--- a/langtools/src/share/classes/com/sun/tools/javac/parser/JavacParser.java	Mon Sep 14 17:13:00 2009 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/parser/JavacParser.java	Tue Sep 15 12:20:55 2009 -0700
@@ -593,7 +593,7 @@
 //where
         boolean isZero(String s) {
             char[] cs = s.toCharArray();
-            int base = ((Character.toLowerCase(s.charAt(1)) == 'x') ? 16 : 10);
+            int base = ((cs.length > 1 && Character.toLowerCase(cs[1]) == 'x') ? 16 : 10);
             int i = ((base==16) ? 2 : 0);
             while (i < cs.length && (cs[i] == '0' || cs[i] == '.')) i++;
             return !(i < cs.length && (Character.digit(cs[i], base) > 0));