Re: [PATCH] format_commit_message: honor `color=auto` for `%C(auto)`

> On Tue, May 24, 2016 at 08:56:49PM -0500, Edward Thomson wrote:
>
>> Check that we are configured to display colors in the given context when
>> the user specifies a format string of `%C(auto)`.  This brings that
>> behavior in line with the behavior of `%C(auto,<colorname>)`, which will
>> display the given color only when the configuration specifies to do so.
>>
>> This allows the user the ability to specify that color should be
>> displayed only when the output is a tty, and to use the default color
>> for the given context (instead of a hardcoded color value).
>>
>> Signed-off-by: Edward Thomson <ethomson@edwardthomson.com>
>
> I somehow had trouble figuring out the problem from this description and
> the patch. It seems to be about much more than just color=auto or a
> given context, and more like:
>
>   When %C(auto) is used, we unconditionally turn on color for any
>   subsequent placeholders, even if the user said "--no-color", or color
>   config is turned off, or it is set to "auto" and we are not going to a
>   tty.

> It's possible somebody is relying on the ability to unconditionally turn
> on color for "auto-colored" placeholders like "%H" or "%d", but I'm
> inclined to call this a strict bug-fix, for two reasons:
>
>   1. It says "%C(auto)", not "%C(on)".
>
>   2. This is documented as behaving like "%C(auto,...)", which as you
>      note works in a more sane way.
>
> I think it's worth mentioning this explicitly in the commit message. We
> could also add "%C(on)", I guess, but it's unclear to me whether anybody
> would want it (they would probably just use "--color" in that case,
> unless they really want unconditional coloring for just _some_
> elements).