Revise pagination_nav.html so that linkurl can be a direct URL as well as a named URL route

wagtail/admin/templates/wagtailadmin/shared/pagination_nav.html

@@ -2,23 +2,18 @@
 {% load wagtailadmin_tags %}
 
 {% comment %}
-    HACK: This template expects to be passed a 'linkurl' parameter, containing a URL name
-    that can be reverse-resolved by the {% url %} tag with no further parameters.
-    Views that have parameters in their URL can work around this by omitting linkurl,
-    which will produce a final URL of the form "?q=123", implicitly preserving the current URL path.
-    Using the {% url ... as ... %} form of the tag ensures that this fails silently,
-    rather than throwing a NoReverseMatch exception.
+    Expects a 'linkurl' parameter to use as the base URL, which may be a URL route name (must be
+    reverse-resolvable with no arguments) or a direct URL path. If omitted, links will be given
+    an href of the form "?p=123", implicitly preserving the current URL path.
 {% endcomment %}
-{% if linkurl %}
-    {% url linkurl as url_to_use %}
-{% endif %}
+{% resolve_url_if_not_absolute linkurl as url_path %}
 
 <nav class="pagination" aria-label="{% trans 'Pagination' %}">
     <p>{% blocktrans with page_num=items.number total_pages=items.paginator.num_pages %}Page {{ page_num }} of {{ total_pages }}.{% endblocktrans %}</p>
     <ul>
         <li class="prev">
             {% if items.has_previous %}
-                <a href="{{ url_to_use }}{% querystring p=items.previous_page_number %}">
+                <a href="{{ url_path }}{% querystring p=items.previous_page_number %}">
                     {% icon name="arrow-left" class_name="default" %}
                     {% trans 'Previous' %}
                 </a>
@@ -26,7 +21,7 @@
         </li>
         <li class="next">
             {% if items.has_next %}
-                <a href="{{ url_to_use }}{% querystring p=items.next_page_number %}">
+                <a href="{{ url_path }}{% querystring p=items.next_page_number %}">
                     {% trans 'Next' %}
                     {% icon name="arrow-right" class_name="default" %}
                 </a>

wagtail/admin/templatetags/wagtailadmin_tags.py

@@ -15,6 +15,7 @@ from django.template.defaultfilters import stringfilter
 from django.template.loader import render_to_string
 from django.templatetags.static import static
 from django.urls import reverse
+from django.urls.exceptions import NoReverseMatch
 from django.utils import timezone
 from django.utils.encoding import force_str
 from django.utils.html import avoid_wrapping, format_html, format_html_join
@@ -716,3 +717,19 @@ def menu_props(context):
 @register.simple_tag
 def get_comments_enabled():
     return getattr(settings, 'WAGTAILADMIN_COMMENTS_ENABLED', True)
+
+
+@register.simple_tag
+def resolve_url_if_not_absolute(url):
+    # Used by wagtailadmin/shared/pagination_nav.html - given an input that may be a URL route
+    # name, or a direct URL path, return it as a direct URL path. On failure (or being passed
+    # an empty / None value), return empty string
+    if not url:
+        return ''
+    elif url.startswith('/'):
+        return url
+    else:
+        try:
+            return reverse(url)
+        except NoReverseMatch:
+            return ''