bug#21168: 25.0.50; ffap-string-at-point-region gets raw cons value, breaking ffap-string-at-point

[Rupert Swarbrick]

My Emacs session has got into a situation where the
ffap-string-at-point-region is the raw cons

  (14812 . 2284)

As a result, the line at the bottom of ffap-string-at-point fails
when it tries to run

  (setcar (cdr ffap-string-at-point-region) end)


I'm running Emacs compiled from commit 123c82e, plus an unrelated commit
to fix the scheme lexer for semantic (hence the weird looking repository
version below).


I think the problem is probably caused by commit e48a116780d (from last
Wednesday), which changes line 1137 of ffap.el to:

            (setcdr ffap-string-at-point-region (point))

because the rest of ffap.el expects the variable to be a list with two
elements rather than a cons pair.


I've changed the line to 

            (setcar (cdr ffap-string-at-point-region) (point))

and stuff seems to work fine.


Rupert

In GNU Emacs 25.0.50.1 (x86_64-unknown-linux-gnu, X toolkit, Xaw scroll bars)
 of 2015-07-31 on <snipped>
Repository revision: b164ad9311b4f2c1a34ac61ac565e75f81aa6eaf
Windowing system distributor `The X.Org Foundation', version 11.0.11300000
System Description:     Red Hat Enterprise Linux Server release 6.4 (Santiago)

Configured using:
 `configure
 --prefix=<snipped>
 --with-xml2 --without-sound --without-rsvg --without-imagemagick
 --with-x-toolkit=lucid'

Configured features:
XPM JPEG TIFF GIF PNG GPM DBUS GCONF NOTIFY ACL LIBSELINUX GNUTLS
LIBXML2 FREETYPE XFT ZLIB TOOLKIT_SCROLL_BARS LUCID X11

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

Major mode: Lisp Interaction

Minor modes in effect:
  elisp-slime-nav-mode: t
  paredit-mode: t
  global-semantic-decoration-mode: t
  global-semanticdb-minor-mode: t
  global-semantic-idle-scheduler-mode: t
  stock-ticker-global-mode: t
  semantic-mode: t
  global-undo-tree-mode: t
  undo-tree-mode: t
  helm-mode: t
  async-bytecomp-package-mode: t
  desktop-save-mode: t
  keyfreq-autosave-mode: t
  keyfreq-mode: t
  show-paren-mode: t
  recentf-mode: t
  diff-auto-refine-mode: t
  magit-auto-revert-mode: t
  global-auto-revert-mode: t
  global-git-commit-mode: t
  shell-dirtrack-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-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
  column-number-mode: t
  line-number-mode: t

Recent messages:
buffer-substring-no-properties: Wrong type argument: consp, 2284
ffap-string-at-point
buffer-substring-no-properties: Wrong type argument: consp, 2284
(14812 . 2284)
buffer-substring-no-properties: Wrong type argument: consp, 2284
Searching for setcar...
Quit [2 times]
Auto-saving...
Mark set
Mark saved where search started

Load-path shadows:
<snipped: contain Broadcom-specific paths>

Features:
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multi-isearch derived helm-command helm-elisp helm-eval edebug
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Memory information:
((conses 16 1489287 73899)
 (symbols 48 59905 10)
 (miscs 40 11051 1377)
 (strings 32 264578 71214)
 (string-bytes 1 8338897)
 (vectors 16 108644)
 (vector-slots 8 1507597 41874)
 (floats 8 747 432)
 (intervals 56 63601 271)
 (buffers 976 125)
 (heap 1024 117679 5838))