bug#9800: Incomplete truncated file buffers from the /proc filesystem

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Date: Thu, 20 Oct 2011 10:44:57 +0200
> Cc: Juri Linkov <juri@jurta.org>, 9800@debbugs.gnu.org
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Does lseek work on these files?
> 
> No.  The contents are completely dynamic, generated on-the-fly when
> reading.
> 
> > Or we could treat those files as non-regular,
> 
> That is the only option.

Are all the files in "/proc" of this nature?  If so, we could consider
all of the files in that directory non-regular; if that is all that's
needed to visit /proc/foo files, insert-file-contents already has code
to deal with non-regular files.

Paul, do you see any downsides to such heuristic?  We could make it a
user option if the heuristic could sometimes backfire, I guess.