__phpunit_id breaks equal assert (phpunit 3.7)

[voda]

After upgrading to PHPUnit 3.7.1 some of my test fail because of the __phpunit_id attribute.
Test code:

$a = $this->getMock('\stdClass');
$b = $this->getMock('\stdClass');
$this->assertEquals($a, $b);

In PHPUnit 3.6 this code works, in 3.7.1 the output is:

Failed asserting that two objects are equal.
--- Expected
+++ Actual
@@ @@
 Mock_stdClass_f9d48dc3 Object (
     '__phpunit_invocationMocker' => null
-    '__phpunit_id' => 'Mock_stdClass_f9d48dc3#0'
+    '__phpunit_id' => 'Mock_stdClass_f9d48dc3#1'
 )

[voda]

I just realized that my tests are wrong written and after fixing them all works well.

[edorian]

Related: sebastianbergmann/phpunit-mock-objects#100

Like you stated the behavior (not matching anymore) is intended as they are two different objects :)