Stopping a server after save-off causes unexpected data loss

Stopping a Minecraft server with the command /stop after the /save-off command has been executed cause the outstanding changes to the world to be discarded.

This can cause an unexpected and unrecoverable loss of data spanning anything from hours to weeks upon shutting down a server.

In combination with MC-3208 this behavior causes the world state to become corrupt in addition to the data loss.

Steps to reproduce

1. Start a Minecraft server
2. Execute /save-off
3. Make changes to the world. (i.e, place some blocks)
4. Stop the server with /stop, and start it up again
5. Observe that the changes made has been discarded

Expected behavior

When stopping, the Minecraft server would save the world to disk, regardless of state of save-on/save-off.

What actually happened

The changes to the world was discarded.