Tests: secure_link inheritance test.

secure_link.t

diff --git a/secure_link.t b/secure_link.t
index 79630d6..4354a54 100644
--- a/secure_link.t
+++ b/secure_link.t
@@ -24,7 +24,7 @@
 select STDERR; $| = 1;
 select STDOUT; $| = 1;
 
-my $t = Test::Nginx->new()->has(qw/http secure_link/)->plan(8);
+my $t = Test::Nginx->new()->has(qw/http secure_link/)->plan(9);
 
 $t->write_file_expand('nginx.conf', <<'EOF');
 
@@ -94,6 +94,21 @@
 
             rewrite ^ /$secure_link break;
         }
+
+        location /inheritance/ {
+            secure_link_secret secret;
+
+            location = /inheritance/test {
+                secure_link      Xr4ilOzQ4PCOq3aQ0qbuaQ==;
+                secure_link_md5  secret;
+
+                if ($secure_link = "1") {
+                    rewrite ^ /test.html break;
+                }
+
+                return 403;
+            }
+        }
     }
 }
 
@@ -135,6 +150,13 @@
 	'request old style fake hash');
 like(http_get('/p/test.html'), qr/^HTTP.*403/, 'request old style no hash');
 
+TODO: {
+local $TODO = 'not yet' unless $t->has_version('1.3.12');
+
+like(http_get('/inheritance/test'), qr/PASSED/, 'inheritance');
+
+}
+
 ###############################################################################
 
 sub encode_base64url {