pkg_fail=no
AC_MSG_CHECKING([for $3])
-if test -z "$[]m4_toupper([$1][_$2])"; then
+if test x"$[]m4_toupper([$1][_$2])" = x; then
_PKG_CONFIG([$1][_$2], [variable=$2], [$4])
else
pkg_cv_$1[]_$2="$[]m4_toupper([$1][_$2])"
fi
-if test -z "[$pkg_cv_$1][_$2]"; then
+if test x"[$pkg_cv_$1][_$2]" = x; then
if test $pkg_failed = yes; then
_PKG_SHORT_ERRORS_SUPPORTED
if test $_pkg_short_errors_supported = yes; then