[9fans] Sed label handling inconsistency

[yard-ape]

P9P sed gives me the error "Label too long" on:

% echo foo | sed 's/./&/;ta;b;:a;s//*/'

but not on:

% echo foo | sed 's/./&/
ta
b
:a
s//*/'

As though the label commands require immediate newlines.

Anyone else experience this?