Attacking a shielded turf in Lords Mobile

In Lords Mobile, if I send my troops to attack someone but they put up a shield before I arrive, what happens?

If a shield gets put up, I usually recall my troops before they reach the destination b/c I don't know what will happen. I'm afraid if they hit the shield, they'll die and I'll lose all my troops, which will take a long time to train up again.

Does anyone know what will happen?

If you send your troops to a destination and that destination puts up a shield before your troops arrive, your troops will turn around immediately upon arrival with no battle.

Effectively, your troops take a long walk and do nothing. You won't lose your troops because no battle happens.