(svn r26744) -Fix [FS6085-ish]: ScriptListSorterItemDescending::FindNext failed to detect the end.

src/script/api/script_list.cpp

@@ -362,7 +362,12 @@ public:
 			this->has_no_more_items = true;
 			return;
 		}
-		this->item_iter--;
+		if (this->item_iter == this->list->items.begin()) {
+			/* Use 'end' as marker for 'beyond begin' */
+			this->item_iter = this->list->items.end();
+		} else {
+			this->item_iter--;
+		}
 		if (this->item_iter != this->list->items.end()) item_next = (*this->item_iter).first;
 	}