From 5635e6b94de7f8ee7c2a1883139ea9f0678d8362 Mon Sep 17 00:00:00 2001
From: 11soda11 <115734183+Sodastream11@users.noreply.github.com>
Date: Wed, 29 Jul 2026 01:08:00 +0200
Subject: [PATCH] add EAGAIN check on write to nonblock sock

---
 src/tool_doswin.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tool_doswin.c b/src/tool_doswin.c
index d218e0dd83..b8a94ebc4d 100644
--- a/src/tool_doswin.c
+++ b/src/tool_doswin.c
@@ -759,6 +759,7 @@ static int swrite_blocking_on_nonblock(curl_socket_t nonblock_sock,
 
   FD_ZERO(&fdwrite);
   FD_ZERO(&fdexcep);
+
   FD_SET(nonblock_sock, &fdwrite);
 
   do {
@@ -783,6 +784,9 @@ static int swrite_blocking_on_nonblock(curl_socket_t nonblock_sock,
     ret = swrite(nonblock_sock, data + nwritten, nbytes - nwritten);
 
     if(ret <= 0) {
+      if(SOCK_EAGAIN(SOCKERRNO))
+        continue;
+
       errorf("socket write error: %d", SOCKERRNO);
       return -1;
     }