tie placement bug

[Christopher]

> I'm not top posting.

% It is hard to tell from looking which note a tie goes with.
% Tie on E is placed as though it is a tie on G or C when the C below it is
% preceded by an accidental.
sharp or flat sign

\version "2.18.0"

\relative g' {
  | <g e ~ c>2 ^\markup \column { "tie E" "can't tell" "C or E" } <g e c>
  \bar "||"
  | <g e ~ ces>2 ^"tie E (!)" <g e ces!>
  | <g e ces ~>2 ^\markup \column { "looks like" "tie C" } <g e ces!>
  \bar "||"
  | <g e ~ cis>2 ^"tie E (!)" <g e cis!>
  | <g ~ e cis>2 ^\markup \column { "looks like" "tie G" }  <g e cis!>
}