Issue 414: for some functions, the parameters were evaluated twice (for example…

Issue 414: for some functions, the parameters were evaluated twice (for example "char(nextval(..))" ran "nextval(..)" twice).

h2/src/main/org/h2/expression/Function.java

@@ -920,7 +920,7 @@ public class Function extends Expression implements FunctionCall {
     }
 
     private static Value getNullOrValue(Session session, Expression[] args, Value[] values, int i) {
-        if (i < values.length) {
+        if (i >= args.length) {
             return null;
         }
         Value v = values[i];