Fixed #8175: don't open files we're about to close. This was a pesky bug to track down; thanks to charmless for tracking it down.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8637 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/fields/files.py

@@ -78,7 +78,12 @@ class FieldFile(File):
     save.alters_data = True
 
     def delete(self, save=True):
-        self.close()
+        # Only close the file if it's already open, which we know by the
+        # presence of self._file
+        if hasattr(self, '_file'):
+            self.close()
+            del self._file
+            
         self.storage.delete(self.name)
 
         self._name = None