Fix pagy.in in pagy_get_items method introduced in 8.4.0 (see #696) (c…

…loses #704) (closes #708) (#707)

docs/troubleshooting.md

@@ -79,4 +79,18 @@ In the specific `bootstrap` example you could override the default bootstrap `"p
 
 !!!
 
+==- Slow Last Page
+
+There has been a single report of a slow last page using very big DB tables. It's a pure DB problem and it's not caused by 
+pagy or by any other ruby code ([#696](https://github.com/ddnexus/pagy/pull/696), 
+[#704](https://github.com/ddnexus/pagy/pull/704)), but a simple pagy override may avoid it:
+
+```rb
+## override pagy_get_items
+def pagy_get_items(collection, pagy)
+  limit = pagy.last == pagy.page ? pagy.in : pagy.items
+  collection.offset(pagy.offset).limit(limit)
+end
+```
+!!!
 ===

gem/lib/pagy/backend.rb

@@ -38,7 +38,7 @@ def pagy_get_page(vars)
     # Sub-method called only by #pagy: here for easy customization of record-extraction by overriding
     # You may need to override this method for collections without offset|limit
     def pagy_get_items(collection, pagy)
-      collection.offset(pagy.offset).limit(pagy.in)
+      collection.offset(pagy.offset).limit(pagy.items)
     end
   end
 end