From 70c88e83227384756ad19ca5159f1d402feb297b Mon Sep 17 00:00:00 2001
From: Benjamin Kietzman <bengilgit@gmail.com>
Date: Fri, 27 Sep 2024 13:25:16 -0700
Subject: [PATCH] assert zero body is written for schema messages

---
 arrow-ipc/src/writer.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arrow-ipc/src/writer.rs b/arrow-ipc/src/writer.rs
index 4b0f4a00b513..09e9da8c92ee 100644
--- a/arrow-ipc/src/writer.rs
+++ b/arrow-ipc/src/writer.rs
@@ -892,8 +892,10 @@ impl<W: Write> FileWriter<W> {
         // write the schema
         let encoded_message = data_gen.schema_to_bytes(schema, &write_options);
 
-        let (meta, _data) =
+        let (meta, data) =
             write_message(&mut writer, written_len, encoded_message, &write_options)?;
+        // The schema message has no body
+        debug_assert_eq!(data, 0);
 
         // written bytes = padded_magic + schema
         written_len += meta;