Merge pull request #11846 from ClickHouse/prohibit-array-join-in-higher-order-functions

Don't allow arrayJoin inside higher order functions

src/Functions/FunctionsMiscellaneous.h

@@ -8,11 +8,13 @@
 #include <Columns/ColumnFunction.h>
 #include <DataTypes/DataTypesNumber.h>
 
+
 namespace DB
 {
 namespace ErrorCodes
 {
     extern const int LOGICAL_ERROR;
+    extern const int BAD_ARGUMENTS;
 }
 
 class ExecutableFunctionExpression : public IExecutableFunctionImpl
@@ -203,6 +205,11 @@ public:
             const String & expression_return_name_)
         : expression_actions(std::move(expression_actions_))
     {
+        /// Check that expression does not contain unusual actions that will break blocks structure.
+        for (const auto & action : expression_actions->getActions())
+            if (action.type == ExpressionAction::Type::JOIN || action.type == ExpressionAction::Type::ARRAY_JOIN)
+                throw Exception("Expression with arrayJoin or other unusual action cannot be captured", ErrorCodes::BAD_ARGUMENTS);
+
         std::unordered_map<std::string, DataTypePtr> arguments_map;
 
         const auto & all_arguments = expression_actions->getRequiredColumnsWithTypes();

src/Functions/array/FunctionArrayMapped.h

@@ -33,7 +33,8 @@ namespace ErrorCodes
   * arrayMap(x1,...,xn -> expression, array1,...,arrayn) - apply the expression to each element of the array (or set of parallel arrays).
   * arrayFilter(x -> predicate, array) - leave in the array only the elements for which the expression is true.
   *
-  * For some functions arrayCount, arrayExists, arrayAll, an overload of the form f(array) is available, which works in the same way as f(x -> x, array).
+  * For some functions arrayCount, arrayExists, arrayAll, an overload of the form f(array) is available,
+  *  which works in the same way as f(x -> x, array).
   *
   * See the example of Impl template parameter in arrayMap.cpp
   */

tests/queries/0_stateless/01330_array_join_in_higher_order_function.sql

@@ -0,0 +1 @@
+SELECT arrayMap(x -> arrayJoin([x, 1]), [1, 2]); -- { serverError 36 }