[php-maint] Bug#321460: php4 gc_probability default is breaking custom GC handlers

[Dmitriy Kropivnitskiy]

Package: libapache-mod-php4
Version: 4:4.3.10-15

The default for session.gc_probability was changed from the upstream
default of 1 (garbage collection runs on 1% of requests) to 0 (no
garbage collection). I believe that the reason for the change was the
bug #267720 <http://bugs.debian.org/267720>. Unfortunately, this breaks
things for people using session_set_save_handler() function to set their
own session management (for example to record sessions in a database).
If existing codebase is using custom garbage collection function an
upgrade to Debian silently stops the garbage collection from happening,
since the cron job from php4-common only cleans up default session temp
files. Also this changes the expected (documented on www.php.net)
behaviour of php session handling. The solution for this would be to either
1. Re-enable the gc_probability and change default ownership and
permissions on /var/lib/php4 to allow www-data deleting files from it
(and disallow regular users any access, something like chmod 770 )
2. Leave this as it is, but bring up a warning message in the package
post-config to bring this to the user's attention