Backport ClickHouse#87520 to 25.8: Fix creating an array of empty tuples

robot-clickhouse · robot-clickhouse · commit 755fc1eb7495 · 2025-11-13T13:24:03.000Z
diff --git a/src/Functions/tuple.h b/src/Functions/tuple.h
@@ -66,7 +66,7 @@ class FunctionTuple : public IFunction
     ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
     {
         if (arguments.empty())
-            return ColumnTuple::create(input_rows_count);
+            return DataTypeTuple({}).createColumnConstWithDefaultValue(input_rows_count);
 
         size_t tuple_size = arguments.size();
         Columns tuple_columns(tuple_size);
diff --git a/tests/queries/0_stateless/03631_array_of_empty_tuples.reference b/tests/queries/0_stateless/03631_array_of_empty_tuples.reference
@@ -0,0 +1,2 @@
+[(),()]
+[(),()]
diff --git a/tests/queries/0_stateless/03631_array_of_empty_tuples.sql b/tests/queries/0_stateless/03631_array_of_empty_tuples.sql
@@ -0,0 +1,2 @@
+select [(), ()] from numbers(2);
+

Original file line number	Diff line number	Diff line change
`@@ -66,7 +66,7 @@ class FunctionTuple : public IFunction`
`66`	`66`	`ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override`
`67`	`67`	`{`
`68`	`68`	`if (arguments.empty())`
`69`		`- return ColumnTuple::create(input_rows_count);`
	`69`	`+ return DataTypeTuple({}).createColumnConstWithDefaultValue(input_rows_count);`
`70`	`70`
`71`	`71`	`size_t tuple_size = arguments.size();`
`72`	`72`	`Columns tuple_columns(tuple_size);`