From 4b6004e8c9ca3cbef8e9efb6aed951160d0697a0 Mon Sep 17 00:00:00 2001
From: Christian Schwarz <christian@neon.tech>
Date: Tue, 9 Jan 2024 10:22:43 +0100
Subject: [PATCH] fix(page_service client): correctly deserialize pagestream
 errors (#6302)

Before this PR, we wouldn't advance the underlying `Bytes`'s cursor.

fixes https://github.com/neondatabase/neon/issues/6298
---
 libs/pageserver_api/src/models.rs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/libs/pageserver_api/src/models.rs b/libs/pageserver_api/src/models.rs
index dea925b468..316d79b634 100644
--- a/libs/pageserver_api/src/models.rs
+++ b/libs/pageserver_api/src/models.rs
@@ -2,7 +2,7 @@ pub mod partitioning;
 
 use std::{
     collections::HashMap,
-    io::Read,
+    io::{BufRead, Read},
     num::{NonZeroU64, NonZeroUsize},
     time::SystemTime,
 };
@@ -813,9 +813,10 @@ impl PagestreamBeMessage {
                     PagestreamBeMessage::GetPage(PagestreamGetPageResponse { page: page.into() })
                 }
                 Tag::Error => {
-                    let buf = buf.get_ref();
-                    let cstr = std::ffi::CStr::from_bytes_until_nul(buf)?;
-                    let rust_str = cstr.to_str()?;
+                    let mut msg = Vec::new();
+                    buf.read_until(0, &mut msg)?;
+                    let cstring = std::ffi::CString::from_vec_with_nul(msg)?;
+                    let rust_str = cstring.to_str()?;
                     PagestreamBeMessage::Error(PagestreamErrorResponse {
                         message: rust_str.to_owned(),
                     })