I recently stumbled upon this inconsistent Mendix Studio behavior: If you make a change in your JavaScript actions ‘Code’ section, this change does not mark the entry as ‘changed’ with the yellow dot indication in the Project Explorer. The change is also not mentioned in the project changes tab during the commit. It is however possible to commit this change to the team server. A side effect of this untracked change in the JavaAction code is that it can not be rolled back as there is no such selection possible in this case (and if you introduce a change in the General settings and roll it back, it does not roll back the code section!)
might lead to confusion – I filed a support ticket with request for information about this behavior where it was suggested to open an idea.