Food myths

[Marc Hartstein]

I'm not sure how these got started, but having spent a bunch of time
looking at eat.c and confirming in wizmode, I'd like to clear up a
couple of food-related myths that keep floating around:

MYTH #1: Blessed comestibles are never rotten.

FACT: Blessed comestibles have just as good a chance of being rotten
as uncursed comestibles. Blessed corpses can be older before they
cause food poisoning or "mild illness". Blessed non-corpse
comestibles can be older before they check for a random chance of
rotting.

MYTH #2: Cursed corpses are always rotten.

FACT: Cursed non-corpse comestibles other than fortune cookies are
always rotten. Cursed corpses have the same chance of being rotten as
uncursed corpses. Cursed corpses cause food poisoning and "mild
illness" at an earlier age.

MYTH #3: Once you get the "Blecch! Rotten <food>!" message, you "pick
off the manky bits" and the food item is safe to eat. (Sorry whoever
came up with that phrase...I love it, it just happens not to really be
true.)

FACT: The food item is only safe to eat if it is the very next thing
you eat (thus "You resume your meal."). Otherwise you are
*guaranteed* to get a "Blecch! Rotten <food>!" message with a chance
at another rotten effect when you next bite into the food. I believe
the safety on resuming to be a bug in the "resume your meal" code.