Fixed bug in 'string.format' with option '%f'

As an example, 'print(string.format("%.99f", 1e70))' may have a
lot of garbage after the number.

The old test to ensure that 'string.format("%.99f", n)' was not too
large, 'fabs(n) < 1e100', assumes that the number will fit in the 99
bytes; but the 99 is not the space for the number, it is the added
extra zeros.  The option worked for smaller numbers because of the
extra space added to MAX_ITEM.
2 files changed