The function IFNULL did not always return the result in the right data type.

h2/src/docsrc/html/changelog.html

@@ -54,6 +54,8 @@ table with an LOB column.
 </li>
 <li>improve performance of queries that use LIKE 'foo%' - 10x in the case of one of my queries
 </li>
+<li>The function IFNULL did not always return the result in the right data type.
+</li>
 <li>Issue #231: Possible infinite loop when initializing the ObjectDataType class
     when concurrently writing into MVStore.
 </li>
@@ -61,6 +63,8 @@ table with an LOB column.
 
 <h2>Version 1.4.191 Beta (2016-01-21)</h2>
 <ul>
+<li>TO_DATE and TO_TIMESTAMP functions. Thanks a lot to Sam Blume for the patch!
+</li>
 <li>Issue #229: DATEDIFF does not work for 'WEEK'.
 </li>
 <li>Issue #156: Add support for getGeneratedKeys() when executing commands via PreparedStatement#executeBatch.

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

@@ -965,6 +965,7 @@ public class Function extends Expression implements FunctionCall {
             if (v0 == ValueNull.INSTANCE) {
                 result = getNullOrValue(session, args, values, 1);
             }
+            result = convertResult(result);
             break;
         }
         case CASEWHEN: {
@@ -1129,6 +1130,10 @@ public class Function extends Expression implements FunctionCall {
         return result;
     }
 
+    private Value convertResult(Value v) {
+        return v.convertTo(dataType);
+    }
+
     private static boolean cancelStatement(Session session, int targetSessionId) {
         session.getUser().checkAdmin();
         Session[] sessions = session.getDatabase().getSessions(false);

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

@@ -76,6 +76,7 @@ public class TestFunctions extends TestBase implements AggregateFunction {
     @Override
     public void test() throws Exception {
         deleteDb("functions");
+        testIfNull();
         testToDate();
         testToDateException();
         testAddMonths();
@@ -1658,6 +1659,21 @@ public class TestFunctions extends TestBase implements AggregateFunction {
 
         conn.close();
     }
+    private void testIfNull() throws SQLException {
+        Connection conn = getConnection("functions");
+        Statement stat = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
+        stat.execute("CREATE TABLE T(f1 double)");
+        stat.executeUpdate("INSERT INTO T VALUES( 1.2 )");
+        stat.executeUpdate("INSERT INTO T VALUES( null )");
+        ResultSet rs = stat.executeQuery("SELECT IFNULL(f1, 0.0) FROM T");
+        ResultSetMetaData metaData = rs.getMetaData();
+        assertEquals("java.lang.Double", metaData.getColumnClassName(1));
+        rs.next();
+        assertEquals("java.lang.Double", rs.getObject(1).getClass().getName());
+        rs.next();
+        assertEquals("java.lang.Double", rs.getObject(1).getClass().getName());
+        conn.close();
+    }
 
     private void testToCharFromNumber() throws SQLException {
         deleteDb("functions");