Avoid unannounced system restart

When installing the .NET SDK or runtime, if the installer wants a system restart, it would do so quietly. This avoids the restart but adds a prompt at the end of the script to inform the user of a restart being required when necessary.

Fixes #57

init.ps1

@@ -44,6 +44,9 @@ $EnvVars = @{}
 if (!$NoPrerequisites) {
  & "$PSScriptRoot\tools\Install-NuGetCredProvider.ps1" -AccessToken $AccessToken -Force:$UpgradePrerequisites
  & "$PSScriptRoot\tools\Install-DotNetSdk.ps1" -InstallLocality $InstallLocality
+ if ($LASTEXITCODE -eq 3010) {
+ Exit 3010
+ }
 
  # The procdump tool and env var is required for dotnet test to collect hang/crash dumps of tests.
  # But it only works on Windows.

tools/Install-DotNetSdk.ps1

@@ -77,8 +77,10 @@ Function Install-DotNet($Version, [switch]$Runtime) {
  Write-Host "Downloading .NET Core $sdkSubstring$Version..."
  $Installer = Get-InstallerExe -Version $Version -Runtime:$Runtime
  Write-Host "Installing .NET Core $sdkSubstring$Version..."
- cmd /c start /wait $Installer /install /quiet
- if ($LASTEXITCODE -ne 0) {
+ cmd /c start /wait $Installer /install /passive /norestart
+ if ($LASTEXITCODE -eq 3010) {
+ Write-Verbose "Restart required"
+ } elseif ($LASTEXITCODE -ne 0) {
  throw "Failure to install .NET Core SDK"
  }
 }
@@ -95,16 +97,24 @@ if ($InstallLocality -eq 'machine') {
  if ($IsMacOS -or $IsLinux) {
  $DotNetInstallDir = '/usr/share/dotnet'
  } else {
+ $restartRequired = $false
  if ($PSCmdlet.ShouldProcess(".NET Core SDK $sdkVersion", "Install")) {
  Install-DotNet -Version $sdkVersion
+ $restartRequired = $restartRequired -or ($LASTEXITCODE -eq 3010)
  }
 
  $runtimeVersions | Get-Unique |% {
  if ($PSCmdlet.ShouldProcess(".NET Core runtime $_", "Install")) {
  Install-DotNet -Version $_ -Runtime
+ $restartRequired = $restartRequired -or ($LASTEXITCODE -eq 3010)
  }
  }
 
+ if ($restartRequired) {
+ Write-Host -ForegroundColor Yellow "System restart required"
+ Exit 3010
+ }
+
  return
  }
 } elseif ($InstallLocality -eq 'repo') {