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

[Juri Linkov]

>> 'C-x p p C-x v L' to see a vc log in another project, and
>> 'C-x p p C-x v d' to open vc-dir, etc.
>
> All right, so we also want to support non-project commands. And you wanted
> to use a common approach for both.
>
> What if we handle them differently, though? For "project" commands (those
> that internally call project-current) we can set one variable, and for the
> rest -- alter default-directory. Then restore the previous value in
> post-command.
>
> The detection of "project commands" could work like this:
>
> - Is it in one of the special maps? E.g. in project-prefix-map. Or maybe
>   it's in project-switch-commands.
> - Does the function name start with 'project-'?
> - Finally, for user-defined commands we could also introduce a property
>   'project-command-p', although the distinction between using
>   project-current-directory-override vs default-directory will not be
>   important for every such command, so maybe being this thorough is not too
>  important.

Sorry, I don't understand how 'C-x p p' could read the user's mind
whether the user afterwards will type a key for a project command
or a non-project command?  And depending on user's intention will
either set project-current-directory-override or default-directory.