Merge branch '5.2' into 5.3

* 5.2:
  [5.2] Add missing `@return` annotations
  [4.4] Add missing `@return` annotations
  Handle lock with long key
  #42227 update phpdoc to recommend createIndex over ensureIndex

Author: nicolas-grekas

Adapter/ExtLdap/Collection.php

@@ -97,20 +97,29 @@ public function offsetExists($offset)
         return isset($this->entries[$offset]);
     }
 
+    /**
+     * @return mixed
+     */
     public function offsetGet($offset)
     {
         $this->toArray();
 
         return $this->entries[$offset] ?? null;
     }
 
+    /**
+     * @return void
+     */
     public function offsetSet($offset, $value)
     {
         $this->toArray();
 
         $this->entries[$offset] = $value;
     }
 
+    /**
+     * @return void
+     */
     public function offsetUnset($offset)
     {
         $this->toArray();

Adapter/ExtLdap/Connection.php

@@ -35,6 +35,9 @@ class Connection extends AbstractConnection
     /** @var resource */
     private $connection;
 
+    /**
+     * @return array
+     */
     public function __sleep()
     {
         throw new \BadMethodCallException('Cannot serialize '.__CLASS__);

Adapter/ExtLdap/Query.php

@@ -38,6 +38,9 @@ public function __construct(Connection $connection, string $dn, string $query, a
         parent::__construct($connection, $dn, $query, $options);
     }
 
+    /**
+     * @return array
+     */
     public function __sleep()
     {
         throw new \BadMethodCallException('Cannot serialize '.__CLASS__);