Warning: Multiple links found for relationship

From Github – https://github.com/salesagility/SuiteCRM/issues/6507

Fixing:
change to /data/Relationships/M2MRelationship.php to downgrade this to a warning so it wouldn’t fill the logs (if log level at Error). This is not an upgrade-safe change.

~ Line 90:

$GLOBALS['log']->warn("Warning: Multiple links found for relationship {$this->name} within module {$module}");             
//$GLOBALS['log']->error("Warning: Multiple links found for relationship {$this->name} within module {$module}");

Fix is from suitecrm https://suitecrm.com/suitecrm/forum/suitecrm-7-0-discussion/12382-help-with-log-errors-multiple-links-found-for-relationship

This seems to come from M2MRelationship.php, which calls getLinkFieldForRelationship from VardefManager.php, which if it isn’t in cache calls getLinkFieldsforModule from the same file.

getLinkFieldsforModule, if I read correctly, returns each $dictionary entry where ‘type’ == ‘link’ and ‘relationship’ key is defined (and not empty). I believe, that if it finds multiple entries, that meet that criteria, the error is thrown. You’ll notice in my accounts<->contacts example, the first and third entries that are created are both ‘type’ == ‘link’ and both have ‘relationship’ key defined.

$dictionary["Account"]["fields"]["accounts_contacts_1"] = array (
  'name' => 'accounts_contacts_1',
  'type' => 'link',
  'relationship' => 'accounts_contacts_1',
  'source' => 'non-db',
  'module' => 'Contacts',
  'bean_name' => 'Contact',
  'vname' => 'LBL_ACCOUNTS_CONTACTS_1_FROM_CONTACTS_TITLE',
  'id_name' => 'accounts_contacts_1contacts_idb',
);
$dictionary["Account"]["fields"]["accounts_contacts_1_name"] = array (
  'name' => 'accounts_contacts_1_name',
  'type' => 'relate',
  'source' => 'non-db',
  'vname' => 'LBL_ACCOUNTS_CONTACTS_1_FROM_CONTACTS_TITLE',
  'save' => true,
  'id_name' => 'accounts_contacts_1contacts_idb',
  'link' => 'accounts_contacts_1',
  'table' => 'contacts',
  'module' => 'Contacts',
  'rname' => 'name',
  'db_concat_fields' =>
  array (
    0 => 'first_name',
    1 => 'last_name',
  ),
);
$dictionary["Account"]["fields"]["accounts_contacts_1contacts_idb"] = array (
  'name' => 'accounts_contacts_1contacts_idb',
  'type' => 'link',
  'relationship' => 'accounts_contacts_1',
  'source' => 'non-db',
  'reportable' => false,
  'side' => 'left',
  'vname' => 'LBL_ACCOUNTS_CONTACTS_1_FROM_CONTACTS_TITLE',
);

Whereas, in modules/Accounts/vardefs.php, contacts is simply defined with one entry:

        'contacts' => array(
            'name' => 'contacts',
            'type' => 'link',
            'relationship' => 'accounts_contacts',
            'module' => 'Contacts',
            'bean_name' => 'Contact',
            'source' => 'non-db',
            'vname' => 'LBL_CONTACTS',
        ),

Now I assume some of that extra code is necessary, but it also seems to generate the error in the logs