bug#51902: 28.0.50; [PATCH] Get mh-e tests to pass

[Mike Kupfer <mkupfer@alum.berkeley.edu>]

Stephen Gildea wrote:

> Mike, bug report https://debbugs.gnu.org/51902 causes me to notice that
> our fix for "+/" works only with nmh.  It fails with GNU Mailutils and
> with MH mocked out.
> 
> I can fix the mocks (and am sad I didn't think to test that before
> committing the patch).

Ah.  So that explains the test failure that Lars reported on emacs-devel
(<871r3g7cdy.fsf@gnus.org>)?

> But what about mailutils?  I think you told me that you had to get a
> bug in nmh fixed before this would work; perhaps mailutils has the same
> bug?  If so, do we need to make an exception in the test as suggested
> by this bug report: expect failure with mailutils?

The bug was in an older version of Mailutils, where it was spewing
garbage from some internal buffer.  Sergey fixed it in Mailutils 3.7,
which was released in 2019.  So I'd configure the test to expect a pass
everywhere, once the mock environment is fixed.

Also, did you catch this comment from Stefan Kangas on emacs-devel:

> I've marked these tests as unstable for now (commit fc8c976298), please
> remove that tag when you fix them.

thanks,
mike