[5.6] Fix issue with Resources when loading a single MergeValue with …

…an associative array (#23414)

*          fix issue with resources loading assoc marge values

*    fix style

src/Illuminate/Http/Resources/ConditionallyLoadsAttributes.php

@@ -80,7 +80,8 @@ protected function removeMissingValues($data, $numericKeys = false)
             }
         }
 
-        return $numericKeys ? array_values($data) : $data;
+        return ! empty($data) && is_numeric(array_keys($data)[0])
+                ? array_values($data) : $data;
     }
 
     /**

tests/Integration/Http/ResourceTest.php

@@ -524,6 +524,26 @@ public function test_original_on_response_is_collection_of_model_when_collection
         });
     }
 
+    public function test_leading_merge__keyed_value_is_merged_correctly()
+    {
+        $filter = new class {
+            use ConditionallyLoadsAttributes;
+
+            public function work()
+            {
+                return $this->filter([
+                    new MergeValue(['name' => 'mohamed', 'location' => 'hurghada']),
+                ]);
+            }
+        };
+
+        $results = $filter->work();
+
+        $this->assertEquals([
+            'name' => 'mohamed', 'location' => 'hurghada',
+        ], $results);
+    }
+
     public function test_leading_merge_value_is_merged_correctly()
     {
         $filter = new class {