Screen Corruption when browsing Command History with Custom Prompt

[Ashley Wilson]

From: root
To: bug-bash@gnu.org,bash@packages.debian.org
Subject: Screen Corruption when browsing Command History with Custom Prompt

Configuration Information [Automatically generated, do not change]:
Machine: i486
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i486'
-DCONF_OSTYPE='linux-gnu'
 -DCONF_MACHTYPE='i486-pc-linux-gnu' -DCONF_VENDOR='pc'
-DLOCALEDIR='/usr/share/locale'
 -DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H   -I.  -I../bash
-I../bash/include -I../bash/lib   -g -O2 -Wall
uname output: Linux Ashley-Ubuntu 2.6.24-19-generic #1 SMP Wed Aug 20
22:56:21 UTC 2008 i686 GNU/Linux
Machine Type: i486-pc-linux-gnu

Bash Version: 3.2
Patch Level: 39
Release Status: release

Description:

        I'm using a custom prompt using ~/.bashrc, given below:

                PS1="\n\e[0;31m\u: \w\n# \e[m"

        When I browse the command history using the up/down arrow buttons,
some of the first few characters
        get stuck to the prompt. However, if I move the cursor until it
reaches the position just after these characters,
        I can type-in the command I want and it works - even though someone
who sees the screen later will wonder
        how it did work.

        For example, this is how my bash screen looks after I've run the ls 
command:

                root: /home/ash
                # gedls
                Desktop  Documents  Examples  Music  My Games  Pictures  Public
Templates  Videos

                root: /home/ash
                #

        It looks as if I've run a command 'gedls', whereas the first three
characters are left-overs from the 'gedit'
        command I ran just before it. The output is exactly what I expect,
but I can't seem to delete the 'ged' from the
        prompt.

Repeat-By:
        
        Set a custom prompt using the PS1 variable as follows:

                PS1="\n\e[0;31m\u: \w\n# \e[m"
        
        Then, browse command history using up/down keys.

        The issue appears when the newline (\n) characters and the coloring
sequences (\e[0;31m, \e[m) are used together
        in the prompt.