From 412fffa1c851899cdf5b137a8442d0c17dc9e778 Mon Sep 17 00:00:00 2001
From: Abdullah Yousuf <23.abdullah.y@gmail.com>
Date: Wed, 13 Oct 2021 20:03:37 -0400
Subject: [PATCH] made background invocation operator use -WorkingDirectory to
 set working directory of new job and added a testto ensure background job
 script block does not use Set-Location to set working directory

---
 .../engine/runtime/Operations/MiscOps.cs      | 19 +++++++++++--------
 .../Microsoft.PowerShell.Core/Job.Tests.ps1   |  6 +++++-
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs b/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
index 8d50fcf5f1aa..fdb01a3b19c4 100644
--- a/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
+++ b/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
@@ -531,12 +531,8 @@ private static string GetParameterText(string parameterName)
                 var pipelineOffset = pipelineAst.Extent.StartOffset;
                 var variables = pipelineAst.FindAll(static x => x is VariableExpressionAst, true);
 
-                // Used to make sure that the job runs in the current directory
-                const string cmdPrefix = @"Microsoft.PowerShell.Management\Set-Location -LiteralPath $using:pwd ; ";
-
                 // Minimize allocations by initializing the stringbuilder to the size of the source string + prefix + space for ${using:} * 2
-                System.Text.StringBuilder updatedScriptblock = new System.Text.StringBuilder(cmdPrefix.Length + scriptblockBodyString.Length + 18);
-                updatedScriptblock.Append(cmdPrefix);
+                System.Text.StringBuilder updatedScriptblock = new System.Text.StringBuilder(scriptblockBodyString.Length + 18);
                 int position = 0;
 
                 // Prefix variables in the scriptblock with $using:
@@ -568,15 +564,22 @@ private static string GetParameterText(string parameterName)
                 var sb = ScriptBlock.Create(updatedScriptblock.ToString());
                 var commandInfo = new CmdletInfo("Start-Job", typeof(StartJobCommand));
                 commandProcessor = context.CommandDiscovery.LookupCommandProcessor(commandInfo, CommandOrigin.Internal, false, context.EngineSessionState);
-                var parameter = CommandParameterInternal.CreateParameterWithArgument(
+                var workingDirectoryParameter = CommandParameterInternal.CreateParameterWithArgument(
+                    parameterAst: pipelineAst,
+                    "WorkingDirectory",
+                    null,
+                    argumentAst: pipelineAst,
+                    context.SessionState.Path.CurrentLocation.Path,
+                    false);
+                var scriptBlockParameter = CommandParameterInternal.CreateParameterWithArgument(
                     parameterAst: pipelineAst,
                     "ScriptBlock",
                     null,
                     argumentAst: pipelineAst,
                     sb,
                     false);
-                commandProcessor.AddParameter(parameter);
-                pipelineProcessor.Add(commandProcessor);
+                commandProcessor.AddParameter(workingDirectoryParameter);
+                commandProcessor.AddParameter(scriptBlockParameter);
                 pipelineProcessor.LinkPipelineSuccessOutput(outputPipe ?? new Pipe(new List<object>()));
 
                 context.PushPipelineProcessor(pipelineProcessor);
diff --git a/test/powershell/Modules/Microsoft.PowerShell.Core/Job.Tests.ps1 b/test/powershell/Modules/Microsoft.PowerShell.Core/Job.Tests.ps1
index 06d84230dce1..c6c7c73974d3 100644
--- a/test/powershell/Modules/Microsoft.PowerShell.Core/Job.Tests.ps1
+++ b/test/powershell/Modules/Microsoft.PowerShell.Core/Job.Tests.ps1
@@ -178,7 +178,7 @@ Describe "Debug-job test" -Tag "Feature" {
     }
 }
 
-Describe "Ampersand background test" -Tag "CI","Slow" {
+Describe "Ampersand background test" -Tag "CI", "Slow" {
     Context "Simple background job" {
         AfterEach {
             Get-Job | Remove-Job -Force
@@ -218,6 +218,10 @@ Describe "Ampersand background test" -Tag "CI","Slow" {
             $j = Get-Location | ForEach-Object -MemberName Path &
             Receive-Job -Wait $j | Should -Be ($PWD.Path)
         }
+        It "Make sure Set-Location is not used in the job's script block to set the working directory" {
+            $j = (get-variable -value ExecutionContext).SessionState.PSVariable.Get("MyInvocation").Value.MyCommand.ScriptBlock & 
+            (Receive-Job -Wait $j).ToString() | Should -BeExactly "(get-variable -value ExecutionContext).SessionState.PSVariable.Get(`"MyInvocation`").Value.MyCommand.ScriptBlock"
+        }
         It "Test that output redirection is done in the background job" {
             $j = Write-Output hello > $TESTDRIVE/hello.txt &
             Receive-Job -Wait $j | Should -BeNullOrEmpty