Make get_next/prev_siblings take an inclusive flag

wagtail/wagtailcore/models.py

@@ -645,11 +645,12 @@ class Page(MP_Node, ClusterableModel, Indexed):
     def get_siblings(self, inclusive=True):
         return Page.objects.sibling_of(self, inclusive)
 
-    def get_next_siblings(self):
-        return self.get_siblings().filter(path__gt=self.path).order_by('path')
+    def get_next_siblings(self, inclusive=False):
+        return self.get_siblings(inclusive).filter(path__gte=self.path).order_by('path')
+
+    def get_prev_siblings(self, inclusive=False):
+        return self.get_siblings(inclusive).filter(path__lte=self.path).order_by('-path')
 
-    def get_prev_siblings(self):
-        return self.get_siblings().filter(path__lt=self.path).order_by('-path')
 
 def get_navigation_menu_items():
     # Get all pages that appear in the navigation menu: ones which have children,

wagtail/wagtailcore/tests/test_page_model.py

@@ -233,6 +233,15 @@ class TestPrevNextSiblings(TestCase):
         christmas_event = Page.objects.get(url_path='/home/events/christmas/')
         self.assertTrue(christmas_event.get_next_siblings().filter(url_path='/home/events/final-event/').exists())
 
+    def test_get_next_siblings_inclusive(self):
+        christmas_event = Page.objects.get(url_path='/home/events/christmas/')
+
+        # First element must always be the current page
+        self.assertEqual(christmas_event.get_next_siblings(inclusive=True).first(), christmas_event)
+
     def test_get_prev_siblings(self):
         final_event = Page.objects.get(url_path='/home/events/final-event/')
         self.assertTrue(final_event.get_prev_siblings().filter(url_path='/home/events/christmas/').exists())
+
+        # First element must always be the current page
+        self.assertEqual(final_event.get_prev_siblings(inclusive=True).first(), final_event)