bug#4454: 23.1.50; vc-call-backend raises wrong-type-argument error

bug#4454: 23.1.50; vc-call-backend raises wrong-type-argument error

[Stephen Berman]

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After updating today, I started emacs -Q and tried to visit a file in my
CVS Emacs tree, and this raised a wrong-type-argument error.  This
happens with any file under version control.  It does not happen with my
previous build from two weeks ago. A backtrace is attached (because it
contains byte code)

In GNU Emacs 23.1.50.3 (i686-pc-linux-gnu, GTK+ Version 2.14.4)
 of 2009-09-16 on escher
Windowing system distributor `The X.Org Foundation', version 11.0.10502000
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=local
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t


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Debugger entered--Lisp error: (wrong-type-argument symbolp (get backend (quote vc-functions)))
  vc-call-backend(RCS registered "/home/steve/cvsroot/emacs/configure")
  #[(b) "\302\b\303	#\205\x14\304	\305\b#\205\x14\306\307\310\"\207" [b file vc-call-backend registered vc-file-setprop vc-backend throw found t] 4](RCS)
  mapc(#[(b) "\302\b\303	#\205\x14\304	\305\b#\205\x14\306\307\310\"\207" [b file vc-call-backend registered vc-file-setprop vc-backend throw found t] 4] (RCS CVS SVN SCCS Bzr Git Hg Mtn Arch))
  byte-code("\303\b\304\"\x19\305\306	\203\x11	\307=\203\x15\n\202\x18	\nB\"\210)\310\b\304\307#\210\311\207" [file backend vc-handled-backends vc-file-getprop vc-backend mapc #[(b) "\302\b\303	#\205\x14\304	\305\b#\205\x14\306\307\310\"\207" [b file vc-call-backend registered vc-file-setprop vc-backend throw found t] 4] none vc-file-setprop nil] 4)
  vc-registered("/home/steve/cvsroot/emacs/configure")
  vc-backend("/home/steve/cvsroot/emacs/configure")
  #[nil "\301\b!\207" [buffer-file-name vc-backend] 2]()
  vc-find-file-hook()
  run-hooks(find-file-hook)
  after-find-file(nil t)
  find-file-noselect-1(#<buffer configure> "~/cvsroot/emacs/configure" nil nil "/Users/steve/cvsroot/emacs/configure" (132524 2056))
  find-file-noselect("/home/steve/cvsroot/emacs/configure" nil nil nil)
  find-file("/home/steve/cvsroot/emacs/configure")
  dired-find-file()
  call-interactively(dired-find-file nil nil)

bug#4454: 23.1.50; vc-call-backend raises wrong-type-argument error

[Stephen Berman]

On Thu, 17 Sep 2009 00:00:27 +0200 Stephen Berman <stephen.berman@gmx.net> wrote:

> After updating today, I started emacs -Q and tried to visit a file in my
> CVS Emacs tree, and this raised a wrong-type-argument error.  This
> happens with any file under version control.

In fact it seems to happen with any file, and with some libraries that
write files to disk on exiting, such as Gnus, this makes it impossible
to exit Emacs normally, only kill -9 works.  I reverted to a week old
revision in order to get a working Emacs.

Steve Berman

bug#4454: 23.1.50; vc-call-backend raises wrong-type-argument error

[Stefan Monnier]

> After updating today, I started emacs -Q and tried to visit a file in my
> CVS Emacs tree, and this raised a wrong-type-argument error.  This
> happens with any file under version control.  It does not happen with my
> previous build from two weeks ago. A backtrace is attached (because it
> contains byte code)

It's the bug I referred to earlier in emacs-devel about CL functions.
Just "re lisp/vc-hooks.elc; make" should fix it for now.

What happens is that vc-hooks.el ended up byte-compiled in a context
where subr.el was loaded after cl.el, so while CL was loaded, the `push'
macro was not the CL one but the plainer one provided by subr.el.
And of course vc-hooks.el uses some of CL's added features of `push'.


        Stefan