Db: Unify connection error handling

adminer/drivers/mssql.inc.php

@@ -25,7 +25,7 @@ if (isset($_GET["mssql"])) {
 				$this->error = rtrim($this->error);
 			}
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				global $adminer;
 				$connection_info = array("UID" => $username, "PWD" => $password, "CharacterSet" => "UTF-8");
 				$ssl = $adminer->connectSsl();
@@ -46,7 +46,7 @@ if (isset($_GET["mssql"])) {
 				} else {
 					$this->get_error();
 				}
-				return (bool) $this->link;
+				return ($this->link ? '' : $this->error);
 			}
 
 			function quote(string $string): string {
@@ -182,9 +182,8 @@ if (isset($_GET["mssql"])) {
 			class Db extends MssqlDb {
 				public string $extension = "PDO_SQLSRV";
 
-				function connect(string $server, string $username, string $password): bool {
+				function attach(?string $server, string $username, string $password): string {
-					$this->dsn("sqlsrv:Server=" . str_replace(":", ",", $server), $username, $password);
+					return $this->dsn("sqlsrv:Server=" . str_replace(":", ",", $server), $username, $password);
-					return true;
 				}
 			}
 
@@ -192,9 +191,8 @@ if (isset($_GET["mssql"])) {
 			class Db extends MssqlDb {
 				public string $extension = "PDO_DBLIB";
 
-				function connect(string $server, string $username, string $password): bool {
+				function attach(?string $server, string $username, string $password): string {
-					$this->dsn("dblib:charset=utf8;host=" . str_replace(":", ";unix_socket=", preg_replace('~:(\d)~', ';port=\1', $server)), $username, $password);
+					return $this->dsn("dblib:charset=utf8;host=" . str_replace(":", ";unix_socket=", preg_replace('~:(\d)~', ';port=\1', $server)), $username, $password);
-					return true;
 				}
 			}
 		}
@@ -298,10 +296,7 @@ if (isset($_GET["mssql"])) {
 		if ($credentials[0] == "") {
 			$credentials[0] = "localhost:1433";
 		}
-		if ($connection->connect($credentials[0], $credentials[1], $credentials[2])) {
+		return ($connection->attach($credentials[0], $credentials[1], $credentials[2]) ?: $connection);
-			return $connection;
-		}
-		return $connection->error;
 	}
 
 	function get_databases($flush) {

adminer/drivers/mysql.inc.php

@@ -14,8 +14,7 @@ if (!defined('Adminer\DRIVER')) {
 				parent::init();
 			}
 
-			/** @see https://php.net/mysqli.construct */
+			function attach(?string $server, string $username, string $password): string {
-			function connect($server = "", $username = "", $password = "", $database = null, $port = null, $socket = null) {
 				global $adminer;
 				mysqli_report(MYSQLI_REPORT_OFF); // stays between requests, not required since PHP 5.3.4
 				list($host, $port) = explode(":", $server, 2); // part after : is used for port or socket
@@ -27,13 +26,13 @@ if (!defined('Adminer\DRIVER')) {
 					($server != "" ? $host : null),
 					($server . $username != "" ? $username : null),
 					($server . $username . $password != "" ? $password : null),
-					$database,
+					null,
+					(is_numeric($port) ? $port : ini_get("mysqli.default_port")),
 					(is_numeric($port) ? intval($port) : null),
-					(!is_numeric($port) ? $port : $socket),
 					($ssl ? ($ssl['verify'] !== false ? 2048 : 64) : 0) // 2048 - MYSQLI_CLIENT_SSL, 64 - MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT (not available before PHP 5.6.16)
 				);
 				$this->options(MYSQLI_OPT_LOCAL_INFILE, false);
-				return $return;
+				return ($return ? '' : $this->error);
 			}
 
 			function set_charset($charset) {
@@ -67,10 +66,9 @@ if (!defined('Adminer\DRIVER')) {
 		class Db extends SqlDb {
 			/** @var resource */ private $link;
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				if (ini_bool("mysql.allow_local_infile")) {
-					$this->error = lang('Disable %s or enable %s or %s extensions.', "'mysql.allow_local_infile'", "MySQLi", "PDO_MySQL");
+					return lang('Disable %s or enable %s or %s extensions.', "'mysql.allow_local_infile'", "MySQLi", "PDO_MySQL");
-					return false;
 				}
 				$this->link = @mysql_connect(
 					($server != "" ? $server : ini_get("mysql.default_host")),
@@ -79,12 +77,11 @@ if (!defined('Adminer\DRIVER')) {
 					true,
 					131072 // CLIENT_MULTI_RESULTS for CALL
 				);
-				if ($this->link) {
+				if (!$this->link) {
-					$this->server_info = mysql_get_server_info($this->link);
+					return mysql_error();
-				} else {
-					$this->error = mysql_error();
 				}
-				return (bool) $this->link;
+				$this->server_info = mysql_get_server_info($this->link);
+				return '';
 			}
 
