Text pasted into end of file has newlines removed on save, then ctrl+z crashes the editor

[claybford]

Pretty much the title:

• open an existing file (for me, editing userChrome.css for Firefox, which was originally created in Windows, if relevant)
• paste code into the end of the file
• save (ctrl+s)
• newlines dissappear (the file does indeed save like this)
• ctrl+z -> editor crashes out

[WatchMkr]

Might be related to https://github.com/pop-os/cosmic-edit/issues/322

[herrdiener]

The crash also occurs on other triggers after final newlines are eaten, e.g. on pressing Enter.