tests: add testcase for legacy FDO rules plus pc_sysrootdir

tests/sysroot.sh

@@ -9,7 +9,8 @@ tests_init \
 	do_not_duplicate_sysroot_dir \
 	uninstalled \
 	uninstalled_pkgconf1 \
-	uninstalled_fdo
+	uninstalled_fdo \
+	uninstalled_fdo_pc_sysrootdir
 
 do_not_eat_slash_body()
 {
@@ -96,3 +97,14 @@ uninstalled_fdo_body()
 		-o inline:"-L/test/lib -lomg \n" \
 		pkgconf --libs omg
 }
+
+uninstalled_fdo_pc_sysrootdir_body()
+{
+	export PKG_CONFIG_PATH="${selfdir}/lib1"
+	export PKG_CONFIG_SYSROOT_DIR="/sysroot"
+	export PKG_CONFIG_FDO_SYSROOT_RULES="1"
+
+	atf_check \
+		-o inline:"-L/sysroot/test/lib -lomg \n" \
+		pkgconf --libs omg-sysroot
+}