bug#45938: [PATCH] Avoid ANSI escape characters (bug#45938)

[Eli Zaretskii <eliz@gnu.org>]

> From: Evgenii Klimov <eugene.dev@lipklim.org>
> Cc: kobarity <kobarity@gmail.com>,  45938@debbugs.gnu.org
> Date: Wed, 28 Aug 2024 17:28:30 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> [...]
> >> diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
> >> index a00289d6de9..7193cc19425 100644
> >> --- a/lisp/progmodes/python.el
> >> +++ b/lisp/progmodes/python.el
> >> @@ -4549,6 +4549,9 @@ (defun python-shell-completion-native-setup ()
> >>              readline.parse_and_bind('tab: complete')
> >>              # Require just one tab to send output.
> >>              readline.parse_and_bind('set show-all-if-ambiguous on')
> >> +            # Avoid ANSI escape characters in the output
> >> +            readline.parse_and_bind('set colored-completion-prefix off')
> >> +            readline.parse_and_bind('set colored-stats off')
> >>              # Avoid replacing common prefix with ellipsis.
> >>              readline.parse_and_bind('set completion-prefix-display-length 0')
> >>  
> >
> > Are these commands available in every version of Python?
> 
> These commands are from GNU Readline, not from Python

Yes, I know.  But not every Python is built with GNU Readline, right?

> - colored-stats was first implemented in readline-6.3 [1]
> - colored-completion-prefix since readline-7.0 [2]
> 
> Just for the reference, completion-prefix-display-length and
> show-all-if-ambiguous, that are already used during the setup, exists
> since readline-6.0 and readline-6.2 [3], respectively.

Which versions of Python or GNU/Linux are likely to have older
versions of Readline?  And what happens in an older Readline when
these commands are sent?