cost of eating an unpaid tin

The cost of an unpaid tin should be calculated before eating, not after,
so the cost will be based on your pre-eating hunger, not post.

doc/fixes33.2

@@ -398,6 +398,7 @@ pets should not try to go after food that they can't reach
 monsters shouldn't use wands of digging in Sokoban
 objects dropped in or travelling across java pools can take damage
 monsters that enter lava can take damage
+eating an unpaid tin should calculate cost before not after eating
 
 
 Platform- and/or Interface-Specific Fixes

src/eat.c

@@ -1014,6 +1014,13 @@ opentin()		/* called during each move whilst opening a tin */
 	    tin.tin->dknown = tin.tin->known = TRUE;
 	    cprefx(tin.tin->corpsenm); cpostfx(tin.tin->corpsenm);
 
+	    if(((!carried(tin.tin) && costly_spot(tin.tin->ox, tin.tin->oy) &&
+		 !tin.tin->no_charge)
+		|| tin.tin->unpaid)) {
+		verbalize("You open it, you bought it!");
+		bill_dummy_object(tin.tin);
+	    }
+
 	    /* check for vomiting added by GAN 01/16/87 */
 	    if(tintxts[r].nut < 0) make_vomiting((long)rn1(15,10), FALSE);
 	    else lesshungry(tintxts[r].nut);
@@ -1038,6 +1045,15 @@ opentin()		/* called during each move whilst opening a tin */
 		    You("discard the open tin.");
 		goto use_me;
 	    }
+
+	    tin.tin->dknown = tin.tin->known = TRUE;
+	    if(((!carried(tin.tin) && costly_spot(tin.tin->ox, tin.tin->oy) &&
+		 !tin.tin->no_charge)
+		|| tin.tin->unpaid)) {
+		verbalize("You open it, you bought it!");
+		bill_dummy_object(tin.tin);
+	    }
+
 	    if (!tin.tin->cursed)
 		pline("This makes you feel like %s!",
 		      Hallucination ? "Swee'pea" : "Popeye");
@@ -1045,7 +1061,6 @@ opentin()		/* called during each move whilst opening a tin */
 	    gainstr(tin.tin, 0);
 	    u.uconduct.food++;
 	}
-	tin.tin->dknown = tin.tin->known = TRUE;
 use_me:
 	if (carried(tin.tin)) useup(tin.tin);
 	else useupf(tin.tin, 1L);