bug#25557: Documentation of format doesn't describe "g" accurately

[Eli Zaretskii]

> Cc: 25557@debbugs.gnu.org
> From: Clément Pit--Claudel <clement.pitclaudel@live.com>
> Date: Sat, 28 Jan 2017 15:06:22 -0500
> 
> > ??? (format "%d" 3.0) => "3"
> > 
> > Or maybe you didn't think 3.0 was an "integral value" by my
> > definition?  I meant by that any value VAL which yields zero when
> > passed through (mod VAL 1.0).
> 
> Yup, I misunderstood your definition of integral value.  But that still 
> doesn't cover formatting e.g. 3.3 as "3.3" instead of "3.30", right?

Yes, but that cannot be a problem, since you said the browsers
supported 2 digits after the decimal.

Or you could get fancier by using %.1f for values for which

  (zerop (mod (* 10 VAL) 1.0))

is non-nil.