Roll back attachment entry in database if attachment file upload attempt fails

When a user attempts to upload an attachment but the file upload process fails, the counter on attachment page and associated information is updated as though the operation succeeded. The database entry is still being made despite upload attempt failing.

Checking the source code shows that the database entry is updated prior to the transfer being attempted to generate the id for the file-name, but if the upload fails then no rollback is performed on the database operation.

Improved behaviour would be to check the file upload success and undo the entry if the attempt was unsuccessful.