Using actual table alias in buildRules causing problems

Need Help
1

I have a table with a belongsTo relationship, where I want to use an actual alias, not just the same name as the className. In buildRules() I refer to that alias, however, during a save() there are SQL errors that say the tabelized alias name is not a table. Here is the class below:

class SolarBuyerTiersPostsTable extends Table
{

    /**
     * Initialize method
     *
     * @param array $config The configuration for the Table.
     * @return void
     */
    public function initialize(array $config)
    {
        parent::initialize($config);

        $this->table('solar_buyer_tiers_posts');
        $this->displayField('id');
        $this->primaryKey('id');

        $this->addBehavior('Timestamp');

        $this->belongsTo('Posts', [
            'foreignKey' => 'post_id',
            'joinType' => 'INNER',
            'className' => 'SolarPosts'
        ]);
    }

    /**
     * Returns a rules checker object that will be used for validating
     * application integrity.
     *
     * @param \Cake\ORM\RulesChecker $rules The rules object to be modified.
     * @return \Cake\ORM\RulesChecker
     */
    public function buildRules(RulesChecker $rules)
    {
        $rules->add($rules->existsIn(['buyer_tier_id'], 'BuyerTiers'));
        $rules->add($rules->existsIn(['post_id'], 'Posts'));
        return $rules;
    }
}

The SQL error during a save() is
SQLSTATE[42S02]: Base table or view not found: 1146 Table 'pingtree.posts' doesn't exist

I know posts doesn’t exist, but solar_posts does, and that’s the className in the association.
The workaround seems to be setting checkRules to false in the save options, or to create a duplicate belongsTo() with the alias as the same name as the className, and then use SolarPosts in the existsIn() call.

I did some debugging, and it seems like the target() method in Association uses the _name instead of the _className. Shouldn’t it use _className?

public function target(Table $table = null)
    {
        if ($table === null && $this->_targetTable) {
            return $this->_targetTable;
        }

        if ($table !== null) {
            return $this->_targetTable = $table;
        }

        if (strpos($this->_className, '.')) {
            list($plugin) = pluginSplit($this->_className, true);
            $registryAlias = $plugin . $this->_name;
        } else {
            $registryAlias = $this->_name;
        }

        $tableLocator = $this->tableLocator();

        $config = [];
        if (!$tableLocator->exists($registryAlias)) {
            $config = ['className' => $this->_className];
        }
        $this->_targetTable = $tableLocator->get($registryAlias, $config);

        return $this->_targetTable;
    }
2

I found 2 solutions to this issue, and I believe this can be either classified as a code bug or a documentation bug.

Solution 1 (re: documentation bug):
In the comments on the Table->belongsTo() method there is an option called ‘targetTable’, which is not listed in the cake docs. It takes an instance of the table object you want to use. In my case, that is SolarPosts. The below change, solves the issue:

    $this->belongsTo('Posts', [
              'foreignKey' => 'post_id',
              'joinType' => 'INNER',
              'className' => 'SolarPosts',
              'targetTable' => TableRegistry::get('SolarPosts')
    ]);

Solution 2 (re: code bug):
Changing Association->target() to use the _className if it is set also solves the problem. I really don’t know the ramifications of this change, but it seems to work. Below is the changed code:

 public function target(Table $table = null)
    {
        if ($table === null && $this->_targetTable) {
            return $this->_targetTable;
        }

        if ($table !== null) {
            return $this->_targetTable = $table;
        }

        if (strpos($this->_className, '.')) {
            list($plugin) = pluginSplit($this->_className, true);
            $registryAlias = $plugin . $this->_name;
        } else {
            $registryAlias = $this->_name;
            /***** this is the change ***/
            if($this->_className) {
                $registryAlias = $this->_className;
            }
            /*** ***/
        }

        $tableLocator = $this->tableLocator();

        $config = [];
        if (!$tableLocator->exists($registryAlias)) {
            $config = ['className' => $this->_className];
        }
        $this->_targetTable = $tableLocator->get($registryAlias, $config);

        return $this->_targetTable;
    }
3

Another update:
Using targetTable in the belongsTo() works for saves(), but find() fails with:
You have contained 'Posts' but that association was bound as 'SolarPosts'.

But, isn’t that the point? I want to contain by using the alias name, not the class name. Removing the targetTable option makes the find() work, but not the save()…hmmm time to file an issue