nutritution consumption/starvation tweaks

Being polymorphed into a creature capable of eating metal objects
was treated as if the hero didn't/couldn't eat.  Treat it the same
as being able to eat ordinary food instead.

Being fainted or unconscious from other than sleep both ran
metabolism at full rate, unlike being asleep which skips per-turn
consumption 9 times out of 10 (but retains periodic ring/amulet
and hunger/regeneration/conflict consumption).  Switch to 'Unaware'
to handle sleep, unconsciousness other than sleep, and fainted
from lack of food as one metabolic condition.  Being paralyzed
isn't included but maybe should be.

Changing how metabolism operates when fainted changes the amount
of time until starvation occurs, so I adjusted that by an arbitrary
amount.  It will probably need tuning.  As things stand, you'll
still faint umpteen times before starving, bringing about lots of
frustration since the player can't do much during that time.

doc/fixes36.1

@@ -234,6 +234,10 @@ effects of cursed potion of levitation were skipped if already levitating
 when engulfed, having swallower be killed by angry deity trying to zap hero
 	no longer violates pacifist conduct (other penalties--reduced luck or
 	alignment--still apply if target is something you shouldn't kill)
+metabolism adjustments: hero poly'd into metallivore form still needs to eat;
+	being fainted or unconscious from other than sleep now consumes
+	nutrition at lower rate, like being asleep already did;
+	starvation threshold shortened due to slower food use while fainting
 
 
 Fixes to Post-3.6.0 Problems that Were Exposed Via git Respository

src/eat.c

@@ -2657,15 +2657,21 @@ bite()
     return 0;
 }
 
-/* as time goes by - called by moveloop() and domove() */
+/* as time goes by - called by moveloop(every move) & domove(melee attack) */
 void
 gethungry()
 {
     if (u.uinvulnerable)
         return; /* you don't feel hungrier */
 
-    if ((!u.usleep || !rn2(10)) /* slow metabolic rate while asleep */
-        && (carnivorous(youmonst.data) || herbivorous(youmonst.data))
+    /* being polymorphed into a creature which doesn't eat prevents
+       this first uhunger decrement, but to stay in such form the hero
+       will need to wear an Amulet of Unchanging so still burn a small
+       amount of nutrition in the 'moves % 20' ring/amulet check below */
+    if ((!Unaware || !rn2(10)) /* slow metabolic rate while asleep */
+        && (carnivorous(youmonst.data)
+            || herbivorous(youmonst.data)
+            || metallivorous(youmonst.data))
         && !Slow_digestion)
         u.uhunger--; /* ordinary food consumption */
 
@@ -2682,8 +2688,8 @@ gethungry()
         /* Conflict uses up food too */
         if (HConflict || (EConflict & (~W_ARTI)))
             u.uhunger--;
-        /* +0 charged rings don't do anything, so don't affect hunger */
-        /* Slow digestion still uses ring hunger */
+        /* +0 charged rings don't do anything, so don't affect hunger.
+           Slow digestion cancels move hunger but still causes ring hunger. */
         switch ((int) (moves % 20)) { /* note: use even cases only */
         case 4:
             if (uleft && (uleft->spe || !objects[uleft->otyp].oc_charged))
@@ -2844,11 +2850,14 @@ boolean incr;
     }
 
     if (newhs == FAINTING) {
+        /* u,uhunger is likely to be negative at this point */
+        int uhunger_div_by_10 = sgn(u.uhunger) * ((abs(u.uhunger) + 5) / 10);
+
         if (is_fainted())
             newhs = FAINTED;
-        if (u.uhs <= WEAK || rn2(20 - u.uhunger / 10) >= 19) {
+        if (u.uhs <= WEAK || rn2(20 - uhunger_div_by_10) >= 19) {
             if (!is_fainted() && multi >= 0 /* %% */) {
-                int duration = 10 - (u.uhunger / 10);
+                int duration = 10 - uhunger_div_by_10;
 
                 /* stop what you're doing, then faint */
                 stop_occupation();
@@ -2863,7 +2872,11 @@ boolean incr;
                 if (!Levitation)
                     selftouch("Falling, you");
             }
-        } else if (u.uhunger < -(int) (200 + 20 * ACURR(A_CON))) {
+
+        /* this used to be -(200 + 20 * Con) but that was when being asleep
+           suppressed per-turn uhunger decrement but being fainted didn't;
+           now uhunger becomes more negative at a slower rate */
+        } else if (u.uhunger < -(100 + 10 * (int) ACURR(A_CON))) {
             u.uhs = STARVED;
             context.botl = 1;
             bot();