Rapid Interface Builder (RIB) is a browser-based design tool for quickly prototyping and creating the user interface for web applications. Layout your UI by dropping widgets onto a canvas. Run the UI in an interactive "Preview mode". Export the generated HTML and Javascript. It's that simple!
I opened a bug for this -- the case was if the user types something bogus into the property field, and then later changes or clears it. We were confirming deletion of a file that didn't even exist.
In what situation will this bug happen?