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

[Live System User <nyc4bos@aol.com>]

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:
 'configure --build=x86_64-redhat-linux-gnu
 --host=x86_64-redhat-linux-gnu --program-prefix=
 --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr
 --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc
 --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64
 --libexecdir=/usr/libexec --localstatedir=/var
 --sharedstatedir=/var/lib --mandir=/usr/share/man
 --infodir=/usr/share/info --with-dbus --with-gif --with-jpeg --with-png
 --with-rsvg --with-tiff --with-xft --with-xpm --with-x-toolkit=gtk3
 --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
 -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong
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 -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64 -mtune=generic'
 LDFLAGS=-Wl,-z,relro
 PKG_CONFIG_PATH=:/usr/lib64/pkgconfig:/usr/share/pkgconfig'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS GCONF GSETTINGS NOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 MODULES XWIDGETS

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
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  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
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  file-name-shadow-mode: t
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  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

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:
None found.

Features:
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Memory information:
((conses 16 87122 4895)
 (symbols 48 19809 0)
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