~/ completes to \~/ on zsh

[FlorianPommerening]

The alias ~ for the home directory is escaped on zsh.

To reproduce

Test environment:

• Ubuntu 24.04
• Python 3.12.3
• argcomplete 3.1.4-1ubuntu0.1 (this is 3.1.4 with a patch back-ported from 3.3.0 to make it compatible with Python 12.3)
• zsh 5.9

Content of foo.py

#! /usr/bin/env python3
# PYTHON_ARGCOMPLETE_OK

import argcomplete, argparse

parser = argparse.ArgumentParser()
arg = parser.add_argument("file")
arg.completer = argcomplete.completers.FilesCompleter()

argcomplete.autocomplete(parser)

./foo.py ~/.bashr<TAB>

Expected completion is ./foo.py ~/.bashrc and this is what happens on bash. However on zsh, I get ./foo.py \~/.bashrc.

In both cases, the FilesCompleter returns the path as ~/.bashrc (not escaped), so the escaping happens later on in the pipeline. In particular, this is part of the zsh built-in _describe which in turn calls compadd to add the string ~/.bashrc to the list of suggestions. At this point the string is escaped. There are options to prevent this escaping that can also be passed to _describe but it is not clear to me, which one to use (https://zsh.sourceforge.io/Doc/zsh_us.pdf, chapter 19.3 for compadd and 20.6 for _describe). For example, -Q would disable escaping completely but this would be an issue for paths with spaces. Then something like -f -W \~ might work but it assumes that the returned values are paths.