Skip to content

Restore ReadOnly after failed Set-Variable option updates #27877

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
David Kontyko (dkontyko) wants to merge 8 commits into
base: master
Choose a base branch
from
+120 −4
Open

Restore ReadOnly after failed Set-Variable option updates #27877

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
a5fdd76
Fix Set-Variable regression where temporary ReadOnly removal leaked s…
dkontyko Aug 21, 2026
3a0656a
Refine Set-Variable readonly restoration
Copilot Aug 21, 2026
9a3caa3
Fix Set-Variable restoration variable scope
Copilot Aug 21, 2026
9a7ee51
Update Set-Variable ReadOnly restoration tests
Copilot Aug 21, 2026
073c4b1
Fix Set-Variable option regression test scope
Copilot Aug 21, 2026
85e3931
Add compatibility tests for Set-Variable constant option failures
dkontyko Aug 21, 2026
b6fd676
Initialize ReadOnly state at declaration
Aug 24, 2026
4704441
Fix Set-Variable regression test scope
Aug 25, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 13 additions & 4 deletions src/Microsoft.PowerShell.Commands.Utility/commands/utility/Var.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -973,6 +973,8 @@ private void SetVariable(string[] varNames, object varValue)
if (ShouldProcess(target, action))
{
object result = null;
bool wasReadOnly = Force &&
(matchingVariable.Options & ScopedItemOptions.ReadOnly) != 0;

try
{
Expand All @@ -983,12 +985,9 @@ private void SetVariable(string[] varNames, object varValue)
// If we want to force setting over a readonly variable
// we have to temporarily mark the variable writable.

bool wasReadOnly = false;
if (Force &&
(matchingVariable.Options & ScopedItemOptions.ReadOnly) != 0)
if (wasReadOnly)
{
matchingVariable.SetOptions(matchingVariable.Options & ~ScopedItemOptions.ReadOnly, true);
wasReadOnly = true;
}

// Now change the value, options, or description
Expand Down Expand Up @@ -1036,6 +1035,11 @@ private void SetVariable(string[] varNames, object varValue)
}
catch (SessionStateException sessionStateException)
{
if (wasReadOnly)
{
matchingVariable.SetOptions(matchingVariable.Options | ScopedItemOptions.ReadOnly, true);
}

WriteError(
new ErrorRecord(
sessionStateException.ErrorRecord,
Expand All @@ -1044,6 +1048,11 @@ private void SetVariable(string[] varNames, object varValue)
}
catch (PSArgumentException argException)
{
if (wasReadOnly)
{
matchingVariable.SetOptions(matchingVariable.Options | ScopedItemOptions.ReadOnly, true);
}

WriteError(
new ErrorRecord(
argException.ErrorRecord,
Expand Down
107 changes: 107 additions & 0 deletions test/powershell/Modules/Microsoft.PowerShell.Utility/Set-Variable.Tests.ps1
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -125,6 +125,113 @@ Describe "Set-Variable DRT Unit Tests" -Tags "CI" {
{ Set-Variable abcaVar -Option None -Scope 1 -ErrorAction Stop } | Should -Throw -ErrorId "VariableNotWritable,Microsoft.PowerShell.Commands.SetVariableCommand"
}

# Issue #27679 cases 1 and 2 intentionally retain value mutation for backward compatibility.
It "Set-Variable preserves value mutation when setting Constant on an existing writable variable fails"{
$name = "SetVariableIssue27679Case1"

try
{
Set-Variable -Name $name -Value 1

$exception = $null
try
{
Set-Variable -Name $name -Value 2 -Option Constant -ErrorAction Stop
}
catch
{
$exception = $_
}

$exception | Should -Not -BeNullOrEmpty
$exception.FullyQualifiedErrorId | Should -BeExactly "VariableCannotBeMadeConstant,Microsoft.PowerShell.Commands.SetVariableCommand"

$var1 = Get-Variable -Name $name
$var1.Value | Should -Be 2
$var1.Options | Should -BeExactly "None"
}
finally
{
Remove-Variable -Name $name -Force -ErrorAction SilentlyContinue
}
}

It "Set-Variable preserves value mutation and restores ReadOnly when setting Constant fails with force"{
$name = "SetVariableIssue27679Case2"

try
{
Set-Variable -Name $name -Value 1 -Option ReadOnly

$exception = $null
try
{
Set-Variable -Name $name -Value 2 -Force -Option Constant -ErrorAction Stop
}
catch
{
$exception = $_
}

$exception | Should -Not -BeNullOrEmpty
$exception.FullyQualifiedErrorId | Should -BeExactly "VariableCannotBeMadeConstant,Microsoft.PowerShell.Commands.SetVariableCommand"

$var1 = Get-Variable -Name $name
$var1.Value | Should -Be 2
$var1.Options | Should -BeExactly "ReadOnly"
}
finally
{
Remove-Variable -Name $name -Force -ErrorAction SilentlyContinue
}
}

It "Set-Variable of ReadOnly variable with force preserves expected options when option update fails for <ExpectedOptions>" -TestCases @(
@{
Name = "SetVariableIssue27679Case3ReadOnly"
Options = [System.Management.Automation.ScopedItemOptions]::ReadOnly
ExpectedOptions = "ReadOnly"
}
@{
Name = "SetVariableIssue27679Case3ReadOnlyPrivate"
Options = [System.Management.Automation.ScopedItemOptions]::ReadOnly -bor [System.Management.Automation.ScopedItemOptions]::Private
ExpectedOptions = "ReadOnly, Private"
}
@{
Name = "SetVariableIssue27679Case3ReadOnlyAllScope"
Options = [System.Management.Automation.ScopedItemOptions]::ReadOnly -bor [System.Management.Automation.ScopedItemOptions]::AllScope
ExpectedOptions = "ReadOnly, AllScope"
}
) {
param($Name, $Options, $ExpectedOptions)

try
{
Set-Variable -Name $Name -Value 1 -Option $Options

$exception = $null
try
{
Set-Variable -Name $Name -Force -Option Constant -ErrorAction Stop
}
catch
{
$exception = $_
}

$exception | Should -Not -BeNullOrEmpty
$exception.FullyQualifiedErrorId | Should -BeExactly "VariableCannotBeMadeConstant,Microsoft.PowerShell.Commands.SetVariableCommand"

$var1 = Get-Variable -Name $Name
$var1.Value | Should -Be 1
$var1.Options.ToString() | Should -BeExactly $ExpectedOptions
}
finally
{
Remove-Variable -Name $Name -Force -ErrorAction SilentlyContinue
}
}

It "Set-Variable of ReadOnly variable with private scope should work"{
Set-Variable foo bar -Description "new description" -Option ReadOnly -Scope "private"
$var1=Get-Variable -Name foo
Expand Down