bug#63648: 29.0.90; project.el: with switch-use-entire-map, switch-project errors on non-project commands

[Dmitry Gutov <dmitry@gutov.dev>]

On 24/05/2023 09:20, Juri Linkov wrote:
>>>> C-x p p some/project RET C-x v +
>>>>
>>>> because I wanted to immediately pull that project.  Intuitively it made
>>>> sense to me that that should work, it would be nice if it did actually
>>>> work.
>>> This should be possible to implement by using 'set-transient-map'.
>>>
>>>> (Tangential further thought: I wonder if we could make C-x p work as a
>>>> prefix for all commands automatically, so for example C-x p C-x C-j
>>>> would open the project root, C-x p M-& would run a shell command in the
>>>> root, etc.  That would be neat.)
>>> IOW, like 'C-x p p' but without asking for another project.  Doable as well.
>>
>> That sounds like a cool potential addition, just we all need to keep in
>> mind that not every command will be 100% compatible with the approach.
> 
> Why not every command?  For example, 100% commands are compatible with
> 'C-x t t.'
> 
>> One example is the bug#58784 where changing default-directory made
>> project-switch-to-buffer behave incorrectly. Maybe there are some less
>> subtle examples as well.
> 
> 'display-buffer-override-next-command' already solved these problems.
> So a similar function could remember 'project-current-directory-override'
> for the next command.

But we were talking about "regular" commands, right? Those don't know 
anything about project-current-directory-override.

So we'd bind default-directory, and that's where the problem could come 
from. Hopefully, only in rare cases, though.