Non-exposed and exposed sorts cause issues with the default sort order

Problem/Motivation

So the issue started when I added a non-exposed sort as the first sort out of three. The other two sorts are exposed, which looks something like this:

1. Enabled: boolean ASC (un-exposed)
2. Issue Date: date DESC (exposed)
3. Title: text ASC (exposed)

The issue is that the default expose_sort_order for exposed forms is taken from the first sort option, which in this case is 'Enabled' and is ASC. The default expose_sort_order, however, should surely be for the first exposed sort option, which in this case is 'Issue Date' DESC.

This is resulting in the default sort order for exposed sorts not being respected. This seems to be mainly an issue in conjunction with Better Exposed Forms which is using the default sort order to rewrite the combined sort options field.

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet