floating down on a trap in which you're already trapped

this would re-trap you, extending your trap time

doc/fixes34.0

@@ -429,6 +429,7 @@ gold detection "materially poor" message inappropriate if you have hidden_gold()
 cannot reflect back an invisible umber hulk or medusa's attack
 monsters with M3_WANTSBOOK often couldn't move in the Wizard-level
 Vlad should want the Candelabrum
+if you float_down on a trap in which you're already trapped, don't retrap
 
 
 Platform- and/or Interface-Specific Fixes

src/trap.c

@@ -2133,7 +2133,8 @@ long hmask, emask;     /* might cancel timeout */
 				break;
 			/* fall into next case */
 		default:
-			dotrap(trap, 0);
+			if (!u.utrap) /* not already in the trap */
+				dotrap(trap, 0);
 	}
 
 	if (!Is_airlevel(&u.uz) && !Is_waterlevel(&u.uz) && !u.uswallow &&