bug#30243: 26.0.91; Infinite recursion in `make-auto-save-file-name' for quoted filenames

[Noam Postavsky]

Philipp Stephani <p.stephani2@gmail.com> writes:

> Noam Postavsky <npostavs@users.sourceforge.net> schrieb am Do., 25.
> Jan. 2018 um 00:04 Uhr:

>     +         (buffer-file-name
>     +          (if (and (memq operation '(make-auto-save-file-name))
>     +                   (string-match "\\`/:" buffer-file-name))
>     +              (substring buffer-file-name (match-end 0))
>     +            buffer-file-name))

> Thanks, when you commit this, could you please also add a regression
> test so we don't reintroduce the bug later? 

Yeah, we need to test more than just that operation though.  I've added
a test for all the operations listed in `(elisp) Magic File Names'.  I
discovered several other similar problems.  With
`file-name-all-completions' I even got Emacs to crash (I presume due to
stack corruption during the recursion).  Also note that the above patch
breaks find-file for /: quoted files, buffer-file-name needs to be bound
more selectively (as in the new patch, attached below).

`file-notify-rm-watch' and `file-notify-valid-p' are still broken, I
can't immediately see how to fix them and it's getting past my bedtime.

v2-0001-Test-and-fix-quoted-file-name-handlers-Bug-30243.patch
Description: patch