Fix compatibility with PHP 8.1 and Psotgresql

ChangeLog

@@ -9,8 +9,8 @@ English Dolibarr ChangeLog
 For users:
 ---------------
 
-NEW: PHP 8.0 compatibility (with mysql):
-     Warning!! Application works correctly with PHP 8.0 but you will experience a lot of PHP warnings into the PHP server
+NEW: PHP 8.0 and 8.1 compatibility (with mysql):
+     Warning!! Application works correctly with PHP 8.0 and 8.1 but you will experience a lot of PHP warnings into the PHP server
      log files (depending on your PHP setup). Removal of all PHP warnings on server side is planned for v17.
 NEW: Support for recurring purchase invoices.
 NEW: #20292 Include German public holidays

htdocs/core/lib/functions.lib.php

@@ -1156,7 +1156,17 @@ function dol_buildpath($path, $type = 0, $returnemptyifnotfound = 0)
 function dol_clone($object, $native = 0)
 {
 	if (empty($native)) {
+		$tmpsavdb = null;
+		if (isset($object->db) && isset($object->db->db) && is_object($object->db->db) && get_class($object->db->db) == 'PgSql\Connection') {
+			$tmpsavdb = $object->db;
+			unset($object->db);		// Such property can not be serialized when PgSql/Connection
+		}
+
 		$myclone = unserialize(serialize($object));	// serialize then unserialize is hack to be sure to have a new object for all fields
+
+		if ($tmpsavdb) {
+			$object->db = $tmpsavdb;
+		}
 	} else {
 		$myclone = clone $object; // PHP clone is a shallow copy only, not a real clone, so properties of references will keep the reference (refering to the same target/variable)
 	}