[gtk/gtk-3-24: 1/2] Winpointer: Fix keyboard state

[Luca Bacci <lbacci src gnome org>]

commit 46c12b2c922d5592cedd29624cbf3be6b4411084
Author: Luca Bacci <luca bacci982 gmail com>
Date:   Mon Jan 3 15:03:55 2022 +0100

    Winpointer: Fix keyboard state
    
    The dwKeyStates field of the POINTER_INFO structure is
    always set to 0 no matter what.
    
    Use GetKeyState instead.
    
    Fixes https://gitlab.com/inkscape/inbox/-/issues/5946

 gdk/win32/gdkdevicemanager-win32.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/gdk/win32/gdkdevicemanager-win32.c b/gdk/win32/gdkdevicemanager-win32.c
index d8f01764f2..f4c258b3c8 100644
--- a/gdk/win32/gdkdevicemanager-win32.c
+++ b/gdk/win32/gdkdevicemanager-win32.c
@@ -1762,10 +1762,12 @@ winpointer_make_event (GdkDisplay *display,
   x /= impl->window_scale;
   y /= impl->window_scale;
 
+  /* info->dwKeyStates is not reliable. We shall use
+   * GetKeyState here even for Ctrl and Shift. */
   state = 0;
-  if (info->dwKeyStates & POINTER_MOD_CTRL)
+  if (GetKeyState (VK_CONTROL) < 0)
     state |= GDK_CONTROL_MASK;
-  if (info->dwKeyStates & POINTER_MOD_SHIFT)
+  if (GetKeyState (VK_SHIFT) < 0)
     state |= GDK_SHIFT_MASK;
   if (GetKeyState (VK_MENU) < 0)
     state |= GDK_MOD1_MASK;