Improve test coverage, remove unnecessary code.

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

@@ -37,6 +37,13 @@ public class ConditionIn extends Condition {
     private Value min, max;
     private int queryLevel;
 
+    /**
+     * Create a new IN(..) condition.
+     *
+     * @param database the database
+     * @param left the expression before IN
+     * @param values the value list (at least one element)
+     */
     public ConditionIn(Database database, Expression left, ObjectArray<Expression> values) {
         this.database = database;
         this.left = left;
@@ -45,9 +52,6 @@ public class ConditionIn extends Condition {
 
     public Value getValue(Session session) throws SQLException {
         Value l = left.getValue(session);
-        if (valueList.size() == 0) {
-            return ValueBoolean.get(false);
-        }
         if (l == ValueNull.INSTANCE) {
             return l;
         }
@@ -80,9 +84,6 @@ public class ConditionIn extends Condition {
     }
 
     public Expression optimize(Session session) throws SQLException {
-        if (valueList.size() == 0) {
-            return ValueExpression.get(ValueBoolean.get(false));
-        }
         left = left.optimize(session);
         boolean constant = left.isConstant();
         if (constant && left == ValueExpression.getNull()) {
@@ -152,6 +153,7 @@ public class ConditionIn extends Condition {
                 }
             }
             filter.addIndexCondition(IndexCondition.getInList(l, valueList));
+            return;
         }
         if (!SysProperties.OPTIMIZE_IN) {
             return;

h2/src/test/org/h2/test/db/TestOptimizations.java

@@ -460,11 +460,20 @@ public class TestOptimizations extends TestBase {
         deleteDb("optimizations");
         Connection conn = getConnection("optimizations");
         Statement stat = conn.createStatement();
+        PreparedStatement prep;
+        ResultSet rs;
+
+        assertFalse(stat.executeQuery("select * from dual where x in()").next());
+        assertFalse(stat.executeQuery("select * from dual where null in(1)").next());
+        assertFalse(stat.executeQuery("select * from dual where null in(null)").next());
+        assertFalse(stat.executeQuery("select * from dual where null in(null, 1)").next());
+
+        assertFalse(stat.executeQuery("select * from dual where 1+x in(3, 4)").next());
+        assertFalse(stat.executeQuery("select * from dual d1, dual d2 where d1.x in(3, 4)").next());
+
         stat.execute("create table test(id int primary key, name varchar)");
         stat.execute("insert into test values(1, 'Hello')");
         stat.execute("insert into test values(2, 'World')");
-        PreparedStatement prep;
-        ResultSet rs;
 
         prep = conn.prepareStatement("select * from test t1 where t1.id in(?)");
         prep.setInt(1, 1);