A completion entry like «complete -a '\\~'» results in completions
that insert \~ into the command line. However we usually want to
insert ~, but there is no way to do that.
There are a couple of longstanding issues about completion escaping
[1]. Until we fix those in a general way, fix the common case by
never escaping tildes when applying custom completions to the command
line. This is a hack but will probably work out fine because we don't
expect literal tildes in arguments.
The tilde is included in completions for cdh, or
__fish_complete_suffix, which simply forwards results from "complete
-C". Revert a workaround to cdh that expanded ~, because we can now
render that without escaping.
Closes#4570, #8441
[ja: tweak patch and commit message]
[1]: https://github.com/fish-shell/fish-shell/pull/8441#discussion_r748803338
