[2218] Make DomainNode::isSubTreeRoot() a public function

This will be required for finding whether a hash is less than,
or greater than all nodes in the origin's subtree in an NSEC3 tree.

src/lib/datasrc/memory/domaintree.h

@@ -373,11 +373,17 @@ private:
         }
     }
 
+public:
+    /// \brief returns if the node is a subtree's root node
+    ///
+    /// This method takes a node and returns \c true if it is the root
+    /// node of the subtree it belongs to.
+    ///
+    /// This method never throws an exception.
     bool isSubTreeRoot() const {
         return ((flags_ & FLAG_SUBTREE_ROOT) != 0);
     }
 
-public:
     /// \brief returns the parent of the root of its subtree
     ///
     /// This method takes a node and returns the parent of the root of

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

@@ -257,7 +257,7 @@ TEST_F(DomainTreeTest, subTreeRoot) {
     // "g.h" is not a subtree root
     EXPECT_EQ(TestDomainTree::EXACTMATCH,
               dtree_expose_empty_node.find(Name("g.h"), &dtnode));
-    EXPECT_FALSE(dtnode->getFlag(TestDomainTreeNode::FLAG_SUBTREE_ROOT));
+    EXPECT_FALSE(dtnode->isSubTreeRoot());
 
     // fission the node "g.h"
     EXPECT_EQ(TestDomainTree::ALREADYEXISTS,
@@ -266,12 +266,12 @@ TEST_F(DomainTreeTest, subTreeRoot) {
 
     // the node "h" (h.down_ -> "g") should not be a subtree root. "g"
     // should be a subtree root.
-    EXPECT_FALSE(dtnode->getFlag(TestDomainTreeNode::FLAG_SUBTREE_ROOT));
+    EXPECT_FALSE(dtnode->isSubTreeRoot());
 
     // "g.h" should be a subtree root now.
     EXPECT_EQ(TestDomainTree::EXACTMATCH,
               dtree_expose_empty_node.find(Name("g.h"), &dtnode));
-    EXPECT_TRUE(dtnode->getFlag(TestDomainTreeNode::FLAG_SUBTREE_ROOT));
+    EXPECT_TRUE(dtnode->isSubTreeRoot());
 }
 
 TEST_F(DomainTreeTest, additionalNodeFission) {
@@ -287,7 +287,7 @@ TEST_F(DomainTreeTest, additionalNodeFission) {
     // "t.0" is not a subtree root
     EXPECT_EQ(TestDomainTree::EXACTMATCH,
               dtree_expose_empty_node.find(Name("t.0"), &dtnode));
-    EXPECT_FALSE(dtnode->getFlag(TestDomainTreeNode::FLAG_SUBTREE_ROOT));
+    EXPECT_FALSE(dtnode->isSubTreeRoot());
 
     // fission the node "t.0"
     EXPECT_EQ(TestDomainTree::ALREADYEXISTS,
@@ -296,12 +296,12 @@ TEST_F(DomainTreeTest, additionalNodeFission) {
 
     // the node "0" ("0".down_ -> "t") should not be a subtree root. "t"
     // should be a subtree root.
-    EXPECT_FALSE(dtnode->getFlag(TestDomainTreeNode::FLAG_SUBTREE_ROOT));
+    EXPECT_FALSE(dtnode->isSubTreeRoot());
 
     // "t.0" should be a subtree root now.
     EXPECT_EQ(TestDomainTree::EXACTMATCH,
               dtree_expose_empty_node.find(Name("t.0"), &dtnode));
-    EXPECT_TRUE(dtnode->getFlag(TestDomainTreeNode::FLAG_SUBTREE_ROOT));
+    EXPECT_TRUE(dtnode->isSubTreeRoot());
 }
 
 TEST_F(DomainTreeTest, findName) {