Fix NPE in Query.initExpression()

h2/src/main/org/h2/command/dml/Query.java

@@ -519,12 +519,10 @@ public abstract class Query extends Prepared {
             }
         }
         if (!isAlias) {
-            if (mustBeInResult) {
-                if (session.getDatabase().getMode().getEnum() != ModeEnum.MySQL) {
-                    if (!checkOrderOther(session, e, expressionSQL)) {
-                        throw DbException.get(ErrorCode.ORDER_BY_NOT_IN_RESULT, e.getSQL());
-                    }
-                }
+            if (expressionSQL == null
+                    || mustBeInResult && session.getDatabase().getMode().getEnum() != ModeEnum.MySQL
+                            && !checkOrderOther(session, e, expressionSQL)) {
+                throw DbException.get(ErrorCode.ORDER_BY_NOT_IN_RESULT, e.getSQL());
             }
             expressions.add(e);
             String sql = e.getSQL();
@@ -549,12 +547,10 @@ public abstract class Query extends Prepared {
         if (expr.isConstant()) {
             return true;
         }
-        if (expressionSQL != null) {
-            String exprSQL = expr.getSQL();
-            for (String sql: expressionSQL) {
-                if (session.getDatabase().equalsIdentifiers(exprSQL, sql)) {
-                    return true;
-                }
+        String exprSQL = expr.getSQL();
+        for (String sql: expressionSQL) {
+            if (session.getDatabase().equalsIdentifiers(exprSQL, sql)) {
+                return true;
             }
         }
         if (expr instanceof Function) {

h2/src/test/org/h2/test/scripts/dml/select.sql

@@ -252,3 +252,18 @@ SELECT A, COUNT(B) FROM TEST GROUP BY A OFFSET 1;
 
 DROP TABLE TEST;
 > ok
+
+CREATE TABLE TEST1(A INT, B INT, C INT) AS SELECT 1, 2, 3;
+> ok
+
+CREATE TABLE TEST2(A INT, B INT, C INT) AS SELECT 4, 5, 6;
+> ok
+
+SELECT A, B FROM TEST1 UNION SELECT A, B FROM TEST2 ORDER BY 1.1;
+> exception ORDER_BY_NOT_IN_RESULT
+
+DROP TABLE TEST1;
+> ok
+
+DROP TABLE TEST2;
+> ok