Sorting nested properties of config entity queries does not work

The patch looks very nice and clean, let's add a quick test and we should be good to go.

Updating to 'Needs work' per #4

+++ b/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityQueryTest.php
@@ -565,6 +565,15 @@ public function testDotted() {
+    $this->assertResults(['1', '3', '2', '4', '5']);
...
+    $this->assertResults(['5', '2', '4', '1', '3']);

The assertions looks a bit weird. Is that because entities with the IDs 2, 4 and 1, 3 have the same data?

We had a lot of trouble with php7 test fails due to sort changes, are you sure this works the same on all php versions we support?

Let's find out. I queued test runs for all php versions.

All the test runs are green, I think we're good to go here.

Reroll against 8.7.x to include changes from #2968519: The entity.query service is essentially deprecated because it relies on \Drupal\Core\Entity\Query\QueryFactory which is

Looked at this again and I think it's ready to go.

The change looks good and is still passing tests but we need a change record to tell people this is possible.

Simple change record here: https://www.drupal.org/node/3155124

Did not fill out the version numbers as I'm hoping this will be backported to Drupal 8.9 as well, along with #3154858: Drupal\Core\Config\Entity\Query\Condition::notExists() does not work when parent property is also missing. which deals with the exact same issue, except it's notExists() being broken there, rather than sort().

+++ b/core/lib/Drupal/Core/Config/Entity/Query/Query.php
@@ -89,7 +89,14 @@ public function execute() {
+        return ($a <= $b) ? $direction : -$direction;

In a follow-up I think this can be rewritten to be ($a <=> $b) * $direction which is more elegant and returns the correct value when we consider them equal. Which will be better for PHP 8 and stable sorts.

For this to be backported to 8.9.x this would have to be considered a bug. I think there are arguments that this is a bug because sorting in these situations sorting does not work where you would expect it to. And therefore my request for a change record is a little bogus and had the affect of derailing the issue for 2 years :( Totally my fault. I should have given more consideration to whether this really was a feature request.

@kristiaanvandeneynde thanks for writing the CR - I'm going to credit you here but delete it as I no longer think this is worthy of a CR - it's fixing things to work as you would expect.

Currently discussing the backport with @catch. Will do that if we agree.

Committed a07a4ba and pushed to 9.1.x. Thanks!

Discussed with @catch and we agreed to backport this.

Had to hotfix the test because this patch removed the $all variable but the test added by #3154858: Drupal\Core\Config\Entity\Query\Condition::notExists() does not work when parent property is also missing. relied on it.