PHP memory leak in unserialize()

== Platform ==

Red Hat Enterprise Linux Server release 6.4 (Santiago)
PHP 5.3.3

Tried with php-pecl-memcache from distro (3.0.4).

== Reporting ==

Added to end of sync loop in memcacheSync.php:

if(($sync + $skipped) % 1000 == 0) printf ("MEM @ %d: %0.2f Mb\n", $sync+$skipped, memory_get_peak_usage()/1024/1024);

== Not calling unserialize ==

Added "return $serializedInfo;" *before* call to unserialize() in SimpleSAML_Memcache::get() (in .../lib/SimpleSAML/Memcache.php):

	return $serializedInfo;
	/* Deserialize the object. */
	$info = unserialize($serializedInfo);

# php memcacheSync.php
Server idp1.id.kent.ac.uk:11211 has 26568 items.
Connecting to: idp1.id.kent.ac.uk:11211
Connected. Finding keys.
Found 26573 key(s).
Server idp2.id.kent.ac.uk:11211 has 26524 items.
Connecting to: idp2.id.kent.ac.uk:11211
Connected. Finding keys.
Found 26530 key(s).
Total number of keys: 53103
Total number of unique keys: 26576
Starting synchronization.
MEM @ 1000: 21.96 Mb
MEM @ 2000: 21.96 Mb
MEM @ 3000: 21.96 Mb
MEM @ 4000: 21.96 Mb
MEM @ 5000: 21.96 Mb
MEM @ 6000: 21.96 Mb
MEM @ 7000: 21.96 Mb
MEM @ 8000: 21.96 Mb
MEM @ 9000: 21.96 Mb
MEM @ 10000: 21.96 Mb
MEM @ 11000: 21.96 Mb
MEM @ 12000: 21.96 Mb
MEM @ 13000: 21.96 Mb
MEM @ 14000: 21.96 Mb
MEM @ 15000: 21.96 Mb
MEM @ 16000: 21.96 Mb
MEM @ 17000: 21.96 Mb
MEM @ 18000: 21.96 Mb
MEM @ 19000: 21.96 Mb
MEM @ 20000: 21.96 Mb
MEM @ 21000: 21.96 Mb
MEM @ 22000: 21.96 Mb
MEM @ 23000: 21.96 Mb
MEM @ 24000: 21.96 Mb
MEM @ 25000: 21.96 Mb
MEM @ 26000: 21.96 Mb
Synchronization done.
26527 keys in sync.
49 keys skipped.
Keys are skipped because they are either expired, or are of a type unknown to simpleSAMLphp.

== Calling unserialize (but nothing else) ==

Moved "return $info;" to directly *after* unserialize() call in .../lib/SimpleSAML/Memcache.php:

	/* Deserialize the object. */
	$info = unserialize($serializedInfo);
	return $info;

# php memcacheSync.php
Server idp1.id.kent.ac.uk:11211 has 26258 items.
Connecting to: idp1.id.kent.ac.uk:11211
Connected. Finding keys.
Found 26275 key(s).
Server idp2.id.kent.ac.uk:11211 has 26240 items.
Connecting to: idp2.id.kent.ac.uk:11211
Connected. Finding keys.
Found 26259 key(s).
Total number of keys: 52534
Total number of unique keys: 26282
Starting synchronization.
MEM @ 1000: 21.75 Mb
MEM @ 2000: 22.20 Mb
MEM @ 3000: 27.16 Mb
MEM @ 4000: 31.99 Mb
MEM @ 5000: 39.82 Mb
MEM @ 6000: 47.56 Mb
MEM @ 7000: 70.48 Mb
MEM @ 8000: 94.52 Mb
MEM @ 9000: 118.95 Mb
PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 32 bytes) in /opt/idp/simplesamlphp/lib/SimpleSAML/Memcache.php on line 50