Issue 329: CASE expression: data type problem is not detected.

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

@@ -1698,13 +1698,16 @@ public class Function extends Expression implements FunctionCall {
             p = 0;
             d = 0;
             for (Expression e : args) {
-                if (e != ValueExpression.getNull() && e.getType() != Value.UNKNOWN) {
-                    t = Value.getHigherOrder(t, e.getType());
+                if (e != ValueExpression.getNull()) {
+                    int type = e.getType();
+                    if (type != Value.UNKNOWN && type != Value.NULL) {
+                        t = Value.getHigherOrder(t, type);
                         s = Math.max(s, e.getScale());
                         p = Math.max(p, e.getPrecision());
                         d = Math.max(d, e.getDisplaySize());
                     }
                 }
+            }
             if (t == Value.UNKNOWN) {
                 t = Value.STRING;
                 s = 0;