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Enable New-Item creates symlinks to non-existent targets #13082

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e7450f5
Enable New-Item creates symlinks to non-existent targets
iSazonov Jul 2, 2020
824cc9a
unify method signature
iSazonov Aug 3, 2020
1155056
target as literal
iSazonov Aug 3, 2020
dc80aa6
Revert "target as literal"
iSazonov Aug 4, 2020
c31ea16
Target as literal 2
iSazonov Aug 4, 2020
edde025
Add tests
iSazonov Aug 4, 2020
94e2706
Remove globbing check
iSazonov Aug 4, 2020
d1754e0
Fix tests
iSazonov Aug 4, 2020
0427aa6
Fix tests 2
iSazonov Aug 4, 2020
06d6056
Fix test 3
iSazonov Aug 4, 2020
a1fbc96
Fix tests 4
iSazonov Aug 4, 2020
0e546fd
Pending test on Unix
iSazonov Aug 6, 2020
2cda01b
Split tests
iSazonov Aug 6, 2020
beb7251
Add reference to tracking issue
iSazonov Aug 6, 2020
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63 changes: 30 additions & 33 deletions src/Microsoft.PowerShell.Commands.Management/commands/management/Navigation.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2114,40 +2114,37 @@ protected override void ProcessRecord()
Path = new string[] { string.Empty };
}

foreach (string path in Path)
try
{
try
{
InvokeProvider.Item.New(path, Name, ItemType, Value, CmdletProviderContext);
}
catch (PSNotSupportedException notSupported)
{
WriteError(
new ErrorRecord(
notSupported.ErrorRecord,
notSupported));
}
catch (DriveNotFoundException driveNotFound)
{
WriteError(
new ErrorRecord(
driveNotFound.ErrorRecord,
driveNotFound));
}
catch (ProviderNotFoundException providerNotFound)
{
WriteError(
new ErrorRecord(
providerNotFound.ErrorRecord,
providerNotFound));
}
catch (ItemNotFoundException pathNotFound)
{
WriteError(
new ErrorRecord(
pathNotFound.ErrorRecord,
pathNotFound));
}
InvokeProvider.Item.New(Path, Name, ItemType, Value, CmdletProviderContext);
}
catch (PSNotSupportedException notSupported)
{
WriteError(
new ErrorRecord(
notSupported.ErrorRecord,
notSupported));
}
catch (DriveNotFoundException driveNotFound)
{
WriteError(
new ErrorRecord(
driveNotFound.ErrorRecord,
driveNotFound));
}
catch (ProviderNotFoundException providerNotFound)
{
WriteError(
new ErrorRecord(
providerNotFound.ErrorRecord,
providerNotFound));
}
catch (ItemNotFoundException pathNotFound)
{
WriteError(
new ErrorRecord(
pathNotFound.ErrorRecord,
pathNotFound));
}
}

Expand Down
4 changes: 2 additions & 2 deletions src/System.Management.Automation/engine/ItemCmdletProviderInterfaces.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -1128,7 +1128,7 @@ public Collection<PSObject> New(
/// If the provider threw an exception.
/// </exception>
internal void New(
string path,
string[] path,
string name,
string type,
object content,
Expand All @@ -1140,7 +1140,7 @@ internal void New(

// Parameter validation is done in the session state object

_sessionState.NewItem(new string[] { path }, name, type, content, context);
_sessionState.NewItem(path, name, type, content, context);
}

/// <summary>
Expand Down
97 changes: 33 additions & 64 deletions src/System.Management.Automation/engine/SessionStateContainer.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -3433,7 +3433,6 @@ internal void NewItem(
}

ProviderInfo provider = null;
PSDriveInfo driveInfo;
CmdletProvider providerInstance = null;

Collection<string> providerPaths = new Collection<string>();
Expand All @@ -3443,7 +3442,7 @@ internal void NewItem(
if (string.IsNullOrEmpty(name))
{
string providerPath =
Globber.GetProviderPath(resolvePath, context, out provider, out driveInfo);
Globber.GetProviderPath(resolvePath, context, out provider, out _);

providerInstance = GetProviderInstance(provider);
providerPaths.Add(providerPath);
Expand All @@ -3459,86 +3458,56 @@ internal void NewItem(
out providerInstance);
}

// Don't support 'New-Item -Type Directory' on the Function provider
// if the runspace has ever been in constrained language mode, as the mkdir
// function can be abused
if (context.ExecutionContext.HasRunspaceEverUsedConstrainedLanguageMode &&
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@SteveL-MSFT SteveL-MSFT Jun 13, 2022

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You should add a test case to cover this

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@iSazonov iSazonov Jun 15, 2022

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It is not new code. It is moved code.

