[tex-eplain] \@getoptionalarg bug ? (or, more likely, ignorance)

[Karl Berry]

Hi John,

    X\@getoptionalarg\relax[dummy] Y

I can't investigate in depth right now, but just looking at this input,
the space after the ] looks significant to me.  Why wouldn't it be?
Did you expect \@getoptionalarg to ignore spaces after the ]?
Evidently I didn't document it one way or the other in the manual.

karl