copy/paste duplicate text bug

[sebdev]

Sometimes when I perform a Copy/Paste from txt file into the CKEDITOR (latest version), the text gets copied multiple times.(2-6-8-10 times) and the browser also freezes when this happens. But this only happens after long periods of use, with a considerable amount of text and it's hard to reproduce.

I'm wondering if there is any way we can prevent this from happening even though we don't really know what the cause of it is.

Any help would be much appreciated.

[Jakub Ś]

1. Which CKEditor version you use (ckeditor/CHANGES.md)?
2. In which browser does it happen?
3. Can this issue be reproduced in default and standalone CKEditor (preferably demo version)? If this is happening only in your application, could you tell me if you use any third-party plugins installed, or have you made any core code customizations?

4. What exactly long period of time is? I have tried pasting, removing editor contents for about 30 minutes but nothing unusual has happened...
5. also is it possible extract some plain steps to reproduce this problem because if editor is used all the time there probably are many things which way influence such behaviour.

[Shaun]

I understand this comment may not help much, but we've experienced a similar problem with the browser freezing while using CKEditor.

Unfortunately, I've tried reproducing for 20 or 30 minutes with the profiler running to no avail. But I've seen it happen (the freeze) a couple times as a co-worker was using the editor.

CKEditor 4.6.2, Windows Chrome.

The first time it happened was after pasting content into the editor. The second time it happened, he had just hit "OK" in the link dialog after trying to link some selected text.

Here is our build-config:

/**
 * @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md or http://ckeditor.com/license
 */

/**
 * This file was added automatically by CKEditor builder.
 * You may re-use it at any time to build CKEditor again.
 *
 * If you would like to build CKEditor online again
 * (for example to upgrade), visit one the following links:
 *
 * (1) http://ckeditor.com/builder
 *     Visit online builder to build CKEditor from scratch.
 *
 * (2) http://ckeditor.com/builder/f081fa97f4d346779f365dda352178ca
 *     Visit online builder to build CKEditor, starting with the same setup as before.
 *
 * (3) http://ckeditor.com/builder/download/f081fa97f4d346779f365dda352178ca
 *     Straight download link to the latest version of CKEditor (Optimized) with the same setup as before.
 *
 * NOTE:
 *    This file is not used by CKEditor, you may remove it.
 *    Changing this file will not change your CKEditor configuration.
 */

var CKBUILDER_CONFIG = {
        skin: 'moono-lisa',
        preset: 'standard',
        ignore: [
                '.bender',
                'bender.js',
                'bender-err.log',
                'bender-out.log',
                'dev',
                '.DS_Store',
                '.editorconfig',
                '.gitattributes',
                '.gitignore',
                'gruntfile.js',
                '.idea',
                '.jscsrc',
                '.jshintignore',
                '.jshintrc',
                'less',
                '.mailmap',
                'node_modules',
                'package.json',
                'README.md',
                'tests'
        ],
        plugins : {
                'a11yhelp' : 1,
                'ajax' : 1,
                'autoembed' : 1,
                'balloonpanel' : 1,
                'basicstyles' : 1,
                'blockquote' : 1,
                'clipboard' : 1,
                'colorbutton' : 1,
                'colordialog' : 1,
                'contextmenu' : 1,
                'copyformatting' : 1,
                'elementspath' : 1,
                'enterkey' : 1,
                'entities' : 1,
                'filebrowser' : 1,
                'filetools' : 1,
                'find' : 1,
                'floatingspace' : 1,
                'font' : 1,
                'format' : 1,
                'horizontalrule' : 1,
                'htmlwriter' : 1,
                'image2' : 1,
                'indentlist' : 1,
                'justify' : 1,
                'link' : 1,
                'list' : 1,
                'liststyle' : 1,
                'magicline' : 1,
                'maximize' : 1,
                'pastefromword' : 1,
                'pastetext' : 1,
                'removeformat' : 1,
                'resize' : 1,
                'showblocks' : 1,
                'showborders' : 1,
                'sourcearea' : 1,
                'sourcedialog' : 1,
                'specialchar' : 1,
                'stylescombo' : 1,
                'tab' : 1,
                'table' : 1,
                'tabletools' : 1,
                'toolbar' : 1,
                'undo' : 1,
                'uploadfile' : 1,
                'uploadimage' : 1,
                'wysiwygarea' : 1
        },
        languages : {
                'en' : 1
        }
};

[Bjoern]

I've got the same problem here.
But I cannot find a scheme to reproduce the error.
After I use the editor intensively in Chrome (57.0.2987.133 (64-bit) - Ubuntu 16.10)
and switch between source mode and wysiwyg mode, the "change" event of the editor fired multiple times when I copy/paste a text into the wysiwyg mode and the text is copied multiple times.
I use 2 instances of the editor in one page with the codemirror plugin.
I try to find a code snippet (or a demo page) which I can reproduce this behavior and post it.

Update: I use an "older" version of CKEditor (4.5.3)

[Jakub Ś]

Since there are couple of people reporting same problem, I will keep it open.

Can anyone provide reproducible scenario for latest CKEditor (4.6.2 at the time of writing). Is is possible to reproduce this problem in standalone CKEditor outside of your application and aside from any third-party scripts which might have influence on this issue?
It is also important that you always use the latest editor version as while something might have been occurring in CKEditor 4.5.3 it is no longer there in latest release.

[an-nikolaev]

Hi, same problem. Version is 4.6.2, do not need to do anything — just leave page idle for few hours (2-3 is enough) then pasted data starts duplicating. Page reload doesn't help if editor is cached, need to real reload from server.