bug#64185: proposal for new function: copy-line

[Juri Linkov]

>> > +(defcustom duplicate-line-pos 0
>> > +  "Where to put point after copying the line.
>> 
>> A better name for this would be duplicate-line-final-position or maybe
>> duplicate-line-point-position.
>> 
>> Also, please mention this variable in NEWS, where duplicate-line is
>> announced.
>
> FWIW -
>
> Point is the cursor position.  So I'd suggest
> just "point" (or "cursor-position", if you
> like), and not "point-position".
>
> We do use `pos' in various names to mean a
> buffer position, but in those cases it
> doesn't stand for point (the cursor position).
> So I agree that `pos' shouldn't be used here.

In the patch a new position is counted by lines,
so maybe a better name would be 'duplicate-line-final-line'.
But this double "line-line" doesn't look nice.