"(contents, N zorkmids)" fix (trunk only)

Some code I recently added was misusing count_unpaid() and would
traverse some or all of inventory instead of just container's contents
when looking for unpaid items.  Add mew routine `is_unpaid(obj)' to do
what I was intending to do with count_unpaid().

include/extern.h

@@ -1975,6 +1975,7 @@ E void NDECL(shopper_financial_report);
 E int FDECL(inhishop, (struct monst *));
 E struct monst *FDECL(shop_keeper, (CHAR_P));
 E boolean FDECL(tended_shop, (struct mkroom *));
+E boolean FDECL(is_unpaid, (struct obj *));
 E void FDECL(delete_contents, (struct obj *));
 E void FDECL(obfree, (struct obj *,struct obj *));
 E void FDECL(home_shk, (struct monst *,BOOLEAN_P));

src/dokick.c

@@ -1311,7 +1311,7 @@ boolean shop_floor_obj;
 		(toloc != MIGR_LADDER_UP && rn2(3));
 
 	container = Has_contents(otmp);
-	unpaid = (otmp->unpaid || (container && count_unpaid(otmp->cobj)));
+	unpaid = is_unpaid(otmp);
 
 	if(OBJ_AT(x, y)) {
 	    for(obj = level.objects[x][y]; obj; obj = obj->nexthere)

src/dothrow.c

@@ -702,13 +702,13 @@ boolean broken;
 	if (broken ||
 	    !costly_spot(x, y) || *in_rooms(x, y, SHOPBASE) != *u.ushops) {
 		/* thrown out of a shop or into a different shop */
-		if (count_unpaid(obj))
+		if (is_unpaid(obj))
 		    (void)stolen_value(obj, u.ux, u.uy,
 				       (boolean)shkp->mpeaceful, FALSE);
 		if (broken) obj->no_charge = 1;
 	} else {
 		if (costly_spot(u.ux, u.uy) && costly_spot(x, y)) {
-		    if (count_unpaid(obj))
+		    if (is_unpaid(obj))
 			subfrombill(obj, shkp);
 		    else if (x != shkp->mx || y != shkp->my)
 			sellobj(obj, x, y);

src/objnam.c

@@ -827,7 +827,7 @@ ring:
 			Strcat(bp, " (alternate weapon; not wielded)");
 	}
 	if(obj->owornmask & W_QUIVER) Strcat(bp, " (in quiver)");
-	if (!iflags.suppress_price && count_unpaid(obj)) {
+	if (!iflags.suppress_price && is_unpaid(obj)) {
 		long quotedprice = unpaid_cost(obj, TRUE);
 
 		Sprintf(eos(bp), " (%s, %ld %s)",

src/shk.c

@@ -769,6 +769,14 @@ register boolean silent;
 	return (struct bill_x *)0;
 }
 
+/* check whether an object or any of its contents belongs to a shop */
+boolean
+is_unpaid(obj)
+struct obj *obj;
+{
+	return (obj->unpaid || (Has_contents(obj) && count_unpaid(obj->cobj)));
+}
+
 /* Delete the contents of the given object. */
 void
 delete_contents(obj)
@@ -2621,14 +2629,13 @@ xchar x, y;
 
 	/* get one case out of the way: nothing to sell, and no gold */
 	if (!isgold && ((offer + gltmp) == 0L || sell_how == SELL_DONTSELL)) {
-		boolean unpaid = (obj->unpaid ||
+		boolean unpaid = is_unpaid(obj);
-				  (container && count_unpaid(obj->cobj)));
 
 		if(container) {
 			dropped_container(obj, shkp, FALSE);
 			if(!obj->unpaid && !saleitem)
 			    obj->no_charge = 1;
-			if(obj->unpaid || count_unpaid(obj->cobj))
+			if (unpaid)
 			    subfrombill(obj, shkp);
 		} else obj->no_charge = 1;