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

[Philip Kaludercic]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Philip Kaludercic <philipk@posteo.net>
>> Cc: 65380@debbugs.gnu.org
>> Date: Sat, 19 Aug 2023 10:48:03 +0000
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> > Please tell more about the use cases where this would be useful.  I
>> > couldn't understand that from the patch itself.
>> 
>> A simple example is where someone sends me a patch with a Elisp function
>> I'd like to evaluate.  If I can't or don't want to apply the patch right
>> now, I can use `diff-kill-ring-save' to copy the function without the
>> leading "+" into my scratch buffer and evaluate it there.
>
> But diffs don't necessarily show the entire body/ies of function(s),
> they show just part of them.  So this seems to be useful only in a
> very small subset of cases?

In theory yes, but as I mentioned in my first message, it comes up
surprisingly often, at least to the degree that I think it would be
something nice to have in general.  If you think the current
implementation is too primitive, one could extend it to check if the
region is a subregion of a hunk, and handle that appropriately.