[gnome-shell] dnd: Skip drag target when its acceptDrop() throws an exception

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 055c007ac26b6475cc2821dbfc2e760ec4f3a9a6
Author: Philip Chimento <philip endlessm com>
Date:   Tue Oct 22 17:48:00 2019 -0700

    dnd: Skip drag target when its acceptDrop() throws an exception
    
    In the case of bugs in a drag target's acceptDrop() function, it may
    throw an exception. In the previous code, this would break out of the
    loop entirely and never cancel the drag, so the mouse button release
    event would be ignored and you would have to press Esc to get out of the
    drag.
    
    In this change, if acceptDrop() throws an exception, we log it and move
    on to the next parent target instead.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/777

 js/ui/dnd.js | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
---
diff --git a/js/ui/dnd.js b/js/ui/dnd.js
index 786d654199..7d3929d6e4 100644
--- a/js/ui/dnd.js
+++ b/js/ui/dnd.js
@@ -573,11 +573,15 @@ var _Draggable = class _Draggable {
         while (target) {
             if (target._delegate && target._delegate.acceptDrop) {
                 let [r_, targX, targY] = target.transform_stage_point(dropX, dropY);
-                if (target._delegate.acceptDrop(this.actor._delegate,
-                                                this._dragActor,
-                                                targX,
-                                                targY,
-                                                event.get_time())) {
+                let accepted = false;
+                try {
+                    accepted = target._delegate.acceptDrop(this.actor._delegate,
+                        this._dragActor, targX, targY, event.get_time());
+                } catch (e) {
+                    // On error, skip this target
+                    logError(e, "Skipping drag target");
+                }
+                if (accepted) {
                     // If it accepted the drop without taking the actor,
                     // handle it ourselves.
                     if (this._dragActor && this._dragActor.get_parent() == Main.uiGroup) {