% Works
\startbuffer[bf1]
\vbox{
test}
\stopbuffer

% Works
\startbuffer[bf2]
\vbox{
test
}
\stopbuffer

% % Breaks in MKII
% \startbuffer[bf3]
% \vbox{test}\stopbuffer  

% Breaks in MkII
% \startbuffer[bf4]
% \vbox{
% test
% }\stopbuffer

% Breaks in MkII
% \startbuffer[bf5]
% \vbox{
% test}\stopbuffer   

\starttext
\getbuffer[bf1]
\getbuffer[bf2]
\getbuffer[bf3]
\getbuffer[bf4]
\getbuffer[bf5]
\stoptext