Don't throw exception when trying to resolve a possible link path (PowerShell#16310)

Author: daxian-dbw

src/System.Management.Automation/engine/NativeCommandProcessor.cs

@@ -990,10 +990,19 @@ private static bool IsWindowsApplication(string fileName)
             //  1. When starting a process on Windows, if the 'FileName' is a symbolic link, the immediate link target will automatically be used,
             //     but the OS does not do recursive resolution when the immediate link target is also a symbolic link.
             //  2. Keep the same behavior as before adopting the 'LinkTarget' and 'ResolveLinkTarget' APIs in .NET 6.
-            string linkTarget = File.ResolveLinkTarget(fileName, returnFinalTarget: false)?.FullName;
-            if (linkTarget is not null)
+            try
+            {
+                string linkTarget = File.ResolveLinkTarget(fileName, returnFinalTarget: false)?.FullName;
+                if (linkTarget is not null)
+                {
+                    fileName = linkTarget;
+                }
+            }
+            catch
             {
-                fileName = linkTarget;
+                // An exception may be thrown from 'File.ResolveLinkTarget' when it fails to resolve a link path,
+                // for example, when the underlying file system doesn't support reparse points.
+                // Just use the original file name in this case.
             }
 
             SHFILEINFO shinfo = new SHFILEINFO();

test/powershell/Language/Scripting/NativeExecution/NativeCommandProcessor.Tests.ps1

@@ -252,3 +252,48 @@ Categories=Application;
         { $dllFile = "$PSHOME\System.Management.Automation.dll"; & $dllFile } | Should -Throw -ErrorId "NativeCommandFailed"
     }
 }
+
+Describe "Run native command from a mounted FAT-format VHD" -tags @("Feature", "RequireAdminOnWindows") {
+    BeforeAll {
+        if (-not $IsWindows) {
+            return;
+        }
+
+        $vhdx = Join-Path -Path $TestDrive -ChildPath ncp.vhdx
+
+        if (Test-Path -Path $vhdx) {
+            Remove-item -Path $vhdx -Force
+        }
+
+        $create_vhdx = Join-Path -Path $TestDrive -ChildPath 'create_vhdx.txt'
+
+        Set-Content -Path $create_vhdx -Force -Value @"
+            create vdisk file="$vhdx" maximum=20 type=fixed
+            select vdisk file="$vhdx"
+            attach vdisk
+            convert mbr
+            create partition primary
+            format fs=fat
+            assign letter="T"
+            detach vdisk
+"@
+
+        diskpart.exe /s $create_vhdx
+        Mount-DiskImage -ImagePath $vhdx > $null
+
+        Copy-Item "$env:WinDir\System32\whoami.exe" T:\whoami.exe
+    }
+
+    AfterAll {
+        if ($IsWindows) {
+            Dismount-DiskImage -ImagePath $vhdx
+            Remove-Item $vhdx, $create_vhdx -Force
+        }
+    }
+
+    It "Should run 'whoami.exe' from FAT file system without error" -Skip:(!$IsWindows) {
+        $expected = & "$env:WinDir\System32\whoami.exe"
+        $result = T:\whoami.exe
+        $result | Should -BeExactly $expected
+    }
+}