(providerInstance is Microsoft.PowerShell.Commands.FunctionProvider) &&
(string.Equals(type, "Directory", StringComparison.OrdinalIgnoreCase)))
{
throw
PSTraceSource.NewNotSupportedException(SessionStateStrings.DriveCmdletProvider_NotSupported);
}

// Symbolic link targets are allowed to not exist on both Windows and Linux
bool allowNonexistingPath = false;
bool isSymbolicJunctionOrHardLink = false;

if (type != null)
{
WildcardPattern typeEvaluator = WildcardPattern.Get(type + "*", WildcardOptions.IgnoreCase | WildcardOptions.Compiled);
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@SteveL-MSFT SteveL-MSFT Jun 13, 2022

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I don't understand the use of the wildcardpattern here, type is a string for filesystem that should be symboliclink, junction, hardlink, etc... right? why isn't this a switch statement?

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@iSazonov iSazonov Jun 15, 2022

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It is not new code. It is moved code.


allowNonexistingPath = typeEvaluator.IsMatch("symboliclink");

isSymbolicJunctionOrHardLink =
typeEvaluator.IsMatch("symboliclink")
|| typeEvaluator.IsMatch("junction")
|| typeEvaluator.IsMatch("hardlink");
}

foreach (string providerPath in providerPaths)
{
// Compose the globbed container and the name together to get a path
// to pass on to the provider.

string composedPath = providerPath;
if (!string.IsNullOrEmpty(name))
{
composedPath = MakePath(providerInstance, providerPath, name, context);
}

// Don't support 'New-Item -Type Directory' on the Function provider
// if the runspace has ever been in constrained language mode, as the mkdir
// function can be abused
if (context.ExecutionContext.HasRunspaceEverUsedConstrainedLanguageMode &&
(providerInstance is Microsoft.PowerShell.Commands.FunctionProvider) &&
(string.Equals(type, "Directory", StringComparison.OrdinalIgnoreCase)))
{
throw
PSTraceSource.NewNotSupportedException(SessionStateStrings.DriveCmdletProvider_NotSupported);
}

bool isSymbolicJunctionOrHardLink = false;
// Symbolic link targets are allowed to not exist on both Windows and Linux
bool allowNonexistingPath = false;

if (type != null)
{
WildcardPattern typeEvaluator = WildcardPattern.Get(type + "*", WildcardOptions.IgnoreCase | WildcardOptions.Compiled);

if (typeEvaluator.IsMatch("symboliclink") || typeEvaluator.IsMatch("junction") || typeEvaluator.IsMatch("hardlink"))
{
isSymbolicJunctionOrHardLink = true;
allowNonexistingPath = typeEvaluator.IsMatch("symboliclink");
}
}
string targetPath = content?.ToString();

if (isSymbolicJunctionOrHardLink)
{
string targetPath;

if (content is null || string.IsNullOrEmpty(targetPath = content.ToString()))
if (string.IsNullOrEmpty(targetPath))
{
throw PSTraceSource.NewArgumentNullException(nameof(content), SessionStateStrings.NewLinkTargetNotSpecified, path);
}

ProviderInfo targetProvider = null;
CmdletProvider targetProviderInstance = null;

var globbedTarget = Globber.GetGlobbedProviderPathsFromMonadPath(
targetPath,
allowNonexistingPath,
context,
out targetProvider,
out targetProviderInstance);

if (!string.Equals(targetProvider.Name, "filesystem", StringComparison.OrdinalIgnoreCase))
{
throw PSTraceSource.NewNotSupportedException(SessionStateStrings.MustBeFileSystemPath);
}

if (globbedTarget.Count > 1)
{
throw PSTraceSource.NewInvalidOperationException(SessionStateStrings.PathResolvedToMultiple, targetPath);
}

if (globbedTarget.Count == 0)
{
throw PSTraceSource.NewInvalidOperationException(SessionStateStrings.PathNotFound, targetPath);
}

// If the original target was a relative path, we want to leave it as relative if it did not require
// globbing to resolve.
if (WildcardPattern.ContainsWildcardCharacters(targetPath))
{
content = globbedTarget[0];
}
targetPath = targetPath?.Replace(StringLiterals.AlternatePathSeparator, StringLiterals.DefaultPathSeparator);
}

NewItemPrivate(providerInstance, composedPath, type, content, context);
NewItemPrivate(providerInstance, composedPath, type, targetPath, context);
}
}
}
Expand Down Expand Up @@ -3574,7 +3543,7 @@ private void NewItemPrivate(
CmdletProvider providerInstance,
string path,
string type,
object content,
string content,
CmdletProviderContext context)
{
// All parameters should have been validated by caller
Expand Down
2 changes: 0 additions & 2 deletions src/System.Management.Automation/namespaces/FileSystemProvider.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2380,8 +2380,6 @@ protected override void NewItem(
}

