PowerShell · daxian-dbw · Aug 7, 2020 · Aug 6, 2020 · Aug 6, 2020 · Aug 6, 2020
diff --git a/src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs b/src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs
@@ -123,6 +123,9 @@ static ExperimentalFeature()
                 new ExperimentalFeature(
                     name: "PSNativePSPathResolution",
                     description: "Convert PSPath to filesystem path, if possible, for native commands"),
+                new ExperimentalFeature(
+                    name: "PSNotApplyErrorActionToStderr",
+                    description: "Don't have $ErrorActionPreference affect stderr output"),
             };
             EngineExperimentalFeatures = new ReadOnlyCollection<ExperimentalFeature>(engineFeatures);
 

diff --git a/src/System.Management.Automation/engine/MshCommandRuntime.cs b/src/System.Management.Automation/engine/MshCommandRuntime.cs
@@ -2831,61 +2831,62 @@ internal void _WriteErrorSkipAllowCheck(ErrorRecord errorRecord, ActionPreferenc
                 this.PipelineProcessor.LogExecutionError(_thisCommand.MyInvocation, errorRecord);
             }
 
-            ActionPreference preference = ErrorAction;
-            if (actionPreference.HasValue)
+            if (!(ExperimentalFeature.IsEnabled("PSNotApplyErrorActionToStderr") && isNativeError))
             {
-                preference = actionPreference.Value;
-            }
+                ActionPreference preference = ErrorAction;
+                if (actionPreference.HasValue)
+                {
+                    preference = actionPreference.Value;
+                }
 
-            // No trace of the error in the 'Ignore' case
-            if (ActionPreference.Ignore == preference)
-            {
-                return; // do not write or record to output pipe
-            }
+                // No trace of the error in the 'Ignore' case
+                if (ActionPreference.Ignore == preference)
+                {
+                    return; // do not write or record to output pipe
+                }
 
-            // 2004/05/26-JonN
-            // The object is not written in the SilentlyContinue case
-            if (ActionPreference.SilentlyContinue == preference)
-            {
-                AppendErrorToVariables(errorRecord);
-                return; // do not write to output pipe
-            }
+                // 2004/05/26-JonN
+                // The object is not written in the SilentlyContinue case
+                if (ActionPreference.SilentlyContinue == preference)
+                {
+                    AppendErrorToVariables(errorRecord);
+                    return; // do not write to output pipe
+                }
 
-            if (ContinueStatus.YesToAll == lastErrorContinueStatus)
-            {
-                preference = ActionPreference.Continue;
-            }
+                if (ContinueStatus.YesToAll == lastErrorContinueStatus)
+                {
+                    preference = ActionPreference.Continue;
+                }
 
-            switch (preference)
-            {
-                case ActionPreference.Stop:
-                    ActionPreferenceStopException e =
-                        new ActionPreferenceStopException(
-                            MyInvocation,
-                            errorRecord,
-                            StringUtil.Format(CommandBaseStrings.ErrorPreferenceStop,
-                                              "ErrorActionPreference",
-                                              errorRecord.ToString()));
-                    throw ManageException(e);
+                switch (preference)
+                {
+                    case ActionPreference.Stop:
+                        ActionPreferenceStopException e =
+                            new ActionPreferenceStopException(
+                                MyInvocation,
+                                errorRecord,
+                                StringUtil.Format(CommandBaseStrings.ErrorPreferenceStop,
+                                                "ErrorActionPreference",
+                                                errorRecord.ToString()));
+                        throw ManageException(e);
+
+                    case ActionPreference.Inquire:
+                        // ignore return value
+                        // this will throw if the user chooses not to continue
+                        lastErrorContinueStatus = InquireHelper(
+                            RuntimeException.RetrieveMessage(errorRecord),
+                            null,
+                            true,  // allowYesToAll
+                            false, // allowNoToAll
+                            true,  // replaceNoWithHalt
+                            false  // hasSecurityImpact
+                        );
+                        break;
+                }
 
