bug#46621: Copy line

[Eli Zaretskii]

> From: Helmut Eller <eller.helmut@gmail.com>
> Date: Mon, 22 Feb 2021 17:28:39 +0100
> 
> One example where copy-line would be useful is editing configuration
> files.  E.g. /etc/ssh/sshd_config list many options with the default
> value but as comments, like so:
> 
>   #SyslogFacility AUTH
>   #LogLevel INFO
>   ... other options ...
>   
> Now, if I want to change LogLevel to say DEBUG, I would copy the line,
> keep the original, and edit the copied line.

I already mentioned M-/ as the alternative.  In the above case, type
"#L M-/", and Emacs will complete to "#LogLevel".  IOW, if these cases
are considered as "repeat a previous word" rather than "copy a
previous line, then edit it", the solution already exists.  I suspect
that people who are looking for this command simply don't know about
M-/ in Emacs, because IME it's still quite a unique feature.