The U+0001 control character is output in terminal

[Woodzy]

when using aptsh (which uses color for its prompt), the xfce-terminal displays odd looking boxes with 1's and 0's (U+0001 control character) no matter what font I choose (even default font). This happens with other terminals (lxterminal, gnome-terminal, etc.) and other applications as well. It does NOT happen when using xterm or pterm, directly. Here is the output of my $PS1

\[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$

echo of $TERM returns: xterm

echo of cat /etc/issue returns: Ubuntu 13.04 \n \l

screenshots (or see attached):

http://en.zimagez.com/zimage/screenshot-10092013-091910am.php

[Woodzy (rtdos)]

....just a note: this does NOT happen when using standard tty modes (i.e. tty1 through tty6) but only when using a terminal emulator such as xfce-terminal. sorry i should have mad that clear.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Thaddaeus Tintenfisch (thad-fisch-deactivatedaccount)]

As of now it looks like only terminal emulators based on libvte are affected. Redirecting the terminal output of aptsh returns:

Generating and mapping caches...
Reading commands history...
^A^[[1;33mapt^A^[[1;31msh^A^[[0m>

[Egmont Koblinger (egmont-gmail)]

Upstream vte bug report: https://bugzilla.gnome.org/show_bug.cgi?id=403130

In the mean time, why does aptsh print these characters?

[Egmont Koblinger (egmont-gmail)]

aptsh has a color prompt, and uses readline. Readline requires that in the prompt, all non-printable characters (e.g. color changing escape sequences) are enclosed between \001 (^A) and \002 (^B).

I suspect it's a bug in aptsh that its prompt doesn't have a balanced pair of \001 and \002 bytes, hence readline prints some of the \001 characters in the terminal.