api/java_awt/Container/index.html#isAncestorOf Container2019 hangs since JDK 7 b15

JCK: JCK-runtime-6b b07
J2SE: FAIL - 7 b15 PASS 7 b14 6u4 b03 6u2 b05
Platform[s]: FAIL - All
switch/Mode: FAIL - default

Test api/java_awt/Container/index.html#isAncestorOf hangs since JDK 7 b15. The problematic code is

Container[] p=new Container[50]; //step Create array of containers
p[0] = new Container();
for (int i=1;i<50;i++) {
p[i-1].add(p[i] = new Container()); //step Create hierarchy
}

6u2 and 7 b14 finish execution of this code almost immediately. 7 b15 executes first ~25 iterations very fast, next ~10 quite slow and looks like locks up at ~35th iteration. Probably this test still can pass after several hours of waiting.