Using convertDoubleTo() to get a whole number, from which to determine
the number of digits we're allowed before the fractional part, fails
if the double isn't a whole number, which lead to the skip being
checked. Use qFloor() of the double (as this should have as many
digits as the double had before its decimal point, which is what we
care about; qCeil() might round up to a power of ten).
This amends commit ff6d2cb0d5
Fixes: QTBUG-105341
Pick-to: 6.4 6.3 6.2
Change-Id: I4e0105d4602682c59e9830ec9a37556c96db884e
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>