Fix and simplify highlight regexp

actionpack/lib/action_view/helpers/text_helper.rb

@@ -120,7 +120,7 @@ def highlight(text, phrases, *args)
           text
         else
           match = Array(phrases).map { |p| Regexp.escape(p) }.join('|')
-          text.gsub(/(#{match})(?!(?:[^<]*?)(?:["'])[^<>]*>)/i, options[:highlighter])
+          text.gsub(/(#{match})(?![^<]*?>)/i, options[:highlighter])
         end.html_safe
       end
 

actionpack/test/template/text_helper_test.rb

@@ -194,6 +194,10 @@ def test_highlight_with_html
       "<p>This is a <strong class=\"highlight\">beautiful</strong> <a href=\"http://example.com/beautiful#top?what=beautiful%20morning&amp;when=now+then\">morning</a>, but also a <strong class=\"highlight\">beautiful</strong> day</p>",
       highlight("<p>This is a beautiful <a href=\"http://example.com/beautiful\#top?what=beautiful%20morning&when=now+then\">morning</a>, but also a beautiful day</p>", "beautiful")
     )
+    assert_equal(
+      "<div>abc <b>div</b></div>",
+      highlight("<div>abc div</div>", "div", :highlighter => '<b>\1</b>')
+    )
   end
 
   def test_excerpt