Styled text pasted from MS Word causes infinite loop

[Jakub Ś]

To reproduce:

1. Use below configuration for editor

   var editor = CKEDITOR.replace( 'editor1', {
   	pasteFromWordRemoveFontStyles:false,
   	pasteFromWordRemoveStyles : false 	
   	//,allowedContent: true //This isn't causing any problems
   } );	
   

2. Open page and clear contents with New Page command
3. Open attached file and Copy styled text or table with styled text
4. Paste it in to editor using Paste From Word dialog or Ctrl+V

Result: CKEditor goes into infinite loop (FF eventually asks if you want to break the script execution).

Problem can be reproduced in all browsers from CKE 4.1 however it looks like ACF is not responsible as setting allowedContent: true doesn't help to resolve this problem.

[Piotrek Koszuliński]

I simplified the test case to this HTML:

<p class="MsoNormal"><span style="font-size:24.0pt">test</span></p>

It completely loops this for loop ​https://github.com/ckeditor/ckeditor-dev/blob/master/core/htmlparser/fragment.js#L529-L534

I also found that commenting out these two lines stops loop: ​https://github.com/ckeditor/ckeditor-dev/blob/master/plugins/pastefromword/filter/default.js#L938-L939

Although this isn't of course fix for this issue. Now it's time to simplified filter rules in order to be able to track how the inf loop looks like, because it is very complex. By marking filtered nodes I only learnt that element#filterChildren starts processing offline nodes that has to be somewhere created.

[Piotrek Koszuliński]

I extracted #10327 which fixes one issue in htmlParser.filter. Unfortunately, fixing this issue reveals whole bunch of other in pastefromword filter. I was able to track one of them easily (styleElement in line :603 does not have parent set to element), but I found next inf loop. I don't want to debug it, because it is a waste of time, since we're planning #9991.

I'll try to find hack for this issue.

[Piotrek Koszuliński]

Pushed ​t/10285 on dev with a hack that prevents from falling in infinite loop.

[Piotrek Koszuliński]

I pushed also a test which helps in validating this patch.

[Frederico Caldeira Knabben]

For instance, I'm not able to reproduce this issue with Word for Mac 2011.

[Piotrek Koszuliński]

Sorry, I forgot to mention that I wasn't able too. Kuba had to send me HTML generated from his Word. We've got nearly the same version (just last two digits differs) and the same OS, but something was different.

Although try pasting that HTML I posted above and you will blow up editor. There's definitely an issue, I'm sure about that.

[Olek Nowodziński]

I confirm that t/10285 fixes inf loop in this case:

<p class="MsoNormal"><span style="font-size:24.0pt">test</span></p>

[Piotrek Koszuliński]

Fixed on master with ​git:3e1df4d on dev and 73f869d on tests.

[Jakub Ś]

I can confirm review_passed. I have tested this issue on all browsers and no infinite loop has occurred.

[Mike Kelley]

I would like to mention that this still occurs. We noticed then when we tried to paste from Outlook to CKEditor.

To reproduce:

1) open any html email in Outlook ( I used 2013 )

2) copy html content, ctrl-a / ctrl-c

3) past content into ckeditor ctrl-v, or click the paste button

The entire browser becomes unresponsive, and has to be killed.

[Piotrek Koszuliński]

I reported #10498 for this issue, because it's not the same issue if it is Outlook. Could you give us more information in that ticket?