\let\@currentlabel\barf ...

    No, read the FAQ. Really. You have to place \string\caption
    \space before using \string\label \space inside of a figure.

Something like that.  Or does _anybody_ know of _any_ intentional use
of a \label _inside_ of a figure, _not_ referring to the figure but
to its section?

I mean, this must be the candidate for the most frequently asked
question on LaTeX, ever.

David Kastrup, Kriemhildstr. 15, 44793 Bochum