parse.y: make shared string modifiable

* parse.y (dedent_string): ensure that the string is modifiable,
  not to set the length of shared string.
  [ruby-core:80987] [Bug #13540]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58561 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 0 deletions

diff --git a/test/ruby/test_parse.rb b/test/ruby/test_parse.rb
index 56e1020c5a..6030dad605 100644
--- a/test/ruby/test_parse.rb
+++ b/test/ruby/test_parse.rb
@@ -988,6 +988,16 @@ x = __ENCODING__
     assert_equal(-100, e.backtrace_locations.first.lineno, bug)
   end
 
+  def test_file_in_indented_heredoc
+    name = '[ruby-core:80987] [Bug #13540]' # long enough to be shared
+    assert_equal(name+"\n", eval("#{<<-"begin;"}\n#{<<-'end;'}", nil, name))
+    begin;
+      <<~HEREDOC
+        #{__FILE__}
+      HEREDOC
+    end;
+  end
+
 =begin
   def test_past_scope_variable
     assert_warning(/past scope/) {catch {|tag| eval("BEGIN{throw tag}; tap {a = 1}; a")}}