Make git-branch, git-show-branch, git-grep, and all the diff-based
programs accept an optional argument <when> for --color. The argument
is a colorbool: "always", "never", or "auto". If no argument is given,
"always" is used; --no-color is an alias for --color=never. This makes
the command-line interface consistent with other GNU tools, such as `ls'
and `grep', and with the git-config color options. Note that, without
an argument, --color and --no-color work exactly as before.
To implement this, two internal changes were made:
1. Allow the first argument of git_config_colorbool() to be NULL,
in which case it returns -1 if the argument isn't "always", "never",
or "auto".
2. Add OPT_COLOR_FLAG(), OPT__COLOR(), and parse_opt_color_flag_cb()
to the option parsing library. The callback uses
git_config_colorbool(), so color.h is now a dependency
of parse-options.c.
Signed-off-by: Mark Lodato <lodatom@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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