CKEditor 3.x vertical scroll bar is hang/not working on Firefox browser

[Siju]

Hi,

We are using 3.x version of CKEditor in our project and when set large data to the editor (1 MB - 2 MB) data, the vertical scroll bar is stopped working. This issue is coming on Firfox and this is working fine for IE browser. For large data, when try to scroll after load it sometimes make the browser also crashing some times.

Really would appreciate if any work around or patch for this issue? Please guide us kindly.

Note: We have a valid license for the CKEditor.

Thank You, Siju Thomas.

[Siju]

Screen shot of the issue in CKEditor Demo site

[Siju]

Hi,

This is in reference of the request from Anna on the discussion forum (​http://cksource.com/forums/viewtopic.php?f=11&t=24426), I am adding more details to this ticket. Please view the screen shot as we could reproduce it on the CKEditor demo site. Here is the summary for reproduce:
1) The issue happens on Firefox browser
2) If load any data having more than 2000 words and click on the up, down button on the scroll bar
3) The normal scrolling on clicking on the bar and scroll works. but click on the buttons didn't work (Please refer the screen shot)

Note:
We have tried to debug the CKEditor.js to trace the issue. What we could figure is the GetScrollPosition function sometimes get null for the current position due to the large data. With a delay in the debug it works. We haven't spent much time to trace the issue on CKEditor.js as for the belief that the workaround should be already there.

Kindly please guide.

Thanks in Advance. Siju Thomas.

[Jakub Ś]

3500 words created 54KB document and I was not able to reproduce your issue with it. Scrollbar buttons worked.

• Could you give me a step by step scenario and sample test data here?

2MB is completely different thing. I have created 2,45MB doc file but it had about 570 pages!![[BR]] When I pasted it into IE it hung, and Firefox worked like almost as you have described - buttons diddn't, clicking on scroll bar didn't, scrolling did work.

*I don't think that this is what you were talking about so could you please provide me with some more details/sample data?

[prodibaugh]

I've attached a sample html file that causes this issue. I opened the html file in my browser and copy/pasted its contents into the demo ckeditor site instance. On Firefox 9.01, I was unable to scroll using the "up" or "down" arrows on the ckeditor scrollbar.

[Jakub Ś]

I have managed to reproduce the issue (See the video)

It seems that this iss has only been reproducible in Firefox from CKEditor 3.3.1.
All other browsers work fine.

Anyway to break the scrollbar button I had to click it quite fast. Single clicks and single click and hold seem to work.

[Jakub Ś]

I have looked through the sample code. It seems there is lot of garbage code - meta tags, title tag tons of   wrapped in span tags. All of this may influence scrollling speed in Firefox.

The issue seems to be happening only with this code (code from demo pasted many times worked perfectly) and when you rapidly click on scrollbar button.

Exact steps to reproduce:

1. Paste HTML from test.html
2. Switch to source
3. Grab scroll bar and go the end of editor
4. Start pressing scrollbar’s up button rapidly. After some time you will see that CKEditor stops responding. But if you click and hold the up button then the scrolling works

(To enable scrolling on single click you have to switch to source and back).

Like I’ve said before issue has only been reproducible in Firefox from CKEditor 3.3.1.

[Jakub Ś]

Neither @garry.yao nor @wwalc were able to reproduce this issue.

[Jakub Ś]

IMO this is quite an edge case with a low priority but does not explain what has changed in CKE 3.3.1 that scrolling has stopped working in this special case.