Total Pages should be at least onetc-git-tower-pagination-links

And the link to the last page cannot be `page=0`.

1 files changed, 11 insertions, 6 deletions

diff --git a/lib/api/helpers/pagination.rb b/lib/api/helpers/pagination.rb
index e86e221e092..95108292aac 100644
--- a/lib/api/helpers/pagination.rb
+++ b/lib/api/helpers/pagination.rb
@@ -11,7 +11,7 @@ module API
 
       def add_pagination_headers(paginated_data)
         header 'X-Total',       paginated_data.total_count.to_s
-        header 'X-Total-Pages', paginated_data.total_pages.to_s
+        header 'X-Total-Pages', total_pages(paginated_data).to_s
         header 'X-Per-Page',    paginated_data.limit_value.to_s
         header 'X-Page',        paginated_data.current_page.to_s
         header 'X-Next-Page',   paginated_data.next_page.to_s
@@ -26,20 +26,25 @@ module API
 
         links = []
 
-        request_params[:page] = paginated_data.current_page - 1
-        links << %(<#{request_url}?#{request_params.to_query}>; rel="prev") unless paginated_data.first_page?
+        request_params[:page] = paginated_data.prev_page
+        links << %(<#{request_url}?#{request_params.to_query}>; rel="prev") if request_params[:page]
 
-        request_params[:page] = paginated_data.current_page + 1
-        links << %(<#{request_url}?#{request_params.to_query}>; rel="next") unless paginated_data.last_page? || paginated_data.out_of_range?
+        request_params[:page] = paginated_data.next_page
+        links << %(<#{request_url}?#{request_params.to_query}>; rel="next") if request_params[:page]
 
         request_params[:page] = 1
         links << %(<#{request_url}?#{request_params.to_query}>; rel="first")
 
-        request_params[:page] = paginated_data.total_pages
+        request_params[:page] = total_pages(paginated_data)
         links << %(<#{request_url}?#{request_params.to_query}>; rel="last")
 
         links.join(', ')
       end
+
+      def total_pages(paginated_data)
+        # Ensure there is in total at least 1 page
+        [paginated_data.total_pages, 1].max
+      end
     end
   end
 end