Re: ds/maintenance-part-3 (was Re: What's cooking in git.git (Nov 2020, #02; Mon, 9))

> 
> Emily Shaffer <emilyshaffer@google.com> writes:
> 
> > Because 'git maintenance unregister' spins a child process to call 'git
> > config --unset maintenance.repo <cwd>', it actually fails if "cwd"
> > contains a POSIX regular expression special character:
> >
> >   git config [<file-option>] --unset name [value_regex]
> 
> Good find.  And it is even worse that value_regex uses ERE, not BRE,
> which means even an otherwise innocuous letter like '+' cannot be
> used without quoting.

> 
> > You can demo it for yourself like so:
> >
> >   git init repro+for+maintenance
> >   git maintenance register
> >   git maintenance unregister
> >   echo $?	# returns '5'
> >   git config --list --global
> >
> > I see two paths forward:
> >
> 
> 0. Quote the value_regex properly, instead of blindly using a value
>    that comes from the environment.
> 
> > 1. Teach 'git config' to learn either which regex parser to use
> > (including fixed), or at least to learn "value isn't a regex", or
> >
> > 2. Don't spin a child process in 'git maintenance [un]register' and
> > instead just call the config API.
> 
> > I'd suggest #2. The config API is very nice, and seems to have a simple
> > way to add or remove configs to your global file in just a couple of
> > lines. If there's a reason why it's not simpler to do it that way, it's
> > my fault for missing the review :)
> 
> My short-to-mid-term preference is to do #1 to allow a value to be
> spelled literally (i.e. remove entry with _this_ value, and add this
> one instead), and optionally do #2 as an optimization that is not
> essential.  I do not offhand know how you can make #2 alone fly
> without doing some form of #1, as I think the same value_regex that
> ought to be ERE to specify entries to be replaced needs to be used
> under the cover even if you use "config API" anyway.