Fix some undesirable frame focus changes

* src/xterm.c (handle_one_xevent): Only detach upon actual
device tree change.

1 files changed, 21 insertions, 6 deletions

diff --git a/src/xterm.c b/src/xterm.c
index 41537ade155..17043e078c7 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -22436,11 +22436,14 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 
           case XI_HierarchyChanged:
             {
-              XIHierarchyEvent *hev = (XIHierarchyEvent *) xi_event;
+              XIHierarchyEvent *hev;
               XIDeviceInfo *info;
               int i, ndevices, n_disabled, *disabled;
               struct xi_device_t *device;
+              bool any_changed;
 
+              any_changed = false;
+              hev = (XIHierarchyEvent *) xi_event;
               disabled = SAFE_ALLOCA (sizeof *disabled * hev->num_info);
               n_disabled = 0;
 
@@ -22450,8 +22453,17 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                     {
                       /* Handle all disabled devices now, to prevent
                          things happening out-of-order later.  */
-                      xi_disable_devices (dpyinfo, disabled, n_disabled);
-                      n_disabled = 0;
+
+                      if (ndevices)
+                        {
+                          xi_disable_devices (dpyinfo, disabled, n_disabled);
+                          n_disabled = 0;
+
+                          /* This flag really just means that disabled
+                             devices were handled early and should be
+                             used in conjunction with n_disabled.  */
+                          any_changed = true;
+                        }
 
                       x_catch_errors (dpyinfo->display);
                       info = XIQueryDevice (dpyinfo->display, hev->info[i].deviceid,
@@ -22502,9 +22514,12 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                  event.  */
               xi_disable_devices (dpyinfo, disabled, n_disabled);
 
-              /* Now that the device hierarchy has been changed,
-                 recompute focus.  */
-              xi_handle_focus_change (dpyinfo);
+              /* If the device hierarchy has been changed, recompute
+                 focus.  This might seem like a micro-optimization but
+                 it actually keeps the focus from changing in some
+                 cases where it would be undesierable.  */
+              if (any_changed || n_disabled)
+                xi_handle_focus_change (dpyinfo);
 
               goto XI_OTHER;
             }