 			/** Set the client character set */
@@ -169,7 +166,7 @@ if (!defined('Adminer\DRIVER')) {
 		class Db extends PdoDb {
 			public string $extension = "PDO_MySQL";
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				global $adminer;
 				$options = array(\PDO::MYSQL_ATTR_LOCAL_INFILE => false);
 				$ssl = $adminer->connectSsl();
@@ -187,13 +184,12 @@ if (!defined('Adminer\DRIVER')) {
 						$options[\PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT] = $ssl['verify'];
 					}
 				}
-				$this->dsn(
+				return $this->dsn(
 					"mysql:charset=utf8;host=" . str_replace(":", ";unix_socket=", preg_replace('~:(\d)~', ';port=\1', $server)),
 					$username,
 					$password,
 					$options
 				);
-				return true;
 			}
 
 			function set_charset($charset) {
@@ -366,24 +362,24 @@ if (!defined('Adminer\DRIVER')) {
 	}
 
 	/** Connect to the database
-	* @param array{string, string, string} $credentials [$server, $username, $password]
+	* @param array{?string, string, string} $credentials [$server, $username, $password]
 	* @return string|Db string for error
 	*/
 	function connect(array $credentials) {
 		global $drivers;
 		$connection = new Db;
-		if ($connection->connect($credentials[0], $credentials[1], $credentials[2])) {
+		$error = $connection->attach($credentials[0], $credentials[1], $credentials[2]);
-			$connection->set_charset(charset($connection));
+		if ($error) {
-			$connection->query("SET sql_quote_show_create = 1, autocommit = 1");
+			if (function_exists('iconv') && !is_utf8($error) && strlen($s = iconv("windows-1250", "utf-8", $error)) > strlen($error)) { // windows-1250 - most common Windows encoding
-			$connection->flavor = (preg_match('~MariaDB~', $connection->server_info) ? 'maria' : 'mysql');
+				$error = $s;
-			$drivers[DRIVER] = ($connection->flavor == 'maria' ? "MariaDB" : "MySQL");
+			}
-			return $connection;
+			return $error;
 		}
-		$return = $connection->error;
+		$connection->set_charset(charset($connection));
-		if (function_exists('iconv') && !is_utf8($return) && strlen($s = iconv("windows-1250", "utf-8", $return)) > strlen($return)) { // windows-1250 - most common Windows encoding
+		$connection->query("SET sql_quote_show_create = 1, autocommit = 1");
-			$return = $s;
+		$connection->flavor = (preg_match('~MariaDB~', $connection->server_info) ? 'maria' : 'mysql');
-		}
+		$drivers[DRIVER] = ($connection->flavor == 'maria' ? "MariaDB" : "MySQL");
-		return $return;
+		return $connection;
 	}
 
 	/** Get cached list of databases

adminer/drivers/oracle.inc.php

@@ -19,15 +19,14 @@ if (isset($_GET["oracle"])) {
 				$this->error = $error;
 			}
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				$this->link = @oci_new_connect($username, $password, $server, "AL32UTF8");
 				if ($this->link) {
 					$this->server_info = oci_server_version($this->link);
-					return true;
+					return '';
 				}
 				$error = oci_error();
-				$this->error = $error["message"];
+				return $error["message"];
-				return false;
 			}
 
 			function quote(string $string): string {
@@ -106,9 +105,8 @@ if (isset($_GET["oracle"])) {
 			public string $extension = "PDO_OCI";
 			public $_current_db;
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
-				$this->dsn("oci:dbname=//$server;charset=AL32UTF8", $username, $password);
+				return $this->dsn("oci:dbname=//$server;charset=AL32UTF8", $username, $password);
-				return true;
 			}
 
 			function select_db(string $database): bool {
@@ -193,10 +191,7 @@ if (isset($_GET["oracle"])) {
 
 	function connect($credentials) {
 		$connection = new Db;
-		if ($connection->connect($credentials[0], $credentials[1], $credentials[2])) {
+		return ($connection->attach($credentials[0], $credentials[1], $credentials[2]) ?: $connection);
-			return $connection;
-		}
-		return $connection->error;
 	}
 
