bug#67310: [PATCH] Include the project--list as history when prompting for a project

[Juri Linkov]

>>>>>>> This change broke the order of 'C-x p p M-n M-n ...',
>>>>>> Could you remind me which behavior in 'M-n M-n' the aforementioned change
>>>>>> relates to? Is this supposed to be like input history as well, or the
>>>>>> contents of the completions table in a certain order?
>>>>> It's inappropriate to overwrite the history with the recently visited 
>>>>> projects.
>>>>> Only user input should be added to history variables because it's actually
>>>>> the history of user input.  Therefore, the remaining way to access a list
>>>>> of recently visited projects is the future history with 'M-n M-n'.
>>>>
>>>> But... we do overwrite it now, manually constructing the value of input
>>>> history from project--list every time.
>>>>
>>>> So it seems like both "past history" and "future history" show the same
>>>> information now. If so, it might make sense to keep only one.
>>> It's usually not good to overwrite past history.  So it's better
>>> to keep only future history.
>>
>> I'm not sure the actual input history is useful here: in most cases,
>> it will be empty or almost empty. project history is different from
>> all others because we almost always detect it automatically. And also
>> because the total set of projects is relatively small, for each user.
>>
>> And "future history" is different for every command, including the
>> logic of how it's formed. Most users are also unaware of its
>> existence, so it wouldn't be a good idea to rely only on it.
>
> Yes, I think it's okay for project history to be treated as minibuffer
> history even though it's not actual input history.  It's not a huge
> deal, especially since the history didn't exist before.

To me the distinction between input history and project history is clear.
Especially since I added a lot of define-advice that update the most
recent project by any activity on a project: such as running 'vc-dir'
adds the current vc project dir to the top of the project list,
using Dired does the same, etc.  So I always have the most recently used
project on 'C-x p p M-n'.  Whereas I expect that 'C-x p p M-p' will get
the last project that was manually selected by the previous completion.