23.0.50; delete-seletion-mode and read-only text

[Johan Bockgård]

In delete-seletion-mode, trying to self insert in read-only text when
there is a selection signals an error that clears pre-command-hook.

emacs -Q

    (delete-selection-mode 1)
    (insert (propertize "12345" 'read-only t))

Select read only text with C-SPC + moving. Press a self-inserting key ("x").

=> pre-command-hook is cleared.

delete-selection-mode does check buffer-read-only, but it does not
protect against read-only text.

-- 
Johan Bockgård