 	function get_databases($flush) {

adminer/drivers/pgsql.inc.php

@@ -19,7 +19,7 @@ if (isset($_GET["pgsql"])) {
 				$this->error = $error;
 			}
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				global $adminer;
 				$db = $adminer->database();
 				set_error_handler(array($this, '_error'));
@@ -38,7 +38,7 @@ if (isset($_GET["pgsql"])) {
 				if ($this->link) {
 					pg_set_client_encoding($this->link, "UTF8");
 				}
-				return (bool) $this->link;
+				return ($this->link ? '' : $this->error);
 			}
 
 			function quote(string $string): string {
@@ -129,7 +129,7 @@ if (isset($_GET["pgsql"])) {
 			public string $extension = "PDO_PgSQL";
 			public int $timeout;
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				global $adminer;
 				$db = $adminer->database();
 				//! client_encoding is supported since 9.1, but we can't yet use min_version here
@@ -138,8 +138,7 @@ if (isset($_GET["pgsql"])) {
 				if (isset($ssl["mode"])) {
 					$dsn .= " sslmode='" . $ssl["mode"] . "'";
 				}
-				$this->dsn($dsn, $username, $password);
+				return $this->dsn($dsn, $username, $password);
-				return true;
 			}
 
 			function select_db(string $database): bool {
@@ -304,19 +303,20 @@ if (isset($_GET["pgsql"])) {
 	function connect($credentials) {
 		global $drivers;
 		$connection = new Db;
-		if ($connection->connect($credentials[0], $credentials[1], $credentials[2])) {
+		$error = $connection->attach($credentials[0], $credentials[1], $credentials[2]);
-			if (min_version(9, 0, $connection)) {
+		if ($error) {
-				$connection->query("SET application_name = 'Adminer'");
+			return $error;
-			}
-			$version = get_val("SELECT version()", 0, $connection);
-			$connection->flavor = (preg_match('~CockroachDB~', $version) ? 'cockroach' : '');
-			$connection->server_info = preg_replace('~^\D*([\d.]+[-\w]*).*~', '\1', $version);
-			if ($connection->flavor == 'cockroach') { // we don't use "PostgreSQL / CockroachDB" by default because it's too long
-				$drivers[DRIVER] = "CockroachDB";
-			}
-			return $connection;
 		}
-		return $connection->error;
+		if (min_version(9, 0, $connection)) {
+			$connection->query("SET application_name = 'Adminer'");
+		}
+		$version = get_val("SELECT version()", 0, $connection);
+		$connection->flavor = (preg_match('~CockroachDB~', $version) ? 'cockroach' : '');
+		$connection->server_info = preg_replace('~^\D*([\d.]+[-\w]*).*~', '\1', $version);
+		if ($connection->flavor == 'cockroach') { // we don't use "PostgreSQL / CockroachDB" by default because it's too long
+			$drivers[DRIVER] = "CockroachDB";
+		}
+		return $connection;
 	}
 
 	function get_databases($flush) {

adminer/drivers/sqlite.inc.php

@@ -11,11 +11,11 @@ if (isset($_GET["sqlite"])) {
 			public string $extension = "SQLite3";
 			private $link;
 
-			function connect(string $filename, string $username = '', string $password = ''): bool {
+			function attach(?string $filename, string $username, string $password): string {
 				$this->link = new \SQLite3($filename);
 				$version = $this->link->version();
 				$this->server_info = $version["versionString"];
-				return true;
+				return '';
 			}
 
 			function query(string $query, bool $unbuffered = false) {
@@ -75,11 +75,11 @@ if (isset($_GET["sqlite"])) {
 		abstract class SqliteDb extends PdoDb {
 			public string $extension = "PDO_SQLite";
 
-			function connect(string $filename, string $username = '', string $password = ''): bool {
+			function attach(?string $filename, string $username, string $password): string {
 				$this->dsn(DRIVER . ":$filename", "", "");
 				$this->query("PRAGMA foreign_keys = 1");
 				$this->query("PRAGMA busy_timeout = 500");
-				return true;
+				return '';
 			}
 		}
 
