Update ORM#is_dirty - swapped isset() for array_key_exists() - isset() will return false when fields have been set null.

Update ORMTest#testIsDirty - added tests for filed set to '' and null

1 files changed, 1 insertions, 1 deletions

diff --git a/idiorm.php b/idiorm.php
index 80e9a4d..ea5f1a0 100644
--- a/idiorm.php
+++ b/idiorm.php
@@ -1964,7 +1964,7 @@
          * object was saved.
          */
         public function is_dirty($key) {
-            return isset($this->_dirty_fields[$key]);
+            return array_key_exists($key, $this->_dirty_fields);
         }
 
         /**