pager: set LV=-c alongside LESS=FRSX

On systems with lv configured as the preferred pager (i.e.,
DEFAULT_PAGER=lv at build time, or PAGER=lv exported in the
environment) git commands that use color show control codes instead of
color in the pager:

	$ git diff
	^[[1mdiff --git a/.mailfilter b/.mailfilter^[[m
	^[[1mindex aa4f0b2..17e113e 100644^[[m
	^[[1m--- a/.mailfilter^[[m
	^[[1m+++ b/.mailfilter^[[m
	^[[36m@@ -1,11 +1,58 @@^[[m

"less" avoids this problem because git uses the LESS environment
variable to pass the -R option ('output ANSI color escapes in raw
form') by default.  Use the LV environment variable to pass 'lv' the
-c option ('allow ANSI escape sequences for text decoration / color')
to fix it for lv, too.

Noticed when the default value for color.ui flipped to 'auto' in
v1.8.4-rc0~36^2~1 (2013-06-10).

Reported-by: Olaf Meeuwissen <olaf.meeuwissen@avasys.jp>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/pager.c b/pager.c
index fa19765..c56a890 100644
--- a/pager.c
+++ b/pager.c
@@ -80,8 +80,15 @@ void setup_pager(void)
 	pager_process.use_shell = 1;
 	pager_process.argv = pager_argv;
 	pager_process.in = -1;
-	if (!getenv("LESS")) {
-		static const char *env[] = { "LESS=FRSX", NULL };
+	if (!getenv("LESS") || !getenv("LV")) {
+		static const char *env[3];
+		int i = 0;
+
+		if (!getenv("LESS"))
+			env[i++] = "LESS=FRSX";
+		if (!getenv("LV"))
+			env[i++] = "LV=-c";
+		env[i] = NULL;
 		pager_process.env = env;
 	}
 	if (start_command(&pager_process))