Patch for makehistory crash on broken timecaf spool

[Russ Allbery]

Jacek Konieczny <jajcus at bnet.pl> writes:

> When I was trying to regenerate history file for broken (after system
> carsh) timecaf spool (to dump valid articles left using "sm")
> makehistory crashed. makehistory is usually used after some spool
> problems so IMHO it should be more fail-proof.

> The attached patch fixes timecaf storage driver so it doesn't crash on
> some broken archives. This worked for me and should not be harmfull for
> anyone else. Similar improvements could be done for other storage
> methods.

I'm a little worried about the speed hit here, but after thinking about it
a little bit, I've gone ahead and applied this patch.  Thanks!

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>