bug#23101: 25.1; Error when visiting a symlink to a VC-controlled file on the command line

[Philipp Stephani]

emacs -Q -nw SYMLINK

where SYMLINK is any symlink to a VC-controlled file. Emacs will
display a curses-like dialog asking whether the symlink should be
followed. After selecting Yes, a signal is raised and the file is not
visited. Stack trace:

Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
file-truename(nil)
find-buffer-visiting(nil)
vc-follow-link()
vc-refresh-state()
run-hooks(find-file-hook)
after-find-file(nil t)
find-file-noselect-1(# "~/emacs/README.link" nil nil "~/emacs/README" (3277016 64513))
find-file-noselect("/home/phst/emacs/README.link")
#[1285 ".\204..\300.!\204..\301\302.\"\207\303\304.!.\"\305.!.... \242B\240\210\211q\210.\242\306U\2043.eb\210.\242Sy\210.\306\240\210.\242\307W\204D.\310.\242S!\210.\306\240\207" [file-name-absolute-p message "Ignoring relative file name (%s) due to nil default-directory" expand-file-name command-line-normalize-file-name find-file-noselect 0 1 move-to-column] 10 "\n\n(fn DISPLAYABLE-BUFFERS DIR LINE COLUMN NAME)"]((nil) "~/emacs/" (0) (0) "README.link")
command-line-1(("-f" "toggle-debug-on-error" "README.link"))
command-line()
normal-top-level()




In GNU Emacs 25.1.50 (x86_64-unknown-linux-gnu, GTK+ Version 3.10.8)
System Description: Ubuntu 14.04 LTS

Configured using:
'configure --disable-build-details CFLAGS=-g'

Configured features:
XPM JPEG TIFF GIF PNG SOUND GSETTINGS NOTIFY FREETYPE XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
value of $LANG: en_US.UTF-8
locale-coding-system: utf-8-unix

Major mode: Debugger

Minor modes in effect:
diff-auto-refine-mode: t
tooltip-mode: t
global-eldoc-mode: t
electric-indent-mode: t
mouse-wheel-mode: t
tool-bar-mode: t
menu-bar-mode: t
file-name-shadow-mode: t
global-font-lock-mode: t
font-lock-mode: t
auto-composition-mode: t
auto-encryption-mode: t
auto-compression-mode: t
buffer-read-only: 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.
Debug on Error enabled globally
Entering debugger...

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message dired dired-loaddefs format-spec
rfc822 mml mml-sec password-cache epa derived epg epg-config gnus-util
rmail rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils debug vc-git diff-mode easy-mmode map seq
byte-opt gv bytecomp byte-compile cconv cl-extra help-mode easymenu
cl-loaddefs pcase cl-lib cus-load term/xterm xterm time-date mule-util
tooltip cus-start eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar
dnd fontset image regexp-opt fringe tabulated-list newcomment elisp-mode
lisp-mode prog-mode register page menu-bar rfn-eshadow timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932
hebrew greek romanian slovak czech european ethiopic indian cyrillic
chinese charscript case-table epa-hook jka-cmpr-hook help simple abbrev
obarray minibuffer cl-preloaded nadvice loaddefs button faces cus-face
macroexp files text-properties overlay sha1 md5 base64 format env
code-pages mule custom widget hashtable-print-readable backquote inotify
dynamic-setting system-font-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 168760 10124)
(symbols 48 21948 0)
(miscs 40 48 94)
(strings 32 54530 7129)
(string-bytes 1 2271107)
(vectors 16 20478)
(vector-slots 8 465697 3482)
(floats 8 331 146)
(intervals 56 226 0)
(buffers 976 13)
(heap 1024 31200 857))

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