fabric/fabric — pull request #738 by matthewwithanm (2012-09-26 14:42:07+00:00)
Title: Fix for #736 (Unexpected prefix Behavior)

This pull request contains both a test to illustrate #736 as well as a few commits which fix it. I took the approach I mentioned in IRC (of refactoring `_setenv` to accept a dict or callable) as this seemed the least messy way to defer something until the context manager was entered.