Trying to spread windows with spread setting turned off sometimes results in a segfault

[Yumekui Neru]

Turning Window spread off in unity tweak tool under the window spread tab and then pressing super+w to spread everything sometimes crashes unity/compiz with a segfault

Nov 27 20:05:04 Meowth kernel: [97870.726840] compiz[14808]: segfault at 1fa4 ip 00007f0dc46700cd sp 00007fff5d4956b8 error 4 in libunityshell.so[7f0dc447d000+484000]

Steps to reproduce-ish:

Open the settings and from there unity tweak tool.
Go to window spread and try turning spread on

Try spreading and unspreading a few times (super + w)
turn off spreading and try spreading (super + w)
if no crash, try spreading a few more times (super +w ), then turn on spreading and spread a few times

turn off spreading and try spreading (super + w)
if no crash, try turning spreading on again and toggle and adjust the icon setting and the spread distance
try spreading and unspreading and turn off spreading

try spreading
if no crash close the settings menu -- at this point I usually crash if not before.

https://github.com/shiznix/unity-gentoo/issues/61