Yii2: wrong condition in ActiveQuery::viaTable()

[cebe]

See https://github.com/yiisoft/yii2/commit/64d8af61a64db0b00d498800e1f20e62b4473329#diff-1776bc9373c1dbb0d6e77ba4d8081a81L762

The change is not correct, using ActiveQuery as $modelClass does not make sense. The call should fail if called on a non-relational query (i.e. if primaryModel is null).

[SilverFire]

Despite it was a bug, it did not affect working code because the viaTable() call on empty primaryModel does not make sense and could be caused only by wrong manual configuration of the ActiveQuery object.

[SilverFire]

Heh, actually it makes sense. Thanks to failed tests to point that out :)
It makes sense for viaTable() called from other query closure (like this) during lazy loading of relations.

Fixed with commits 025dd072c and b9ee17014
Seems to be OK now