Fix window version of MODE()

h2/src/main/org/h2/expression/aggregate/Aggregate.java

@@ -199,7 +199,7 @@ public class Aggregate extends AbstractAggregate {
             }
             break;
         case MODE:
-            v = orderByList.get(0).expression.getValue(session);
+            v = remembered != null ? remembered[0] : orderByList.get(0).expression.getValue(session);
             break;
         default:
             // Use argument as is

h2/src/test/org/h2/test/scripts/functions/aggregate/mode.sql

@@ -52,15 +52,35 @@ SELECT MODE(V ORDER BY V DESC) FROM TEST;
 SELECT MODE(V ORDER BY V + 1) FROM TEST;
 > exception IDENTICAL_EXPRESSIONS_SHOULD_BE_USED
 
-SELECT MODE() WITHIN GROUP(ORDER BY V) FROM TEST;
+SELECT MODE() WITHIN GROUP (ORDER BY V) FROM TEST;
 >> 1
 
-SELECT MODE() WITHIN GROUP(ORDER BY V ASC) FROM TEST;
+SELECT MODE() WITHIN GROUP (ORDER BY V ASC) FROM TEST;
 >> 1
 
-SELECT MODE() WITHIN GROUP(ORDER BY V DESC) FROM TEST;
+SELECT MODE() WITHIN GROUP (ORDER BY V DESC) FROM TEST;
 >> 3
 
+SELECT
+    MODE() WITHIN GROUP (ORDER BY V) OVER () MA,
+    MODE() WITHIN GROUP (ORDER BY V DESC) OVER () MD,
+    MODE() WITHIN GROUP (ORDER BY V) OVER (ORDER BY V) MWA,
+    MODE() WITHIN GROUP (ORDER BY V DESC) OVER (ORDER BY V) MWD,
+    V FROM TEST;
+> MA MD MWA  MWD  V
+> -- -- ---- ---- ----
+> 1  3  1    1    1
+> 1  3  1    1    1
+> 1  3  1    1    1
+> 1  3  1    2    2
+> 1  3  1    2    2
+> 1  3  1    2    2
+> 1  3  1    3    3
+> 1  3  1    3    3
+> 1  3  1    3    3
+> 1  3  null null null
+> rows: 10
+
 DROP TABLE TEST;
 > ok