Scope of 'scrollopt' too much?

[Gary Johnson]

I've noticed a problem when I have multiple tab pages open, each
containing two windows that are diff'd, and I execute :diffoff! or
:tabclose! in one of the tabs. Either one of those commands resets
the value of 'scrollopt' from "ver,jump,hor" to "ver,jump". The
problem is that 'scrollopt' is a global options, so its reset value
affects the diffs in all the tab pages, not just the one in which
:diffoff! or :tabclose! was executed.

I encounter this problem frequently when using the Fugitive ":Git
difftool -y" command and close one of the tabs. It is not a bug in
Fugitive; I can reproduce it starting with "$ vim -N -u NONE -i
NONE -p file1 file2".

I could execute :diffoff again after :diffoff! as mentioned in
":help :diffoff", but that's annoying and not even possible in the
:tabclose! case.

Would it be possible to fix this problem, perhaps by doing something
like making 'scrollopt' tab-local (I know there's currently no such
thing) or resetting it to "ver,jump" only when no window in any tab
page is in diff mode?

Regards,
Gary

[Bram Moolenaar]

> I've noticed a problem when I have multiple tab pages open, each
> containing two windows that are diff'd, and I execute :diffoff! or
> :tabclose! in one of the tabs. Either one of those commands resets
> the value of 'scrollopt' from "ver,jump,hor" to "ver,jump". The
> problem is that 'scrollopt' is a global options, so its reset value
> affects the diffs in all the tab pages, not just the one in which
> :diffoff! or :tabclose! was executed.

The ex_difoff() function removes "hor" from 'scrollopt' when there are
no windows in diff mode in the current tab.

> I encounter this problem frequently when using the Fugitive ":Git
> difftool -y" command and close one of the tabs. It is not a bug in
> Fugitive; I can reproduce it starting with "$ vim -N -u NONE -i
> NONE -p file1 file2".
>
> I could execute :diffoff again after :diffoff! as mentioned in
> ":help :diffoff", but that's annoying and not even possible in the
> :tabclose! case.
>
> Would it be possible to fix this problem, perhaps by doing something
> like making 'scrollopt' tab-local (I know there's currently no such
> thing) or resetting it to "ver,jump" only when no window in any tab
> page is in diff mode?

We don't have tab-local options yet, and implementing them will be some
work. It's also not clear if we need new commands or that :setlocal
could be used.

We could check in ex_diffoff() if there is a window in another tab still
in diff mode and not remove "hor" from 'scrollopt' then. I wonder if
that would work for everyone.

--
When I die, I want to go peacefully in my sleep like my grandfather.
Not screaming in terror, like his passengers.

/// Bram Moolenaar -- Br...@Moolenaar.net -- http://www.Moolenaar.net \\\
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