1 files changed, 28 insertions, 5 deletions
diff --git a/app/lib/sanitize_config.rb b/app/lib/sanitize_config.rb
index 1bba4a5a6..e6e861eb9 100644
--- a/app/lib/sanitize_config.rb
+++ b/app/lib/sanitize_config.rb
@@ -19,27 +19,50 @@ class Sanitize
       node['class'] = class_list.join(' ')
     end
 
+    IMG_TAG_TRANSFORMER = lambda do |env|
+      node = env[:node]
+
+      return unless env[:node_name] == 'img'
+
+      node.name = 'a'
+
+      node['href'] = node['src']
+      if node['alt'].present?
+        node.content = "[🖼  #{node['alt']}]"
+      else
+        url = node['href']
+        prefix = url.match(/\Ahttps?:\/\/(www\.)?/).to_s
+        text   = url[prefix.length, 30]
+        text   = text + "…" if url[prefix.length..-1].length > 30
+        node.content = "[🖼  #{text}]"
+      end
+    end
+
     MASTODON_STRICT ||= freeze_config(
-      elements: %w(p br span a),
+      elements: %w(p br span a abbr del pre blockquote code b strong u sub i em h1 h2 h3 h4 h5 ul ol li),
 
       attributes: {
-        'a'    => %w(href rel class),
-        'span' => %w(class),
+        'a'          => %w(href rel class title),
+        'span'       => %w(class),
+        'abbr'       => %w(title),
+        'blockquote' => %w(cite),
       },
 
       add_attributes: {
         'a' => {
-          'rel' => 'nofollow noopener',
+          'rel' => 'nofollow noopener tag',
           'target' => '_blank',
         },
       },
 
       protocols: {
-        'a' => { 'href' => HTTP_PROTOCOLS },
+        'a'          => { 'href' => HTTP_PROTOCOLS },
+        'blockquote' => { 'cite' => HTTP_PROTOCOLS },
       },
 
       transformers: [
         CLASS_WHITELIST_TRANSFORMER,
+        IMG_TAG_TRANSFORMER,
       ]
     )