Uncaught DOMException: Failed to execute 'setStart' on 'Range' upon Undo/Redo

[bsilvern]

Type of report

Bug

Provide detailed reproduction steps (if any)

While performing Undo or Redo, on numerous seemingly random occasions, I've observed messages such as the following in the console:
Uncaught DOMException: Failed to execute 'setStart' on 'Range': There is no child at offset 6, accompanied by a loss of function of the Undo/Redo keys, as if the snapshot stack had become truncated.

The presence of <br>'s rather than <p>'s appears to be a critical element in this issue. The following sequence provides a repeatable example:

1. Go to https://ckeditor.com/docs/ckeditor4/latest/examples/htmlformatting.html.

2. Replace the contents of the editor (in Source mode) with the following:
   <img alt="" src="https://ckeditor.com/apps/ckfinder/userfiles/images/pebbles.jpg" style="float:left; height:40px; width:60px">​​​​

3. Click Source (to go to WYSIWYG mode)

4. Click the image

5. Hit the following keys:

   • Ctrl-X (Cut)
   • Ctrl-V (Paste)
   • End
   • Shift-Enter (to enter a <br>)
   • Paste
   • Shift-Enter (to enter a <br>)
   • foo (enter any text)
   • Undo

Expected result

The entered text "foo" should be removed. Further Undos should remove the images.

Actual result

"foo" is removed, but Undo/Redo no longer function.

The following error is observed in the console:

ckeditor.js:454 Uncaught DOMException: Failed to execute 'setStart' on 'Range': There is no child at offset 6.
    at CKEDITOR.dom.selection.selectRanges (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:454:418)
    at CKEDITOR.dom.selection.selectBookmarks (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:457:393)
    at CKEDITOR.plugins.undo.UndoManager.restoreImage (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:1093:96)
    at CKEDITOR.plugins.undo.UndoManager.redo (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:1094:454)
    at window.CKEDITOR.window.CKEDITOR.dom.CKEDITOR.command.exec (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:1087:467)
    at window.CKEDITOR.window.CKEDITOR.dom.CKEDITOR.command.exec (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:201:500)
    at a.execCommand (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:270:143)
    at window.CKEDITOR.window.CKEDITOR.dom.CKEDITOR.keystrokeHandler.e (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:242:238)
    at $.h (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:10:70)
    at $.fire (https://ckeditor.com/docs/vendors/4.11.4/ckeditor/ckeditor.js:11:433)
selectRanges @ ckeditor.js:454
selectBookmarks @ ckeditor.js:457
restoreImage @ ckeditor.js:1093
redo @ ckeditor.js:1094
exec @ ckeditor.js:1087
exec @ ckeditor.js:201
execCommand @ ckeditor.js:270
e @ ckeditor.js:242
h @ ckeditor.js:10
(anonymous) @ ckeditor.js:11
(anonymous) @ ckeditor.js:63

Other details

• Browser: Vivaldi 2.5.1525.48
• OS: Win 8.1
• CKEditor version: at least 4.10.0
• Installed CKEditor plugins: dialogui,dialog,a11yhelp,about,basicstyles,blockquote,notification,button,toolbar,clipboard,panel,floatpanel,menu,contextmenu,elementspath,indent,indentlist,list,enterkey,entities,popup,filetools,filebrowser,floatingspace,listblock,richcombo,format,horizontalrule,htmlwriter,image,fakeobjects,link,magicline,maximize,pastefromword,pastetext,removeformat,resize,menubutton,scayt,showborders,sourcearea,specialchar,stylescombo,tab,table,tabletools,tableselection,undo,lineutils,widgetselection,widget,notificationaggregator,uploadwidget,uploadimage,wsc,wysiwygarea

[jacekbogdanski]

I can reproduce the issue on Chrome. It looks like a selection bookmarked by the undo manager is somehow corrupted after inserting the next image at the next line broken with br (using SHIFT + ENTER).

[remigasas]

I can reproduce this issue as well.
Chrome & ckeditor: "4.11.1".

No reliable way to reproduce it, happens editing li element and doing undo.
DOMException: Failed to execute 'setStart' on 'Range': The offset 14 is larger than the node's length (7).
Because exception refers to text nodes (nodeName: "#text") and offset difference (offset - length) is typically 7.

Perhaps it is somehow related to 8203 chars ?

[jacekbogdanski]

Perhaps it is somehow related to 8203 chars ?

Yes, that's the case. The issue exists only on chromium browsers. We are currently investigating it and hopefully will be able to provide bug fix soon.

[Comandeer]

The issue is present also in Safari browsers. The same reproduction steps throw following error:

[Error] IndexSizeError: The index is not in the allowed range.
	setStart (selection.js:2206)
	selectRanges (selection.js:2206)
	selectBookmarks (selection.js:2402)
	restoreImage (plugin.js:443)
	undo (plugin.js:528)
	exec (plugin.js:33)
	exec (command.js:56)
	execCommand (editor.js:976)
	(anonymous function) (plugin.js:87)
	execute (plugin.js:165)
	(anonymous function) (plugin.js:197)
	(anonymous function) (tools.js:828)
	callFunction (tools.js:856)
	onclick (Script Element 4:1)

[mudasir-ganayee124]

i have the sam issue in office.com/setup