From e0561dc65dac23879453f7f1e40f9ec4d915d48d Mon Sep 17 00:00:00 2001
From: Licht-T <licht-t@outlook.jp>
Date: Fri, 27 Oct 2017 01:29:11 +0900
Subject: [PATCH] ENH: Add zero_copy_only option check

---
 cpp/src/arrow/python/arrow_to_pandas.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/cpp/src/arrow/python/arrow_to_pandas.cc b/cpp/src/arrow/python/arrow_to_pandas.cc
index 9e47b3437303c..74b75bcce6207 100644
--- a/cpp/src/arrow/python/arrow_to_pandas.cc
+++ b/cpp/src/arrow/python/arrow_to_pandas.cc
@@ -968,6 +968,11 @@ class CategoricalBlock : public PandasBlock {
 
     if (data.num_chunks() == 1 && indices_first.null_count() == 0) {
       RETURN_NOT_OK(AllocateNDArrayFromIndices<T>(npy_type, indices_first));
+    } else if (options_.zero_copy_only) {
+      std::stringstream ss;
+      ss << "Needed to copy " << data.num_chunks() << " chunks with "
+         << indices_first.null_count() << " indices nulls, but zero_copy_only was True";
+      return Status::Invalid(ss.str());
     }
     else {
       RETURN_NOT_OK(AllocateNDArray(npy_type, 1));