Description of problem:
The default PROMPT_COMMAND values set in /etc/bashrc interpret backslash escapes in $USER, $HOSTNAME and $PWD. This causes junk to be printed before the prompt if certain escape sequences are encountered, when any sequences should be printed literally.

Version-Release number of selected component (if applicable):
/etc/bashrc distributed with Bash in RHEL4.8 (3.00.15), RHEL5.5 (3.2.25) and RHEL6.0 (4.1.2).

How reproducible:
Always.

Steps to Reproduce:
$ cp /etc/skel/.bashrc ~
$ bash -il
$ mkdir 'foo\abar'
$ cd foo\\abar
Examine prompt, 'bar' appears at the beginning.

Or log on with a username containing an escape code (DOMAIN\alex) and examine prompt.
  
Actual results:
bar[alex@server foo\abar]$ 


Expected results:
[alex@server foo\abar]$ 

Additional info:
Fixed versions:
xterm: PROMPT_COMMAND='echo -ne "\033]0;" ; echo -nE "${USER}@${HOSTNAME%%.*}:${PWD/#$HOME/~}" ; echo -ne "\007"'
screen: PROMPT_COMMAND='echo -ne "\033_" ; echo -nE "${USER}@${HOSTNAME%%.*}:${PWD/#$HOME/~}" ; echo -ne "\033\\"'