entering gehennom

When you first attempt to walk down the stairs from the Valley of the
Dead to the second level of the Gehennom branch, the game prompts you about
whether you really want to proceed.  But if wasn't keeping track of whether
you had previously level teleported past that point (which is possible when
starting from the Valley rather than from higher up), so would still issue
that once-only prompt if you used the stairs later.  Mark the prompt as if
it has already given whenever you reach a Gehennom level beyond the Valley.

doc/fixes34.4

@@ -130,6 +130,8 @@ hero could still see for brief period after being blinded by potion vapors
 avoid crash when thrown potion hits bars before a monster
 don't give messages about seeing things happen while asleep
 protect hero from mind flayer's remote mental blast during successful prayer
+recognize if hero has already entered Gehennom by means other than usual route
+	so that prompt can be skipped if Valley's stairs are subsequently used
 
 
 Platform- and/or Interface-Specific Fixes

src/do.c

@@ -1315,6 +1315,8 @@ boolean at_stairs, falling, portal;
 		You_hear("groans and moans everywhere.");
 	    } else pline("It is hot here.  You smell smoke...");
 	}
+	/* in case we've managed to bypass the Valley's stairway down */
+	if (Inhell && !Is_valley(&u.uz)) u.uevent.gehennom_entered = 1;
 
 	if (familiar) {
 	    static const char * const fam_msgs[4] = {