Improve MPX interaction with drag-and-drop

* src/xfns.c (Fx_set_mouse_absolute_pixel_position): Use
internal client pointer record.
* src/xterm.c (x_dnd_cancel_dnd_early): New function.  Only used
on XI2 builds so far.
(x_dnd_begin_drag_and_drop): Set the pointer device used for DND
events.
(xi_disable_devices): Cancel the drag-and-drop operation if that
device is disabled.
(x_send_scroll_bar_event): Update outdated comment.
(handle_one_xevent): Only accept DND events from that device.
(frame_set_mouse_pixel_position): Use internal client pointer
record.

1 files changed, 9 insertions, 10 deletions

diff --git a/src/xfns.c b/src/xfns.c
index 2845ecca6a9..144f64f6f62 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -6851,17 +6851,16 @@ The coordinates X and Y are interpreted in pixels relative to a position
 #ifdef HAVE_XINPUT2
   int deviceid;
 
-  if (FRAME_DISPLAY_INFO (f)->supports_xi2)
+  deviceid = FRAME_DISPLAY_INFO (f)->client_pointer_device;
+
+  if (FRAME_DISPLAY_INFO (f)->supports_xi2
+      && deviceid != -1)
     {
-      XGrabServer (FRAME_X_DISPLAY (f));
-      if (XIGetClientPointer (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
-                              &deviceid))
-        {
-          XIWarpPointer (FRAME_X_DISPLAY (f), deviceid, None,
-                         FRAME_DISPLAY_INFO (f)->root_window,
-                         0, 0, 0, 0, xval, yval);
-        }
-      XUngrabServer (FRAME_X_DISPLAY (f));
+      x_catch_errors_for_lisp (FRAME_X_DISPLAY (f));
+      XIWarpPointer (FRAME_X_DISPLAY (f), deviceid, None,
+                     FRAME_DISPLAY_INFO (f)->root_window,
+                     0, 0, 0, 0, xval, yval);
+      x_uncatch_errors_for_lisp (FRAME_X_DISPLAY (f));
     }
   else
 #endif