How Do I do meta_attributes?

There are actually two different DSL's associated with html//1

I ran into this situation - because I don't want the 304 bug I reported to appear during the workshop,
I decided I'd use the old 'add a random parameter' trick to my images, so 

/f/someimage.png?r=239323

to defeat caching.

I s/img/\img_fix/  

html(\img_fix([src('/f/'+File), class(illustration), alt(Alt)], [])),


and write img_fix

:- html_meta img_fix(+, html, ?, ?).

img_fix(Attribs, Contents) -->
{
            member(src(Src), Attribs),
            random(N),
    format(atom(UniqSrc), '~w?r=~w', [Src, N]),
    select(src(Src), Attribs, src(UniqSrc), NewAttribs)
        },
    html(img(NewAttribs, Contents)).
img_fix(Attribs, Contents) -->
    html(img(Attribs, Contents)).

Oops!   Generated HTML is suddenly 

<img src="/f/ + organization.png?r=0.7694838936298265" class="illustration" alt="Overall Server Organization">


I can't change first param of html_meta to html because the attributes aren't recognized as html.

Do we need an additional type for html_meta,  'attributes'  ?
Or to somehow expose html_write:attributes/2 ?
Or perhaps I'm misunderstanding html_quoted_attribute?

8cS Small bit of unniftiness invades Annie's mostly nifty swipl world.