From b77a43cbcdd1a681bfefe0e7d4de93cc699db249 Mon Sep 17 00:00:00 2001
From: Viktor Szakats <commit@vsz.me>
Date: Tue, 16 Jun 2026 13:55:43 +0200
Subject: [PATCH] main_window_loop

---
 tests/server/util.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/server/util.c b/tests/server/util.c
index 7a57db863e..95e0a0ccf5 100644
--- a/tests/server/util.c
+++ b/tests/server/util.c
@@ -525,17 +525,27 @@ static DWORD WINAPI main_window_loop(void *lpParameter)
   WNDCLASS wc;
   BOOL ret;
   MSG msg;
+#ifdef DEBUG_WIN32_CALLBACKS
   DWORD err;
   char buffer[WINAPI_ERROR_LEN];
+#else
+  DWORD dwWritten;
+#endif
 
   ZeroMemory(&wc, sizeof(wc));
   wc.lpfnWndProc = (WNDPROC)main_window_proc;
   wc.hInstance = (HINSTANCE)lpParameter;
   wc.lpszClassName = TEXT("MainWClass");
   if(!RegisterClass(&wc)) {
+#ifdef DEBUG_WIN32_CALLBACKS
     err = GetLastError();
     curlx_winapi_strerror(err, buffer, sizeof(buffer));
     fprintf(stderr, "RegisterClass failed: %s\n", buffer);
+#else
+    static const char str[] = "RegisterClass() failed\n";
+    WriteFile(GetStdHandle(STD_ERROR_HANDLE), str, sizeof(str) - 1,
+              &dwWritten, NULL);
+#endif
     return (DWORD)-1;
   }
 
@@ -547,18 +557,30 @@ static DWORD WINAPI main_window_loop(void *lpParameter)
                                       (HWND)NULL, (HMENU)NULL,
                                       wc.hInstance, NULL);
   if(!hidden_main_window) {
+#ifdef DEBUG_WIN32_CALLBACKS
     err = GetLastError();
     curlx_winapi_strerror(err, buffer, sizeof(buffer));
     fprintf(stderr, "CreateWindowEx failed: (0x%08lx) - %s\n", err, buffer);
+#else
+    static const char str[] = "CreateWindowEx() failed\n";
+    WriteFile(GetStdHandle(STD_ERROR_HANDLE), str, sizeof(str) - 1,
+              &dwWritten, NULL);
+#endif
     return (DWORD)-1;
   }
 
   do {
     ret = GetMessage(&msg, NULL, 0, 0);
     if(ret == -1) {
+#ifdef DEBUG_WIN32_CALLBACKS
       err = GetLastError();
       curlx_winapi_strerror(err, buffer, sizeof(buffer));
       fprintf(stderr, "GetMessage failed: (0x%08lx) - %s\n", err, buffer);
+#else
+      static const char str[] = "GetMessage() failed\n";
+      WriteFile(GetStdHandle(STD_ERROR_HANDLE), str, sizeof(str) - 1,
+                             &dwWritten, NULL);
+#endif
       return (DWORD)-1;
     }
     else if(ret) {