From 25640faaebaad1a8f9c988e7ed4acb55acd5f21c Mon Sep 17 00:00:00 2001
From: Leonardo de Moura <leonardo@microsoft.com>
Date: Mon, 9 Jun 2014 16:43:01 -0700
Subject: [PATCH] fix(util/trie): bug in for_each method

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
---
 src/util/trie.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/util/trie.h b/src/util/trie.h
index 9ed877020..c0d2d1519 100644
--- a/src/util/trie.h
+++ b/src/util/trie.h
@@ -139,8 +139,10 @@ public:
 
     template<typename F>
     void for_each(F && f) const {
-        buffer<Key> prefix;
-        for_each(f, *this, prefix);
+        if (m_ptr) {
+            buffer<Key> prefix;
+            for_each(f, *this, prefix);
+        }
     }
 
     // for debugging purposes