From fc6bca2c0f407f9c81677b07234e9996e7c2af95 Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Tue, 6 Jun 2017 16:15:10 +0200
Subject: [PATCH] catch and log event errors on outputarea.element

we already do this on global events,
but the new events on output_area.element were unsafe,
allowing extension code to prevent actions such as clear_output, etc. from completing.
---
 notebook/static/notebook/js/outputarea.js | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/notebook/static/notebook/js/outputarea.js b/notebook/static/notebook/js/outputarea.js
index be1ffa89d..c785a2fa1 100644
--- a/notebook/static/notebook/js/outputarea.js
+++ b/notebook/static/notebook/js/outputarea.js
@@ -54,7 +54,18 @@ define([
      **/
 
     OutputArea.prototype.create_elements = function () {
-        this.element = $("<div/>");
+        var element = this.element = $("<div/>");
+        // wrap element in safe trigger,
+        // so that errors (e.g. in widget extensions) are logged instead of
+        // breaking everything.
+        this.element._original_trigger = this.element.trigger;
+        this.element.trigger = function (name, data) {
+            try {
+                this._original_trigger.apply(this, arguments);
+            } catch (e) {
+                console.error("Exception in event handler for " + name, e, arguments);
+            }
+        }
         this.collapse_button = $("<div/>");
         this.prompt_overlay = $("<div/>");
         this.wrapper.append(this.prompt_overlay);