parse.y: do not use disposed string

* parse.y (parser_here_document): do not append already appended
  and disposed code fragment.  [ruby-dev:48647] [Bug #10392]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47973 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Thu Oct 16 15:05:07 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* parse.y (parser_here_document): do not append already appended
+	  and disposed code fragment.  [ruby-dev:48647] [Bug #10392]
+
 Thu Oct 16 10:35:33 2014  Eric Wong  <e@80x24.org>
 
 	* test/-ext-/bug_reporter/test_bug_reporter.rb

parse.y

@@ -6575,7 +6575,10 @@ parser_here_document(struct parser_params *parser, NODE *here)
 	    if (pend < lex_pend) rb_str_cat(str, "\n", 1);
 	    lex_goto_eol(parser);
 	    if (nextc() == -1) {
-		if (str) dispose_string(str);
+		if (str) {
+		    dispose_string(str);
+		    str = 0;
+		}
 		goto error;
 	    }
 	} while (!whole_match_p(eos, len, indent));

test/ripper/test_scanner_events.rb

@@ -708,6 +708,10 @@ class TestRipper::ScannerEvents < Test::Unit::TestCase
     assert_equal ["there\n""heredoc", "\n"],
                  scan('tstring_content', "<<""EOS\n""there\n""heredoc\#@foo\nEOS"),
                  bug7255
+    bug10392 = '[ruby-dev:48647] [Bug #10392]'
+    assert_equal [" E\n\n"],
+                 scan('tstring_content', "<<""'E'\n E\n\n"),
+                 bug10392
   end
 
   def test_heredoc_end