Cancellation explodes magical traps

src/trap.c

@@ -346,7 +346,7 @@ maketrap(int x, int y, int typ)
     struct rm *lev = &levl[x][y];
 
     if ((ttmp = t_at(x, y)) != 0) {
-        if (ttmp->ttyp == MAGIC_PORTAL || ttmp->ttyp == VIBRATING_SQUARE)
+        if (undestroyable_trap(ttmp->ttyp))
             return (struct trap *) 0;
         oldplace = TRUE;
         if (u.utrap && x == u.ux && y == u.uy
@@ -2441,7 +2441,7 @@ dotrap(register struct trap* trap, unsigned int trflags)
                 trapname(ttype, FALSE));
             return;
         }
-        if (!Fumbling && ttype != MAGIC_PORTAL && ttype != VIBRATING_SQUARE
+        if (!Fumbling && !undestroyable_trap(ttype)
             && ttype != ANTI_MAGIC && !forcebungle && !plunged
             && !conj_pit && !adj_pit
             && (!rn2(5) || (is_pit(ttype)