Package: bash
Version: 5.2.15-2+b2
Bash will produce erroneous output when PS1 contains escape sequences.
It will also misplace the cursor and corrupt the state the current line.
To replicate this issue:
1. Modify P1 to contain one or more ANSI escape sequences, for example
"\e[45m" (tput setab 5, changes the background color to purple) or
"\e(B\e[m" (tput sgr0, reset for xterm terminals):
$ PS1="x$(printf '\e(B\e[m') \\\$ "
2. Press the up arrow to recall the last command. The command line will
now show [■ indicates the position of the cursor]:
x $ PS1="x$(printf '\e(B\e[m') \\\$ "■
3. Press the down arrow to go back to the empty prompt.
What one should see at this point is just the prompt
x $ ■
Instead, left-overs from the recalled line will be visible and the
cursor will be placed in the wrong spot:
x $ PS1="x■
The amount of garbage left on the prompt is proportional to the number
of escape sequences:
PS1="x$(printf '\e(B\e[m')\\\$ " => 6 left-over chars
PS1="x$(printf '\e(B\e[m%.0s' {1..2})\\\$ " => 12 left-over chars
PS1="x$(printf '\e(B\e[m%.0s' {1..4})\\\$ " => 24 left-over chars
Tested with TERM = linux, xterm, xterm-256color.
--
Gioele Barabucci
