help-echo property disappearing

[Nicolas P. Rougier (inria)]

I'm playing with the help-echo property and it keeps disappearing 
for no obvious reason. I would like to confirm the behavior and to 
know if this is the intended behavior. Here is a simple example:

(progn
 (goto-char (point-min))
 (insert (propertize "TEST"
                     'another-property "Test message"
                     'help-echo "Test message"))
 (goto-char (point-min))
 (kill-visual-line) (yank))

Before kill/yank, the string has both the `help-echo` and 
`another-property` set, but the yanked string has only the 
`another-property` set. This is in text-mode, using Emacs 29.1. I 
also observed that in prog-modes, I cannot set the help-echo 
property at all (with no warning).

Nicolas

--
Nicolas P. Rougier —— www.labri.fr/perso/nrougier
Institute of Neurodegenerative Diseases, Bordeaux