Re: [PATCH v3 4/5] builtin/config: special-case retrieving colors without a key

[Junio C Hamano <gitster@pobox.com>]

Patrick Steinhardt <ps@pks.im> writes:

> Our documentation for git-config(1) has a section where it explains how
> to parse and use colors as Git would configure them. In order to get the
> ANSI color escape sequence to reset the colors to normal we recommend
> the following command:
>
>     $ git config get --type=color --default="reset" ""
>
> This command is not supposed to parse any configuration keys. Instead,
> it is expected to parse the "reset" default value and turn it into a
> proper ANSI color escape sequence.
>
> It was reported though [1] that this command doesn't work:
>
>     $ git config get --type=color --default="reset" ""
>     error: key does not contain a section:
>
> This error was introduced in 4e51389000 (builtin/config: introduce "get"
> subcommand, 2024-05-06), where we introduced the "get" subcommand to
> retrieve configuration values. The preimage of that commit used `git
> config --get-color "" "reset"` instead, which still works.
>
> This use case is really quite specific to parsing colors, as it wouldn't
> make sense to give git-config(1) a default value and an empty config key
> only to return that default value unmodified. But with `--type=color` we
> don't return the value directly; we instead parse the value into an ANSI
> escape sequence.
>
> As such, we can easily special-case this one use case:
>
>     - If the provided config key is empty;
>
>     - the user is asking for a color code and the user; and

"and the user;" -> ";" perhaps?

>
>     - the user has provided a default value,
>
> then we call `get_color()` directly. Do so to make the documented
> command work as expected.

If we are willing to handle this as a special case anyway, I wonder
if it can easily be arranged to take this as a(nother) special case.

    $ git config get --type=color --default="reset"

I.e., instead of (or in addition to) "if the config key is empty",
special case "if the config key is not given", which may be slightly
more intuitive.

But even without it, what is presented is a vast improvement enough
;-)