Query::toIterable() should support mixed result queries with scalar mappings

[alex-dev]

Fix #8520 and supersedes #8467.

AbstractHydrator::toIterable reuses AbstractHydrator::iterate which had as only problem , as far as I know, weirdly normalized data. The real cause here is AbstractHydrator::hydrateRow, but since it is not internal, it could not be fixed. Therefore, AbstractHydrator::toIterable normalizes rows returned by AbstractHydrator::iterate.

[alex-dev]

Ok. What the f**k. I get several failed tests that don't even consume my changeset.

Case in point: Doctrine\Tests\ORM\Functional\QueryTest::testToIterableWithMultipleSelectElements fails. Fair enough.
Debug some and I dump the output of a Query::getResult() call. I have not touched any ::getResult() code path.
So I look at the dump...

array(3) {
  [0] => class Doctrine\Tests\Models\CMS\CmsArticle#12754 (6) {
    ...
    public $user => class Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser#12782 (15) {...}
    ...
  }
  [1] => class Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser#12782 (15) {...}
  [2] => class Doctrine\Tests\Models\CMS\CmsArticle#12783 (6) {
    ...
    public $user => class Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser#12782 (15) {...}
    ...
  }
}

Check the DQL... It seems legit: select a, u from ' . CmsArticle::class . ' a JOIN ' . CmsUser::class . ' u WITH a.user = u.
I'd expect

array(3) {
  [0] => class Doctrine\Tests\Models\CMS\CmsArticle#12754 (6) {
    ...
    public $user => class Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser#12782 (15) {...}
    ...
  }
  [1] => class Doctrine\Tests\Models\CMS\CmsArticle#12783 (6) {
    ...
    public $user => class Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser#12782 (15) {...}
    ...
  }
}

Reset to 2.8.x and test passes. Re-add my dump. Same unexpected output .

Anyone got an idea?