System Details

• posh-git version/path: 0.7.1 from the PowerShell Gallery.
• PowerShell version: 5.1.14393.1198
• Git version: 2.7.1.windows.2
• Operating system name and version:
  • Edition: Windows 10 Enterprise
  • Version: 1607
  • Build: 14393.1198

Issue Description

Write-Prompt checks to see if the $ForegroundColor parameter is empty by performing the check !$ForegroundColor. This works in all cases except when $ForegroundColor is [ConsoleColor]::Black, since Black evaluates to 0 and !0 == True.

The offending line is posh-git/src/GitPrompt.ps1:135:

function Write-Prompt($Object, $ForegroundColor = $null, $BackgroundColor = $null) {
    $s = $global:GitPromptSettings
    if ($s -and !$ForegroundColor) {
        $ForegroundColor = $s.DefaultForegroundColor
    }

I see that this was fixed by #454 on GitHub (the condition is now ($null -eq $ForegroundColor)) but the copy I obtained from PSGallery via Install-Module earlier today does not have this fix.