On Fri, Jun 07, 2019 at 04:30:34PM +0700, Nguyễn Thái Ngọc Duy wrote:
> "git <cmd> --git-completion-helper" could fail if the command checks for
> a repo before parse_options(). If the result is cached, later on when
> the user moves to a worktree with repo, tab completion will still fail.
>
> Avoid this by detecting errors and not cache the completion output. We
> can try again and hopefully succeed next time (e.g. when a repo is
> found).
>
> Of course if --git-completion-helper fails permanently because of other
> reasons (*), this will slow down completion. But I don't see any better
> option to handle that case.
I think a permanently failing 'git cmd --git-completion-helper'
shouldn't really happen, unless there is a bug in the completion
script or the git installation or similar exceptional situation. And
then that issue should be fixed, but I don't think we should worry
about an extra subshell and git process in those situations.
> (*) one of those cases is if __gitcomp_builtin is called on a command
> that does not support --git-completion-helper. And we do have a
> generic call
>
> __git_complete_common "$command"
>
> but this case is protected with __git_support_parseopt_helper so we're
> good.
>
> Reported-by: Felipe Contreras <felipe.contreras@xxxxxxxxx>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
> ---
> contrib/completion/git-completion.bash | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
> index 9f71bcde96..a515de8501 100644
> --- a/contrib/completion/git-completion.bash
> +++ b/contrib/completion/git-completion.bash
> @@ -398,13 +398,15 @@ __gitcomp_builtin ()
> eval "options=\$$var"
>
> if [ -z "$options" ]; then
> + local nocache=
> # leading and trailing spaces are significant to make
> # option removal work correctly.
> - options=" $incl $(__git ${cmd/_/ } --git-completion-helper) "
> + options=" $incl $(__git ${cmd/_/ } --git-completion-helper) " || nocache=t
Why not just 'return' here?
If we return, then it won't list any options, and the shell should fall
back to regular file completion. With this patch it will still list
extra options, if there are any, and I don't really see the point in
doing that.
> +
> for i in $excl; do
> options="${options/ $i / }"
> done
> - eval "$var=\"$options\""
> + test -n "$nocache" || eval "$var=\"$options\""
> fi
>
> __gitcomp "$options"
> --
> 2.22.0.rc0.322.g2b0371e29a
>
