elixir-lang/elixir — pull request #1341 by jarsen (2013-06-30 02:30:57+00:00)
Title: Return empty string when given 0 for n in String.duplicate

In Ruby and Python, duplicating a string like "abc" * 0 returns an empty string.
It actually turns out to already be the default behavior of :binary.copy as well, so it's only an issue of changing the guard clause.