Param::Set truncates floating point numbers

[scpeters]

Environment

• OS Version: confirmed on Ubuntu / macOS
• Source or binary build? tested on sdf13 branch

Description

• Expected behavior: when passing a value containing floating point values to Param::Set, all the precision should be preserved
• Actual behavior: some precision is lost when using Param::Set

Steps to reproduce

1. Check out and build f45d371
2. Observe failure of test cases added to UNIT_Param_TEST demonstrating this bug

Output

[ RUN      ] Param.Double
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:117: Failure
Expected equality of these values:
  sixteenDigits
    Which is: 12345678.876543211
  value
    Which is: 12345700
[  FAILED  ] Param.Double (0 ms)
[ RUN      ] Param.Vector3d
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:142: Failure
Expected equality of these values:
  0.0 + fifteenDigits
    Which is: 0.123456789012345
  value.X()
    Which is: 0.123457
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:143: Failure
Expected equality of these values:
  1.0 + fifteenDigits
    Which is: 1.123456789012345
  value.Y()
    Which is: 1.1234599999999999
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:144: Failure
Expected equality of these values:
  2.0 + fifteenDigits
    Which is: 2.1234567890123448
  value.Z()
    Which is: 2.1234600000000001
[  FAILED  ] Param.Vector3d (0 ms)
[ RUN      ] Param.Pose3d
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:176: Failure
Expected equality of these values:
  0.0 + fifteenDigits
    Which is: 0.123456789012345
  value.Pos().X()
    Which is: 0.123457
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:177: Failure
Expected equality of these values:
  1.0 + fifteenDigits
    Which is: 1.123456789012345
  value.Pos().Y()
    Which is: 1.1234599999999999
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:178: Failure
Expected equality of these values:
  2.0 + fifteenDigits
    Which is: 2.1234567890123448
  value.Pos().Z()
    Which is: 2.1234600000000001
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:179: Failure
Expected equality of these values:
  0.5 * fifteenDigits
    Which is: 0.061728394506172499
  value.Rot().Euler().X()
    Which is: 0.06172840000000001
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:180: Failure
Expected equality of these values:
  1.0 * fifteenDigits
    Which is: 0.123456789012345
  value.Rot().Euler().Y()
    Which is: 0.123457
/Users/scpeters/ws/garden/src/sdformat/src/Param_TEST.cc:181: Failure
Expected equality of these values:
  2.0 * fifteenDigits
    Which is: 0.24691357802468999
  value.Rot().Euler().Z()
    Which is: 0.24691400000000005
[  FAILED  ] Param.Pose3d (0 ms)

[scpeters]

fix in #1137

[scpeters]

fixed by #1137