Merge branch '3641-cleanup-dead_nodes-from-prune_tree' into 'main'

Cleanup the dead nodes when pruning the tree

Closes #3641

See merge request isc-projects/bind9!7012

CHANGES

@@ -1,3 +1,6 @@
+6012.	[func]		Cleanup the dead nodes while pruning the tree.
+			[GL #3641]
+
 6011.	[func]		Refactor the privilege setting part of named_os unit
 			to make libcap on Linux mandatory and use setreuid
 			and setregid if available. [GL #3583]

lib/dns/rbtdb.c

@@ -2254,6 +2254,12 @@ prune_tree(isc_task_t *task, isc_event_t *event) {
 		decrement_reference(rbtdb, node, 0, &nlocktype, &tlocktype,
 				    true);
 
+		/*
+		 * We have both write locks, we might as well do a light
+		 * dead nodes cleaning.
+		 */
+		cleanup_dead_nodes(rbtdb, locknum);
+
 		if (parent != NULL && parent->down == NULL) {
 			/*
 			 * node was the only down child of the parent and has