>> But actually the customization for "1" doesn't affect popping to "2"
>> because pop-to-buffer still selects windows and creates such layout:
>>
>>    *scratch*
>>    Buffer "1"
>>    Buffer "2"
>>
>> Only post-command-hook selects the original window afterwards
>> instead of leaving the buffer "2" selected.
>
> And if the customization for "2" meant to select the window, the final
> outcome will depend on whichever (de-)selection comes last in the
> 'post-command-hook'.  You should at least document that in the manual.
> It looks pretty fragile to me.

A practical use of this feature is for commands that display a single buffer
that is an overwhelming majority of the commands.

However, the name 'select-window' would be too confusing for users
because based on such name they will expect that it will select
the window immediately after it's displayed.

Therefore I propose to rename it to the less ambiguous name
'post-command-select-window'.  Of course it should be documented in
any case, but this will help the users who never read the documentation.

Ok, here is a complete patch with the documentation: