[ruby/rdoc] Convert a backtick to an open single quote

https://github.com/ruby/rdoc/commit/82eaefbae4

lib/rdoc/text.rb

@@ -240,6 +240,14 @@ module RDoc::Text
       when s.scan(/''/) then # tick double quote
         html << encoded[:close_dquote]
         after_word = nil
+      when s.scan(/`/) then # backtick
+        if insquotes or after_word
+          html << '`'
+          after_word = false
+        else
+          html << encoded[:open_squote]
+          insquotes = true
+        end
       when s.scan(/&#39;|'/) then # single quote
         if insquotes
           html << encoded[:close_squote]

test/rdoc/test_rdoc_markup_to_html.rb

@@ -712,7 +712,7 @@ EXPECTED
 
   def test_convert_underscore_adjacent_to_code
     assert_equal "\n<p><code>aaa</code>_</p>\n", @to.convert(%q{+aaa+_})
-    assert_equal "\n<p>`<code>i386-mswin32_</code><em>MSRTVERSION</em>&#39;</p>\n", @to.convert(%q{`+i386-mswin32_+_MSRTVERSION_'})
+    assert_equal "\n<p>\u{2018}<code>i386-mswin32_</code><em>MSRTVERSION</em>\u{2019}</p>\n", @to.convert(%q{`+i386-mswin32_+_MSRTVERSION_'})
   end
 
   def test_gen_url