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