Description:
------------
Recently some code adding assertions to code in Drupal caused some really weird failures when running tests. It seems you need a couple things to trigger this.

1) You have an object stored on a property
2) You call an assert that calls a method on an argument.
3) You reference the protected property after that assertion.


Test script:
---------------
<?php

class class1 {
  protected $prop;
  public function __construct($prop) { $this->prop = $prop; }
  public function getThing($arg) {
    assert('$arg->isValid();');
    $this->prop->method();
  }
}

class class2 {
  public function method() { echo "here\n"; }
}

class class3 {
  public function isValid() { return false; }
}

$tmp = new class1(new class2());
$tmp->getThing(new class3());

Expected result:
----------------
the script outputs "here"

Actual result:
--------------
PHP Fatal error:  Uncaught Error: Cannot access protected property class1::$prop in /home/jgilliland/public_html/d8_1/assert_protected_property.txt:8
Stack trace:
#0 /home/jgilliland/public_html/d8_1/assert_protected_property.txt(21): class1->getThing(Object(class3))
#1 {main}
  thrown in /home/jgilliland/public_html/d8_1/assert_protected_property.txt on line 8