From cd721c4e86e3d55cf3fd6661875a6f0ba4800a78 Mon Sep 17 00:00:00 2001
From: Pepijn Van Eeckhoudt <pepijn@vaneeckhoudt.net>
Date: Thu, 10 Apr 2025 16:46:40 +0200
Subject: [PATCH] GH-74: Correct length calculation of value buffers of
 variable-sized arrays

---
 .../org/apache/arrow/c/BufferImportTypeVisitor.java  | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/c/src/main/java/org/apache/arrow/c/BufferImportTypeVisitor.java b/c/src/main/java/org/apache/arrow/c/BufferImportTypeVisitor.java
index 2661c12cda..1feb5bdf0e 100644
--- a/c/src/main/java/org/apache/arrow/c/BufferImportTypeVisitor.java
+++ b/c/src/main/java/org/apache/arrow/c/BufferImportTypeVisitor.java
@@ -228,9 +228,8 @@ public List<ArrowBuf> visit(ArrowType.Utf8 type) {
           type,
           start,
           end);
-      final int len = end - start;
       offsets.getReferenceManager().retain();
-      return Arrays.asList(maybeImportBitmap(type), offsets, importData(type, len));
+      return Arrays.asList(maybeImportBitmap(type), offsets, importData(type, end));
     }
   }
 
@@ -279,9 +278,8 @@ public List<ArrowBuf> visit(ArrowType.LargeUtf8 type) {
           type,
           start,
           end);
-      final long len = end - start;
       offsets.getReferenceManager().retain();
-      return Arrays.asList(maybeImportBitmap(type), offsets, importData(type, len));
+      return Arrays.asList(maybeImportBitmap(type), offsets, importData(type, end));
     }
   }
 
@@ -296,9 +294,8 @@ public List<ArrowBuf> visit(ArrowType.Binary type) {
           type,
           start,
           end);
-      final int len = end - start;
       offsets.getReferenceManager().retain();
-      return Arrays.asList(maybeImportBitmap(type), offsets, importData(type, len));
+      return Arrays.asList(maybeImportBitmap(type), offsets, importData(type, end));
     }
   }
 
@@ -320,9 +317,8 @@ public List<ArrowBuf> visit(ArrowType.LargeBinary type) {
           type,
           start,
           end);
-      final long len = end - start;
       offsets.getReferenceManager().retain();
-      return Arrays.asList(maybeImportBitmap(type), offsets, importData(type, len));
+      return Arrays.asList(maybeImportBitmap(type), offsets, importData(type, end));
     }
   }