From 342c7da4bd2c60796d722970f82300b6d5ba0b42 Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Thu, 21 Dec 2023 10:39:10 +0800
Subject: [PATCH] fix(channel): use os_write() instead of fwrite() for stderr
 (#26689)

This handles EAGAIN.

Related #26688
---
 src/nvim/channel.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/nvim/channel.c b/src/nvim/channel.c
index 8c4fa8f5ad..e62c240636 100644
--- a/src/nvim/channel.c
+++ b/src/nvim/channel.c
@@ -30,6 +30,7 @@
 #include "nvim/message.h"
 #include "nvim/msgpack_rpc/channel.h"
 #include "nvim/msgpack_rpc/server.h"
+#include "nvim/os/fs.h"
 #include "nvim/os/os_defs.h"
 #include "nvim/os/shell.h"
 #include "nvim/path.h"
@@ -574,7 +575,10 @@ size_t channel_send(uint64_t id, char *data, size_t len, bool data_owned, const
       goto retfree;
     }
     // unbuffered write
-    written = len * fwrite(data, len, 1, stderr);
+    ptrdiff_t wres = os_write(STDERR_FILENO, data, len, false);
+    if (wres >= 0) {
+      written = (size_t)wres;
+    }
     goto retfree;
   }