[gtk/gtk-3-24] Fix window unresponsive to mouse after app-switch w/drawing tablet

[Matthias Clasen <matthiasc src gnome org>]

commit 86d38e6ae2cccb46cc01facdbd3bdfa9b47a10ed
Author: Steven Calwas <calwas2 hotmail com>
Date:   Sat Aug 29 00:49:12 2020 -0700

    Fix window unresponsive to mouse after app-switch w/drawing tablet
    
    Partially fixes issue #2191 regarding switching to another app while
    hovering a stylus over a drawing tablet causes subsequent mouse
    clicks in the app to be ignored. I was not able to reproduce the
    other behavior described in #2191 concerning tiling a window.

 gdk/win32/gdkevents-win32.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gdk/win32/gdkevents-win32.c b/gdk/win32/gdkevents-win32.c
index 67df5026ec..e3c7f824ac 100644
--- a/gdk/win32/gdkevents-win32.c
+++ b/gdk/win32/gdkevents-win32.c
@@ -3742,7 +3742,11 @@ gdk_event_translate (MSG  *msg,
       GDK_NOTE (EVENTS, g_print (" %s thread: %" G_GINT64_FORMAT,
                                 msg->wParam ? "YES" : "NO",
                                 (gint64) msg->lParam));
+      
+      // Clear graphics tablet state
+      _gdk_input_ignore_core = 0;
       break;
+      
     case WM_NCHITTEST:
       /* TODO: pass all messages to DwmDefWindowProc() first! */
       return_val = handle_nchittest (msg->hwnd, window,