From 82013066a6149aa906b1fda3f8f1f27bd272a6c2 Mon Sep 17 00:00:00 2001
From: Viktor Szakats <commit@vsz.me>
Date: Sat, 22 Nov 2025 01:42:15 +0100
Subject: [PATCH] file: do not pass invalid mode flags to `open()` on upload
 (Windows)

Ref: https://learn.microsoft.com/cpp/c-runtime-library/reference/open-wopen

Ref: #19645
Cherry-picked from #19643
Closes #19647
---
 lib/file.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/file.c b/lib/file.c
index 826bed6d80..6937069074 100644
--- a/lib/file.c
+++ b/lib/file.c
@@ -343,7 +343,10 @@ static CURLcode file_upload(struct Curl_easy *data,
   else
     mode |= O_TRUNC;
 
-#if (defined(ANDROID) || defined(__ANDROID__)) && \
+#ifdef _WIN32
+  fd = curlx_open(file->path, mode,
+                  data->set.new_file_perms & (_S_IREAD | _S_IWRITE));
+#elif (defined(ANDROID) || defined(__ANDROID__)) && \
   (defined(__i386__) || defined(__arm__))
   fd = curlx_open(file->path, mode, (mode_t)data->set.new_file_perms);
 #else