Re: [RFC PATCH 1/6] hex: add functionality for lowercase-only hex

> We currently allow both upper and lower case for all hex values in Git.
> However, in a future commit, we'll want to change that to allow only
> lowercase values in some cases.  To prepare for that case, provide a
> table to convert hex values using lowercase only and an enum to let us
> choose which we want, wiring it up to the hexval function.
>
> For now, keep things completely the same by specifying only the
> variant that accepts both lowercase and uppercase to avoid changing
> behavior.
>
> Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
> ---
>  color.c    |  2 +-
>  hex-ll.c   | 37 ++++++++++++++++++++++++++++++++++++-
>  hex-ll.h   | 14 ++++++++++----
>  pkt-line.c |  8 ++++----
>  4 files changed, 51 insertions(+), 10 deletions(-)

> +const signed char hexval_lc_table[256] = {
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 00-07 */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 08-0f */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 10-17 */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 18-1f */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 20-27 */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 28-2f */
> +	  0,  1,  2,  3,  4,  5,  6,  7,		/* 30-37 */
> +	  8,  9, -1, -1, -1, -1, -1, -1,		/* 38-3f */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 40-47 */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 48-4f */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 50-57 */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 58-5f */
> +	 -1, 10, 11, 12, 13, 14, 15, -1,		/* 60-67 */
> +	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 68-67 */