facebook/hhvm — pull request #4307 by adsr (2014-11-21 23:16:49+00:00)
Title: Use the native implementation for Memcached::decrement

Summary: Calling Memcached::decrementByKey with an empty string causes all
decrement operations to hash to a single node in the server list. I suspect
the intention was to pass along a NULL, but calling the native implementation
like ::increment seems cleaner either way.