Fix $PSNativeCommandArgPassing = Windows to handle empty args correctly (PowerShell#16639)

SteveL-MSFT · web-flow · commit 0f21156dee50 · 2022-01-11T23:21:32.000-08:00
diff --git a/src/System.Management.Automation/engine/NativeCommandParameterBinder.cs b/src/System.Management.Automation/engine/NativeCommandParameterBinder.cs
@@ -314,7 +314,7 @@ private void AppendOneNativeArgument(ExecutionContext context, CommandParameterI
                         }
                         else
                         {
-                            if (argArrayAst != null && ArgumentPassingStyle == NativeArgumentPassingStyle.Standard)
+                            if (argArrayAst != null && ArgumentPassingStyle != NativeArgumentPassingStyle.Legacy)
                             {
                                 // We have a literal array, so take the extent, break it on spaces and add them to the argument list.
                                 foreach (string element in argArrayAst.Extent.Text.Split(' ', StringSplitOptions.RemoveEmptyEntries))
@@ -331,7 +331,7 @@ private void AppendOneNativeArgument(ExecutionContext context, CommandParameterI
                         }
                     }
                 }
-                else if (ArgumentPassingStyle == NativeArgumentPassingStyle.Standard && currentObj != null)
+                else if (ArgumentPassingStyle != NativeArgumentPassingStyle.Legacy && currentObj != null)
                 {
                     // add empty strings to arglist, but not nulls
                     AddToArgumentList(parameter, arg);
diff --git a/test/powershell/Language/Scripting/NativeExecution/NativeCommandArguments.Tests.ps1 b/test/powershell/Language/Scripting/NativeExecution/NativeCommandArguments.Tests.ps1
@@ -171,7 +171,7 @@ Describe "Will error correctly if an attempt to set variable to improper value"
     }
 }
 
-foreach ( $argumentListValue in "Standard","Legacy" ) {
+foreach ( $argumentListValue in "Standard","Legacy","Windows" ) {
     $PSNativeCommandArgumentPassing = $argumentListValue
     Describe "Native Command Arguments (${PSNativeCommandArgumentPassing})" -tags "CI" {
         # When passing arguments to native commands, quoted segments that contain
@@ -263,6 +263,28 @@ foreach ( $argumentListValue in "Standard","Legacy" ) {
                 $lines[$i] | Should -BeExactly "Arg $i is <$($expected[$i])>"
             }
         }
+
+        It "Should handle empty args correctly (ArgumentList=${PSNativeCommandArgumentPassing})" {
+            if ($PSNativeCommandArgumentPassing -eq 'Legacy') {
+                $expectedLines = 2
+            }
+            else {
+                $expectedLines = 3
+            }
+
+            $lines = testexe -echoargs 1 '' 2
+            $lines.Count | Should -Be $expectedLines
+            $lines[0] | Should -BeExactly 'Arg 0 is <1>'
+
+            if ($expectedLines -eq 2) {
+                $lines[1] | Should -BeExactly 'Arg 1 is <2>'
+            }
+            else {
+                $lines[1] | Should -BeExactly 'Arg 1 is <>'
+                $lines[2] | Should -BeExactly 'Arg 2 is <2>'
+            }
+
+        }
     }
 }
 Describe 'PSPath to native commands' -tags "CI" {

Original file line number	Diff line number	Diff line change
`@@ -314,7 +314,7 @@ private void AppendOneNativeArgument(ExecutionContext context, CommandParameterI`
`314`	`314`	`}`
`315`	`315`	`else`
`316`	`316`	`{`
`317`		`- if (argArrayAst != null && ArgumentPassingStyle == NativeArgumentPassingStyle.Standard)`
	`317`	`+ if (argArrayAst != null && ArgumentPassingStyle != NativeArgumentPassingStyle.Legacy)`
`318`	`318`	`{`
`319`	`319`	`// We have a literal array, so take the extent, break it on spaces and add them to the argument list.`
`320`	`320`	`foreach (string element in argArrayAst.Extent.Text.Split(' ', StringSplitOptions.RemoveEmptyEntries))`
`@@ -331,7 +331,7 @@ private void AppendOneNativeArgument(ExecutionContext context, CommandParameterI`
`331`	`331`	`}`
`332`	`332`	`}`
`333`	`333`	`}`
`334`		`- else if (ArgumentPassingStyle == NativeArgumentPassingStyle.Standard && currentObj != null)`
	`334`	`+ else if (ArgumentPassingStyle != NativeArgumentPassingStyle.Legacy && currentObj != null)`
`335`	`335`	`{`
`336`	`336`	`// add empty strings to arglist, but not nulls`
`337`	`337`	`AddToArgumentList(parameter, arg);`