Version Control "Undo Last Check In" gives no warning that all changes will be lost on next check out.
Lyx 2.0.6 on Linux Mint 13 (like Ubuntu Precise LTS) with Xfce 4.10 using RCS 5.7.25
1. I make changes to document in Lyx then check in these - using RCS, file will be saved.
2. I accidentally, (or on purpose) click File>Version Control>Undo Last Check In.
This invokes command rcs -o<version> <file-name> 3. No changes are made to the current document but it is made Read-Only.
4. When I File>Version Control>Check Out for Edit - any changes made after the previous Check In are deleted.
I think this is the behaviour that I would expect. However, I think there should be a strong warning saying "You are about to loose all changes since the previous check in. Do you wish to proceed." Perhaps it might suggest doing a "Compare With Older Version" to see and preserve changes so that I might save them and not loose them unintentionally.