[luatex] Minor formatting bugs in output

[Joseph Wright]

Hello all,

Setting up some tests which use log file differences, I've run across a
few oddities with LuaTeX. These may or may not be bugs: what I'm after
is status on them. (All tested with an up-to-date TL2014 pretest, luatex
executable.)

First one is the 'more help text for something like:

    \def\foo{#1}

which with LuaTeX reads:

    You meant to type ## instead of #, right?
    Or maybe a } was forgotten somewhere earlier, and things
    are all screwed up? I''m going to assume that you meant ##.

Notice the extra "'" in "I'm" on on the last line. Clear bug, I think :-)

The second one is

    \immediate\write0{\the\foo}

where if we scroll down the log a bit we get

    ! Forbidden control sequence found while scanning text of \write.
    <inserted text>
                    }
    <to be read again>
                       \endwrite
    <inserted text> }\endwrite

    l.5 \immediate\write0{\the\foo}

    ?
    0
    ! Missing { inserted.
    <to be read again>

The difference this time is a space: with pdfTeX/XeTeX that "0" has a
space after it, but with LuaTeX it doesn't. No idea if this is deliberate!

Third one is more serious or at least surprising:

    \expandafter\show\csname foo#\endcsname

gives

    > \foo##=\relax.
    <recently read> \foo##

with LuaTeX but

    > \foo#=\relax.
    <recently read> \foo#

with pdfTeX/XeTeX. The pdfTeX behaviour allows for use of 'odd' catcodes
in csnames, whereas the LuaTeX behaviour means a test would be needed.
--
Joseph Wright