lyrics placement change from 2.18 to 2.19 ?

[Johannes Waldmann]

Hi.

The following snippet is interpreted
differently by 2.18.* and 2.19.* :

\score {
<<
\new Staff { \key a \minor \relative c'' {
  a1   \new Voice { c2 d2 } e1
}}
\addlyrics  { foo bar }
>>
}

notes are displayed identically,
but lyrics placement is changed:

with 2.18.2,  foo -> a1, bar -> e1,
with 2.19.27, foo -> a1, bar -> c2.

This breaks a bunch of my scores (so I don't like it).
Is this a bug? Or a bug-fix?
What is the relevant section of documentation?

Thanks - J.W.