[BUGFIX] Fix access to empty ObjectStorage with numeric key

This prevents a warning error triggered by spl_object_hash being called
with an integer/string and can be caused by Fluid like this:

{object.relations.0}

Resolves: #62553
Releases: master, 6.2
Change-Id: Ie7d2a249e17f719142482781c2a96d093ff5f94c
Reviewed-on: http://review.typo3.org/33615


Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>

typo3/sysext/extbase/Classes/Persistence/ObjectStorage.php

@@ -157,7 +157,7 @@ class ObjectStorage implements \Countable, \Iterator, \ArrayAccess, ObjectMonito
 	 * @return bool
 	 */
 	public function offsetExists($object) {
-		return isset($this->storage[spl_object_hash($object)]);
+		return is_object($object) && isset($this->storage[spl_object_hash($object)]);
 	}
 
 	/**

typo3/sysext/extbase/Tests/Unit/Persistence/ObjectStorageTest.php

@@ -102,6 +102,22 @@ class ObjectStorageTest extends \TYPO3\CMS\Core\Tests\UnitTestCase {
 		$this->assertEquals($objectStorage->offsetExists($object2), FALSE);
 	}
 
+	/**
+	 * @test
+	 */
+	public function offsetExistsWorksWithEmptyStorageAndIntegerKey() {
+		$objectStorage = new \TYPO3\CMS\Extbase\Persistence\ObjectStorage();
+		$this->assertEquals($objectStorage->offsetExists(0), FALSE);
+	}
+
+	/**
+	 * @test
+	 */
+	public function offsetExistsWorksWithEmptyStorageAndStringKey() {
+		$objectStorage = new \TYPO3\CMS\Extbase\Persistence\ObjectStorage();
+		$this->assertEquals($objectStorage->offsetExists('0'), FALSE);
+	}
+
 	/**
 	 * @test
 	 */