Backport #49971 to 23.4: [RFC] Revert "groupArray returns cannot be nullable"

src/AggregateFunctions/AggregateFunctionGroupArray.cpp

@@ -121,7 +121,7 @@ AggregateFunctionPtr createAggregateFunctionGroupArraySample(
 
 void registerAggregateFunctionGroupArray(AggregateFunctionFactory & factory)
 {
-    AggregateFunctionProperties properties = { .returns_default_when_only_null = true, .is_order_dependent = true };
+    AggregateFunctionProperties properties = { .returns_default_when_only_null = false, .is_order_dependent = true };
 
     factory.registerFunction("groupArray", { createAggregateFunctionGroupArray<false>, properties });
     factory.registerFunction("groupArraySample", { createAggregateFunctionGroupArraySample, properties });

src/AggregateFunctions/AggregateFunctionNull.cpp

@@ -72,7 +72,7 @@ class AggregateFunctionCombinatorNull final : public IAggregateFunctionCombinato
         {
             /// Currently the only functions that returns not-NULL on all NULL arguments are count and uniq, and they returns UInt64.
             if (properties.returns_default_when_only_null)
-                return std::make_shared<AggregateFunctionNothing>(arguments, params, nested_function->getResultType());
+                return std::make_shared<AggregateFunctionNothing>(arguments, params, std::make_shared<DataTypeUInt64>());
             else
                 return std::make_shared<AggregateFunctionNothing>(arguments, params, std::make_shared<DataTypeNullable>(std::make_shared<DataTypeNothing>()));
         }

tests/queries/0_stateless/00529_orantius.reference

@@ -3,7 +3,7 @@
 1
 1
 [[1],[-1]]
-[]
+\N
 1
 42	42
 [NULL,'','',NULL]

tests/queries/0_stateless/01664_array_slice_ubsan.reference

@@ -1 +1 @@
-['\0','\0','\0']
+[0,0,0]