Avoid emojifying on invisible text (#5558)

1 files changed, 20 insertions, 6 deletions

diff --git a/app/lib/formatter.rb b/app/lib/formatter.rb
index 57f105da7..733a1c4b7 100644
--- a/app/lib/formatter.rb
+++ b/app/lib/formatter.rb
@@ -89,20 +89,28 @@ class Formatter
     end
   end
 
+  def count_tag_nesting(tag)
+    if tag[1] == '/' then -1
+    elsif tag[-2] == '/' then 0
+    else 1
+    end
+  end
+
   def encode_custom_emojis(html, emojis)
     return html if emojis.empty?
 
     emoji_map = emojis.map { |e| [e.shortcode, full_asset_url(e.image.url(:static))] }.to_h
 
     i                     = -1
-    inside_tag            = false
+    tag_open_index        = nil
     inside_shortname      = false
     shortname_start_index = -1
+    invisible_depth       = 0
 
     while i + 1 < html.size
       i += 1
 
-      if inside_shortname && html[i] == ':'
+      if invisible_depth.zero? && inside_shortname && html[i] == ':'
         shortcode = html[shortname_start_index + 1..i - 1]
         emoji     = emoji_map[shortcode]
 
@@ -116,12 +124,18 @@ class Formatter
         end
 
         inside_shortname = false
-      elsif inside_tag && html[i] == '>'
-        inside_tag = false
+      elsif tag_open_index && html[i] == '>'
+        tag = html[tag_open_index..i]
+        tag_open_index = nil
+        if invisible_depth.positive?
+          invisible_depth += count_tag_nesting(tag)
+        elsif tag == '<span class="invisible">'
+          invisible_depth = 1
+        end
       elsif html[i] == '<'
-        inside_tag       = true
+        tag_open_index   = i
         inside_shortname = false
-      elsif !inside_tag && html[i] == ':'
+      elsif !tag_open_index && html[i] == ':'
         inside_shortname      = true
         shortname_start_index = i
       end