Word pasting is extremely slow in IE7 and IE8

[Tomas]

I've noticed that our typical word document used in our for pasting into the CK editor runs extremely sow in IE7 and IE8. This is true if you compare 3.4.1. between FF 3.5 and IE. Its also true if you compare IE behavior between 3.0.1 and 3.4 in IE. Its a factor 10 or more. Application become unresponsive. I have attached a document that can be used to paste into the editor to see the behavior.

[Tomas]

A file that takes minutes to paste into editor in IE

[Garry Yao]

We understand that the filter that we introduced in 3.1 has indeed performance impacts, I'm not saying you should not have such big document, but even you try this with a bare bone browser paste your provided document are far more than seconds.

So we recommend you to provide your own CKEDITOR.cleanWord replacement if you frequently have this kind of monster paste.

CKEDITOR.cleanWord = function( data, editor )
{
   // Your custom content processing.
   return data;
}

[Tomas]

I understand what you are saying. Such an performance decrease (from 3.0.1) should however in my opinion be addressed. In IE7 it takes 100 seconds in FF it takes 12 seconds.

[Garry Yao]

Leave this open to gain attention on performance tunning.

[Krzysztof Studnik]

Changing to "confirmed", due it is a known issue

[Frederico Caldeira Knabben]

We need a patch here before targeting it.

[Tom Robinson]

This is not a problem with CKEditor, it is strictly an IE problem. I created this tiny test page:

 <div contenteditable=true>paste here</div>

Pasting your test document from Word into IE9 took over 15 minutes, at which point I gave up. However, if I first pasted/copied through Chrome (3 seconds), then the paste in IE took 1 second. Pasting from Chrome into IE9 CKEditor was also very quick. I'm running Windows 7 64-bit.

[Jakub Ś]

I can confirm what @Tom Robinson has said. This is happening in IE8-10.
I have tried simple textarea or editable div and in both cases this word file has taken ages to get processed.

Since native IE doesn't handle this, neither will editor which works inside native IE.
In editor such paste took about 1-2 min. I was kind of surprised with this fact because it was much faster than in native textarea and a little bit faster than in native editable div.

[Tade0]

Managed to paste it in 2016 in IE8 with PFW processing. What a time to be alive.