Fix crash on attempt to transfer component of a combined artifact

lib/gameState/CGameStateCampaign.cpp

@@ -120,6 +120,11 @@ void CGameStateCampaign::trimCrossoverHeroesParameters(const CampaignTravel & tr
 				if(!info)
 					return false;
 
+				// FIXME: double-check how H3 handles case of transferring components of a combined artifact if entire combined artifact is not transferrable
+				// For example, what happens if hero has assembled Angelic Alliance, AA is not marked is transferrable, but Sandals can be transferred? Should artifact be disassembled?
+				if (info->locked)
+					return false;
+
 				// TODO: why would there be nullptr artifacts?
 				const CArtifactInstance *art = info->artifact;
 				if(!art)