bug#63785: 29.0.91; Clearing package list filters also clears flags

[Eshel Yaron via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Robert Pluim <rpluim@gmail.com> writes:

>>>>>> On Mon, 29 May 2023 19:48:45 +0300, Eshel Yaron <me@eshelyaron.com> said:
>
>     Eshel> Robert Pluim <rpluim@gmail.com> writes:
>     >> M-x list-packages
>     >> / n ack ;; navigate to the line for 'ack'
>     >> i ;; 'ack' has the 'I' flag
>     >> / / ;; 'ack' no longer has the I flag
>     >> 
>     >> This makes it harder to do 'search for foo, mark,
>     >> search for bar, mark, install', you have to remember to execute the
>     >> action after each mark command.
>     >> 
>
>     Eshel> That's an interesting issue, it can be a bit tricky because while
>     Eshel> filtering for "bar", "foo" is no longer anywhere to be found in the
>     Eshel> buffer.  So AFAIU to solve this Emacs needs to maintain something like a
>     Eshel> buffer-local association between list entry (package) ids and the tags
>     Eshel> they were given.
>
>     Eshel> This sounds like something that applies more broadly to other
>     Eshel> `tabulated-list-mode` derivatives as well.  The attached patch adds a
>     Eshel> `tabulated-list-maintain-tags` variable and enables it in
>     Eshel> `package-menu-mode`.  With it I can search and mark foo, then search and
>     Eshel> mark bar, and then install both, as you say.  WDYT?
>
> Itʼs close. The following is still suprising
>
> / n helm
> i
> / /
> / n ack
> i
> x
>
> That only offer to installs ack, even though Iʼve marked helm. If I
> clear the filters then 'x' offers to install both.  Although I could
> argue that Iʼm in a filtered state, so offering to install only
> visible packages is normal :-)

Yes, that's what I thought.  Only installing visible packages when the
menu is filtered seems sensible to me.  Although I guess
`package-menu-execute` could be extended with some option that says what
to do in these cases, maybe by default it could suggest clearing the
filter first?