[fpc-devel] Rounding inconsistent (critical)

[Graeme Geldenhuys]

Hi,

I created the follow fpcUnit tests.  For those that don't know
fpcUnit, the AssertEquals takes three parameters: Failing message,
Expected Value, Actual Value.

Now from the tests below, I am formatting all values to 2 decimal
values.  I expected all tests to pass, but it doesn't. Test 9 fails
and said it expected 0.00 which is wrong.

Rules for rounding.  If a decimal is exactly halfway (5) or more,
rounding goes up. If decimal is < 5, rounding goes down.  This rules
is proven by tests 5, 6, 7 and 8.  So why is test 9 failing?  Is this
a bug?

  AssertEquals('Failing on 1', '0.10', FormatFloat('0.00', 0.1));
  AssertEquals('Failing on 2', '0.01', FormatFloat('0.00', 0.01));
  AssertEquals('Failing on 3', '0.00', FormatFloat('0.00', 0.001));
  AssertEquals('Failing on 4', '0.50', FormatFloat('0.00', 0.5));
  AssertEquals('Failing on 5', '0.01', FormatFloat('0.00', 0.0051));
  AssertEquals('Failing on 6', '0.05', FormatFloat('0.00', 0.049));
  AssertEquals('Failing on 7', '0.00', FormatFloat('0.00', 0.0049));
  AssertEquals('Failing on 8', '0.05', FormatFloat('0.00', 0.045));
  AssertEquals('Failing on 9', '0.01', FormatFloat('0.00', 0.005));


---------------- Test Output  -------------------
[graemeg-linux] FloatToStr > ./fpcunit_formatfloat -a --format=plain
Test: TTestFormatFloat.TestFormat1
Failing on 9 expected: <0.01> but was: <0.00>

List of failures:
  Failure:
    Message:           TTestFormatFloat.TestFormat1: Failing on 9
expected: <0.01> but was: <0.00>
    Exception class:   EAssertionFailedError
    Exception message: Failing on 9 expected: <0.01> but was: <0.00>

------------------  end -----------------------------

I am using FPC 2.1.1 (r4642) under Linux.  Considering that I am
writing Accounting Software, I am taking this as a critical bug!

Regards,
  - Graeme -