bug#1199: bookmark.el in Emacs 22 doesn't handle old-style bookmarks correctly

[Drew Adams]

If you use Emacs 20 to create a bookmark, then Emacs 22 chokes on that
bookmark. Emacs 23 is fixed in this regard.
 
The problem is in bookmark-get-bookmark-record. It blithely assumes
the new format.  The cdr gives the alist, and the car of that is not
the alist, but just its first element - e.g. (filename . "/foo/bar")
instead of ((filename . "/foo/bar")...). Then, bookmark-get-filename
tries to do `(cdr (assq 'filename' of (filename . "/foo/bar"), which
gives an error message that is incomprehensible to a user.
 
To reproduce: Use Emacs 20 to add a bookmark of the old style, then
use Emacs 22, say (bookmark-jump-noselect name-of-old-bookmark).
 
The Emacs 23 fix for this would seem to be worth backporting, if there
is to ever be an Emacs 22.4.
 

In GNU Emacs 22.3.1 (i386-mingw-nt5.1.2600)
 of 2008-09-06 on SOFT-MJASON
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4)'