copy and paste omits file extension if (possibly) unknown

[cmburg]

What Happened?

I have a jupyter notebook which I copy-pasted via ctrt+c and ctrl+v in pantheon files. Although the text (copy) has been added, the extension .ipynb was not. This issue does not appear on more common extensions as .txt or .py

Steps to Reproduce

1. Create a file, e.g, foo.ipynb via the right mouse-button menu.
2. Select the file and press ctrl+c, ctrl+v

Expected Behavior

The extension is kept

OS Version

6.x (Odin)

Software Version

Latest release (I have run all updates)

Log Output

No response

Hardware Info

No response