New lines are added when pasting formatted text on composer

[alagane]

Summernote version 0.8.18

When I paste formatted text on the composer, newlines are added (<p><br/></p>), before what is pasted, and between lines.
Example of formatted text with resulting pasted text is provided here: #522 (comment)

When I press backspace or delete before I paste the text, there are no newlines added, there seem to be a <p><br/></p> that is removed when pressing one of those keys.
If I add a space before pasting (after removing the p), it does not seem to add newlines between pasted text paragraphs.
If I add space, move the cursor before and paste, the text is pasted last paragraph first (somewhat upside down).

Those problems do not happen on summernote standalone (simple html page with only summernote, same version 0.8.18). Note that we must use the pasteHTML command because this is what we use when we override the paste behaviour for HTML content on esn-frontend-inbox composer. Tests were done on summernote standalone the same way, with pasteHTML command.

This is not related to options (setting INBOX_SUMMERNOTE_OPTIONS to {} does not solve the problem).

This problem might we related with AgularJS behaviour with summernote.

[alagane]

Can reproduce with demo angular app (angular-seed) with angular-summernote plugin and summernote 0.8.18.
Reproduce only with pasteHTML, but not reproduced by pasting only.

[alagane]

Using directly summernote on AngularJS instead of angular-summernote seems to fix the problem, but we need to analyse the impact of removing this third party.
Mistested

[fabienmoyon]

@alagane great, thanks
We need to analyse the source code and check if there are issues related to that in angular-summernote

[alagane]

There seems to be no issue about the problem on angular-summernote, and the project development seems stopped or very slow.

[alagane]

summernote/summernote#3370
I think this is the issue, and it still seems to be in the latest version.
A commenter said they switched to quilljs and it worked great.

[alagane]

Tests against summernote 0.8.18 (on angularjs demo, without angular-summernote)
+ is the cursor, _ is space, number is to easily reference the case

Number	Content	Pasted	Result
1	+	<p>Hello</p><p>World</p>	<p>Hello</p><p>World</p>
2	<br>+	<p>Hello</p><p>World</p>	<p>Hello</p><p>World</p>
3	<p><br></p>+	<p>Hello</p><p>World</p>	<p><br></p><p>Hello</p><p>World</p>
4	<p><br></p><p><br></p>+	<p>Hello</p><p>World</p>	<p><br></p><p>Hello</p><p>World</p><p><br></p>
5	+	<p>Hello</p>_<p>World</p>	<p>Hello</p><p>_World</p>
6	<br>+	<p>Hello</p>_<p>World</p>	<p>Hello</p><p>_World</p>
7	<p><br></p>+	<p>Hello</p>_<p>World</p>	<p><br></p><p>Hello</p><p>_<br></p><p>World</p>
8	<p><br></p><p><br></p>+	<p>Hello</p>_<p>World</p>	<p><br></p><p>Hello</p><p>_<br></p><p>World</p><p><br></p>

Strange behaviour happens in:
4. Both p are inserted between the 2 <p><br></p>
5 & 6. Space is moved inside the second p
7. a <p> <br></p> is inserted between the 2 p
8. This one is a mess