MySQL, PostgreSQL: Fix queries splitting and string constants

Thanks to alxivnov (https://github.com/vrana/adminer/pull/490).

adminer/drivers/mssql.inc.php

@@ -630,6 +630,10 @@ WHERE sys1.xtype = 'TR' AND sys2.name = " . q($table)
 		return array();
 	}
 
+	function is_c_style_escapes() {
+		return true;
+	}
+
 	function show_status() {
 		return array();
 	}

adminer/drivers/mysql.inc.php

@@ -1056,6 +1056,18 @@ if (!defined("DRIVER")) {
 		return get_key_vals("SHOW VARIABLES");
 	}
 
+	/** Checks if C-style escapes are supported
+	* @return bool
+	*/
+	function is_c_style_escapes() {
+		static $c_style = null;
+		if ($c_style === null) {
+			$variables = get_key_vals("SHOW VARIABLES LIKE 'sql_mode'");
+			$c_style = strpos($variables["sql_mode"], 'NO_BACKSLASH_ESCAPES') === false;
+		}
+		return $c_style;
+	}
+
 	/** Get process list
 	* @return array ($row)
 	*/

adminer/drivers/oracle.inc.php

@@ -479,6 +479,10 @@ AND c_src.TABLE_NAME = " . q($table);
 		return get_key_vals('SELECT name, display_value FROM v$parameter');
 	}
 
+	function is_c_style_escapes() {
+		return true;
+	}
+
 	function process_list() {
 		return get_rows('SELECT sess.process AS "process", sess.username AS "user", sess.schemaname AS "schema", sess.status AS "status", sess.wait_class AS "wait_class", sess.seconds_in_wait AS "seconds_in_wait", sql.sql_text AS "sql_text", sess.machine AS "machine", sess.port AS "port"
 FROM v$session sess LEFT OUTER JOIN v$sql sql

adminer/drivers/pgsql.inc.php

@@ -860,6 +860,15 @@ AND typelem = 0"
 		return get_key_vals("SHOW ALL");
 	}
 
+	function is_c_style_escapes() {
+		static $c_style = null;
+		if ($c_style === null) {
+			$vals = get_vals("SHOW standard_conforming_strings");
+			$c_style = $vals[0] == "off";
+		}
+		return $c_style;
+	}
+
 	function process_list() {
 		return get_rows("SELECT * FROM pg_stat_activity ORDER BY " . (min_version(9.2) ? "pid" : "procpid"));
 	}

adminer/drivers/sqlite.inc.php

@@ -764,6 +764,10 @@ if (isset($_GET["sqlite"]) || isset($_GET["sqlite2"])) {
 		return $return;
 	}
 
+	function is_c_style_escapes() {
+		return true;
+	}
+
 	function show_status() {
 		$return = array();
 		foreach (get_vals("PRAGMA compile_options") as $option) {

adminer/sql.inc.php

@@ -81,7 +81,15 @@ if (!$error && $_POST) {
 					$offset = $pos + strlen($found);
 
 					if ($found && rtrim($found) != $delimiter) { // find matching quote or comment end
-						while (preg_match('(' . ($found == '/*' ? '\*/' : ($found == '[' ? ']' : (preg_match('~^-- |^#~', $found) ? "\n" : preg_quote($found) . "|\\\\."))) . '|$)s', $query, $match, PREG_OFFSET_CAPTURE, $offset)) { //! respect sql_mode NO_BACKSLASH_ESCAPES
+						$c_style_escapes = is_c_style_escapes() || ($jush == "pgsql" && ($pos > 0 && strtolower($query[$pos - 1]) == "e"));
+
+						$pattern = ($found == '/*' ? '\*/'
+							: ($found == '[' ? ']'
+							: (preg_match('~^-- |^#~', $found) ? "\n"
+							: preg_quote($found) . ($c_style_escapes ? "|\\\\." : "")
+						)));
+
+						while (preg_match("($pattern|\$)s", $query, $match, PREG_OFFSET_CAPTURE, $offset)) {
 							$s = $match[0][0];
 							if (!$s && $fp && !feof($fp)) {
 								$query .= fread($fp, 1e5);