Use pagination without counts when appropriate

app/controllers/concerns/issuable_collections.rb

@@ -41,10 +41,13 @@ module IssuableCollections
   end
 
   def set_pagination
+    row_count = finder.row_count
+
     @issuables          = @issuables.page(params[:page])
     @issuables          = per_page_for_relative_position if params[:sort] == 'relative_position'
+    @issuables          = @issuables.without_count if row_count == -1
     @issuable_meta_data = Gitlab::IssuableMetadata.new(current_user, @issuables).data
-    @total_pages        = issuable_page_count(@issuables)
+    @total_pages        = page_count_for_relation(@issuables, row_count)
   end
   # rubocop:enable Gitlab/ModuleWithInstanceVariables
 
@@ -58,10 +61,6 @@ module IssuableCollections
   end
   # rubocop: enable CodeReuse/ActiveRecord
 
-  def issuable_page_count(relation)
-    page_count_for_relation(relation, finder.row_count)
-  end
-
   def page_count_for_relation(relation, row_count)
     limit = relation.limit_value.to_f
 

app/helpers/pagination_helper.rb

 # frozen_string_literal: true
 
 module PaginationHelper
-  def paginate_collection(collection, remote: nil)
+  # total_pages will be inferred from the collection if nil. It is ignored if
+  # the collection is a Kaminari::PaginatableWithoutCount
+  def paginate_collection(collection, remote: nil, total_pages: nil)
     if collection.is_a?(Kaminari::PaginatableWithoutCount)
       paginate_without_count(collection)
     elsif collection.respond_to?(:total_pages)
-      paginate_with_count(collection, remote: remote)
+      paginate_with_count(collection, remote: remote, total_pages: total_pages)
     end
   end
 
@@ -17,7 +19,7 @@ module PaginationHelper
     )
   end
 
-  def paginate_with_count(collection, remote: nil)
-    paginate(collection, remote: remote, theme: 'gitlab')
+  def paginate_with_count(collection, remote: nil, total_pages: nil)
+    paginate(collection, remote: remote, theme: 'gitlab', total_pages: total_pages)
   end
 end

app/views/projects/issues/_issues.html.haml

@@ -20,4 +20,4 @@
       = render empty_state_path
 
   - if @issues.present?
-    = paginate @issues, theme: "gitlab", total_pages: @total_pages
+    = paginate_collection @issues, total_pages: @total_pages

app/views/projects/merge_requests/_merge_requests.html.haml

@@ -5,4 +5,4 @@
     = render 'shared/empty_states/merge_requests'
 
 - if @merge_requests.present?
-  = paginate @merge_requests, theme: "gitlab", total_pages: @total_pages
+  = paginate_collection @merge_requests, total_pages: @total_pages

ee/app/views/shared/_epics.html.haml

@@ -2,4 +2,4 @@
   %ul.content-list.issuable-list
     = render partial: 'groups/epics/epic', collection: @epics
 
-= paginate @epics, theme: "gitlab"
+= paginate_collection @epics