Discoveryd Alternative to Replace mDNSResponder Argument?
Since 10.10.1, the simplest way to fix this is to add --AlwaysAppendSearchDomains to ProgramArguments in plist file /System/Library/LaunchDaemons/com.apple.discoveryd.plist

Then restart com.apple.discoveryd.plist with:

sudo launchctl unload /System/Library/LaunchDaemons/com.apple.discoveryd.plist
sudo launchctl load /System/Library/LaunchDaemons/com.apple.discoveryd.plist


All this according to the help printed by:

/usr/libexec/discoveryd --help


That will do the same as it did for mDNSResponder as far as I can tell.