Color support for "git-add -i"

This is mostly lifted from earlier series by Dan Zwell, but updated to
use "git config --get-color" and "git config --get-colorbool" to make it
simpler and more consistent with commands written in C.

A new configuration color.interactive variable is like color.diff and
color.status, and controls if "git-add -i" uses color.

A set of configuration variables, color.interactive.<slot>, are used to
define what color is used for the prompt, header, and help text.

For perl scripts, Git.pm provides $repo->get_color() method, which takes
the slot name and the default color, and returns the terminal escape
sequence to color the output text.  $repo->get_colorbool() method can be
used to check if color is set to be used for a given operation.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 0e45ec547..736fcd71c 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -391,6 +391,18 @@ color.diff.<slot>::
 	whitespace).  The values of these variables may be specified as
 	in color.branch.<slot>.
 
+color.interactive::
+	When set to `always`, always use colors in `git add --interactive`.
+	When false (or `never`), never.  When set to `true` or `auto`, use
+	colors only when the output is to the terminal. Defaults to false.
+
+color.interactive.<slot>::
+	Use customized color for `git add --interactive`
+	output. `<slot>` may be `prompt`, `header`, or `help`, for
+	three distinct types of normal output from interactive
+	programs.  The values of these variables may be specified as
+	in color.branch.<slot>.
+
 color.pager::
 	A boolean to enable/disable colored output when the pager is in
 	use (default is true).