printf format specifier with zero padding behaves incorrectly for negative zero (`-0.0`) on .NET Core

[jwosty]

printf formatting a value of -0.0 with %010f (or anything which adds some zero padding) incorrectly places the - symbol.

Expected behavior

sprintf "%010.3f" -0.0 should display -00000.000 sprintf "%010.3f" -0.0 should display 00000.000 (to match .NET Framework).

This works correctly for other negative values. For example, sprintf "%010.3f" -0.01 displays -00000.100.

Actual behavior

Displays 0000-0.000

Known workarounds

None known.

Related information

Potentially related to: #15557

• macOS 12.6
• .NET 6.0.15

[jwosty]

Noting here that this bug only affects FSharp.Core under .NET Core. See: #18147 (comment)