[pmwiki-users] Flexible $DiffKeepDays [was: Urgent -- Memory size exausted - line 660]

[kirpi at kirpi.it]

> > Luigi:
> > Is there no way to tell the system something like: "apply the
> > $DiffKeepDays = nn; rule only for files beyond a certain size..."? (or
> > something similar...)

> Patrick:
> The purpose of using time instead of size to limit the history has been
> to prevent someone from effectively causing things to "fall off" the
> end of the page history by issuing a bunch of small changes in
> rapid succession.  If we limit the page history by its size alone,
> that opens up an opportunity for a malicious author to "erase history"
> by making a bunch of posts that cause the page history to grow beyond
> the limit.
>
> But I'm guessing you're asking for something slightly different --
> i.e., keep a minimum amount of history at all times, and only use
> the $DiffKeepDays rule when that minimum is exceeded.  Then,
> presumably, $DiffKeepDays could be kept small but would only
> affect pages that have lots of changes.
>
> That has possibility, but there's still the caveat that if
> $DiffKeepDays is set too small, then a malicious author could
> still use a lot of posts to cause history to expire (at least
> the part that is older than the small value of $DiffKeepDays).

If we take as an example my own file, it was heavily edited (about 100
changes each day) since 1 and a half year, steadily, every day. It
then "exploded".
I can hardly think of anybody (if not a horde of zombies) making so
many edits to a single file in a rather short time.

Thus, let's say that I can now feel rather safe when I say to my
system: "if any file grows beyond a certain size, then apply
$DiffKeepDays = 180"

Do you really think it would be that unsafe?
To me it looks rather sound, and could save the wiki from "exploding"
as yesterday happened.

Luigi