Issue 5333 - Ensure links in metadata and in most tags can be made relative

cms/converters.py

 # This file is part of the Adblock Plus web scripts,
 # Copyright (C) 2006-present eyeo GmbH
 #
 # Adblock Plus is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 3 as
 # published by the Free Software Foundation.
 #
 # Adblock Plus is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
@@ skipping 308 matching lines @@
                     post += ' hreflang="{}"'\
                         .format(jinja2.Markup.escape(locale))
 
             if self._params['relative']:
                 current_page = '/{}/{}'.format(self._params['locale'],
                                                self._params['page'])
                 url = make_relative(current_page, url)
 
             return ''.join((pre, jinja2.Markup.escape(url), post))
 
-        text = re.sub(r'(<a\s[^<>]*\b(href)=\")([^<>\"]+)(\")',
+        text = re.sub(r'(<[\w]+\s[^<>]*\b(href)=\")([^<>\"]+)(\")',
                       process_link, text)
         text = re.sub(r'(<img\s[^<>]*\b(src)=\")([^<>\"]+)(\")',
                       process_link, text)
         return text
 
     include_start_regex = '<'
     include_end_regex = '>'
 
     def resolve_includes(self, text):
         def resolve_include(match):
@@ skipping 249 matching lines @@
             stack[-1]['subitems'].append(item)
             stack.append(item)
         return structured
 
 
 converters = {
     'html': RawConverter,
     'md': MarkdownConverter,
     'tmpl': TemplateConverter,
 }