@@ -87,16 +87,16 @@ if (isset($_GET["sqlite"])) {
 
 	if (class_exists('Adminer\SqliteDb')) {
 		class Db extends SqliteDb {
-			function connect(string $filename, string $username = '', string $password = ''): bool {
+			function attach(?string $filename, string $username, string $password): string {
-				parent::connect($filename);
+				parent::attach($filename, $username, $password);
 				$this->query("PRAGMA foreign_keys = 1");
 				$this->query("PRAGMA busy_timeout = 500");
-				return true;
+				return '';
 			}
 
 			function select_db(string $filename): bool {
 				if (is_readable($filename) && $this->query("ATTACH " . $this->quote(preg_match("~(^[/\\\\]|:)~", $filename) ? $filename : dirname($_SERVER["SCRIPT_FILENAME"]) . "/$filename") . " AS a")) {
-					return self::connect($filename);
+					return !self::attach($filename, '', '');
 				}
 				return false;
 			}
@@ -172,8 +172,7 @@ if (isset($_GET["sqlite"])) {
 			return lang('Database does not support password.');
 		}
 		$connection = new Db;
-		$connection->connect(":memory:", "", "");
+		return ($connection->attach(":memory:", "", "") ?: $connection);
-		return $connection;
 	}
 
 	function get_databases($flush) {
@@ -369,7 +368,7 @@ if (isset($_GET["sqlite"])) {
 		}
 		try {
 			$link = new Db();
-			$link->connect($db);
+			$link->attach($db, '', '');
 		} catch (\Exception $ex) {
 			$connection->error = $ex->getMessage();
 			return false;
@@ -382,7 +381,7 @@ if (isset($_GET["sqlite"])) {
 
 	function drop_databases($databases) {
 		global $connection;
-		$connection->connect(":memory:"); // to unlock file, doesn't work in PDO on Windows
+		$connection->attach(":memory:", '', ''); // to unlock file, doesn't work in PDO on Windows
 		foreach ($databases as $db) {
 			if (!@unlink($db)) {
 				$connection->error = lang('File exists.');
@@ -397,7 +396,7 @@ if (isset($_GET["sqlite"])) {
 		if (!check_sqlite_name($name)) {
 			return false;
 		}
-		$connection->connect(":memory:");
+		$connection->attach(":memory:", '', '');
 		$connection->error = lang('File exists.');
 		return @rename(DB, $name);
 	}

adminer/include/db.inc.php

@@ -13,8 +13,10 @@ abstract class SqlDb {
 	public string $error; // last error message
 	/** @var Result|bool */ protected $multi; // used for multiquery
 
-	/** Connect to server */
+	/** Connect to server
-	abstract function connect(string $server, string $username, string $password): bool;
+	* @return string error message
+	*/
+	abstract function attach(?string $server, string $username, string $password): string;
 
 	/** Quote string to use in SQL
 	* @return string escaped string enclosed in '

adminer/include/pdo.inc.php

@@ -8,16 +8,18 @@ if (extension_loaded('pdo')) {
 
 		/** Connect to server using DSN
 		* @param mixed[] $options
+		* @return string error message
 		*/
-		function dsn(string $dsn, string $username, string $password, array $options = array()): void {
+		function dsn(string $dsn, string $username, string $password, array $options = array()): string {
 			$options[\PDO::ATTR_ERRMODE] = \PDO::ERRMODE_SILENT;
 			$options[\PDO::ATTR_STATEMENT_CLASS] = array('Adminer\PdoResult');
 			try {
 				$this->pdo = new \PDO($dsn, $username, $password, $options);
 			} catch (\Exception $ex) {
-				auth_error(h($ex->getMessage()));
+				return $ex->getMessage();
 			}
 			$this->server_info = @$this->pdo->getAttribute(\PDO::ATTR_SERVER_VERSION);
+			return '';
 		}
 
 		function quote(string $string): string {

plugins/drivers/clickhouse.php

@@ -56,11 +56,11 @@ if (isset($_GET["clickhouse"])) {
 				return $this->rootQuery($this->_db, $query);
 			}
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				preg_match('~^(https?://)?(.*)~', $server, $match);
 				$this->url = ($match[1] ?: "http://") . urlencode($username) . ":" . urlencode($password) . "@$match[2]";
 				$return = $this->query('SELECT 1');
-				return (bool) $return;
+				return ($return ? '' : $this->error);
 			}
 
 			function select_db(string $database): bool {
@@ -230,10 +230,7 @@ if (isset($_GET["clickhouse"])) {
 		if (!preg_match('~^(https?://)?[-a-z\d.]+(:\d+)?$~', $server)) {
 			return lang('Invalid server.');
 		}
-		if ($connection->connect($server, $username, $password)) {
+		return ($connection->attach($server, $username, $password) ?: $connection);
-			return $connection;
-		}
-		return $connection->error;
 	}
 
 	function get_databases($flush) {

plugins/drivers/elastic.php

@@ -61,14 +61,14 @@ if (isset($_GET["elastic"])) {
 				}
 			}
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				preg_match('~^(https?://)?(.*)~', $server, $match);
 				$this->url = ($match[1] ?: "http://") . urlencode($username) . ":" . urlencode($password) . "@$match[2]";
 				$return = $this->rootQuery('');
 				if ($return) {
 					$this->server_info = $return['version']['number'];
 				}
-				return (bool) $return;
+				return ($return ? '' : $this->error);
 			}
 
 			function select_db(string $database): bool {
@@ -290,15 +290,11 @@ if (isset($_GET["elastic"])) {
 		if (!preg_match('~^(https?://)?[-a-z\d.]+(:\d+)?$~', $server)) {
 			return lang('Invalid server.');
 		}
-		if ($password != "" && $connection->connect($server, $username, "")) {
+		if ($password != "" && $connection->attach($server, $username, "")) {
 			return lang('Database does not support password.');
 		}
 
