Fix for strict variables

Author: SahAssar

assets/sitemap_xml.twig

@@ -22,8 +22,8 @@
                     {% if record.fieldtype(key) == "image" and value != "" %}
                         <image:image>
                             <image:loc>{{app.paths.hosturl}}{{value|image(app.config.get('general/thumbnails/default_image')|first,app.config.get('general/thumbnails/default_image')|last,app.config.get('general/thumbnails/default_image')|slice(0,1))}}</image:loc>
-                            <image:title><![CDATA[{{value.alt ? value.alt : value.title}}]]></image:title>
-                            <image:caption><![CDATA[{{value.title ? value.title : value.alt}}]]></image:caption>
+                            <image:title><![CDATA[{{value.alt|default(false) ? value.alt : value.title|default('')}}]]></image:title>
+                            <image:caption><![CDATA[{{value.title|default(false) ? value.title : value.alt|default('')}}]]></image:caption>
                         </image:image>
                     {% elseif record.fieldtype(key) == "imagelist" and attribute(record, key) is not empty %}
                         {% set list = attribute(record, key) %}