From 6f2e851663cf8d0345796c415b56de182f260ed3 Mon Sep 17 00:00:00 2001
From: Benjamin Kietzman <bengilgit@gmail.com>
Date: Wed, 11 Oct 2023 10:28:20 -0400
Subject: [PATCH] correct value count

---
 cpp/src/arrow/array/concatenate.cc | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/cpp/src/arrow/array/concatenate.cc b/cpp/src/arrow/array/concatenate.cc
index 7110c8a5b649e..37c7271b5b95c 100644
--- a/cpp/src/arrow/array/concatenate.cc
+++ b/cpp/src/arrow/array/concatenate.cc
@@ -260,8 +260,7 @@ class ConcatenateImpl {
     if (out_->buffers[0] != nullptr) {
       i = in_[0]->length;
       VisitNullBitmapInline(
-          out_->buffers[0]->data(), in_[0]->length, out_->length, out_->null_count,
-          [&] { ++i; },
+          out_->buffers[0]->data(), i, out_->length - i, out_->null_count, [&] { ++i; },
           [&] {
             views[i++] = {};  // overwrite views under null bits with an empty view
           });