bug#28655: 25.2; Problem with find-file-noselect

bug#28655: 25.2; Problem with find-file-noselect

[Live System User]

Hi,

        I experienced a problem with `find-file-noselect`.

        The partion where my /home directory is mounted became
        unrelatedly readonly.

        When I tried to visit a file, readonly "C-x C-r"
        `(find-file-read-only),` I got the following
        *Backtrace* (see below).

`       Executing `(find-file-noselect)` and `(file-truemame)`
        interactively yeilds the expected reults:

                M-: (find-file-noselect "~/dt.el" nil nil t)
                #<buffer dt.el>

                [I don't get the "(wrong-type-argument arrayp nil)"
                error as in the *Backtrace]

                M-: (file-truename "~/dt.el")
                "/home/liveuser/dt.el"

        I realize that this is an unusal circumstance but peraps
        there is some way that Emacs could be able to visit a file
        in readonly-mode when the underlying filesystem has become
        readonly.

        Thanks.

Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
  file-truename(nil)
  find-file-noselect-1(#<buffer dt.el<2>> "~/dt.el" nil nil "~/dt.el" (6637 64770))
  find-file-noselect("~/dt.el" nil nil t)
  find-file("~/dt.el" t)
  find-file--read-only(find-file "~/dt.el" t)
  find-file-read-only("~/dt.el" t)
  funcall-interactively(find-file-read-only "~/dt.el" t)
  call-interactively(find-file-read-only nil nil)
  command-execute(find-file-read-only)




In GNU Emacs 25.2.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.20.10)
 of 2017-05-02 built on buildvm-17.phx2.fedoraproject.org
Windowing system distributor 'Fedora Project', version 11.0.11803000
Configured using:
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 --with-gpm=no --with-xwidgets --with-modules
 build_alias=x86_64-redhat-linux-gnu host_alias=x86_64-redhat-linux-gnu
 'CFLAGS=-DMAIL_USE_LOCKF -O2 -g -pipe -Wall -Werror=format-security
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 LDFLAGS=-Wl,-z,relro
 PKG_CONFIG_PATH=:/usr/lib64/pkgconfig:/usr/share/pkgconfig'

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ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
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Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
C-h C-g is undefined
Quit

Load-path shadows:
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bug#28655: 25.2; Problem with find-file-noselect

[Glenn Morris]

Live System User wrote:

>         The partion where my /home directory is mounted became
>         unrelatedly readonly.
>
>         When I tried to visit a file, readonly "C-x C-r"
>         `(find-file-read-only),` I got the following
>         *Backtrace* (see below).
[...]
> Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
>   file-truename(nil)
>   find-file-noselect-1(#<buffer dt.el<2>> "~/dt.el" nil nil "~/dt.el" (6637 64770))
>   find-file-noselect("~/dt.el" nil nil t)
>   find-file("~/dt.el" t)
>   find-file--read-only(find-file "~/dt.el" t)
>   find-file-read-only("~/dt.el" t)
>   funcall-interactively(find-file-read-only "~/dt.el" t)
>   call-interactively(find-file-read-only nil nil)
>   command-execute(find-file-read-only)

I can't reproduce this. I tried with:

mount -t tmpfs -o size=10m tmpfs /mnt/
HOME=/mnt emacs-25.2 -Q &
...
mount -r -o remount /mnt/

and C-x C-r continues to work fine.

The above backtrace isn't detailed enough to debug this issue.
I can only guess that buffer-file-name somehow became nil.
How, I have no idea.

bug#28655: 25.2; Problem with find-file-noselect

[Live System User]

Glenn Morris <rgm@gnu.org> writes:

> Live System User wrote:
>
>>         The partion where my /home directory is mounted became
>>         unrelatedly readonly.
>>
>>         When I tried to visit a file, readonly "C-x C-r"
>>         `(find-file-read-only),` I got the following
>>         *Backtrace* (see below).
> [...]
>> Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
>>   file-truename(nil)
>>   find-file-noselect-1(#<buffer dt.el<2>> "~/dt.el" nil nil "~/dt.el" (6637 64770))
>>   find-file-noselect("~/dt.el" nil nil t)
>>   find-file("~/dt.el" t)
>>   find-file--read-only(find-file "~/dt.el" t)
>>   find-file-read-only("~/dt.el" t)
>>   funcall-interactively(find-file-read-only "~/dt.el" t)
>>   call-interactively(find-file-read-only nil nil)
>>   command-execute(find-file-read-only)
>
> I can't reproduce this. I tried with:
>
> mount -t tmpfs -o size=10m tmpfs /mnt/
> HOME=/mnt emacs-25.2 -Q &
> ...
> mount -r -o remount /mnt/
>
> and C-x C-r continues to work fine.
>
> The above backtrace isn't detailed enough to debug this issue.
> I can only guess that buffer-file-name somehow became nil.
> How, I have no idea.

 As the process is now gone, no additional info is no longer
 available, I guess this bug report can be closed.

 Thanks for looking into this.