Limit is ignored when joins is specified

Turns out it has nothing to do with the joins.

Animal.limit(1).count
=> 1297

Is that expected behavior?

Found this by trying to do (essentially) Animal.limit(1).update_all(...) -- not surprisingly based on the above, it's updating every record.

Model.limit(1).count generate correct sql (select count(*) from model limit 1), it's mysql's behavior:

mysql> select count(*) from knowledges limit 1;
+----------+
| count(*) |
+----------+
|      842 |
+----------+
1 row in set (0.00 sec)

Yeah -- that makes perfect sense -- forgot that count and size actually modify the query and return a single row.

So what about my specific case with update_all? It builds the update_all query including the "wheres" and discards the limit:
Animal.limit(1).joins(:lot).where("animals.location_id" => 20).where("lots.species" => "Horse").update_all(:location_id => 20)

AREL (2.7ms) UPDATE animals INNER JOIN lots ON lots.id = animals.lot_id SET location_id = 20 WHERE animals.location_id = 20 AND lots.species = 'Horse'