TryGhost/Ghost — pull request #1821 by schneidmaster (2014-01-03 04:50:32+00:00)
Title: Modified github.js to ensure __ is not escaped in foo_bar_baz

closes #1791

Added (?!__), which ensures that the regex will not match expressions that begin with __. This never happens in a legitimate case (foo_bar_baz never begins with __) but resolves the case at the beginning of a line (__test__).