Reread the spec. size attribute is valid for any type of <input> element.

jowens.wiki wrote:

So we really want a tiny 30 pixel wide filename input? I know on my Firefox
1.0.6 I get an input 110px wide anyway, and that's not enough really.

avarab wrote:

(In reply to comment #2)

So we really want a tiny 30 pixel wide filename input?

The report was that the size attribute was invalid and shouldn't be used, the
value of that attribute is another issue.

Most probably the w3c spec forgot the that <input> with the 'file'
type also 'almost' use character size for the width.

Sample test:
1width:<input type='file' size='1' /><br>
2width:<input type='file' size='2' /><br>
30width:<input type='file' size='30' /><br>
31width:<input type='file' size='31' /><br>
800width:<input type='file' size='800' />

Render the same under linux firefox and win32 ie6.

Now if you find that the W3C is wrong or that browser does not render
stuff correctly send them a bug report.

Closing bug.