Tie running through stems

[Sebastiano Vigna]

Dear developers,
the following example (from Scarlatti K460) sports a tie (second bar, on
the a-flat) that should be up, down instead is down and runs through
stems.

\score {
           \context Staff = upper {
           \time 2/2
           \key c \major
           \relative c' {

              { c'4 g'8 c, b4 c }
              <<
                { g'4 f8 es d4 c  d2 d' ~ d8 d c b b4 c } \\
                { aes,2  aes' ~ aes4  g8 f es4 d es2 r } % Bug 1
              >>
          }

}
}

Of course, easily fixed with \tiesUp.

-- 
Ciao,

                                        seba