rcfile: reject key names that are wrong or too long

Meta keys should have a dash as second character, and apart from ^Space
and M-Space key names should be at most two or three characters long.

This fixes https://savannah.gnu.org/bugs/?44688.

Reviewed-by: Benno Schulenberg <bensberg@justemail.net>
Signed-off-by: Rishabh Dave <rishabhddave@gmail.com>
1 file changed