1 files changed, 10 insertions, 8 deletions
diff --git a/activerecord/lib/active_record/associations/through_association.rb b/activerecord/lib/active_record/associations/through_association.rb
index af1bce523c..d0ec3e8015 100644
--- a/activerecord/lib/active_record/associations/through_association.rb
+++ b/activerecord/lib/active_record/associations/through_association.rb
@@ -15,12 +15,6 @@ module ActiveRecord
           scope = super
           reflection.chain.drop(1).each do |reflection|
             relation = reflection.klass.all
-
-            reflection_scope = reflection.scope
-            if reflection_scope && reflection_scope.arity.zero?
-              relation = relation.merge(reflection_scope)
-            end
-
             scope.merge!(
               relation.except(:select, :create_with, :includes, :preload, :joins, :eager_load)
             )
@@ -82,13 +76,21 @@ module ActiveRecord
 
         def ensure_mutable
           unless source_reflection.belongs_to?
-            raise HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(owner, reflection)
+            if reflection.has_one?
+              raise HasOneThroughCantAssociateThroughHasOneOrManyReflection.new(owner, reflection)
+            else
+              raise HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(owner, reflection)
+            end
           end
         end
 
         def ensure_not_nested
           if reflection.nested?
-            raise HasManyThroughNestedAssociationsAreReadonly.new(owner, reflection)
+            if reflection.has_one?
+              raise HasOneThroughNestedAssociationsAreReadonly.new(owner, reflection)
+            else
+              raise HasManyThroughNestedAssociationsAreReadonly.new(owner, reflection)
+            end
           end
         end