fixed pgsql test break

framework/db/schema/pgsql/CPgsqlSchema.php

@@ -419,16 +419,17 @@ public function alterColumn($table, $column, $type)
 	 * Builds a SQL statement for creating a new index.
 	 * @param string $name the name of the index. The name will be properly quoted by the method.
 	 * @param string $table the table that the new index will be created for. The table name will be properly quoted by the method.
-	 * @param string $column the column(s) that should be included in the index. If there are multiple columns, please separate them
+	 * @param string $columns the column(s) that should be included in the index. If there are multiple columns, please separate them
 	 * by commas. Each column name will be properly quoted by the method, unless a parenthesis is found in the name.
 	 * @param boolean $unique whether to add UNIQUE constraint on the created index.
 	 * @return string the SQL statement for creating a new index.
 	 * @since 1.1.6
 	 */
-	public function createIndex($name, $table, $column, $unique=false)
+	public function createIndex($name, $table, $columns, $unique=false)
 	{
 		$cols=array();
-		$columns=preg_split('/\s*,\s*/',$column,-1,PREG_SPLIT_NO_EMPTY);
+		if (is_string($columns))
+			$columns=preg_split('/\s*,\s*/',$columns,-1,PREG_SPLIT_NO_EMPTY);
 		foreach($columns as $col)
 		{
 			if(strpos($col,'(')!==false)