From 7db2f1fe089b82e5051fe5902c87614d540a7027 Mon Sep 17 00:00:00 2001
From: Kyle Evans <kevans@FreeBSD.org>
Date: Thu, 16 Aug 2018 01:27:16 +0000
Subject: [PATCH] ls(1): Fix color env var checking

CLICOLOR will behavior as always- if present at all in the environment,
allow colors.

COLORTERM, recently enforced, will have to be both present and not empty.

Submitted by:	imp
---
 bin/ls/ls.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/bin/ls/ls.c b/bin/ls/ls.c
index 7c7174f25f4..bba6fde7f57 100644
--- a/bin/ls/ls.c
+++ b/bin/ls/ls.c
@@ -60,6 +60,7 @@ __FBSDID("$FreeBSD$");
 #include <limits.h>
 #include <locale.h>
 #include <pwd.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -152,6 +153,29 @@ char *enter_bold;		/* ANSI sequence to set color to bold mode */
 
 static int rval;
 
+static bool
+do_color_from_env(void)
+{
+	const char *p;
+	bool doit;
+
+	doit = false;
+	p = getenv("CLICOLOR");
+	if (p == NULL) {
+		/*
+		 * COLORTERM is the more standard name for this variable.  We'll
+		 * honor it as long as it's both set and not empty.
+		 */
+		p = getenv("COLORTERM");
+		if (p != NULL && *p != '\0')
+			doit = true;
+	} else
+		doit = true;
+
+	return (doit &&
+	    (isatty(STDOUT_FILENO) || getenv("CLICOLOR_FORCE")));
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -368,8 +392,7 @@ main(int argc, char *argv[])
 		f_listdot = 1;
 
 	/* Enabling of colours is conditional on the environment. */
-	if ((getenv("CLICOLOR") || getenv("COLORTERM")) &&
-	    (isatty(STDOUT_FILENO) || getenv("CLICOLOR_FORCE")))
+	if (do_color_from_env())
 #ifdef COLORLS
 		if (tgetent(termcapbuf, getenv("TERM")) == 1) {
 			ansi_fgcol = tgetstr("AF", &bp);