Paste over selected texts changes styling of pasted text

[Tomas]

It seems as the when selecting text in the editor and pasting over that, the paste keeps the previous styling in some strange way.

To reproduce:

Select the text below and paste into a empty editor:

Start text:
text that is styled bold text that is unstyled
End text

After the text has been pasted. Do ctrl+a to select all and then ctrl+v to paste the same text again.

All text is now bold. Repeating this introduces a new nested bold tag each time.

1. In my opinion application should clear styling when select all (ctrl+a) is issued.
   
2. And not insert a strong tag when there already is one.
   
3. In word you get the styling of what you paste not the styling of what you paste plus the styling of where you paste.
   

I understand that this is a area where different people would argue that different behavior is right. My opinion is that MS word behavior makes sense to me.

[Tomas]

Replying to toma25: Forgot to mention, FF 3.6 behaves same way as word. IE 7 and IE 8 is where I experience the problems.

[Garry Yao]

The point is that MS Word provide a feature called "paste options", as a post-decision that have option to keep the original formatting or to adapt to the context styles.

We could consider implementing such a feature to eliminate any arguments around the expected result.

[Tomas]

In my opinion IE and FF should behave the same way, at the moment they don't (why I consider it a bug). But I agree, one could argue for different behavior.

[Jakub Ś]

DUP of #7796

Please have a look at comment4 ​https://dev.ckeditor.com/ticket/7796#comment:4 from @fredck. It explains a source of the problem. Any way "contextual pasting" will be discussed in #7796