Bugfix association loading behavior when counter cache is zero

2 files changed, 13 insertions, 16 deletions

diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index 4a25567c9d..6f5df807fe 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -210,7 +210,8 @@ module ActiveRecord
       # This method is abstract in the sense that it relies on
       # +count_records+, which is a method descendants have to provide.
       def size
-        if !find_target? || loaded?
+        if !find_target?
+          loaded! unless loaded?
           target.size
         elsif @association_ids
           @association_ids.size
@@ -233,7 +234,7 @@ module ActiveRecord
       # loaded and you are going to fetch the records anyway it is better to
       # check <tt>collection.length.zero?</tt>.
       def empty?
-        if loaded? || @association_ids
+        if loaded? || @association_ids || reflection.has_cached_counter?
           size.zero?
         else
           target.empty? && !scope.exists?
diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index f6fdbcde54..4be2edbf30 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -36,14 +36,6 @@ module ActiveRecord
         super
       end
 
-      def empty?
-        if reflection.has_cached_counter?
-          size.zero?
-        else
-          super
-        end
-      end
-
       private
 
         # Returns the number of records in this collection.
@@ -60,20 +52,24 @@ module ActiveRecord
         # If the collection is empty the target is set to an empty array and
         # the loaded flag is set to true as well.
         def count_records
-          count = if reflection.has_cached_counter?
-            owner._read_attribute(reflection.counter_cache_column).to_i
-          else
-            scope.count(:all)
-          end
+          count = counter_cache_value || scope.count(:all)
 
           # If there's nothing in the database and @target has no new records
           # we are certain the current target is an empty array. This is a
           # documented side-effect of the method that may avoid an extra SELECT.
-          (@target ||= []) && loaded! if count == 0
+          loaded! if count == 0
 
           [association_scope.limit_value, count].compact.min
         end
 
+        def counter_cache_value
+          reflection.has_cached_counter? ? owner._read_attribute(reflection.counter_cache_column).to_i : nil
+        end
+
+        def find_target?
+          super && !counter_cache_value&.zero?
+        end
+
         def update_counter(difference, reflection = reflection())
           if reflection.has_cached_counter?
             owner.increment!(reflection.counter_cache_column, difference)