From 3179ab5f0d63b385f36e79d61308b945ba3f50c3 Mon Sep 17 00:00:00 2001
From: Keith Winstein <keithw@mit.edu>
Date: Fri, 12 Aug 2011 05:38:56 -0400
Subject: [PATCH] More debugging

---
 keystroke.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/keystroke.cpp b/keystroke.cpp
index e2f4556..20e4f54 100644
--- a/keystroke.cpp
+++ b/keystroke.cpp
@@ -7,6 +7,7 @@ void KeyStroke::subtract( KeyStroke * const prefix )
   for ( deque<char>::iterator i = prefix->user_bytes.begin();
 	i != prefix->user_bytes.end();
 	i++ ) {
+    assert( !user_bytes.empty() );
     assert( *i == user_bytes.front() );
     user_bytes.pop_front();
   }