Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

According to about_Redirection:

Using the redirection operator with a file target is functionally equivalent to piping to Out-File with no extra parameters.

The documentation for Out-File -NoNewLine says:

No newline is added after the last output string.

Which means Out-File does normally add a newline. And this is what you see in PowerShell 7.3.10. If the output does not end in a newline, Out-File and file redirection add a newline. But in PowerShell 7.4.0, with file redirection that newline is no longer added.

To make this easy to repro you'll want a native executable that outputs character data but no newline (LF or CR/LF) at the end. Here's a C# program that does that. You don't have to use this program to repro the problem. It just helps.

namespace Example;

internal class Program
{
    static void Main()
    {
        Console.Write("Hello"); // Note that it's not WriteLine()
    }
}

This appears to be related to the PR: #17857 by @SeeminglyScience that was added in preview 4

Appears to be related to #20747 and #20808.

Expected behavior

# See "Steps to reproduce" for source code for Hello.exe

PS> .\Hello.exe >x.txt

PS> (Get-Content x.txt -Raw).EndsWith([System.Environment]::NewLine)
True

Actual behavior

# See "Steps to reproduce" for source code for Hello.exe

PS> .\Hello.exe >x.txt

PS> (Get-Content x.txt -Raw).EndsWith([System.Environment]::NewLine)
False

Error details

N/A

Environment data

Name                           Value
----                           -----
PSVersion                      7.4.0
PSEdition                      Core
GitCommitId                    7.4.0
OS                             Microsoft Windows 10.0.19044
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Visuals

7.3.10

7.4.0