Add multi-level nesting support to sitemap.xml

Fixes #1481.

docs/about/release-notes.md

@@ -88,6 +88,9 @@ authors should review how [search and themes] interact.
 * Update links to Python-Markdown library (#1360).
 * Document how to generate manpages for MkDocs commands (#686).
 
+## Version 0.17.4
+* Bugfix: Add multi-level nesting support to sitemap.xml (#1482).
+
 ## Version 0.17.3 (2018-03-07)
 
 * Bugfix: Set dependency `tornado>=4.1,<5.0` due to changes in 5.0 (#1428).

mkdocs/templates/sitemap.xml

@@ -1,20 +1,20 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
-{% for nav_item in nav %}
-    {% if nav_item.children %}
-        {% for nav_item in nav_item.children %}
+{%- macro nav_item(item) -%}
+    {%- if item.children -%}
+        {%- for child in item.children -%}
+            {{ nav_item(child) }}
+        {%- endfor -%}
+    {%- else %}
     <url>
-     <loc>{{ config.site_url }}{{ nav_item.abs_url }}</loc>
-     {% if nav_item.update_date %}<lastmod>{{nav_item.update_date}}</lastmod>{% endif %}
+     <loc>{% if item.canonical_url %}{{ item.canonical_url }}{% else %}{{ item.abs_url }}{% endif %}</loc>
+     {% if item.update_date %}<lastmod>{{item.update_date}}</lastmod>{% endif %}
      <changefreq>daily</changefreq>
     </url>
-        {% endfor %}
-    {% else %}
-    <url>
-     <loc>{{ config.site_url }}{{ nav_item.abs_url }}</loc>
-     {% if nav_item.update_date %}<lastmod>{{nav_item.update_date}}</lastmod>{% endif %}
-     <changefreq>daily</changefreq>
-    </url>
-    {% endif %}
-{% endfor %}
+    {%- endif -%}
+{%- endmacro -%}
+
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+{%- for item in nav -%}
+    {{ nav_item(item) }}
+{%- endfor %}
 </urlset>