> From: Ihor Radchenko <yanta...@posteo.net> > Cc: monn...@iro.umontreal.ca, emacs-orgmode@gnu.org, 65...@debbugs.gnu.org, > maniku...@gmail.com, i...@whxvd.name > Date: Thu, 11 Jan 2024 16:15:13 +0000 > > Eli Zaretskii <e...@gnu.org> writes: > > >> So, I'd like some way to configure `kill-whole-line'/`kill-line' to warn > >> user about killing hidden text when we detect that we are deleting a > >> folded heading. Something like: > >> > >> (y-or-n-p "Kill hidden subtree along with headline? ") > >> > >> I believe that it might be useful in other situations as well. Like in > >> outline-mode or outline-minor-mode. > > > > How would kill-line know that it's about to kill a subtree? All it > > knows is that it is killing some invisible text. > > I imagine the following: > > 1. `kill-*-line' function will, by default, test if invisible text of > length size is killed and query the user when called interactively. > > 2. Major modes could also set buffer-local `kill-line-query-function' > that will return nil when killing should proceed without query or a > string with query text.
If the command is only sensitive to invisible text, it could warn about so-and-so many invisible characters being killed, but it could not warn about "subtrees", which is what you wanted. Invisible text in a buffer could have nothing to do with subtrees, even if the buffer is under org-mode.
