bug#65380: [PATCH] Add command to copy contents in a diff-mode buffer

[Jim Porter]

On 8/20/2023 2:29 PM, Gregory Heytings wrote:
> > That's not quite what I mean. "C-x r y" ('yank-rectangle') yanks the 
> > rectangle *as a rectangle*. That is, if I just copied a rectangle with 
> > 5 lines, and yank it with 'yank-rectangle', it will add it to the next 
> > 5 existing lines. Instead, what I want is to insert 5 new lines.
>
> Indeed, I see what you mean.  Perhaps a new C-x r command that would do 
> that could be added to Emacs?

Yeah, the question then is: should it be new kill/copy commands or a new 
yank command? The former would mean you could use all the existing yank 
functions to paste the text in, but the latter means you can defer your 
decision about how to yank the text (as a regular region or as a 
rectangle) until you're ready to actually yank.

I'd lean a bit towards the former, but that does mean (potentially) two 
new key bindings.



... hmm, or maybe you could make the existing rectangle kill/copy 
commands also add to the "regular" kill ring automatically? But then 
that might cause issues with 'rectangle-mark-mode', where 'C-y' performs 
'yank-rectangle'[1]: how would I use 'rectangle-mark-mode' to copy a 
rect and then paste it as a regular region?

[1] Well, technically 'rectangle--insert-for-yank', but they both call 
'insert-rectangle' in the end.