Fix another regression caused by 805eddaefd9503b5dbbd924bd6da66e29c4768f3

Also added a unit test for #4431

1 files changed, 3 insertions, 3 deletions

diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index b46730e22..66ef913c9 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -542,7 +542,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				$s = $m[0][$i][1] + strlen($m[0][$i][0]), $i++)
 			{
 				$temp = substr($cond, $s, ($m[0][$i][1] - $s));
-				$newcond .= preg_match("/(.*)([\[\]\w\.'-]+)(\s*[^\"\[`'\w]+\s*)(.+)/i", $temp, $match)
+				$newcond .= preg_match("/(\(*)?([\[\]\w\.'-]+)(\s*[^\"\[`'\w]+\s*)(.+)/i", $temp, $match)
 						? $match[1].$this->protect_identifiers($match[2]).$match[3].$this->protect_identifiers($match[4])
 						: $temp;
 
@@ -552,9 +552,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$cond = ' ON '.$newcond;
 		}
 		// Split apart the condition and protect the identifiers
-		elseif ($escape === TRUE && preg_match("/([\[\]\w\.'-]+)(\s*[^\"\[`'\w]+\s*)(.+)/i", $cond, $match))
+		elseif ($escape === TRUE && preg_match("/(\(*)?([\[\]\w\.'-]+)(\s*[^\"\[`'\w]+\s*)(.+)/i", $cond, $match))
 		{
-			$cond = ' ON '.$this->protect_identifiers($match[1]).$match[2].$this->protect_identifiers($match[3]);
+			$cond = ' ON '.$match[1].$this->protect_identifiers($match[2]).$match[3].$this->protect_identifiers($match[4]);
 		}
 		elseif ( ! $this->_has_operator($cond))
 		{