Relationship contact reports with group and relation type filters fails

When you extract a report filtered with a specific relation type and a specific group, the report fails no matching contacts.

I debug this issue and I think that the problem is that the function "whereGroupClause" from the file "CRM/Report/Form.php" is not enough for a relationship report because it don't check if the contact comes from a "b_a" relationship.

I don't know if this is a correct solution, but I patched this issue adding the same "whereGroupClause" function in the file "CRM/Report/Form/Contact/Relationship.php" only modifying the following lines:

+if ($this->relationType == 'a_b') $relationship_contact=$this->_aliases['civicrm_contact'];
+ else $relationship_contact=$this->_aliases['civicrm_contact_b'];
  
+ return " {$relationship_contact}.id {$sqlOp} (
- return " {$this->_aliases['civicrm_contact']}.id {$sqlOp} (