Fixed possible use of invalid HWND.

src/win32_window.c

@@ -930,6 +930,12 @@ static int createWindow(_GLFWwindow* window,
 
     free(wideTitle);
 
+    if (!window->win32.handle)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Win32: Failed to create window");
+        return GL_FALSE;
+    }
+
     if (_glfw_ChangeWindowMessageFilterEx)
     {
         _glfw_ChangeWindowMessageFilterEx(window->win32.handle,
@@ -942,12 +948,6 @@ static int createWindow(_GLFWwindow* window,
 
     DragAcceptFiles(window->win32.handle, TRUE);
 
-    if (!window->win32.handle)
-    {
-        _glfwInputError(GLFW_PLATFORM_ERROR, "Win32: Failed to create window");
-        return GL_FALSE;
-    }
-
     if (!_glfwCreateContext(window, ctxconfig, fbconfig))
         return GL_FALSE;