[2218] Add a copy constructor for DomainTreeNodeChain

src/lib/datasrc/memory/domaintree.h

@@ -697,8 +697,17 @@ public:
                                          isc::dns::NameComparisonResult::EQUAL)
     {}
 
+    DomainTreeNodeChain(const DomainTreeNodeChain<T>& other) :
+        level_count_(other.level_count_),
+	last_compared_(other.last_compared_),
+	last_comparison_(other.last_comparison_)
+    {
+        for (size_t i = 0; i < level_count_; i++) {
+	    nodes_[i] = other.nodes_[i];
+        }
+    }
+
 private:
-    DomainTreeNodeChain(const DomainTreeNodeChain<T>&);
     DomainTreeNodeChain<T>& operator=(const DomainTreeNodeChain<T>&);
     //@}
 

src/lib/datasrc/memory/tests/domaintree_unittest.cc

@@ -596,6 +596,10 @@ TEST_F(DomainTreeTest, chainLevel) {
     // by default there should be no level in the chain.
     EXPECT_EQ(0, chain.getLevelCount());
 
+    // Copy should be consistent
+    TestDomainTreeNodeChain chain2(chain);
+    EXPECT_EQ(chain.getLevelCount(), chain2.getLevelCount());
+
     // insert one node to the tree and find it.  there should be exactly
     // one level in the chain.
     TreeHolder tree_holder(mem_sgmt_, TestDomainTree::create(mem_sgmt_, true));
@@ -607,6 +611,11 @@ TEST_F(DomainTreeTest, chainLevel) {
               tree.find(node_name, &cdtnode, chain));
     EXPECT_EQ(1, chain.getLevelCount());
 
+    // Copy should be consistent
+    TestDomainTreeNodeChain chain3(chain);
+    EXPECT_EQ(chain.getLevelCount(), chain3.getLevelCount());
+    EXPECT_EQ(chain.getAbsoluteName(), chain3.getAbsoluteName());
+
     // Check the name of the found node (should have '.' as both non-absolute
     // and absolute name
     EXPECT_EQ(".", cdtnode->getLabels().toText());