`string->number' vs. `read'

Hi,

R5RS does not make it clear whether `string->number' converts from a
number's external representation or not (e.g., converts from some
locale-dependent representation that may use comma instead of point,
etc.).  IOW, it is not clear whether the two following forms are
equivalent:

  1.  (string->number str)

  2.  (with-input-from-string str read)

My guess is that most implementations and users assume that they are but
I couldn't find any evidence about it.

Hints?

Thanks,
Ludovic.