--- liblzf/lzf_c.c	2008/08/30 06:43:38	1.35
+++ liblzf/lzf_c.c	2009/05/01 00:30:53	1.36
@@ -170,12 +170,13 @@
           unsigned int maxlen = in_end - ip - len;
           maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
 
+          if (expect_false (op + 3 + 1 >= out_end)) /* first a faster conservative test */
+            if (op - !lit + 3 + 1 >= out_end) /* second the exact but rare test */
+              return 0;
+
           op [- lit - 1] = lit - 1; /* stop run */
           op -= !lit; /* undo run if length is zero */
 
-          if (expect_false (op + 3 + 1 >= out_end))
-            return 0;
-
           for (;;)
             {
               if (expect_true (maxlen > 16))