motion diff: amendment and nested list (dot in text)

[reiterl]

Describe the bug
The motion diff of a motion with a nested list and a dot and an amendment with a change to second level of the
nested list is an all deleted (red) and everything new added (green).
I also see an warn message in the console:

Added sequential number mapping view without meeting id

and the amendment hasn't got a title.

How to Reproduce

1. Go the motion list in a meeting
2. Create a new motion with following text: <ul><li>Ebene 1<ul><li>Ebene 2.1</li><li>Ebene 2.2</li></ul></li></ul>
3. Create an amendment to this motion with <ul><li>Ebene 1<ul><li>Ebene 2.1 foo</li><li>Ebene 2.2</li></ul></li></ul>. The foo is the only change
4. Look at the motion detail view

Expected behavior
It should work like:
motion text: <ul><li>Ebene 1<ul><li>Ebene 2A</li><li>Ebene 2B</li></ul></li></ul>
amendment text: <ul><li>Ebene 1<ul><li>Ebene 2A foo</li><li>Ebene 2B</li></ul></li></ul>
So it should only show the foo in green (as change).

Additional context
I think it is a problem with the HTML Diff stuff

motion-txt:

<ul><li>Ebene 1<ul><li>Ebene 2.1</li><li>Ebene 2.2</li></ul></li></ul>

amendment-text

<ul><li>Ebene 1<ul><li>Ebene 2.1 foo</li><li>Ebene 2.2</li></ul></li></ul>

[reiterl]

Also see #5856 for another problem in this context.

[reiterl]

Added a test in the motion diff service about this, see the pr #5872

[Elblinator]

The warning has nothing to do with the motion diff issue
Additionally this issue should be gone when Rel-DB is merged everywhere. So it should also not fixed.

[Elblinator]

The end of this bug is that the diffDetectBrokenDiffHtml(...) is detecting broken html that's why the complete original text is deleted and the new amenment text is inserted. The program simply doesn't know what the correct union of that is.

From what I could see is that the html is wrongly calculated

[MSoeb]

#2956 - part of the Meta