parse.y: trim newline in erred code

* parse.y (parser_yyerror): trim a newline at the end of the erred
  code which was replaced with an extra space in the succeeding
  cursor line.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66927 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

parse.y

@@ -4689,6 +4689,7 @@ parser_yyerror(struct parser_params *p, const YYLTYPE *yylloc, const char *msg)
 
     pt = (p->ruby_sourceline == yylloc->end_pos.lineno) ?
 	    p->lex.pbeg + yylloc->end_pos.column : p->lex.pend;
+    if ((p->lex.pbeg < pt) && (*(pt-1) == '\n')) pt--;
     ptr = ptr_end = pt < pend ? pt : pend;
     lim = ptr - p->lex.pbeg > max_line_margin ? ptr - max_line_margin : p->lex.pbeg;
     while ((lim < ptr) && (*(ptr-1) != '\n')) ptr--;

test/ruby/test_syntax.rb

@@ -1142,6 +1142,12 @@ eom
     end;
   end
 
+  def test_syntax_error_at_newline
+    expected = "\n        ^"
+    assert_syntax_error("%[abcdef", expected)
+    assert_syntax_error("%[abcdef\n", expected)
+  end
+
   def test_invalid_jump
     assert_in_out_err(%w[-e redo], "", [], /^-e:1: /)
   end