Bug 470377

Description of problem:
For security reasons, it was decided a few releases ago that .bash_logout should invoke /usr/bin/clear.  Unfortunately, if invoking this fails, the logout can hang, making it impossible to log in again.  For a box attached exclusively via serial console (routine in some lab environments), this can make the system inaccessible.

Version-Release number of selected component (if applicable):
bash-3.2-29.fc10.x86_64

How reproducible:
sometimes

Steps to Reproduce:
1. Install a KVM guest using a kickstart with an empty %packages section and a bootloader --location=mbr --append="console=ttyS0" directive.
2. Boot the guest and connect to its serial console.
3. Log in.
4. hit ctrl-d to logout

Actual results:
Bash complains that /usr/bin/clear is not found, and sometimes hangs without terminating or accepting further input.  If the connection was through SSH, the session may hang until the user kills it with an escape sequence or by killing the window containing it on the client side.

Expected results:
Bash always exits gracefully, allowing ssh sessions to close and gettys to respawn.

Additional info:
This is trivially fixed by making bash depend on ncurses, though it would be preferable in the long term to fix the root cause without introducing that dependency.