From c39f782deb377c9e500817af57cf0b1cbffb695f Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Fri, 2 Sep 2011 14:28:42 +0100
Subject: [PATCH] reset the last_leaf counts every time we enter a new subtree

---
 btree_checker.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/btree_checker.h b/btree_checker.h
index 9bfbadc..78d1d0d 100644
--- a/btree_checker.h
+++ b/btree_checker.h
@@ -78,6 +78,9 @@ namespace persistent_data {
 			if (already_visited(n))
 				return false;
 
+			if (!key)
+			  new_root(level);
+
 			check_block_nr(n);
 			check_max_entries(n);
 			check_nr_entries(n, !key);
@@ -92,12 +95,16 @@ namespace persistent_data {
 			if (already_visited(n))
 				return false;
 
+			if (!key)
+			  new_root(level);
+
 			check_block_nr(n);
 			check_max_entries(n);
 			check_nr_entries(n, !key);
 			check_ordered_keys(n);
 			check_parent_key(key, n);
 			check_leaf_key(level, n);
+			
 			return true;
 		}
 
@@ -107,6 +114,9 @@ namespace persistent_data {
 			if (already_visited(n))
 				return false;
 
+			if (!key)
+			  new_root(level);
+
 			check_block_nr(n);
 			check_max_entries(n);
 			check_nr_entries(n, !key);
@@ -239,6 +249,12 @@ namespace persistent_data {
 			last_leaf_key_[level] = n.key_at(n.get_nr_entries() - 1);
 		}
 
+     	        void new_root(unsigned level) {
+		  // we're starting a new subtree, so should
+		  // reset the last_leaf value.
+		  last_leaf_key_[level] = boost::optional<uint64_t>();
+	        }
+
 		block_counter &counter_;
 		std::set<block_address> seen_;
 		error_set::ptr errs_;