fix incorrect override caching through upcoming_events

test plan:
* make sure the dashboard sidebar has correct due dates
 for overridden assignments

closes #CNVS-23993

Change-Id: I09ab704768b51aebe294515aad1791340b51f67f
Reviewed-on: https://gerrit.instructure.com/66467
Tested-by: Jenkins
Reviewed-by: Derek Bender <djbender@instructure.com>
QA-Review: Jason Carter <jcarter@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>

app/models/assignment.rb

@@ -1885,10 +1885,12 @@ class Assignment < ActiveRecord::Base
   # Return all assignments and their active overrides where either the
   # assignment or one of its overrides is due between start and ending.
   scope :due_between_with_overrides, lambda { |start, ending|
-    eager_load(:assignment_overrides).
-        where('assignments.due_at BETWEEN ? AND ?
-              OR assignment_overrides.due_at_overridden AND
-              assignment_overrides.due_at BETWEEN ? AND ?', start, ending, start, ending)
+    joins("LEFT OUTER JOIN #{AssignmentOverride.quoted_table_name} assignment_overrides
+          ON assignment_overrides.assignment_id = assignments.id").
+    group("assignments.id").
+    where('assignments.due_at BETWEEN ? AND ?
+          OR assignment_overrides.due_at_overridden AND
+          assignment_overrides.due_at BETWEEN ? AND ?', start, ending, start, ending)
   }
 
   scope :updated_after, lambda { |*args|

lib/assignment_override_applicator.rb

@@ -336,7 +336,7 @@ module AssignmentOverrideApplicator
     # preloads the override students for a particular user for many objects at once, instead of doing separate queries for each
     quizzes, assignments = items.partition{|i| i.is_a?(Quizzes::Quiz)}
 
-    ActiveRecord::Associations::Preloader.new(assignments, :quiz).run
+    ActiveRecord::Associations::Preloader.new(assignments, [:quiz, :assignment_overrides]).run
 
     if assignments.any?
       override_students = AssignmentOverrideStudent.where(:assignment_id => assignments, :user_id => user).index_by(&:assignment_id)

spec/lib/assignment_override_applicator_spec.rb

@@ -1117,4 +1117,28 @@ describe AssignmentOverrideApplicator do
     @overridden_assignment = AssignmentOverrideApplicator.assignment_overridden_for(@assignment, @student)
     expect(@overridden_assignment.due_at).to eq @section_override.due_at
   end
+
+  it "should not cache incorrect overrides through due_between_with_overrides" do
+    course_with_student(:active_all => true)
+    @assignment = create_assignment(:course => @course, :submission_types => "online_upload")
+
+    so = assignment_override_model(:assignment => @assignment)
+    so.set = @course.default_section
+    so.override_due_at(30.days.from_now) # set it outside of the default upcoming events range
+    so.save!
+
+    other_so = assignment_override_model(:assignment => @assignment)
+    other_so.set = @course.course_sections.create!
+    other_so.override_due_at(5.days.from_now) # set it so it would be included in the upcoming events query
+    other_so.save!
+
+    Timecop.freeze(5.seconds.from_now) do
+      enable_cache do
+        @student.upcoming_events # prime the cache
+
+        @assignment.reload
+        expect(@assignment.overridden_for(@student).due_at).to eq so.due_at # should have cached correctly
+      end
+    end
+  end
 end