fixed unset.

framework/CHANGELOG.md

@@ -60,7 +60,7 @@ Yii Framework 2 Change Log
 - Bug: Fixed the issue that query cache returns the same data for the same SQL but different query methods (qiangxue)
 - Bug: Fixed URL parsing so it's now properly giving 404 for URLs like `http://example.com//////site/about` (samdark)
 - Bug: Fixed `HelpController::getModuleCommands` issue where it attempts to scan a module's controller directory when it doesn't exist (jom)
-- Bug: Fixed an issue with Filehelper and not accessable directories which resulted in endless loop (cebe)
+- Bug: Fixed an issue with FileHelper and not accessible directories which resulted in endless loop (cebe)
 - Bug: Fixed `$model->load($data)` returned `true` if `$data` and `formName` were empty (samdark)
 - Bug: Fixed issue with `ActiveRelationTrait` preventing `ActiveQuery` from clearing events and behaviors on clone (jom)
 - Bug: `Query::queryScalar` wasn't making `SELECT DISTINCT` queries subqueries (jom)

framework/db/BaseActiveRecord.php

@@ -1390,7 +1390,10 @@ abstract class BaseActiveRecord extends Model implements ActiveRecordInterface
 	 */
 	public function offsetUnset($offset)
 	{
-		// use unset to trigger __unset()
-		unset($this->$offset);
+		if (property_exists($this, $offset)) {
+			$this->$offset = null;
+		} else {
+			unset($this->$offset);
+		}
 	}
 }