joyent/node — pull request #8043 by sam-github (2014-07-31 23:49:03+00:00)
Title: cluster: disconnect should not be synchronous

Callbacks in node are usually asynchronous, and should never be
sometimes synchronous, and sometimes asynchronous.

Test is backported from https://github.com/joyent/node/commit/6f40abe2d445516de629d289afe21f458e7cc1e9

and enhanced to assert the non-synchronicity of the callback.