Add execution-time check for invalid grouped window queries

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

@@ -113,6 +113,8 @@ public class Select extends Query {
     private boolean isPrepared, checkInit;
     private boolean sortUsingIndex;
 
+    private boolean isGroupWindowStage2;
+
     public Select(Session session) {
         super(session);
     }
@@ -383,7 +385,12 @@ public class Select extends Query {
                 updateAgg(columnCount, true);
             }
             groupData.done();
-            processGroupResult(columnCount, result, offset, quickOffset);
+            try {
+                isGroupWindowStage2 = true;
+                processGroupResult(columnCount, result, offset, quickOffset);
+            } finally {
+                isGroupWindowStage2 = false;
+            }
         } finally {
             groupData.reset();
         }
@@ -1462,6 +1469,16 @@ public class Select extends Query {
         return isWindowQuery;
     }
 
+    /**
+     * Checks if window stage of group window query is performed. If true,
+     * column resolver may not be used.
+     *
+     * @return true if window stage of group window query is performed
+     */
+    public boolean isGroupWindowStage2() {
+        return isGroupWindowStage2;
+    }
+
     @Override
     public void addGlobalCondition(Parameter param, int columnId,
             int comparisonType) {

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

@@ -184,6 +184,9 @@ public class ExpressionColumn extends Expression {
                 if (v != null) {
                     return v;
                 }
+                if (select.isGroupWindowStage2()) {
+                    throw DbException.get(ErrorCode.MUST_GROUP_BY_COLUMN_1, getSQL());
+                }
             }
         }
         Value value = columnResolver.getValue(column);

h2/src/test/org/h2/test/scripts/functions/aggregate/array-agg.sql

@@ -158,5 +158,8 @@ SELECT ARRAY_AGG(ARRAY_AGG(ID ORDER  BY ID)) OVER (PARTITION BY NAME), NAME FROM
 > ((4, 5, 6))                                                   c
 > rows: 2
 
+SELECT ARRAY_AGG(ID) OVER() FROM TEST GROUP BY NAME;
+> exception MUST_GROUP_BY_COLUMN_1
+
 DROP TABLE TEST;
 > ok