Re: [PATCH v2] completion: reduce overhead of clearing cached --options

> To get the names of all '$__git_builtin_*' variables caching --options
> of builtin commands in order to unset them, 8b0eaa41f2 (completion:
> clear cached --options when sourcing the completion script,
> 2018-03-22) runs a 'set |sed s///' pipeline.  This works both in Bash
> and in ZSH, but has a higher than necessary overhead with the extra
> processes.
>
> In Bash we can do better: run the 'compgen -v __gitcomp_builtin_'
> builtin command, which lists the same variables, but without a
> pipeline and 'sed' it can do so with lower overhead.
> ZSH will still continue to run that pipeline.
> 
> This change also happens to work around an issue in the default Bash
> ...
> Updated the commit message to explicitly mention that ZSH is
> unaffected.  The patch is the same.