diff --git a/cake/libs/model/datasources/dbo_source.php b/cake/libs/model/datasources/dbo_source.php
index 8f7c090cb..34edf294d 100644
--- a/cake/libs/model/datasources/dbo_source.php
+++ b/cake/libs/model/datasources/dbo_source.php
@@ -1449,56 +1449,10 @@ class DboSource extends DataSource {
 		if (empty($alias)) {
 			$alias = $model->alias;
 		}
-
-		if (!is_array($fields)) {
-			if (!empty($fields)) {
-				$depth = 0;
-				$offset = 0;
-				$buffer = '';
-				$results = array();
-				$length = strlen($fields);
-
-				while ($offset <= $length) {
-					$tmpOffset = -1;
-					$offsets = array(strpos($fields, ',', $offset), strpos($fields, '(', $offset), strpos($fields, ')', $offset));
-					for ($i = 0; $i < 3; $i++) {
-						if ($offsets[$i] !== false && ($offsets[$i] < $tmpOffset || $tmpOffset == -1)) {
-							$tmpOffset = $offsets[$i];
-						}
-					}
-					if ($tmpOffset !== -1) {
-						$buffer .= substr($fields, $offset, ($tmpOffset - $offset));
-						if ($fields{$tmpOffset} == ',' && $depth == 0) {
-							$results[] = $buffer;
-							$buffer = '';
-						} else {
-							$buffer .= $fields{$tmpOffset};
-						}
-						if ($fields{$tmpOffset} == '(') {
-							$depth++;
-						}
-						if ($fields{$tmpOffset} == ')') {
-							$depth--;
-						}
-						$offset = ++$tmpOffset;
-					} else {
-						$results[] = $buffer . substr($fields, $offset);
-						$offset = $length + 1;
-					}
-				}
-				if (empty($results) && !empty($buffer)) {
-					$results[] = $buffer;
-				}
-
-				if (!empty($results)) {
-					$fields = array_map('trim', $results);
-				} else {
-					$fields = array();
-				}
-			}
-		}
 		if (empty($fields)) {
 			$fields = array_keys($model->schema());
+		} elseif (!is_array($fields)) {
+			$fields = String::tokenize($fields);
 		} else {
 			$fields = array_filter($fields);
 		}
diff --git a/cake/libs/string.php b/cake/libs/string.php
index d65134dd2..3293852be 100644
--- a/cake/libs/string.php
+++ b/cake/libs/string.php
@@ -370,6 +370,66 @@ class String extends Object {
 		}
 		return $_this->ascii($upperCase);
 	}
+/**
+ * Tokenizes a string using $separator, ignoring any instance of $separator that appears between $leftBound
+ * and $rightBound
+ *
+ * @param string $data The data to tokenize
+ * @param string $separator The token to split the data on
+ * @return string
+ * @access public
+ * @static
+ */
+	function tokenize($data, $separator = ',', $leftBound = '(', $rightBound = ')') {
+	    if(empty($data) || is_array($data)) {
+	        return $data;
+	    }
+
+		$depth = 0;
+		$offset = 0;
+		$buffer = '';
+		$results = array();
+		$length = strlen($data);
+
+		while ($offset <= $length) {
+			$tmpOffset = -1;
+			$offsets = array(strpos($data, $separator, $offset), strpos($data, $leftBound, $offset), strpos($data, $rightBound, $offset));
+			for ($i = 0; $i < 3; $i++) {
+				if ($offsets[$i] !== false && ($offsets[$i] < $tmpOffset || $tmpOffset == -1)) {
+					$tmpOffset = $offsets[$i];
+				}
+			}
+			if ($tmpOffset !== -1) {
+				$buffer .= substr($data, $offset, ($tmpOffset - $offset));
+				if ($data{$tmpOffset} == $separator && $depth == 0) {
+					$results[] = $buffer;
+					$buffer = '';
+				} else {
+					$buffer .= $data{$tmpOffset};
+				}
+				if ($data{$tmpOffset} == $leftBound) {
+					$depth++;
+				}
+				if ($data{$tmpOffset} == $rightBound) {
+					$depth--;
+				}
+				$offset = ++$tmpOffset;
+			} else {
+				$results[] = $buffer . substr($data, $offset);
+				$offset = $length + 1;
+			}
+		}
+		if (empty($results) && !empty($buffer)) {
+			$results[] = $buffer;
+		}
+
+		if (!empty($results)) {
+			$data = array_map('trim', $results);
+		} else {
+			$data = array();
+		}
+		return $data;
+	}
 /**
  * Return the Code points range for Unicode characters
  *
diff --git a/cake/tests/cases/libs/controller/components/session.test.php b/cake/tests/cases/libs/controller/components/session.test.php
index c8cd6a08d..962279671 100644
--- a/cake/tests/cases/libs/controller/components/session.test.php
+++ b/cake/tests/cases/libs/controller/components/session.test.php
@@ -43,7 +43,7 @@ class SessionComponentTest extends CakeTestCase {
 
 	function testSessionAutoStart() {
 		$this->Session->startup(new SessionTestController());
-		$this->assertTrue(isset($_SESSION) && empty($_SESSION));
+		$this->assertTrue(isset($_SESSION));
 	}
 
 	function testSessionWriting() {