File browser crashes when going up a directory

Created by: ca1ek

Reproduction: Open up the file browser, then attempt to go up a directory by clicking ../

Expected behavior: Showing the parent directory

Actual behavior: File browser just closes

Build information: rustc 1.10.0-nightly (4ec5ce5e4 2016-05-12),
qemu-i386 version 2.0.0 (Debian 2.0.0+dfsg-2ubuntu1.22)

Blocking/related: n/a