From d9d8ca0b8f70415d4d35a2e86929de8f6b9feeeb Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Thu, 6 Jul 2017 04:12:51 +0000
Subject: [PATCH] lexer.rb: ignore dedented space

* ext/ripper/lib/ripper/lexer.rb (on_heredoc_dedent): replace an
  empty string content because of dedentation with :on_ignored_sp.
  an empty token makes the sorted order unstable.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59269 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ext/ripper/lib/ripper/lexer.rb |  5 +++++
 test/ripper/test_lexer.rb      | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/ext/ripper/lib/ripper/lexer.rb b/ext/ripper/lib/ripper/lexer.rb
index 63dcf85132..300c8eef51 100644
--- a/ext/ripper/lib/ripper/lexer.rb
+++ b/ext/ripper/lib/ripper/lexer.rb
@@ -72,6 +72,11 @@ class Ripper
         if Elem === e and e.event == :on_tstring_content
           tok = e.tok.dup if w > 0 and /\A\s/ =~ e.tok
           if (n = dedent_string(e.tok, w)) > 0
+            if e.tok.empty?
+              e.tok = tok[0, n]
+              e.event = :on_ignored_sp
+              next
+            end
             ignored_sp << [i, Elem.new(e.pos.dup, :on_ignored_sp, tok[0, n])]
             e.pos[1] += n
           end
diff --git a/test/ripper/test_lexer.rb b/test/ripper/test_lexer.rb
index 72b7f1b5fd..30e5d78884 100644
--- a/test/ripper/test_lexer.rb
+++ b/test/ripper/test_lexer.rb
@@ -32,4 +32,23 @@ class TestRipper::Lexer < Test::Unit::TestCase
     E
     assert_equal(str, Ripper.tokenize(str).join(""), bug)
   end
+
+  def test_embedded_expr_in_heredoc
+    src = <<~'E'
+    <<~B
+      #{1}
+    B
+    E
+    expect = %I[
+      on_heredoc_beg
+      on_nl
+      on_ignored_sp
+      on_embexpr_beg
+      on_int
+      on_embexpr_end
+      on_tstring_content
+      on_heredoc_end
+    ]
+    assert_equal expect, Ripper.lex(src).map {|e| e[1]}
+  end
 end