Bugfix for object accessor setters

When supplying null, it resulted in an error

Author: harm-less

src/PE/Nodes/EncoderNodeVariable.php

@@ -233,7 +233,7 @@ public function getPostNodeGetter() {
 	 * @return ObjectSetter
 	 */
 	public function objectSetter(ObjectSetter $setter = null) {
-		$setter->setVariable($this);
+		if ($setter) $setter->setVariable($this);
 		$this->objectSetter = $setter;
 		return $setter;
 	}
@@ -259,7 +259,7 @@ public function getObjectSetter() {
 	 * @return ObjectGetter
 	 */
 	public function objectGetter(ObjectGetter $getter = null) {
-		$getter->setVariable($this);
+		if ($getter) $getter->setVariable($this);
 		$this->objectGetter = $getter;
 		return $getter;
 	}

tests/PE/Tests/Nodes/EncoderNodeVariableTest.php

@@ -130,6 +130,10 @@ public function testObjectSetter() {
 		$this->assertEquals($objectSetter, $variable->getObjectSetter());
 		$this->assertTrue($variable->hasObjectSetter());
 		$this->assertEquals($variable, $objectSetter->getVariable());
+
+		// disable the object setter
+		$variable->objectSetter(null);
+		$this->assertNull($variable->getObjectSetter());
 	}
 
 	public function testObjectGetter() {
@@ -141,5 +145,9 @@ public function testObjectGetter() {
 		$this->assertEquals($objectGetter, $variable->getObjectGetter());
 		$this->assertTrue($variable->hasObjectGetter());
 		$this->assertEquals($variable, $objectGetter->getVariable());
+
+		// disable the object setter
+		$variable->objectGetter(null);
+		$this->assertNull($variable->getObjectGetter());
 	}
 }