Merge pull request #7981 from cakephp/issue-7808

Fix BelongsToMany saving incorrectly when _joinData is used.

src/ORM/Association/BelongsToMany.php

@@ -626,7 +626,6 @@ class BelongsToMany extends Association
             if (!$joint || !($joint instanceof EntityInterface)) {
                 $joint = new $entityClass([], ['markNew' => true, 'source' => $junctionAlias]);
             }
-
             $sourceKeys = array_combine($foreignKey, $sourceEntity->extract($bindingKey));
             $targetKeys = array_combine($assocForeignKey, $e->extract($targetPrimaryKey));
 

src/ORM/Marshaller.php

@@ -657,7 +657,7 @@ class Marshaller
             return [];
         }
 
-        if (!in_array('_joinData', $associated) && !isset($associated['_joinData'])) {
+        if (!empty($associated) && !in_array('_joinData', $associated) && !isset($associated['_joinData'])) {
             return $this->mergeMany($original, $value, $options);
         }
 

tests/TestCase/ORM/MarshallerTest.php

@@ -1731,6 +1731,46 @@ class MarshallerTest extends TestCase
     }
 
     /**
+     * Test that _joinData is marshalled consistently with both
+     * new and existing records
+     *
+     * @return void
+     */
+    public function testMergeBelongsToManyHandleJoinDataConsistently()
+    {
+        TableRegistry::clear();
+        $articles = TableRegistry::get('Articles');
+        $articles->belongsToMany('Tags', [
+            'through' => 'SpecialTags'
+        ]);
+
+        $entity = $articles->get(1);
+        $data = [
+            'title' => 'Haz data',
+            'tags' => [
+                ['id' => 3, 'tag' => 'Cake', '_joinData' => ['highlighted' => true]],
+            ]
+        ];
+        $marshall = new Marshaller($articles);
+        $result = $marshall->merge($entity, $data, ['associated' => 'Tags']);
+        $this->assertInstanceOf('Cake\ORM\Entity', $result->tags[0]->_joinData);
+        $this->assertTrue($result->tags[0]->_joinData->highlighted);
+
+        // Also ensure merge() overwrites existing data.
+        $entity = $articles->get(1, ['contain' => 'Tags']);
+        $data = [
+            'title' => 'Haz data',
+            'tags' => [
+                ['id' => 3, 'tag' => 'Cake', '_joinData' => ['highlighted' => true]],
+            ]
+        ];
+        $marshall = new Marshaller($articles);
+        $result = $marshall->merge($entity, $data, ['associated' => 'Tags']);
+        $this->assertInstanceOf('Cake\ORM\Entity', $result->tags[0]->_joinData);
+        $this->assertTrue($result->tags[0]->_joinData->highlighted);
+    }
+
+    /**
      * Test merging belongsToMany data doesn't create 'new' entities.
      *
      * @return void