The testbed(Debug) 'Examples/Body Types' crashed when changed body type.

[zero-meta]

When press key 's' or 'k' to change body type, it will crash. It's a debug build.

• Here is the screenshot.
• Here is the llbd report:

   thread #1, queue = 'com.apple.main-thread', stop reason = hit program assert
     frame #4: 0x00000001000741cf testbed`b2Island::Add(this=0x00007ff7bfefeaf0, contact=0x000000010084f000) at b2_island.h:67:5
    64  	
    65  	  void Add(b2Contact* contact)
    66  	  {
  > 67  	    b2Assert(m_contactCount < m_contactCapacity);
    68  	    m_contacts[m_contactCount++] = contact;
    69  	  }
    70  	
  arget 0: (testbed) stopped.