Fix issues

Author: lazychaser

README.markdown

@@ -24,7 +24,8 @@ Hit `composer update` in the terminal, and you are ready to go next!
 ### Schema
 
 Storing hierarchies in a database requires additional columns for the table, so these
-fields need to be included in the migration. There is a helper for this:
+fields need to be included in the migration. Also, the root node is required.
+So, basic migration looks like this:
 
 ```php
 <?php

src/Kalnoy/Nestedset/Collection.php

@@ -35,7 +35,7 @@ public function toDictionary($key = null)
     /**
      * Build tree from node list.
      *
-     * To succesfully build tree "id" and "parent_id" keys must present.
+     * To succesfully build tree "id", "_lft" and "parent_id" keys must present.
      * 
      * If {@link rootNodeId} is provided, the tree will contain only descendants
      * of the node with such primary key value.
@@ -49,7 +49,7 @@ public function toTree($rootNodeId = null)
         $dictionary = $this->toDictionary();
         $result = new static();
 
-        // If root node is not specified we take parent id from node with
+        // If root node is not specified we take parent id of node with
         // least lft value as root node id.
         if ($rootNodeId === null) 
         {

src/Kalnoy/Nestedset/QueryBuilder.php

@@ -86,6 +86,8 @@ public function withDepth($key = 'depth')
             "((select count(*) from $table _ where $table.$lft between _.$lft and _.$rgt)-1) as $key"
         );
 
+        if ($this->columns === null) $this->columns = array('*');
+
         return $this->addSelect($column);
     }
 

tests/NodeTest.php

@@ -229,6 +229,13 @@ public function testWithDepthWithCustomKeyWorks()
         $this->assertTrue(isset($node['level']));
     }
 
+    public function testWithDepthWorksAlongWithDefaultKeys()
+    {
+        $node = Category::withDepth()->first();
+
+        $this->assertTrue(isset($node->name));
+    }
+
     public function testParentIdAttributeAccessorAppendsNode()
     {
         $node = new Category(array('name' => 'lg', 'parent_id' => 5));