[gnome-shell/gnome-3-34] dnd: Skip drag target when its acceptDrop() throws an exception

[Marco Trevisan <marcotrevi src gnome org>]

commit 750c5acd30ef724b2398bb9d9178a130b58e046b
Author: Philip Chimento <philip endlessm com>
Date:   Wed Oct 23 00:48:00 2019 +0000

    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
    
    
    (cherry picked from commit 055c007ac26b6475cc2821dbfc2e760ec4f3a9a6)

 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) {