Merge branch 'aderyabin-fix7'

Closes #6007

2 files changed, 21 insertions, 23 deletions

diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index e94fe35170..2447914640 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -50,18 +50,7 @@ module ActiveRecord
           end
         else
           column  = "#{reflection.quoted_table_name}.#{reflection.association_primary_key}"
-          relation = scoped
-
-          including = (relation.eager_load_values + relation.includes_values).uniq
-
-          if including.any?
-            join_dependency = ActiveRecord::Associations::JoinDependency.new(reflection.klass, including, [])
-            relation = join_dependency.join_associations.inject(relation) do |r, association|
-              association.join_relation(r)
-            end
-          end
-
-          relation.pluck(column)
+          scoped.pluck(column)
         end
       end
 
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index 54c93332bb..22c3e6a324 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -107,7 +107,8 @@ module ActiveRecord
       relation = with_default_scope
 
       if relation.equal?(self)
-        if eager_loading? || (includes_values.present? && references_eager_loaded_tables?)
+
+        if has_include?(column_name)
           construct_relation_for_association_calculations.calculate(operation, column_name, options)
         else
           perform_calculation(operation, column_name, options)
@@ -155,21 +156,25 @@ module ActiveRecord
         column_name = "#{table_name}.#{column_name}"
       end
 
-      result = klass.connection.select_all(select(column_name).arel, nil, bind_values)
+      if has_include?(column_name)
+        construct_relation_for_association_calculations.pluck(column_name)
+      else
+        result = klass.connection.select_all(select(column_name).arel, nil, bind_values)
 
-      key    = result.columns.first
-      column = klass.column_types.fetch(key) {
-        result.column_types.fetch(key) {
-          Class.new { def type_cast(v); v; end }.new
+        key    = result.columns.first
+        column = klass.column_types.fetch(key) {
+          result.column_types.fetch(key) {
+            Class.new { def type_cast(v); v; end }.new
+          }
         }
-      }
 
-      result.map do |attributes|
-        raise ArgumentError, "Pluck expects to select just one attribute: #{attributes.inspect}" unless attributes.one?
+        result.map do |attributes|
+          raise ArgumentError, "Pluck expects to select just one attribute: #{attributes.inspect}" unless attributes.one?
 
-        value = klass.initialize_attributes(attributes).values.first
+          value = klass.initialize_attributes(attributes).values.first
 
-        column.type_cast(value)
+          column.type_cast(value)
+        end
       end
     end
 
@@ -185,6 +190,10 @@ module ActiveRecord
 
     private
 
+    def has_include?(column_name)
+      eager_loading? || (includes_values.present? && (column_name || references_eager_loaded_tables?))
+    end
+
     def perform_calculation(operation, column_name, options = {})
       operation = operation.to_s.downcase