From 899fc2e0cd2bcb4f5f9333b612b160bb9c6e803b Mon Sep 17 00:00:00 2001
From: Jean-Philippe Lang <jp_lang@yahoo.fr>
Date: Sat, 16 Nov 2019 09:47:01 +0000
Subject: [PATCH] Merged r18247 to 3.3-stable (#31520).

git-svn-id: http://svn.redmine.org/redmine/branches/3.3-stable@19075 e93f8b46-1217-0410-a6f0-8f06a7374b81
---
 lib/redcloth3.rb | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/redcloth3.rb b/lib/redcloth3.rb
index d0bd217d3..2f62f9333 100644
--- a/lib/redcloth3.rb
+++ b/lib/redcloth3.rb
@@ -1213,7 +1213,13 @@ class RedCloth3 < String
     
     ALLOWED_TAGS = %w(redpre pre code kbd notextile)
     def escape_html_tags(text)
-      text.gsub!(%r{<(\/?([!\w]+)[^<>\n]*)(>?)}) {|m| ALLOWED_TAGS.include?($2) ? "<#{$1}#{$3}" : "&lt;#{$1}#{'&gt;' unless $3.blank?}" }
+        text.gsub!(%r{<(\/?([!\w]+)[^<>\n]*)(>?)}) do |m|
+            if ALLOWED_TAGS.include?($2) && $3.present?
+                "<#{$1}#{$3}"
+            else
+                "&lt;#{$1}#{'&gt;' unless $3.blank?}"
+            end
+        end
     end
 end