Deprecate mysqli::init()

In favor of parent::__construct().

Part of https://wiki.php.net/rfc/deprecations_php_8_1.

Author: nikic

ext/mysqli/mysqli.stub.php

@@ -158,7 +158,10 @@ public function get_server_info(): string {}
      */
     public function get_warnings(): mysqli_warning|false {}
 
-    /** @return bool|null */
+    /**
+     * @deprecated
+     * @return bool|null
+     * */
     public function init() {}
 
     /**

ext/mysqli/mysqli_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 2f96f80badee5623220fd720e91aec7795e32723 */
+ * Stub hash: 3a51cb95700990b4722dfefe341aeeb0b28461d7 */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_mysqli_affected_rows, 0, 1, MAY_BE_LONG|MAY_BE_STRING)
 	ZEND_ARG_OBJ_INFO(0, mysql, mysqli, 0)
@@ -989,7 +989,7 @@ static const zend_function_entry class_mysqli_methods[] = {
 #endif
 	ZEND_ME_MAPPING(get_server_info, mysqli_get_server_info, arginfo_class_mysqli_get_server_info, ZEND_ACC_PUBLIC)
 	ZEND_ME_MAPPING(get_warnings, mysqli_get_warnings, arginfo_class_mysqli_get_warnings, ZEND_ACC_PUBLIC)
-	ZEND_ME(mysqli, init, arginfo_class_mysqli_init, ZEND_ACC_PUBLIC)
+	ZEND_ME(mysqli, init, arginfo_class_mysqli_init, ZEND_ACC_PUBLIC|ZEND_ACC_DEPRECATED)
 	ZEND_ME_MAPPING(kill, mysqli_kill, arginfo_class_mysqli_kill, ZEND_ACC_PUBLIC)
 	ZEND_ME_MAPPING(multi_query, mysqli_multi_query, arginfo_class_mysqli_multi_query, ZEND_ACC_PUBLIC)
 	ZEND_ME_MAPPING(more_results, mysqli_more_results, arginfo_class_mysqli_more_results, ZEND_ACC_PUBLIC)

ext/mysqli/tests/bug33263.phpt

@@ -13,7 +13,7 @@ require_once('skipifconnectfailure.inc');
     class test extends mysqli
     {
         public function __construct($host, $user, $passwd, $db, $port, $socket) {
-            parent::init();
+            parent::__construct();
             parent::real_connect($host, $user, $passwd, $db, $port, $socket);
         }
     }

ext/mysqli/tests/bug46109.phpt

@@ -8,12 +8,15 @@ require_once('skipifconnectfailure.inc');
 ?>
 --FILE--
 <?php
-    require_once("connect.inc");
+require_once("connect.inc");
 
-    $mysqli = new mysqli();
-    $mysqli->init();
-    $mysqli->init();
-    echo "done";
+$mysqli = new mysqli();
+$mysqli->init();
+$mysqli->init();
+echo "done";
 ?>
---EXPECT--
+--EXPECTF--
+Deprecated: Method mysqli::init() is deprecated in %s on line %d
+
+Deprecated: Method mysqli::init() is deprecated in %s on line %d
 done

ext/mysqli/tests/connect.inc

@@ -92,7 +92,7 @@
                 $flags = ($enable_env_flags) ? $connect_flags : 0;
 
                 if ($flags !== false) {
-                    parent::init();
+                    parent::__construct();
                     $this->real_connect($host, $user, $passwd, $db, $port, $socket, $flags);
                 } else {
                     parent::__construct($host, $user, $passwd, $db, $port, $socket);