[XeTeX] ^^J in the plain XeTeX format

[Joseph Wright]

Hello all,

Doing some experiments on writing to the log, I find that the XeTeX
format shows different behaviour from other formats with respect to ^^J.
Trying

    \immediate\write-1{Hello^^Jworld}
    \bye

with pdfTeX or LuaTeX gives two lines in the log

    Hello
    world

but with XeTeX gives

    Hello^^Jworld

LaTeX and ConTeXt (MkII) show identical behaviour for XeTeX and pdfTeX
(and LuaTeX in the LaTeX case).

Anyone know why this is, and if it's deliberate?
-- 
Joseph Wright