Multiple Count annotation with filter doesn't work properly.

[Roman Krejčík]

Lets have following models

class User(models.Model):
   pass

class Subscription(models.Model):
    user = models.ForeignKey(User, models.CASCADE)   
    valid_to = models.DateTimeField()

class SubscriptionToAuthor(models.Model):
    user = models.ForeignKey(User, models.CASCADE)   
    valid_to = models.DateTimeField()

then annotate on only one related model works fine

# this is ok

User.objects.annotate(
    subscribed_authors=Count('subscriptiontoauthor', filter=Q(subscriptiontoauthor__valid_to__gt=now))
)

or

# this is ok

User.objects.annotate(
    subscribed_newspapers=Count('subscription', filter=Q(subscription__valid_to__gt=now))
)

but Count returns incorrect (too big) count numbers when both annotations are used on single query set

# wrong result

User.objects.annotate(
  subscribed_authors=Count('subscriptiontoauthor', filter=Q(subscriptiontoauthor__valid_to__gt=now))
).annotate(
  subscribed_newspapers=Count('subscription', filter=Q(subscription__valid_to__gt=now))
)

[Mariusz Felisiak]

Duplicate of #10060 (see ​documentation).