[11.x] Move $ownerKey check for null to MorphTo as BelongsTo …

…relationship will always return a `string` (#53592)

* [11.x] Move `$ownerKey` check for `null` to `MorphTo` as `BelongsTo` relationship will always return a `string`

Improvements based on #53573 PR

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* formatting

---------

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
Co-authored-by: Taylor Otwell <taylor@laravel.com>

src/Illuminate/Database/Eloquent/Relations/BelongsTo.php

@@ -344,10 +344,6 @@ public function getOwnerKeyName()
      */
     public function getQualifiedOwnerKeyName()
     {
-        if (is_null($this->ownerKey)) {
-            return '';
-        }
-
         return $this->related->qualifyColumn($this->ownerKey);
     }
 

src/Illuminate/Database/Eloquent/Relations/MorphTo.php

@@ -93,6 +93,7 @@ public function __construct(Builder $query, Model $parent, $foreignKey, $ownerKe
     }
 
     /** @inheritDoc */
+    #[\Override]
     public function addEagerConstraints(array $models)
     {
         $this->buildDictionary($this->models = Collection::make($models));
@@ -199,6 +200,7 @@ public function createModelByType($type)
     }
 
     /** @inheritDoc */
+    #[\Override]
     public function match(array $models, Collection $results, $relation)
     {
         return $models;
@@ -230,6 +232,7 @@ protected function matchToMorphParents($type, Collection $results)
      * @param  TRelatedModel|null  $model
      * @return TDeclaringModel
      */
+    #[\Override]
     public function associate($model)
     {
         if ($model instanceof Model) {
@@ -254,6 +257,7 @@ public function associate($model)
      *
      * @return TDeclaringModel
      */
+    #[\Override]
     public function dissociate()
     {
         $this->parent->setAttribute($this->foreignKey, null);
@@ -263,11 +267,8 @@ public function dissociate()
         return $this->parent->setRelation($this->relationName, null);
     }
 
-    /**
-     * Touch all of the related models for the relationship.
-     *
-     * @return void
-     */
+    /** @inheritDoc */
+    #[\Override]
     public function touch()
     {
         if (! is_null($this->getParentKey())) {
@@ -276,6 +277,7 @@ public function touch()
     }
 
     /** @inheritDoc */
+    #[\Override]
     protected function newRelatedInstanceFor(Model $parent)
     {
         return $parent->{$this->getRelationName()}()->getRelated()->newInstance();
@@ -412,6 +414,17 @@ protected function replayMacros(Builder $query)
         return $query;
     }
 
+    /** @inheritDoc */
+    #[\Override]
+    public function getQualifiedOwnerKeyName()
+    {
+        if (is_null($this->ownerKey)) {
+            return '';
+        }
+
+        return parent::getQualifiedOwnerKeyName();
+    }
+
     /**
      * Handle dynamic method calls to the relationship.
      *