diff --git a/lib/prettyprint.rb b/lib/prettyprint.rb
index a65407c1304df9..44ca5e816fb527 100644
--- a/lib/prettyprint.rb
+++ b/lib/prettyprint.rb
@@ -487,8 +487,10 @@ def delete(group)
   # It is passed to be similar to a PrettyPrint object itself, by responding to:
   # * #text
   # * #breakable
+  # * #fill_breakable
   # * #nest
   # * #group
+  # * #group_sub
   # * #flush
   # * #first?
   #
@@ -522,6 +524,13 @@ def breakable(sep=' ', width=nil)
       @output << sep
     end
 
+    # Appends +sep+ to the text to be output. By default +sep+ is ' '
+    #
+    # +width+ argument is here for compatibility. It is a noop argument.
+    def fill_breakable(sep=' ', width=nil)
+      @output << sep
+    end
+
     # Takes +indent+ arg, but does nothing with it.
     #
     # Yields to a block.
@@ -545,6 +554,15 @@ def group(indent=nil, open_obj='', close_obj='', open_width=nil, close_width=nil
       @first.pop
     end
 
+    # Yields to a block for compatibility.
+    def group_sub # :nodoc:
+      yield
+    end
+
+    # Method present for compatibility, but is a noop
+    def break_outmost_groups # :nodoc:
+    end
+
     # Method present for compatibility, but is a noop
     def flush # :nodoc:
     end
diff --git a/test/test_prettyprint.rb b/test/test_prettyprint.rb
index 27e7198886bcf0..a9ea55d5b3a018 100644
--- a/test/test_prettyprint.rb
+++ b/test/test_prettyprint.rb
@@ -518,4 +518,75 @@ def test_27
 
 end
 
+class SingleLineFormat < Test::Unit::TestCase # :nodoc:
+
+  def test_singleline_format_with_breakables
+    singleline_format = PrettyPrint.singleline_format("".dup) do |q|
+      q.group 0, "(", ")" do
+        q.text "abc"
+        q.breakable
+        q.text "def"
+        q.breakable
+        q.text "ghi"
+        q.breakable
+        q.text "jkl"
+        q.breakable
+        q.text "mno"
+        q.breakable
+        q.text "pqr"
+        q.breakable
+        q.text "stu"
+      end
+    end
+    expected = <<'End'.chomp
+(abc def ghi jkl mno pqr stu)
+End
+
+    assert_equal(expected, singleline_format)
+  end
+
+  def test_singleline_format_with_fill_breakables
+    singleline_format = PrettyPrint.singleline_format("".dup) do |q|
+      q.group 0, "(", ")" do
+        q.text "abc"
+        q.fill_breakable
+        q.text "def"
+        q.fill_breakable
+        q.text "ghi"
+        q.fill_breakable
+        q.text "jkl"
+        q.fill_breakable
+        q.text "mno"
+        q.fill_breakable
+        q.text "pqr"
+        q.fill_breakable
+        q.text "stu"
+      end
+    end
+      expected = <<'End'.chomp
+(abc def ghi jkl mno pqr stu)
+End
+
+    assert_equal(expected, singleline_format)
+  end
+
+  def test_singleline_format_with_group_sub
+    singleline_format = PrettyPrint.singleline_format("".dup) do |q|
+      q.group 0, "(", ")" do
+        q.group_sub do
+          q.text "abc"
+          q.breakable
+          q.text "def"
+        end
+        q.breakable
+        q.text "ghi"
+      end
+    end
+    expected = <<'End'.chomp
+(abc def ghi)
+End
+
+    assert_equal(expected, singleline_format)
+  end
+end
 end
diff --git a/tool/lib/vcs.rb b/tool/lib/vcs.rb
index 4169031436e993..ce545ec368eef9 100644
--- a/tool/lib/vcs.rb
+++ b/tool/lib/vcs.rb
@@ -595,15 +595,6 @@ def changelog_formatter(path, arg, base_url = nil)
               s = s.join('')
             end
 
-            s.gsub!(%r[(?!<\w)([-\w]+/[-\w]+)(?:@(\h{8,40})|#(\d{5,}))\b]) do
-              path = defined?($2) ? "commit/#{$2}" : "pull/#{$3}"
-              "[#$&](https://github.com/#{$1}/#{path})"
-            end
-            if %r[^ +(https://github\.com/[^/]+/[^/]+/)commit/\h+\n(?=(?: +\n(?i: +Co-authored-by: .*\n)+)?(?:\n|\Z))] =~ s
-              issue = "#{$1}pull/"
-              s.gsub!(/\b(?:(?i:fix(?:e[sd])?) +|GH-)\K#(?=\d+\b)|\(\K#(?=\d+\))/) {issue}
-            end
-
             s.gsub!(/ +\n/, "\n")
             s.sub!(/^Notes:/, '  \&')
             w.print sep, h, s