GetFileSystemInfo(normalizedTargetPath, out isDirectory);

strTargetPath = strTargetPath.Replace(StringLiterals.AlternatePathSeparator, StringLiterals.DefaultPathSeparator);
}
else
{
Expand Down
31 changes: 21 additions & 10 deletions src/System.Management.Automation/namespaces/LocationGlobber.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -757,20 +757,31 @@ internal Collection<string> GetGlobbedProviderPathsFromMonadPath(
}

PSDriveInfo drive = null;
string providerPath = GetProviderPath(path, context, out provider, out drive);

if (providerPath == null)
provider = null;
try
{
providerInstance = null;
s_tracer.WriteLine("provider returned a null path so return an empty array");
string providerPath = GetProviderPath(path, context, out provider, out drive);

s_pathResolutionTracer.WriteLine("Provider '{0}' returned null", provider);
return new Collection<string>();
}
if (providerPath == null)
{
providerInstance = null;
s_tracer.WriteLine("provider returned a null path so return an empty array");

if (drive != null)
s_pathResolutionTracer.WriteLine("Provider '{0}' returned null", provider);
return new Collection<string>();
}

if (drive != null)
{
context.Drive = drive;
}
}
catch (DriveNotFoundException)
{
context.Drive = drive;
if (!allowNonexistingPaths)
{
throw;
}
}

Collection<string> paths = new Collection<string>();
Expand Down
60 changes: 49 additions & 11 deletions test/powershell/Modules/Microsoft.PowerShell.Management/New-Item.Tests.ps1
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Original file line number Diff line number Diff line change
Expand Up @@ -277,22 +277,15 @@ Describe "New-Item with links" -Tags @('CI', 'RequireAdminOnWindows') {

Describe "New-Item: symlink with absolute/relative path test" -Tags @('CI', 'RequireAdminOnWindows') {
BeforeAll {
# on macOS, the /tmp directory is a symlink, so we'll resolve it here
$TestPath = $TestDrive
if ($IsMacOS)
{
$item = Get-Item $TestPath
$dirName = $item.BaseName
$item = Get-Item $item.PSParentPath -Force
if ($item.LinkType -eq "SymbolicLink")
{
$TestPath = Join-Path $item.Target $dirName
}
}

Push-Location $TestPath

$null = New-Item -Type Directory someDir
$null = New-Item -Type File someFile

$targets = "./$PID.tmp", ".\$PID.tmp"
$links = "$PID-Link0.tmp", "$PID-Link1.tmp"
}

AfterAll {
Expand All @@ -319,6 +312,51 @@ Describe "New-Item: symlink with absolute/relative path test" -Tags @('CI', 'Req
New-Item -Type SymbolicLink someFileLinkRelative -Target ./someFile
Get-Item someFileLinkRelative | Should -BeOfType System.IO.FileInfo
}

It "Can create symlink with relative nonexistent target '<target>'" -TestCases @{ link = $links[0]; target = $targets[0] }, @{ link = $links[1]; target = $targets[1] } {
param($link, $target)

$null = New-Item -Type SymbolicLink $link -Target $target

# Make sure the relative target path was recorded as such and uses
# the platform-appropriate separator.
(Get-Item $link).Target | Should -Be ($target -replace '[\\/]', [IO.Path]::DirectorySeparatorChar)
}

It "Can create symlink with absolute existent target as literal path" {
$fileName = 'file[1].txt'
$absolutePath = (New-Item -Type File $fileName).FullName

$link = New-Item -Type SymbolicLink globbedAbsoluteLink1 -Target $absolutePath
(Get-Item $link).Target | Should -BeExactly $absolutePath
}

It "Can create symlink with relative existent target as literal path" {
$fileName = 'file[1].txt'

if (-not $IsWindows) {
# Tracking issue https://github.com/PowerShell/PowerShell/issues/13365
Set-ItResult -Pending -Because "On Unix the Target property is always resolved to an absolute path."
}

$link = New-Item -Type SymbolicLink globbedRelativeLink1 -Target ./$fileName
(Get-Item $link).Target | Should -BeExactly ("./$fileName" -replace '[\\/]', [IO.Path]::DirectorySeparatorChar)
}

It "Can create symlink with absolute nonexistent target as literal path" {
$fileName = 'noexist_file[2].txt'
$absolutePath = Join-Path $pwd $fileName

$link = New-Item -Type SymbolicLink globbedAbsoluteLink2 -Target $absolutePath
(Get-Item $link).Target | Should -BeExactly $absolutePath
}

It "Can create symlink with relative nonexistent target as literal path" {
$fileName = 'noexist_file[2].txt'

$link = New-Item -Type SymbolicLink globbedRelativeLink2 -Target ./$fileName
(Get-Item $link).Target | Should -BeExactly ("./$fileName" -replace '[\\/]', [IO.Path]::DirectorySeparatorChar)
}
}

Describe "New-Item with links fails for non elevated user if developer mode not enabled on Windows." -Tags "CI" {
Expand Down