-		if ($connection->connect($server, $username, $password)) {
+		return ($connection->attach($server, $username, $password) ?: $connection);
-			return $connection;
-		}
-
-		return $connection->error;
 	}
 
 	function support($feature) {

plugins/drivers/firebird.php

@@ -14,17 +14,15 @@ if (isset($_GET["firebird"])) {
 		class Db extends SqlDb {
 			public string $extension = "Firebird", $_link;
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				$this->_link = ibase_connect($server, $username, $password);
 				if ($this->_link) {
 					$url_parts = explode(':', $server);
 					$service_link = ibase_service_attach($url_parts[0], $username, $password);
 					$this->server_info = ibase_server_info($service_link, IBASE_SVC_SERVER_VERSION);
-				} else {
+					return '';
-					$this->errno = ibase_errcode();
-					$this->error = ibase_errmsg();
 				}
-				return (bool) $this->_link;
+				return ibase_errmsg();
 			}
 
 			function quote(string $string): string {
@@ -105,10 +103,7 @@ if (isset($_GET["firebird"])) {
 
 	function connect($credentials) {
 		$connection = new Db;
-		if ($connection->connect($credentials[0], $credentials[1], $credentials[2])) {
+		return ($connection->attach($credentials[0], $credentials[1], $credentials[2]) ?: $connection);
-			return $connection;
-		}
-		return $connection->error;
 	}
 
 	function get_databases($flush) {

plugins/drivers/imap.php

@@ -24,13 +24,10 @@ if (isset($_GET["imap"])) {
 			private $mailbox;
 			private $imap;
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				$this->mailbox = "{" . "$server:993/ssl}"; // Adminer disallows specifying privileged port in server name
 				$this->imap = @imap_open($this->mailbox, $username, $password, OP_HALFOPEN, 1);
-				if (!$this->imap) {
+				return ($this->imap ? '' : imap_last_error());
-					$this->error = imap_last_error();
-				}
-				return $this->imap;
 			}
 
 			function select_db(string $database): bool {
@@ -275,10 +272,7 @@ if (isset($_GET["imap"])) {
 
 	function connect($credentials) {
 		$connection = new Db;
-		if ($connection->connect($credentials[0], $credentials[1], $credentials[2])) {
+		return ($connection->attach($credentials[0], $credentials[1], $credentials[2]) ?: $connection);
-			return $connection;
-		}
-		return $connection->error;
 	}
 
 	function support($feature) {

plugins/drivers/mongo.php

@@ -12,7 +12,7 @@ if (isset($_GET["mongo"])) {
 			public \MongoDB\Driver\Manager $_link;
 			public $_db, $_db_name;
 
-			function connect(string $server, string $username, string $password): bool {
+			function attach(?string $server, string $username, string $password): string {
 				$options = array();
 				if ($username . $password != "") {
 					$options["username"] = $username;
@@ -27,6 +27,7 @@ if (isset($_GET["mongo"])) {
 				}
 				$this->_link = new \MongoDB\Driver\Manager("mongodb://$server", $options);
 				$this->executeDbCommand($options["db"], array('ping' => 1));
+				return '';
 			}
 
 			function executeCommand($command) {
@@ -435,11 +436,7 @@ if (isset($_GET["mongo"])) {
 		if ($server == "") {
 			$server = "localhost:27017";
 		}
-		$connection->connect($server, $username, $password);
+		return ($connection->attach($server, $username, $password) ?: $connection);
-		if ($connection->error) {
-			return $connection->error;
-		}
-		return $connection;
 	}
 
 	function alter_indexes($table, $alter) {

plugins/drivers/simpledb.php

@@ -10,6 +10,10 @@ if (isset($_GET["simpledb"])) {
 		class Db extends SqlDb {
 			public string $extension = "SimpleXML", $server_info = '2009-04-15', $timeout, $next;
 
+			function attach(?string $server, string $username, string $password): string {
+				return '';
+			}
+
 			function select_db(string $database): bool {
 				return ($database == "domain");
 			}