Auto merge of #4767 - nox:cargo-home-escape, r=matklad
authorbors <bors@rust-lang.org>
Fri, 1 Dec 2017 08:33:36 +0000 (08:33 +0000)
committerbors <bors@rust-lang.org>
Fri, 1 Dec 2017 08:33:36 +0000 (08:33 +0000)
Don't recurse out of CARGO_HOME when looking for workspace root

This fixes #4765.


Trivial merge