Root/Busybox in 4.3

[BrandoCommando]

It seems that root access is not working on Android 4.3. Traced it down to FileManagerApplication.areShellCommandsPresent() which is used to determine if the device is rooted, and whether or not to allocate a privileged console.
This was tested with the SuperSU daemon binary, which may be the cause of the problem. This is on a 2012 Nexus 7 with JWR66V stock Android 4.3, CWM recovery, Chainfire SuperSU 1.43, and busybox installed using "Smart Install".
Two binaries that are "required" are missing:
/system/xbin/cp
/system/xbin/grep
When I installed busybox with "Normal Install", it appears root access works.

[bkensey]

What application was used to install the busybox binaries? I'll do some double checking, but it sounds like our app is requiring a full normal installation of busybox. I'm thinking it would be a good idea to provide that functionality within our app, and control the busybox installation for the user. It would make for a much better experience for stock rooted users.

At the very least, we should provide a more descriptive error that lets the user know what is wrong.