DynamicTextSpanner not printed

[Xavier Scheuer]

% In the following example the DynamicTextSpanner is not printed.
%
% The worst is that it does not even give a warning!
%

\score {
  \relative c' {
    \crescTextCresc
    c'4\p\< c\!  % cresc not printed  % no problem without \p
    c c
  }
}

%% same with Reinhold's new postfix \cresc
\score {
  \relative c' {
    c'4\p\cresc c\!  % cresc not printed  % no problem without \p
    c c
  }
}