Including suggested changes to function_internal.h

Author: tadeja

cpp/src/arrow/compute/function_internal.h

@@ -347,7 +347,7 @@ static inline Result<std::shared_ptr<Scalar>> GenericToScalar(
 static inline Result<std::shared_ptr<Scalar>> GenericToScalar(
     const std::shared_ptr<DataType>& value) {
   if (!value) {
-    return Status::Invalid("shared_ptr<DataType> is nullptr");
+    return std::make_shared<NullScalar>();
   }
   return MakeNullScalar(value);
 }
@@ -448,6 +448,9 @@ static inline enable_if_same_result<T, SortKey> GenericFromScalar(
 template <typename T>
 static inline enable_if_same_result<T, std::shared_ptr<DataType>> GenericFromScalar(
     const std::shared_ptr<Scalar>& value) {
+      if (value->type->id() == Type::NA) {
+        return std::shared_ptr<NullType>();
+      }
   return value->type;
 }
 

python/pyarrow/tests/test_compute.py

@@ -202,7 +202,6 @@ def test_option_class_equality(request):
         pc.WeekOptions(week_starts_monday=True, count_from_zero=False,
                        first_week_is_fully_in_year=False),
         pc.ZeroFillOptions(4, "0"),
-        pc.InversePermutationOptions(output_type=pa.int32()),
     ]
     # Timezone database might not be installed on Windows or Emscripten
     if request.config.pyarrow.is_enabled["timezone_data"]: