That's great, thanks.

Regarding your comment about a memory leak: valgrind is not going to report memleaks from calls to emalloc, but --enable-debug will. I'm not sure how emalloc is implemented, but my guess is that PHP will keep track of such allocations and free them in its GC pass; this is why you have a different function to allocate data that is supposed to survive between requests. That's my understanding at least.

I will try to see if I can reproduce it.

I'm not sure if it is of any help, but I get the reported memory leak when simply running the unit tests with a php binary that has been compiled with --enable-debug

This is the report that I get:

/home/mike/dev/php-5.3.10/ext/redis/library.c(324) :  Freeing 0x7FAFEA5972C0 (79 bytes), script=TestRedis.php
Last leak repeated 5 times
=== Total 6 memory leaks detected ===

If I skip testZX by modifying the TestSuite::run() method to ignore that one, the memory leak goes away. However, if pull the whole testZX() method out into another script, it doesn't report a leak any more!

I was able to further narrow it down by progressively commenting lines in the testZX method, and I am pretty sure it has to do with zunion/inter with weights. The first line where a leak will be reported is 1770 in TestRedis.php, which is this:

$this->assertTrue(4 === $this->redis->zUnion('keyZ', array('key1', 'key2'), array(1, 1)));

Cheers,
Mike