-                case ActionPreference.Inquire:
-                    // ignore return value
-                    // this will throw if the user chooses not to continue
-                    lastErrorContinueStatus = InquireHelper(
-                        RuntimeException.RetrieveMessage(errorRecord),
-                        null,
-                        true,  // allowYesToAll
-                        false, // allowNoToAll
-                        true,  // replaceNoWithHalt
-                        false  // hasSecurityImpact
-                    );
-                    break;
+                AppendErrorToVariables(errorRecord);
             }
 
-            // 2005/01/20 Do not write the object to $error if
-            // ManageException has already done so
-            AppendErrorToVariables(errorRecord);
-
             // Add this note property and set its value to true for F&O
             // to decide whether to call WriteErrorLine or WriteLine.
             // We want errors to print in red in both cases.

diff --git a/test/powershell/Host/ConsoleHost.Tests.ps1 b/test/powershell/Host/ConsoleHost.Tests.ps1
@@ -100,19 +100,6 @@ Describe "ConsoleHost unit tests" -tags "Feature" {
             { & $powershell -outp blah -comm { $input } } | Should -Throw -ErrorId "IncorrectValueForFormatParameter"
         }
 
-        It "Verify Validate Dollar Error Populated should throw exception" {
-            $origEA = $ErrorActionPreference
-            $ErrorActionPreference = "Stop"
-            $a = 1,2,3
-            $e = {
-                $a | & $powershell -noprofile -command { wgwg-wrwrhqwrhrh35h3h3}
-            } | Should -Throw -ErrorId "CommandNotFoundException" -PassThru
-
-            $e.ToString() | Should -Match "wgwg-wrwrhqwrhrh35h3h3"
-
-            $ErrorActionPreference = $origEA
-        }
-
         It "Verify Validate Output Format As Text Explicitly Child Single Shell does not throw" {
             {
                 "blahblah" | & $powershell -noprofile -out text -com { $input }

diff --git a/test/powershell/Language/Scripting/NativeExecution/NativeCommandProcessor.Tests.ps1 b/test/powershell/Language/Scripting/NativeExecution/NativeCommandProcessor.Tests.ps1
@@ -140,6 +140,10 @@ Describe "Native Command Processor" -tags "Feature" {
             [Console]::OutputEncoding = $originalOutputEncoding
         }
     }
+
+    It '$ErrorActionPreference does not apply to redirected stderr output' -Skip:(!$EnabledExperimentalFeatures.Contains('PSNotApplyErrorActionToStderr')) {
+        pwsh -noprofile -command '$ErrorActionPreference = ''Stop''; testexe -stderr stop 2>$null; ''hello''; $error' | Should -BeExactly 'hello'
+    }
 }
 
 Describe "Open a text file with NativeCommandProcessor" -tags @("Feature", "RequireAdminOnWindows") {

diff --git a/test/powershell/Language/Scripting/NativeExecution/NativeStreams.Tests.ps1 b/test/powershell/Language/Scripting/NativeExecution/NativeStreams.Tests.ps1
@@ -21,8 +21,7 @@ Describe "Native streams behavior with PowerShell" -Tags 'CI' {
 
         # this check should be the first one, because $error is a global shared variable
         It 'should not add records to $error variable' {
-            # we are keeping existing Windows PS v5.1 behavior for $error variable
-            $error.Count | Should -Be 9
+            $error.Count | Should -Be 0
         }
 
         It 'uses ErrorRecord object to return stderr output' {

@@ -24,6 +24,9 @@ static int Main(string[] args)
                         // Used to test functionality depending on $LASTEXITCODE, like &&/|| operators
                         Console.WriteLine(args[1]);
                         return int.Parse(args[1]);
+                    case "-stderr":
+                        Console.Error.WriteLine(args[1]);
+                        break;
                     default:
                         Console.WriteLine("Unknown test {0}", args[0]);
                         break;