Validation exception thrown only if internal nesting level == 1

I wonder why Validation exception is thrown only if internal nesting level of transaction is 1 and the manual nesting level is not considered.

Line 262 - lib/Doctrine/Transaction.php:

if ($this->_internalNestingLevel == 1) {
    $tmp = $this->invalid;
    $this->invalid = array();
    throw new Doctrine_Validator_Exception($tmp);
}

I have a large database with a lot of tables and relationships. At some case the validation exception is not thrown if the validation fails.

If I add $this->_nestingLevel into this condition:

if ($this->_internalNestingLevel == 1 || $this->_nestingLevel == 1) {
    $tmp = $this->invalid;
    $this->invalid = array();
    throw new Doctrine_Validator_Exception($tmp);
}

Then the validation exception is thrown as excepted.

I don't know why you ignore here the nesting level.

It would be great if you could explain me more about these lines.

I ran the unit test with this modification and got the same result.