MC-38105: Unable to set native session handler that is different from the one define in php.ini

Author: engcom-Echo

dev/tests/integration/testsuite/Magento/Framework/Session/SessionManagerTest.php

@@ -326,7 +326,7 @@ public function testConstructor(string $saveMethod): void
             $this->assertArrayHasKey('session.use_only_cookies', self::$isIniSetInvoked);
             $this->assertEquals('1', self::$isIniSetInvoked['session.use_only_cookies']);
             foreach ($sessionConfig->getOptions() as $option => $value) {
-                if ($option == 'session.save_handler' && $value == 'user') {
+                if ($option === 'session.save_handler' && !$value === 'memcached') {
                         $this->assertArrayNotHasKey('session.save_handler', self::$isIniSetInvoked);
                 } else {
                         $this->assertArrayHasKey($option, self::$isIniSetInvoked);

lib/internal/Magento/Framework/Session/SessionManager.php

@@ -619,9 +619,9 @@ private function initIniOptions()
         }
 
         foreach ($this->sessionConfig->getOptions() as $option => $value) {
-            // It is now explicitly forbidden to set the module name to "user".
-            // Formerly, this has been silently ignored.
-            if ($option === 'session.save_handler' && $value === 'user') {
+            // Since PHP 7.2 it is explicitly forbidden to set the module name to "user".
+            // Need to skip all handlers except memcached. Redis and Db have implements SessionHandlerInterface.
+            if ($option === 'session.save_handler' && !$value === 'memcached') {
                 continue;
             } else {
                 $result = ini_set($option, $value);