From cbada6fe03d7cd8d43e0e393cd7d39c121fb6041 Mon Sep 17 00:00:00 2001
From: avogar <pav.cruglov@yandex.ru>
Date: Mon, 9 May 2022 15:42:59 +0000
Subject: [PATCH] Fix Illegal column Nothing while using arrayMap

---
 src/Functions/IFunction.cpp                        | 14 ++++++++++++++
 .../02294_nothing_arguments_in_functions.reference |  6 ++++++
 .../02294_nothing_arguments_in_functions.sql       |  6 ++++++
 3 files changed, 26 insertions(+)
 create mode 100644 tests/queries/0_stateless/02294_nothing_arguments_in_functions.reference
 create mode 100644 tests/queries/0_stateless/02294_nothing_arguments_in_functions.sql

diff --git a/src/Functions/IFunction.cpp b/src/Functions/IFunction.cpp
index 19638c78daf..95dafcbb575 100644
--- a/src/Functions/IFunction.cpp
+++ b/src/Functions/IFunction.cpp
@@ -275,6 +275,11 @@ ColumnPtr IExecutableFunction::executeWithoutSparseColumns(const ColumnsWithType
 
 ColumnPtr IExecutableFunction::execute(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count, bool dry_run) const
 {
+    /// Result type Nothing means that we don't need to execute function at all.
+    /// Example: select arrayMap(x -> 2 * x, []);
+    if (isNothing(result_type))
+        return result_type->createColumn();
+
     if (useDefaultImplementationForSparseColumns())
     {
         size_t num_sparse_columns = 0;
@@ -430,6 +435,15 @@ DataTypePtr IFunctionOverloadResolver::getReturnTypeWithoutLowCardinality(const
         }
     }
 
+    /// If one of the arguments is Nothing, then we won't really execute
+    /// the function and the result type should be also Nothing.
+    /// Example: select arrayMap(x -> 2 * x, []);
+    for (const auto & arg : arguments)
+    {
+        if (isNothing(arg.type))
+            return std::make_shared<DataTypeNothing>();
+    }
+
     return getReturnTypeImpl(arguments);
 }
 
diff --git a/tests/queries/0_stateless/02294_nothing_arguments_in_functions.reference b/tests/queries/0_stateless/02294_nothing_arguments_in_functions.reference
new file mode 100644
index 00000000000..954015207ad
--- /dev/null
+++ b/tests/queries/0_stateless/02294_nothing_arguments_in_functions.reference
@@ -0,0 +1,6 @@
+[]
+Array(Nothing)
+[]
+Array(Nothing)
+[]
+Array(Nothing)
diff --git a/tests/queries/0_stateless/02294_nothing_arguments_in_functions.sql b/tests/queries/0_stateless/02294_nothing_arguments_in_functions.sql
new file mode 100644
index 00000000000..3df2577e465
--- /dev/null
+++ b/tests/queries/0_stateless/02294_nothing_arguments_in_functions.sql
@@ -0,0 +1,6 @@
+select arrayMap(x -> 2 * x, []);
+select toTypeName(arrayMap(x -> 2 * x, []));
+select arrayMap((x, y) -> x + y, [], []);
+select toTypeName(arrayMap((x, y) -> x + y, [], []));
+select arrayMap((x, y) -> x + y, [], CAST([], 'Array(Int32)'));
+select toTypeName(arrayMap((x, y) -> x + y, [], CAST([], 'Array(Int32)')));