UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.75 Safari/537.36

Example URL:
https://www.froala.com/wysiwyg-editor/

Steps to reproduce the problem:
1. document.execCommand('strikethrough',false,null); //returns true 
2. document.execCommand('underline',false,null); //returns true
3. enter some text in editable //text got underline and strikethrough
4. document.execCommand('striketrough' or 'underline',false,null); //returns true
5. document.queryCommandState('striketrough' or 'underline'); //returns true for both
6. type a character in editable and query for command from 4 returns false as expected 
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there is no difference when using styling with tags or css

What is the expected behavior?
in 5 command executed in 4 should return false, works perfectly in firefox,old opera

What went wrong?
text, editing on this editor page make a new line click underline,strikethrough type characters, click underline,strikethrough and watch the bug, many other editors are affected

Does it occur on multiple sites: Yes

Is it a problem with a plugin? N/A 

Did this work before? N/A 

Does this work in other browsers? Yes 

Chrome version: 50.0.2661.75  Channel: stable
OS Version: Arch
Flash Version: