[1608] handled glues *at* a zone cut with tests.

this identified an independent bug in the database data source (#1771).

src/lib/datasrc/memory_datasrc.cc

@@ -1291,7 +1291,7 @@ addAdditional(RBNodeRRset* rrset, ZoneData* zone_data) {
         // child zone), mark the node as "GLUE", so we can selectively
         // include/exclude them when we use it.
 
-        // TODO: zone cut consideration (NS or DNAME), empty node case
+        // TODO: zone cut consideration (DNAME), empty node case, wildcard
         RBTreeNodeChain<Domain> node_path;
         DomainNode* node = NULL;
         // The callback argument is a pair of bools: the first is a flag to
@@ -1305,7 +1305,11 @@ addAdditional(RBNodeRRset* rrset, ZoneData* zone_data) {
                 &node, node_path, checkZoneCut, &callback_arg);
         if (result == DomainTree::EXACTMATCH) {
             assert(node != NULL);
-            if (callback_arg.second) {
+            if (callback_arg.second ||
+                (node->getFlag(DomainNode::FLAG_CALLBACK) &&
+                 node->getData()->find(RRType::NS()) !=
+                 node->getData()->end())) {
+                // The node is under or at a zone cut; mark it as a glue.
                 node->setFlag(DOMAINFLAG_GLUE);
             }
             rrset->addAdditionalNode(node);

src/lib/datasrc/tests/testdata/contexttest.zone

@@ -1,7 +1,7 @@
 ;; test zone file used for ZoneFinderContext tests.
 ;; RRSIGs are (obviouslly) faked ones for testing.
 
-example.org. 3600 IN SOA	ns1.example.org. bugs.x.w.example.org. 22 3600 300 3600000 3600
+example.org. 3600 IN SOA	ns1.example.org. bugs.x.w.example.org. 29 3600 300 3600000 3600
 example.org.			      3600 IN NS	ns1.example.org.
 example.org.			      3600 IN NS	ns2.example.org.
 example.org.			      3600 IN MX	1 mx1.example.org.
@@ -28,6 +28,17 @@ ns2.a.example.org.		      3600 IN A		192.0.2.6
 ns2.a.example.org.		      3600 IN AAAA	2001:db8::6
 mx.a.example.org.		      3600 IN A		192.0.2.7
 
+;; delegation, one of its NS names is at zone cut.
+b.example.org.			      3600 IN NS	ns.b.example.org.
+b.example.org.			      3600 IN NS	b.example.org.
+b.example.org.			      3600 IN AAAA	2001:db8::8
+
+ns.b.example.org.		      3600 IN A		192.0.2.9
+
+;; The MX name is at a zone cut.  shouldn't be included in the
+;; additional section.
+mxatcut.example.org.		      3600 IN MX	1 b.example.org.
+
 ;; CNAME
 alias.example.org. 3600 IN CNAME cname.example.org.
 

src/lib/datasrc/tests/zone_finder_context_unittest.cc

@@ -214,6 +214,26 @@ TEST_P(ZoneFinderContextTest, getAdditionalDelegation) {
                 result_sets_.begin(), result_sets_.end());
 }
 
+TEST_P(ZoneFinderContextTest, getAdditionalDelegationAtZoneCut) {
+    // Similar to the previous case, but one of the NS addresses is at the
+    // zone cut.
+
+    // XXX: the current database-based data source incorrectly rejects this
+    // setup (see #1771)
+    if (GetParam() == createSQLite3Client) {
+        return;
+    }
+
+    ZoneFinderContextPtr ctx = finder_->find(Name("www.b.example.org"),
+                                             RRType::SOA());
+    EXPECT_EQ(ZoneFinder::DELEGATION, ctx->code);
+
+    ctx->getAdditional(REQUESTED_BOTH, result_sets_);
+    rrsetsCheck("b.example.org. 3600 IN AAAA 2001:db8::8\n"
+                "ns.b.example.org. 3600 IN A 192.0.2.9\n",
+                result_sets_.begin(), result_sets_.end());
+}
+
 TEST_P(ZoneFinderContextTest, getAdditionalMX) {
     // Similar to the previous cases, but for MX addresses.  The test zone
     // contains MX name under a zone cut.  Its address shouldn't be returned.
@@ -239,6 +259,21 @@ TEST_P(ZoneFinderContextTest, getAdditionalMX) {
                 result_sets_.begin(), result_sets_.end());
 }
 
+TEST_P(ZoneFinderContextTest, getAdditionalMXAtZoneCut) {
+    // XXX: the current database-based data source incorrectly rejects this
+    // setup (see #1771)
+    if (GetParam() == createSQLite3Client) {
+        return;
+    }
+
+    ZoneFinderContextPtr ctx = finder_->find(Name("mxatcut.example.org."),
+                                             RRType::MX());
+    EXPECT_EQ(ZoneFinder::SUCCESS, ctx->code);
+
+    ctx->getAdditional(REQUESTED_BOTH, result_sets_);
+    EXPECT_TRUE(result_sets_.empty());
+}
+
 TEST_P(ZoneFinderContextTest, getAdditionalWithSIG) {
     // Similar to the AuthNS test, but the original find() requested DNSSEC
     // RRSIGs.  Then additional records will also have RRSIGs.