bug#5705: 23.1.93; recursive load error when loading tramp

[Paul Pogonyshev <p.pogonyshev@anakreon.net>]

Severity: important

Occasionally, I "break" Emacs after which it starts printing the
following message in the minibuffer in response to any command
requiring it to open a file:

    require: Recursive load: "/usr/local/share/emacs/23.1.93/lisp/net/tramp.elc", "/usr/local/share/emacs/23.1.93/lisp/net/tramp-cmds.elc", "/usr/local/share/emacs/23.1.93/lisp/net/tramp.elc", "/usr/local/share/emacs/23.1.93/lisp/net/tramp-cmds.elc", "/usr/local/share/emacs/23.1.93/lisp/net/tramp.elc", "/usr/local/share/emacs/23.1.93/lisp/net/tramp-cmds.elc", "/usr/local/share/emacs/23.1.93/lisp/net/tramp.elc", "/usr/local/share/emacs/23.1.93/lisp/net/tramp-cmds.elc", "/usr/local/share/emacs/23.1.93/lisp/net/tramp.elc"

This includes C-x C-f, C-x C-c and many others.  I.e. after this Emacs
becomes unusable and even impossible to quit cleanly.  I have to kill
it from command line with 'killall emacs'.

I'm pretty certain this is caused by hitting C-g when C-x C-f loads a
directory (I'm using ido-mode, so completions are loaded all the
time).  Looks like some place lacks 'unwind-protect' (or something
else similar to try..finally), so that a feature is marked as loaded
in one place, but not in another.

So, to reproduce:
- enable ido-mode;
- try hitting C-x C-f, navigate into a particularly large directory
  and hit C-g while completion list is being built.

You may need to repeat the second step several times as the bug
doesn't seem to deterministic.

Cannot provide normal standard bug information, because after this
happens practically nothing in Emacs works, including M-x report-bug:
window is opened, but it is empty except for From/To/Subject headers.

This has been happening for quite a lot of time, so this bug is not
something new in recent versions.

Paul