[PATCH] test-lib-functions: avoid non POSIX ERE in test_dir_is_empty()

0be7d9b73d (test-lib: add test_dir_is_empty(), 2014-06-19) uses an
ERE through the egrep tool (which is not POSIX) using an ? operator
that isn't either.

replace invocation with two equivalent simpler BRE instead.

Signed-off-by: Carlo Marcelo Arenas Belón <redacted>
---
 t/test-lib-functions.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index e28411bb75..2803c97df3 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh

@@ -790,7 +790,7 @@ test_path_exists () {
 test_dir_is_empty () {
 	test "$#" -ne 1 && BUG "1 param"
 	test_path_is_dir "$1" &&
-	if test -n "$(ls -a1 "$1" | egrep -v '^\.\.?$')"
+	if test -n "$(ls -a1 "$1" | grep -v '^\.$' | grep -v '^\.\.$')"
 	then
 		echo "Directory '$1' is not empty, it contains:"
 		ls -la "$1"

-- 
2.33.0.481.g26d3bed244