns-0.10-avahi-socket.patch, +nss-mdns-0.10-r1.ebuild,
+ -nss-mdns-0.8.ebuild, -nss-mdns-0.9-r1.ebuild, metadata.xml:
+ Make search-domains optional (bug #201948 by Jonathan Barnard, Dennis
+ Schridde, Paweł Hajdan, Jr. and many others), also fix bug #226823 by
+ flameeyes. Drop old.