branch: colour upstream branches

Otherwise when using 'git branch -vv' it's hard to see them among so
much output.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -807,7 +807,8 @@ color.branch::
 color.branch.<slot>::
 	Use customized color for branch coloration. `<slot>` is one of
 	`current` (the current branch), `local` (a local branch),
-	`remote` (a remote-tracking branch in refs/remotes/), `plain` (other
+	`remote` (a remote-tracking branch in refs/remotes/),
+	`upstream` (upstream tracking branch), `plain` (other
 	refs).
 +
 The value for these configuration variables is a list of colors (at most

builtin/branch.c

@@ -41,13 +41,15 @@ static char branch_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_RED,		/* REMOTE */
 	GIT_COLOR_NORMAL,	/* LOCAL */
 	GIT_COLOR_GREEN,	/* CURRENT */
+	GIT_COLOR_BLUE,		/* UPSTREAM */
 };
 enum color_branch {
 	BRANCH_COLOR_RESET = 0,
 	BRANCH_COLOR_PLAIN = 1,
 	BRANCH_COLOR_REMOTE = 2,
 	BRANCH_COLOR_LOCAL = 3,
-	BRANCH_COLOR_CURRENT = 4
+	BRANCH_COLOR_CURRENT = 4,
+	BRANCH_COLOR_UPSTREAM = 5
 };
 
 static enum merge_filter {
@@ -72,6 +74,8 @@ static int parse_branch_color_slot(const char *var, int ofs)
 		return BRANCH_COLOR_LOCAL;
 	if (!strcasecmp(var+ofs, "current"))
 		return BRANCH_COLOR_CURRENT;
+	if (!strcasecmp(var+ofs, "upstream"))
+		return BRANCH_COLOR_UPSTREAM;
 	return -1;
 }
 
@@ -418,36 +422,52 @@ static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
 	int ours, theirs;
 	char *ref = NULL;
 	struct branch *branch = branch_get(branch_name);
+	struct strbuf fancy = STRBUF_INIT;
 
 	if (!stat_tracking_info(branch, &ours, &theirs)) {
 		if (branch && branch->merge && branch->merge[0]->dst &&
-		    show_upstream_ref)
-			strbuf_addf(stat, "[%s] ",
-			    shorten_unambiguous_ref(branch->merge[0]->dst, 0));
+		    show_upstream_ref) {
+			ref = shorten_unambiguous_ref(branch->merge[0]->dst, 0);
+			if (want_color(branch_use_color))
+				strbuf_addf(stat, "[%s%s%s] ",
+						branch_get_color(BRANCH_COLOR_UPSTREAM),
+						ref, branch_get_color(BRANCH_COLOR_RESET));
+			else
+				strbuf_addf(stat, "[%s] ", ref);
+		}
 		return;
 	}
 
-	if (show_upstream_ref)
+	if (show_upstream_ref) {
 		ref = shorten_unambiguous_ref(branch->merge[0]->dst, 0);
+		if (want_color(branch_use_color))
+			strbuf_addf(&fancy, "%s%s%s",
+					branch_get_color(BRANCH_COLOR_UPSTREAM),
+					ref, branch_get_color(BRANCH_COLOR_RESET));
+		else
+			strbuf_addstr(&fancy, ref);
+	}
+
 	if (!ours) {
 		if (ref)
-			strbuf_addf(stat, _("[%s: behind %d]"), ref, theirs);
+			strbuf_addf(stat, _("[%s: behind %d]"), fancy.buf, theirs);
 		else
 			strbuf_addf(stat, _("[behind %d]"), theirs);
 
 	} else if (!theirs) {
 		if (ref)
-			strbuf_addf(stat, _("[%s: ahead %d]"), ref, ours);
+			strbuf_addf(stat, _("[%s: ahead %d]"), fancy.buf, ours);
 		else
 			strbuf_addf(stat, _("[ahead %d]"), ours);
 	} else {
 		if (ref)
 			strbuf_addf(stat, _("[%s: ahead %d, behind %d]"),
-				    ref, ours, theirs);
+				    fancy.buf, ours, theirs);
 		else
 			strbuf_addf(stat, _("[ahead %d, behind %d]"),
 				    ours, theirs);
 	}
+	strbuf_release(&fancy);
 	strbuf_addch(stat, ' ');
 	free(ref);
 }