parse.y: indent at invalid identifier

* parse.y (parser_heredoc_identifier): set indent only when valid
  identifier, not to dedent non-existent contents later.
  [ruby-core:79772] [Bug #13253]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57717 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

parse.y

@@ -6234,6 +6234,7 @@ parser_heredoc_identifier(struct parser_params *parser)
     int token = tSTRING_BEG;
     long len;
     int newline = 0;
+    int indent = 0;
 
     if (c == '-') {
 	c = nextc();
@@ -6242,8 +6243,7 @@ parser_heredoc_identifier(struct parser_params *parser)
     else if (c == '~') {
 	c = nextc();
 	func = STR_FUNC_INDENT;
-	heredoc_indent = INT_MAX;
-	heredoc_line_indent = 0;
+	indent = INT_MAX;
     }
     switch (c) {
       case '\'':
@@ -6282,7 +6282,7 @@ parser_heredoc_identifier(struct parser_params *parser)
 	if (!parser_is_identchar()) {
 	    pushback(c);
 	    if (func & STR_FUNC_INDENT) {
-		pushback(heredoc_indent > 0 ? '~' : '-');
+		pushback(indent > 0 ? '~' : '-');
 	    }
 	    return 0;
 	}
@@ -6305,6 +6305,8 @@ parser_heredoc_identifier(struct parser_params *parser)
 				  lex_lastline);		/* nd_orig */
     parser_set_line(lex_strterm, ruby_sourceline);
     ripper_flush(parser);
+    heredoc_indent = indent;
+    heredoc_line_indent = 0;
     return token;
 }
 

test/ruby/test_syntax.rb

@@ -656,6 +656,10 @@ eom
     assert_equal(expected, actual, bug7559)
   end
 
+  def test_dedented_heredoc_invalid_identifer
+    assert_syntax_error('<<~ "#{}"', /unexpected <</)
+  end
+
   def test_lineno_operation_brace_block
     expected = __LINE__ + 1
     actual = caller_lineno\