Subject: bug#27966: 25.1.50; Bad behaviour #'generate-new-buffer-name if buffer "nil" exists

From: Aidan Kehoe <[email-masked]>
Date: Sat, 5 Aug 2017 10:15:54 +0100

I start emacs:

$ emacs -Q

I type the following into *scratch*:

(progn (get-buffer-create "nil")
       (generate-new-buffer-name "nil")) C-j

This gives the string "nil". This is incorrect behaviour, since "nil" is
the name of an existing buffer. On line 1080 of buffer.c, IGNORE should
be checked to be non-nil before calling Fstring_equal(). 

In GNU Emacs 25.1.50.2 (i386-apple-darwin10.8.0, NS appkit-1038.36 Version 10.6.8 (Build 10K549))
 of 2016-08-11 built on bonbon
Repository revision: 2e0a2b376f51dd515ffeb6449181cc37fe912f5e
Windowing system distributor 'Apple', version 10.3.1038
Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Entering debugger...
Back to top level
Mark activated

Configured features:
RSVG IMAGEMAGICK DBUS NOTIFY ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS
NS

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

Major mode: Lisp Interaction

Minor modes in effect:
  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
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message subr-x puny seq byte-opt gv
bytecomp byte-compile cl-extra cconv 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 help-mode easymenu cl-loaddefs pcase
cl-lib debug time-date mule-util tooltip eldoc electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel term/ns-win ns-win
ucs-normalize term/common-win 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 dbusbind kqueue cocoa ns multi-tty
make-network-process emacs)

Memory information:
((conses 8 207947 15960)
 (symbols 24 20538 0)
 (miscs 20 103 415)
 (strings 16 18679 5954)
 (string-bytes 1 597873)
 (vectors 8 34682)
 (vector-slots 4 685880 8462)
 (floats 8 184 228)
 (intervals 28 416 257)
 (buffers 520 15))

-- 
‘As I sat looking up at the Guinness ad, I could never figure out /
How your man stayed up on the surfboard after forty pints of stout’
(C. Moore)