Problem:

my_strntoull10rnd_8bit() handled incorrectly cases when the input
string contains a decimal point and is long enough to overrun the
'unsigned long long' type. The position of the decimal point was not
taken into account which resulted in miscalculated numbers and
truncation to appropriate SQL data type limits.

Solution:

Fix my_strntoull10rnd_8bit() to take the position of a decimal point
into account in such cases.