[BalusC]

PostponedFetchRoot postponed every fetch. Since 82cf971 it is also used on Hibernate when the page has a limit. A fetched @ManyToOne then dropped out of the select list. Ordering on it under DISTINCT, which optional criteria cause, failed on H2 and PostgreSQL with "Order by expression must be in the result list".

PostponedFetchRoot now fetches a singular association with a left fetch join in the paged query, via the new SingularFetch, because it does not multiply rows. Everything else is postponed as before, embeddables included. A postponed fetch nested in a singular association also postpones all its ancestor paths, so that the secondary query can build the fetch joins down to it. Those ancestors are then fetched once more by the secondary query.

• New IT testPhonePageWithOwnersSortedByOwnerEmailAndOptionalCriteria reproduces the failure. New IT testPhonePageWithOwnerPhonesAndPagination covers a plural fetch nested in a singular one.
• PostponedFetchTest#rootFetchByAnyOverloadIsPostponed asserted the old contract, so it is replaced by tests for the new one.
• Locally run on WildFly only. EclipseLink and OpenJPA now also do real singular fetch joins, so check their CI jobs one by one.

#61 has the same origin but is a separate bug: @OneToMany ordering is still skipped under PostponedFetchRoot.

🤖 Generated with Claude Opus 5.5