Hello,

I do the following:

* Create a new message (plaintext)
* Write something, at least so much a linebreak is introduced at default 78 characters.

Hallo, ich schreibe hier was bis ich achtzig Zeichen erreicht habe und dann
wird ein linebreak gemacht.

* Close and save
* Reopen
* Edit the first line, enter something. The linebreak reflows to the next line and breaks the second line, though it's shorter then ~80 characters:

Hallo, ich schreibe (here I insert something) hier was bis ich achtzig Zeichen
erreicht habe und dann
wird ein linebreak gemacht.

This makes editing messages a real pain since you manually have to remove all linebreaks when text before them is added.

There is https://bugs.kde.org/show_bug.cgi?id=105485 from 2005 but it's wishlist item, for me it's clearly a bug.

I've disabled auto-word wrap at 78 characters for now...