1 files changed, 8 insertions, 6 deletions
diff --git a/fast_encoder.h b/fast_encoder.h
index e968f64..e37ad7f 100644
--- a/fast_encoder.h
+++ b/fast_encoder.h
@@ -1,6 +1,5 @@
 /*  Lzip - LZMA lossless data compressor
-    Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013, 2014
-    Antonio Diaz Diaz.
+    Copyright (C) 2008-2014 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -50,10 +49,13 @@ public:
     {
     while( --n >= 0 )
       {
-      key4 = ( ( key4 << 4 ) ^ buffer[pos+3] ) & key4_mask;
-      const int newpos = prev_positions[key4];
-      prev_positions[key4] = pos + 1;
-      pos_array[cyclic_pos] = newpos;
+      if( available_bytes() >= 4 )
+        {
+        key4 = ( ( key4 << 4 ) ^ buffer[pos+3] ) & key4_mask;
+        const int newpos = prev_positions[key4];
+        prev_positions[key4] = pos + 1;
+        pos_array[cyclic_pos] = newpos;
+        }
       move_pos();
       }
     }