Fixed #31 -- Old file was not removed if updated

When you updated a StdImageField the file was not deleted by the pre_save_delete util.

Author: martinmaillard

setup.py

@@ -22,7 +22,7 @@ def run(self):
 
 setup(
     name='django-stdimage',
-    version='1.0.6',
+    version='1.0.7',
     description='Django Standarized Image Field',
     author='codingjoe',
     url='https://github.com/codingjoe/django-stdimage',

stdimage/utils.py

@@ -75,5 +75,6 @@ def pre_save_delete_callback(sender, instance, **kwargs):
             if isinstance(field, StdImageField):
                 obj_field = getattr(obj, field.name)
                 instance_field = getattr(instance, field.name)
-                if obj_field and not instance_field:
+                if obj_field and obj_field != instance_field:
                     obj_field.delete(False)
+

tests/tests.py

@@ -122,13 +122,20 @@ def test_deletion_singnal_receiver(self):
         obj.delete()
         self.assertFalse(os.path.exists(os.path.join(IMG_DIR, 'image.gif')))
 
-    def test_pre_save_delete_callback(self):
+    def test_pre_save_delete_callback_clear(self):
         AdminDeleteModel.objects.create(image=self.fixtures['100.gif'])
         self.client.post('/admin/tests/admindeletemodel/1/', {
             'image-clear': 'checked',
         })
         self.assertFalse(os.path.exists(os.path.join(IMG_DIR, 'image.gif')))
 
+    def test_pre_save_delete_callback_new(self):
+        AdminDeleteModel.objects.create(image=self.fixtures['100.gif'])
+        self.client.post('/admin/tests/admindeletemodel/1/', {
+            'image': self.fixtures['600x400.jpg'],
+        })
+        self.assertFalse(os.path.exists(os.path.join(IMG_DIR, 'image.gif')))
+
     def test_upload_to_auto_slug_class_name_dir(self):
         UploadToAutoSlugClassNameDirModel.objects.create(
             name='foo bar',