From 44e4a50050ebb063e113e4cbb75a871bdace554e Mon Sep 17 00:00:00 2001
From: Howard Hinnant <howard.hinnant@gmail.com>
Date: Wed, 16 Sep 2015 13:59:34 -0400
Subject: [PATCH] Fix stack bug in upper_bound

---
 src/ripple/shamap/impl/SHAMap.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/ripple/shamap/impl/SHAMap.cpp b/src/ripple/shamap/impl/SHAMap.cpp
index a743aef62..7b5cb15c0 100644
--- a/src/ripple/shamap/impl/SHAMap.cpp
+++ b/src/ripple/shamap/impl/SHAMap.cpp
@@ -501,7 +501,11 @@ SHAMap::peekFirstItem(NodeStack& stack) const
     stack.push({root_.get(), SHAMapNodeID{}});
     SHAMapTreeNode* node = firstBelow(root_.get(), stack);
     if (!node)
+    {
+        while (!stack.empty())
+            stack.pop();
         return nullptr;
+    }
     return node->peekItem().get();
 }
 
@@ -604,11 +608,9 @@ SHAMap::upper_bound(uint256 const& id) const
             auto leaf = static_cast<SHAMapTreeNode*>(node);
             if (leaf->peekItem()->key() > id)
                 return const_iterator(this, leaf->peekItem().get(), std::move(stack));
-            stack.pop();
         }
         else
         {
-            stack.pop();
             auto inner = static_cast<SHAMapInnerNode*>(node);
             for (auto branch = nodeID.selectBranch(id) + 1; branch < 16; ++branch)
             {
@@ -625,6 +627,7 @@ SHAMap::upper_bound(uint256 const& id) const
                 }
             }
         }
+        stack.pop();
     }
     return end();
 }