Backport #46569 to 22.12: Fix processing Const(LowCardinality) in arrayMap

src/Functions/array/FunctionArrayMapped.h

@@ -7,6 +7,7 @@
 #include <Columns/ColumnFunction.h>
 #include <Columns/ColumnMap.h>
 #include <Columns/ColumnNullable.h>
+#include <Columns/ColumnLowCardinality.h>
 #include <Columns/IColumn.h>
 
 #include <Common/Exception.h>
@@ -343,9 +344,15 @@ class FunctionArrayMapped : public IFunction
             replicated_column_function->appendArguments(arrays);
 
             auto lambda_result = replicated_column_function->reduce();
+
+            /// Convert LowCardinality(T) -> T and Const(LowCardinality(T)) -> Const(T),
+            /// because we removed LowCardinality from return type of lambda expression.
             if (lambda_result.column->lowCardinality())
                 lambda_result.column = lambda_result.column->convertToFullColumnIfLowCardinality();
 
+            if (const auto * const_column = checkAndGetColumnConst<ColumnLowCardinality>(lambda_result.column.get()))
+                lambda_result.column = const_column->removeLowCardinality();
+
             if (Impl::needBoolean())
             {
                 /// If result column is Nothing or Nullable(Nothing), just create const UInt8 column with 0 value.

tests/queries/0_stateless/02667_array_map_const_low_cardinality.reference

@@ -0,0 +1 @@
+[2]

tests/queries/0_stateless/02667_array_map_const_low_cardinality.sql

@@ -0,0 +1 @@
+SELECT arrayMap(x -> (toLowCardinality(1) + 1::Nullable(UInt8)), [1]);