The problem I have is caused by Emacs.lineSpacing: 1 in my X resources (thanks to NickD for help in pinpointing this), which equates to:
(setq-default line-spacing 1)
With that in effect, I call find-file (C-x C-f) and my minibuffer says:
Find file: ~/.Xresources
There I select the file name and call kill-ring-save (M-w). Now my minibuffer says:
Find file: ~/.Xresources [Saved text until: "~/.Xresources"]
How do I stop that appended message and retain a line spacing of 1?