tin variety followup (trunk only)

include/hack.h

@@ -257,6 +257,7 @@ NEARDATA extern coord bhitpos;	/* place where throw or zap hits or stops */
 #define HOMEMADE_TIN 5
 #define FRENCH_FRIED_TIN 11
 #define SPINACH_TIN (-1)
+#define RANDOM_TIN (-2)
 
 /* Flags to control menus */
 #define MENUTYPELEN sizeof("traditional ")

include/obj.h

@@ -30,7 +30,7 @@ struct obj {
 
 	schar spe;		/* quality of weapon, armor or ring (+ or -)
 				   number of charges for wand ( >= -1 )
-				   marks your eggs, spinach tins
+				   marks your eggs, tin variety and spinach tins
 				   royal coffers for a court ( == 2)
 				   tells which fruit a fruit is
 				   special for uball and amulet

src/eat.c

@@ -1008,13 +1008,13 @@ int forcetype;
 		return;
 	} else if (forcetype >= 0 && forcetype < TTSZ-1) {
 		r = forcetype;
-	} else {
+	} else {	/* RANDOM_TIN */
 		r = rn2(TTSZ-1);		/* take your pick */
 		if (r == ROTTEN_TIN && (obj->corpsenm == PM_LIZARD ||
 			 		obj->corpsenm == PM_LICHEN))
 			r = HOMEMADE_TIN;	/* lizards don't rot */
 	}
-	obj->spe = -(r+1);
+	obj->spe = -(r+1);	/* offset by 1 to allow index 0 */
 }
 
 STATIC_OVL int
@@ -1027,7 +1027,7 @@ struct obj *obj;
 		r = ROTTEN_TIN;			/* always rotten if cursed */
 	} else if (obj->spe < 0) {
 		r = -(obj->spe);
-		--r;
+		--r;		/* get rid of the offset */
 	} else 
 		r = rn2(TTSZ-1);
 

src/mkobj.c

@@ -431,7 +431,7 @@ boolean artif;
 		    if (mons[mndx].cnutrit &&
 			    !(mvitals[mndx].mvflags & G_NOCORPSE)) {
 			otmp->corpsenm = mndx;
-			set_tin_variety(otmp, 0);
+			set_tin_variety(otmp, RANDOM_TIN);
 			break;
 		    }
 		}

src/objnam.c

@@ -1802,7 +1802,7 @@ boolean from_user;
 #endif
 		ispoisoned = isgreased = eroded = eroded2 = erodeproof =
 		halfeaten = islit = unlabeled = ishistoric = isdiluted = 0;
-	tvariety = -1;
+	tvariety = RANDOM_TIN;
 	mntmp = NON_PM;
 #define UNDEFINED 0
 #define EMPTY 1