#
#
# patch "database.cc"
#  from [0e55fc85ea2dfec7e34ed8de385881c60ea4316f]
#    to [a66238a6b633d82f988003ae8c114bf19366b6a1]
#
============================================================
--- database.cc	0e55fc85ea2dfec7e34ed8de385881c60ea4316f
+++ database.cc	a66238a6b633d82f988003ae8c114bf19366b6a1
@@ -3201,7 +3201,8 @@ database_impl::add_prefix_matching_const
       string upper_bound(binary_prefix);
 
       string::reverse_iterator ity(upper_bound.rbegin());
-      ++(*ity);
+      if (ity != upper_bound.rend())
+        ++(*ity);
       while ((*ity == 0) && ity != upper_bound.rend())
         {
           ++ity;