--- a/pyrect/translator/grep_translator.py	Wed Nov 10 19:15:03 2010 +0900
+++ b/pyrect/translator/grep_translator.py	Wed Nov 10 22:00:24 2010 +0900
@@ -191,14 +191,15 @@
 
     def emit_booster(self, min_len, chars):
         self.emiti("void booster(%s) {" % self.interface)
+        self.emit(   "UCHARP end_ = end - %d;" % (min_len-1))
+        self.emit(   "if (buf > end_) return;")
         self.emiti(  "do {")
-        self.emit(     "if (buf > end) return;")
         self.emiti(    "switch (buf[%d]) {" % (min_len-1))
         for c in chars:
             self.emit(   "case %d: /* %s */" % (ord(c), Character.ascii(c)))
         self.emit(       "goto ret;")
         self.emitd(    "}")
-        self.emitd(  "} while(buf += %d);" % min_len)
+        self.emitd(  "} while((buf += %d) <= end_);" % min_len)
         self.emit(   "ret: return %s(%s);" % (self.state_name(self.cg.start) , self.args))
         self.emitd("}", 2)