[gtk/gtk-3-24: 2/3] Wintab: Set the CXO_SYSTEM option

[Chun-wei Fan <fanchunwei src gnome org>]

commit f67bf8d8927159d77006c22f7adcb0cc4cfd4cc6
Author: Luca Bacci <luca bacci982 gmail com>
Date:   Mon Jun 7 14:04:09 2021 +0200

    Wintab: Set the CXO_SYSTEM option
    
    Fixes https://gitlab.gnome.org/GNOME/gtk/-/issues/3860

 gdk/win32/gdkdevicemanager-win32.c | 11 +++++++++++
 1 file changed, 11 insertions(+)
---
diff --git a/gdk/win32/gdkdevicemanager-win32.c b/gdk/win32/gdkdevicemanager-win32.c
index b91d089d49..70a2734616 100644
--- a/gdk/win32/gdkdevicemanager-win32.c
+++ b/gdk/win32/gdkdevicemanager-win32.c
@@ -516,6 +516,17 @@ wintab_init_check (GdkDeviceManagerWin32 *device_manager)
                                 devix, *hctx));
 
       wintab_contexts = g_list_append (wintab_contexts, hctx);
+
+      /* Set the CXO_SYSTEM flag */
+      if (!(lc.lcOptions & CXO_SYSTEM))
+        {
+          lc.lcOptions |= CXO_SYSTEM;
+          if (!p_WTSetA (hctx, &lc))
+            {
+              g_warning ("Could not set the CXO_SYSTEM option in the WINTAB context");
+            }
+        }
+
 #if 0
       (*p_WTEnable) (*hctx, TRUE);
 #endif