NHibernate's version of lastIndexOfLetter also doesn't allow the underscore. Perhaps I need to port this change, but some things are unclear. If someone remembers, can you please clarify the following:

1) What was the actual exception that triggered this bug report? It claims there is a problem in lastIndexOfLetter() but it would be useful to know what the real-world problem with not allowing the underscore was.

2) Steve Ebersole suggests that this stems from the change in Column.GetAlias() for HHH-8073 Closed (https://github.com/hibernate/hibernate-orm/commit/79073a98f0e4ed225fe4608b67594196f86d48d7), but I don't see how? Before that change, GetAlias() would also cut the column name at the underscore and add a suffix.