Articulate and tied tremolo - unexpected result

[David Baptista]

Good morning to all, I have recently picked up an unexpected behaviour when
using the articulate script in conjuction with tremolo and ties. Here is a
minimal example:

\include "articulate.ly"

\score{
c'1:16~ c'1:16
\layout{}
}

\score{
\articulate { c'1:16~ c'1:16 }
\layout{}
}

When  this type of notation appears in scores, the meaning is that the
tremolo is to last (in this example) for 2 measures. But the resulting
output of articulate has one long sustained note with tremolo only in the
second measure. I suspect the underlying bug is that the tied C is being
replicated resulting in a sequence of tied Cs, but musically this is an
incorrect behaviour.

I reproduced this bug both in the latest stable (2.18.2) and unstable
(2.19.48) release.