Fix Move-Item to throw error when moving into itself (#24004)

SteveL-MSFT · web-flow · commit 2d83b95539e2 · 2024-07-08T23:53:17.000Z
diff --git a/src/System.Management.Automation/namespaces/FileSystemProvider.cs b/src/System.Management.Automation/namespaces/FileSystemProvider.cs
@@ -5838,8 +5838,10 @@ protected override void MoveItem(
                         destination = MakePath(destination, dir.Name);
                     }
 
-                    // Don't allow moving a directory into itself
-                    if (destination.StartsWith(Path.TrimEndingDirectorySeparator(path) + Path.DirectorySeparatorChar))
+                    // Don't allow moving a directory into itself or its sub-directory.
+                    string pathWithoutEndingSeparator = Path.TrimEndingDirectorySeparator(path);
+                    if (destination.StartsWith(pathWithoutEndingSeparator + Path.DirectorySeparatorChar)
+                        || destination.Equals(pathWithoutEndingSeparator, StringComparison.OrdinalIgnoreCase))
                     {
                         string error = StringUtil.Format(FileSystemProviderStrings.TargetCannotBeSubdirectoryOfSource, destination);
                         var e = new IOException(error);
diff --git a/src/System.Management.Automation/resources/FileSystemProviderStrings.resx b/src/System.Management.Automation/resources/FileSystemProviderStrings.resx
@@ -334,7 +334,7 @@
     <value>Skip already-visited directory {0}.</value>
   </data>
   <data name="TargetCannotBeSubdirectoryOfSource" xml:space="preserve">
-    <value>Destination path cannot be a subdirectory of the source: {0}.</value>
+    <value>Destination path cannot be a subdirectory of the source or the source itself: {0}.</value>
   </data>
   <data name="NewItemTargetIsSameAsLink" xml:space="preserve">
     <value>The target and path cannot be the same.</value>
diff --git a/test/powershell/Modules/Microsoft.PowerShell.Management/FileSystem.Tests.ps1 b/test/powershell/Modules/Microsoft.PowerShell.Management/FileSystem.Tests.ps1
@@ -201,6 +201,25 @@ Describe "Basic FileSystem Provider Tests" -Tags "CI" {
             { Move-Item -Path $src -Destination $dest -ErrorAction Stop } | Should -Throw -ErrorId 'MoveItemArgumentError,Microsoft.PowerShell.Commands.MoveItemCommand'
         }
 
+        It 'Verify Move-Item fails when destination is same as source w/wo directory separator: <source>' -TestCases @(
+            @{ source = './Empty/' }
+            @{ source = './Empty' }
+            @{ source = '.\Empty\' }
+            @{ source = '.\Empty' }
+        ) {
+            param($source)
+
+            try {
+                Push-Location $TestDrive
+                New-Item -ItemType Directory -Path 'Empty'
+                { Move-Item -Path $source -ErrorAction Stop } | Should -Throw -ErrorId 'MoveItemArgumentError,Microsoft.PowerShell.Commands.MoveItemCommand'
+            }
+            finally {
+                Pop-Location
+                Remove-Item 'Empty' -Force
+            }
+        }
+
         It "Verify Move-Item throws correct error for non-existent source" {
             { Move-Item -Path /does/not/exist -Destination $testFile -ErrorAction Stop } | Should -Throw -ErrorId 'PathNotFound,Microsoft.PowerShell.Commands.MoveItemCommand'
         }

Original file line number	Diff line number	Diff line change
`@@ -5838,8 +5838,10 @@ protected override void MoveItem(`
`5838`	`5838`	`destination = MakePath(destination, dir.Name);`
`5839`	`5839`	`}`
`5840`	`5840`
`5841`		`- // Don't allow moving a directory into itself`
`5842`		`- if (destination.StartsWith(Path.TrimEndingDirectorySeparator(path) + Path.DirectorySeparatorChar))`
	`5841`	`+ // Don't allow moving a directory into itself or its sub-directory.`
	`5842`	`+ string pathWithoutEndingSeparator = Path.TrimEndingDirectorySeparator(path);`
	`5843`	`+ if (destination.StartsWith(pathWithoutEndingSeparator + Path.DirectorySeparatorChar)`
	`5844`	`+ \|\| destination.Equals(pathWithoutEndingSeparator, StringComparison.OrdinalIgnoreCase))`
`5843`	`5845`	`{`
`5844`	`5846`	`string error = StringUtil.Format(FileSystemProviderStrings.TargetCannotBeSubdirectoryOfSource, destination);`
`5845`	`5847`	`var e = new IOException(error);`