bug#46621: Copy line

[Juri Linkov <juri@linkov.net>]

>   > >> In programming modes, if you need to declare a bunch of variables, you
>   > >> may duplicate the current line several times and then proceed to rename
>   > >> them.  I see the proposed new command may be useful in that scenario.
>
> Once in a while I want to do that.  It is easy: C-a C-k C-k,
> they C-y as many times as needed.

Let's compare these two solutions.  Trying to copy 10 lines:

  C-a C-k C-k C-y C-y C-y C-y C-y C-y C-y C-y C-y C-y

and adds an unrequested entry to the kill ring
that the user needs to remove from the kill ring later.

When bound to a short key, it's just

  C-12 C-c c

and doesn't change the contents of the kill ring.

> Instead of a command to duplicate the current line repeatedly,
> how about a command to yank the current kill repeatedly?
> That would be useful in a much broader range of situations.
>
> I wonder if the current meaning of the numeric argument to C-y (reach
> back in the kill ring) is actually useful.  Would it be better for
> it to repeat the yank in this way?

It's not realistic to change the meaning of the numeric arg to C-y.
People already use the current meaning for decades.