bug#73387: 30.0.90; C-x v v in diff-mode doesn't work after C-c C-n

[Dmitry Gutov <dgutov@yandex.ru>]

On 30/09/2024 12:38, Sean Whitton wrote:
> Hello,
> 
> On Mon 30 Sep 2024 at 03:27am +03, Dmitry Gutov wrote:
> 
>> On 30/09/2024 02:46, Sean Whitton wrote:
>>> Hello,
>>> On Fri 27 Sep 2024 at 10:13pm +03, Dmitry Gutov wrote:
>>>
>>>>> What do you think about this:
>>>>> - add a command which does the kill-all-but-this-hunk (or hunks in
>>>>>      region if mark active) thing -- it's generally useful.
>>>>> - make C-x v v on a narrowed buffer, by default, issue a message saying
>>>>>      "Cannot commit patch when narrowed, consider <binding of new command>"
>>>> Or it would implement that previous alternative - using the modified buffer
>>>> string that's limited to the current narrowing.
>>>>
>>>> I'm somewhat concerned about supporting both approaches (how different are the
>>>> code paths going to be?), but if that's needed for usability, perhaps it's
>>>> okay.
>>> Hmm, I thought that we thought the modified buffer string approach was
>>> too messy.  Would you mind outlining your proposal as a whole and how it
>>> differs from my most recent one?
>> Actually, how about we start with your suggested steps, sans for the last one,
>> for now. Meaning, just aborting with a message when the buffer is narrowed,
>> without the user option.
>>
>> We would not be removing any existing functionality this way (this scenario
>> didn't work before, after all), and we could add it later.
>>
>> Would that work for your habits/scenarios?
> You mean, just adding the command which kills hunks?

Just these two points:

- add a command which does the kill-all-but-this-hunk (or hunks in
   region if mark active) thing -- it's generally useful.

- make C-x v v on a narrowed buffer, by default, issue a message saying
   "Cannot commit patch when narrowed, consider <binding of new command>"