Comment #1 on issue 2608 by [email protected]: Lyrics bug http://code.google.com/p/lilypond/issues/detail?id=2608
The problem is that context "b" is iterated after being terminated. That means it does not have a parent context anymore, and its now_mom function enters into infinite recursion (it finds the ultimate parent and calls its now_mom function. Usually the ultimate parent is a global context, and its virtual non_mom function is different from that of normal contexts. After the context has been disconnected, however, its parent context is 0, and so it considers itself as its ultimate parent).
