Debug (Windows): ensures UTF-8 output

Author: CarterLi

src/common/impl/debug_windows.c

@@ -1,27 +1,34 @@
 #include "common/debug.h"
+#include "common/windows/nt.h"
 
 #include <windows.h>
 
 const char* ffDebugWin32Error(DWORD errorCode) {
-    static char buffer[256];
+    static char buffer[512];
 
-    DWORD len = FormatMessageA(
+    wchar_t bufferW[256];
+    ULONG len = FormatMessageW(
         FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
         NULL,
         (DWORD) errorCode,
         0,
-        buffer,
+        bufferW,
         sizeof(buffer),
         NULL);
 
     if (len == 0) {
         snprintf(buffer, sizeof(buffer), "Unknown error code (%lu)", errorCode);
     } else {
         // Remove trailing newline
-        while (len > 0 && (buffer[len - 1] == '\r' || buffer[len - 1] == '\n')) {
-            buffer[--len] = '\0';
+        while (len > 0 && (bufferW[len - 1] == '\r' || bufferW[len - 1] == '\n')) {
+            --len;
+        }
+
+        if (NT_SUCCESS(RtlUnicodeToUTF8N(buffer, sizeof(buffer), &len, bufferW, len * sizeof(wchar_t)))) {
+            snprintf(buffer + len, sizeof(buffer) - len, " (%lu)", errorCode);
+        } else {
+            snprintf(buffer, sizeof(buffer), "Unknown error (%lu)", errorCode);
         }
-        snprintf(buffer + len, sizeof(buffer) - len + 2, " (%lu)", errorCode);
     }
 
     return buffer;