win32u: Fix handling uninitialized process_layout.

dlls/win32u/sysparams.c

@@ -375,7 +375,7 @@ union sysparam_all_entry
 
 static UINT system_dpi;
 static RECT work_area;
-DWORD process_layout = ~0u;
+static DWORD process_layout = ~0u;
 
 static HDC display_dc;
 static pthread_mutex_t display_dc_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -1631,6 +1631,11 @@ DPI_AWARENESS get_thread_dpi_awareness(void)
     }
 }
 
+DWORD get_process_layout(void)
+{
+    return process_layout == ~0u ? 0 : process_layout;
+}
+
 /**********************************************************************
  *              get_thread_dpi
  */

dlls/win32u/win32u_private.h

@@ -326,7 +326,6 @@ extern void track_scroll_bar( HWND hwnd, int scrollbar, POINT pt ) DECLSPEC_HIDD
 
 /* sysparams.c */
 extern BOOL enable_thunk_lock DECLSPEC_HIDDEN;
-extern DWORD process_layout DECLSPEC_HIDDEN;
 extern HBRUSH get_55aa_brush(void) DECLSPEC_HIDDEN;
 extern DWORD get_dialog_base_units(void) DECLSPEC_HIDDEN;
 extern LONG get_char_dimensions( HDC hdc, TEXTMETRICW *metric, LONG *height ) DECLSPEC_HIDDEN;
@@ -335,6 +334,7 @@ extern UINT get_monitor_dpi( HMONITOR monitor ) DECLSPEC_HIDDEN;
 extern BOOL get_monitor_info( HMONITOR handle, MONITORINFO *info ) DECLSPEC_HIDDEN;
 extern UINT get_win_monitor_dpi( HWND hwnd ) DECLSPEC_HIDDEN;
 extern RECT get_primary_monitor_rect( UINT dpi ) DECLSPEC_HIDDEN;
+extern DWORD get_process_layout(void) DECLSPEC_HIDDEN;
 extern COLORREF get_sys_color( int index ) DECLSPEC_HIDDEN;
 extern HBRUSH get_sys_color_brush( unsigned int index ) DECLSPEC_HIDDEN;
 extern HPEN get_sys_color_pen( unsigned int index ) DECLSPEC_HIDDEN;

dlls/win32u/window.c

@@ -5094,7 +5094,7 @@ HWND WINAPI NtUserCreateWindowEx( DWORD ex_style, UNICODE_STRING *class_name,
             (class_name->Length != sizeof(messageW) ||
              wcsnicmp( class_name->Buffer, messageW, ARRAYSIZE(messageW) )))
         {
-            if (process_layout & LAYOUT_RTL) cs.dwExStyle |= WS_EX_LAYOUTRTL;
+            if (get_process_layout() & LAYOUT_RTL) cs.dwExStyle |= WS_EX_LAYOUTRTL;
             parent = get_desktop_window();
         }
     }