From c04958bc17bd98605df959e8ea98ad2db09a0c0c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADctor=20D=C3=ADaz?= <victor@victordiaz.me>
Date: Thu, 21 Sep 2017 15:43:29 +0200
Subject: [PATCH] Allow setting custom morphTo ownerKey. (#21310)

---
 .../Eloquent/Concerns/HasRelationships.php      | 17 ++++++++++-------
 .../Database/Eloquent/Relations/MorphTo.php     | 10 +++++++---
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/Illuminate/Database/Eloquent/Concerns/HasRelationships.php b/src/Illuminate/Database/Eloquent/Concerns/HasRelationships.php
index d5599da4378c..a6d6f7ede8db 100644
--- a/src/Illuminate/Database/Eloquent/Concerns/HasRelationships.php
+++ b/src/Illuminate/Database/Eloquent/Concerns/HasRelationships.php
@@ -128,9 +128,10 @@ public function belongsTo($related, $foreignKey = null, $ownerKey = null, $relat
      * @param  string  $name
      * @param  string  $type
      * @param  string  $id
+     * @param  string  $ownerKey
      * @return \Illuminate\Database\Eloquent\Relations\MorphTo
      */
-    public function morphTo($name = null, $type = null, $id = null)
+    public function morphTo($name = null, $type = null, $id = null, $ownerKey = null)
     {
         // If no name is provided, we will use the backtrace to get the function name
         // since that is most likely the name of the polymorphic interface. We can
@@ -145,8 +146,8 @@ public function morphTo($name = null, $type = null, $id = null)
         // the relationship. In this case we'll just pass in a dummy query where we
         // need to remove any eager loads that may already be defined on a model.
         return empty($class = $this->{$type})
-                    ? $this->morphEagerTo($name, $type, $id)
-                    : $this->morphInstanceTo($class, $name, $type, $id);
+                    ? $this->morphEagerTo($name, $type, $id, $ownerKey)
+                    : $this->morphInstanceTo($class, $name, $type, $id, $ownerKey);
     }
 
     /**
@@ -155,12 +156,13 @@ public function morphTo($name = null, $type = null, $id = null)
      * @param  string  $name
      * @param  string  $type
      * @param  string  $id
+     * @param  string  $ownerKey
      * @return \Illuminate\Database\Eloquent\Relations\MorphTo
      */
-    protected function morphEagerTo($name, $type, $id)
+    protected function morphEagerTo($name, $type, $id, $ownerKey)
     {
         return new MorphTo(
-            $this->newQuery()->setEagerLoads([]), $this, $id, null, $type, $name
+            $this->newQuery()->setEagerLoads([]), $this, $id, $ownerKey, $type, $name
         );
     }
 
@@ -171,16 +173,17 @@ protected function morphEagerTo($name, $type, $id)
      * @param  string  $name
      * @param  string  $type
      * @param  string  $id
+     * @param  string  $ownerKey
      * @return \Illuminate\Database\Eloquent\Relations\MorphTo
      */
-    protected function morphInstanceTo($target, $name, $type, $id)
+    protected function morphInstanceTo($target, $name, $type, $id, $ownerKey)
     {
         $instance = $this->newRelatedInstance(
             static::getActualClassNameForMorph($target)
         );
 
         return new MorphTo(
-            $instance->newQuery(), $this, $id, $instance->getKeyName(), $type, $name
+            $instance->newQuery(), $this, $id, $ownerKey ?? $instance->getKeyName(), $type, $name
         );
     }
 
diff --git a/src/Illuminate/Database/Eloquent/Relations/MorphTo.php b/src/Illuminate/Database/Eloquent/Relations/MorphTo.php
index 2739786d5e7e..073b887e8487 100644
--- a/src/Illuminate/Database/Eloquent/Relations/MorphTo.php
+++ b/src/Illuminate/Database/Eloquent/Relations/MorphTo.php
@@ -120,12 +120,14 @@ protected function getResultsByType($type)
     {
         $instance = $this->createModelByType($type);
 
+        $ownerKey = $this->ownerKey ?? $instance->getKeyName();
+
         $query = $this->replayMacros($instance->newQuery())
                             ->mergeConstraintsFrom($this->getQuery())
                             ->with($this->getQuery()->getEagerLoads());
 
         return $query->whereIn(
-            $instance->getTable().'.'.$instance->getKeyName(), $this->gatherKeysByType($type)
+            $instance->getTable().'.'.$ownerKey, $this->gatherKeysByType($type)
         )->get();
     }
 
@@ -178,8 +180,10 @@ public function match(array $models, Collection $results, $relation)
     protected function matchToMorphParents($type, Collection $results)
     {
         foreach ($results as $result) {
-            if (isset($this->dictionary[$type][$result->getKey()])) {
-                foreach ($this->dictionary[$type][$result->getKey()] as $model) {
+            $ownerKey = ! is_null($this->ownerKey) ? $result->{$this->ownerKey} : $result->getKey();
+
+            if (isset($this->dictionary[$type][$ownerKey])) {
+                foreach ($this->dictionary[$type][$ownerKey] as $model) {
                     $model->setRelation($this->relation, $result);
                 }
             }