Attributes: Reset callbacks upon clone

Author: nilmerg

src/Attributes.php

@@ -609,5 +609,10 @@ public function __clone()
         foreach ($this->attributes as &$attribute) {
             $attribute = clone $attribute;
         }
+
+        // Reset callbacks to avoid memory leaks
+        $this->callbacks = [];
+        $this->newCallbacks = [];
+        $this->setterCallbacks = [];
     }
 }

tests/AttributesTest.php

@@ -668,4 +668,18 @@ public function testRenderThrowsIfLegacyAndNewAttributeCallbacksConflict(): void
 
         $attributes->render();
     }
+
+    /**
+     * @depends testRenderHandlesCallbackResultsCorrectly
+     */
+    public function testCallbacksAreResetUponClone(): void
+    {
+        $attributes = (new Attributes())
+            ->setCallback('callback', fn() => 'foo')
+            ->registerAttributeCallback('callback2', fn() => 'bar');
+
+        $clone = clone $attributes;
+
+        $this->assertSame('', $clone->render());
+    }
 }