bug#32989: 26.1; Opening PDF attachments in Gnus with doc-view-mode causes error on Windows

[Eli Zaretskii <eliz@gnu.org>]

> From: Jordan Wilson <jordan.t.wilson@gmx.com>
> Cc: 32989@debbugs.gnu.org
> Date: Wed, 10 Oct 2018 11:45:57 +0100
> 
> 
> [1:text/plain Hide]
> 
> On 2018-10-08 (Mon) at 23:02 (ZZZ), Eli Zaretskii <eliz@gnu.org> wrote:
> >> From: Jordan Wilson <jordan.t.wilson@gmx.com>
> >> Date: Mon, 08 Oct 2018 15:44:55 +0100
> >> 
> >>   File error: "Opening output file", "Invalid argument", "c:/Users/Jordan/Emacs/.cache/docview-cache/ *mm*-012345" 
> >> 
> >> this leaves a buffer showing the file literally. If I rename that buffer
> >> to something not containing an asterisk, it displays fine when running
> >> "doc-view-mode". Windows apparently can't handle asterisks in
> >> directory/file names.
> >
> > Windows doesn't allow '*' (and a few other characters) in any file
> > name, not just in directory name.  Gnus should run the file name
> > through convert-standard-filename to get something that is guaranteed
> > to work on any filesystem.
> Looking, it seems to be on doc-view's side -- if a buffer isn't
> associated with a file, it uses the buffer name for the file's cache
> directory. Here's a patch to the 26 and trunk branches of doc-view.el to
> run the file names through `convert-standard-filename'. It fixes the
> problem for me, at least.

Thanks, pushed to the emacs-26 branch (will be merged to master from
there shortly).