Allow sorting of unpaged results

[naihil]

QuerydslPredicateExecutor provides a method Page<T> findAll(Predicate predicate, Pageable pageable);
You can pass Pageable.unpaged() to get all rows in single page, in this case result not sorted.
If you write custom implementation of unpaged() that has some sort and pass it to findAll, this doesnt work because of this code:
https://github.com/spring-projects/spring-data-jpa/blob/main/spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/support/Querydsl.java#L117
`

	if (pageable.isUnpaged()) {
		return query;
	}

	query.offset(pageable.getOffset());
	query.limit(pageable.getPageSize());

	return applySorting(pageable.getSort(), query);

`
Sorting applied after isUnpaged() check.

We can change code to:
`

	if (pageable.isPaged()) {
		query.offset(pageable.getOffset());
		query.limit(pageable.getPageSize());
	}

	return applySorting(pageable.getSort(), query);

`
And this code allows sorting of unpaged queries.
Linked with #3761

[schauder]

Could you please clarify why you would want to use sorting with pagination if you actually do not want to page the result?

Instead you could use one of the methods that allow direct supply of sorting.

[naihil]

Simple example: frontend with data table and rows-per-page combobox with option "All rows", from request you get pageable, pass it to repository without any additional logic and receive page that can be sorted/unsorted/one from any others or single page with all rows

[mp911de]

Pageable.unpaged() is a substitute for null. Previously, we accepted null as parameter for Pageable. Following that line of thought, there would not be a Sort associated with a null Pageable.