Improve XI2 valuator reset logic

* src/xterm.c (handle_one_xevent): Clear valuators on XI_Leave
instead of XI_Enter.

1 files changed, 17 insertions, 26 deletions

diff --git a/src/xterm.c b/src/xterm.c
index d52d7311bb1..30a3aee20ee 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -10390,32 +10390,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
             {
 #ifdef HAVE_XWIDGETS
               struct xwidget_view *xwidget_view = xwidget_view_from_window (enter->event);
-#else
-              bool xwidget_view = false;
-#endif
-
-              /* One problem behind the design of XInput 2 scrolling is
-                 that valuators are not unique to each window, but only
-                 the window that has grabbed the valuator's device or
-                 the window that the device's pointer is on top of can
-                 receive motion events.  There is also no way to
-                 retrieve the value of a valuator outside of each motion
-                 event.
-
-                 As such, to prevent wildly inaccurate results when the
-                 valuators have changed outside Emacs, we reset our
-                 records of each valuator's value whenever the pointer
-                 re-enters a frame after its valuators have potentially
-                 been changed elsewhere.  */
-              if (enter->detail != XINotifyInferior
-                  && enter->mode != XINotifyPassiveUngrab
-                  /* See the comment under FocusIn in
-                     `x_detect_focus_change'.  The main relevant culprit
-                     these days seems to be XFCE.  */
-                  && enter->mode != XINotifyUngrab
-                  && (xwidget_view
-                      || (any && enter->event == FRAME_X_WINDOW (any))))
-                xi_reset_scroll_valuators_for_device_id (dpyinfo, enter->deviceid);
+#endif
 
 #ifdef HAVE_XWIDGETS
               if (xwidget_view)
@@ -10457,6 +10432,22 @@ handle_one_xevent (struct x_display_info *dpyinfo,
             ev.window = leave->event;
             any = x_top_window_to_frame (dpyinfo, leave->event);
 
+            /* One problem behind the design of XInput 2 scrolling is
+               that valuators are not unique to each window, but only
+               the window that has grabbed the valuator's device or
+               the window that the device's pointer is on top of can
+               receive motion events.  There is also no way to
+               retrieve the value of a valuator outside of each motion
+               event.
+
+               As such, to prevent wildly inaccurate results when the
+               valuators have changed outside Emacs, we reset our
+               records of each valuator's value whenever the pointer
+               moves out of a frame (and not into one of its
+               children, which we know about).  */
+            if (leave->detail != XINotifyInferior && any)
+              xi_reset_scroll_valuators_for_device_id (dpyinfo, enter->deviceid);
+
 #ifdef HAVE_XWIDGETS
             {
               struct xwidget_view *xvw