Made addnode and findnode aware of the case where the result of the

comparison is "subdomain" but the full name at the existing node is
not in common with the input name -- when the last label is a bitstring
with some common bits.

lib/dns/rbt.c

@@ -15,7 +15,7 @@
  * SOFTWARE.
  */
 
-/* $Id: rbt.c,v 1.39 1999/04/16 16:12:15 tale Exp $ */
+/* $Id: rbt.c,v 1.40 1999/04/16 18:30:03 tale Exp $ */
 
 /* Principal Authors: DCL */
 
@@ -433,7 +433,8 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
                         add_labels   = FAST_COUNTLABELS(&add_name);
                         current_labels = FAST_COUNTLABELS(&current_name);
 
-			if (compared == dns_namereln_subdomain) {
+			if (compared == dns_namereln_subdomain &&
+			    common_bits == 0) {
 				/*
 				 * All of the exising labels are in common,
 				 * so the new name is in a subtree.
@@ -470,7 +471,9 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
 				 */
 
 				INSIST(compared == dns_namereln_commonancestor
-				       || compared == dns_namereln_contains);
+				       || compared == dns_namereln_contains
+				       || (compared == dns_namereln_subdomain
+					   && common_bits > 0));
 
 				/*
 				 * Ensure the number of levels in the tree
@@ -690,7 +693,7 @@ dns_rbt_findnode(dns_rbt_t *rbt, dns_name_t *name, dns_name_t *foundname,
 	dns_namereln_t compared;
 	dns_result_t result, saved_result;
 	isc_region_t r;
-	unsigned int current_labels, common_labels, common_bits;
+	unsigned int common_labels, common_bits;
 	unsigned int first_common_label;
 	int order;
 
@@ -761,12 +764,11 @@ dns_rbt_findnode(dns_rbt_t *rbt, dns_name_t *name, dns_name_t *foundname,
 			 * the current node's name length, then follow the
 			 * down pointer and search in the new tree.
 			 */
-			current_labels = FAST_COUNTLABELS(current_name);
-
-			if (common_labels == current_labels) {
+			if (compared == dns_namereln_subdomain &&
+			    common_bits == 0) {
 				/*
 				 * Set up new name to search for as
-				 * the not-in-common part, and build foundname.
+				 * the not-in-common part.
 				 */
 				if (search_name == &name2) {
 					current_name = &name2;
@@ -842,14 +844,19 @@ dns_rbt_findnode(dns_rbt_t *rbt, dns_name_t *name, dns_name_t *foundname,
 
 			} else {
 				/*
-				 * Though there is a suffix in common, it
-				 * is shorter than the length of the name at
-				 * this node, which means there is no down
-				 * pointer and the name does not exist.
+				 * Though there are labels in common, the
+				 * entire name at this node is not common
+				 * with the search name so the search
+				 * name does not exist in the tree.
 				 * Add this node to the ancestor chain
 				 * to simplify things for the chain fixing
 				 * logic below then end the loop.
 				 */
+				INSIST(compared == dns_namereln_commonancestor
+				       || compared == dns_namereln_contains
+				       || (compared == dns_namereln_subdomain
+					   && common_bits > 0));
+
 				ADD_ANCESTOR(chain, current);
 				current = NULL;
 			}
@@ -2074,6 +2081,15 @@ dns_rbtnodechain_next(dns_rbtnodechain_t *chain, dns_name_t *name,
 	if (successor != NULL) {
 		chain->end = successor;
 
+		/*
+		 * It is not necessary to use dns_rbtnodechain_next like
+		 * the other functions because this function will never
+		 * find a node in the topmost level.  This is because the
+		 * root level will never be more than one name, and everything
+		 * in the megatree is a successor to that node, down at
+		 * the second level or below.
+		 */
+
 		NODENAME(chain->end, name);
 
 		if (new_origin) {