Bug? Output not flushed?

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

Easily reproduced:

% { print XXX; return 0; } >| /tmp/newfile; print $(</tmp/newfile)
% print $(</tmp/newfile)
XXX

That is, when a return statement appears in a current-shell complex
list, the output is not flushed until the parser reaches the top level
again.  If the return statement is removed, all is well:

% { print YYY; } >| /tmp/newfile; print $(</tmp/newfile)
YYY
%

Any idea where to start looking for this?