[pull] master from PowerShell:master

.github/workflows/copilot-setup-steps.yml

@@ -0,0 +1,61 @@
+name: "Copilot Setup Steps"
+
+# Allow testing of the setup steps from your repository's "Actions" tab.
+on:
+  workflow_dispatch:
+
+  pull_request:
+    branches:
+      - master
+    paths:
+      - ".github/workflows/copilot-setup-steps.yml"
+
+jobs:
+  # The job MUST be called `copilot-setup-steps` or it will not be picked up by Copilot.
+  # See https://docs.github.com/en/copilot/customizing-copilot/customizing-the-development-environment-for-copilot-coding-agent
+  copilot-setup-steps:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+
+    # You can define any steps you want, and they will run before the agent starts.
+    # If you do not check out your code, Copilot will do this for you.
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          fetch-depth: 1000
+
+      - name: Bootstrap
+        if: success()
+        run: |-
+          $title = 'Import Build.psm1'
+          Write-Host "::group::$title"
+          Import-Module ./build.psm1 -Verbose -ErrorAction Stop
+          Write-LogGroupEnd -Title $title
+
+          $title = 'Switch to public feed'
+          Write-LogGroupStart -Title $title
+          Switch-PSNugetConfig -Source Public
+          Write-LogGroupEnd -Title $title
+
+          $title = 'Bootstrap'
+          Write-LogGroupStart -Title $title
+          Start-PSBootstrap -Scenario DotNet
+          Write-LogGroupEnd -Title $title
+
+          $title = 'Install .NET Tools'
+          Write-LogGroupStart -Title $title
+          Start-PSBootstrap -Scenario Tools
+          Write-LogGroupEnd -Title $title
+
+          $title = 'Sync Tags'
+          Write-LogGroupStart -Title $title
+          Sync-PSTags -AddRemoteIfMissing
+          Write-LogGroupEnd -Title $title
+
+          $title = 'Setup .NET environment variables'
+          Write-LogGroupStart -Title $title
+          Find-DotNet -SetDotnetRoot
+          Write-LogGroupEnd -Title $title
+        shell: pwsh

.globalconfig

@@ -574,6 +574,10 @@ dotnet_diagnostic.CA2016.severity = suggestion
 # https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2021
 dotnet_diagnostic.CA2021.severity = warning
 
+# CA2022: Avoid inexact read with 'Stream.Read'
+# https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2022
+dotnet_diagnostic.CA2022.severity = warning
+
 # CA2100: Review SQL queries for security vulnerabilities
 # https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2100
 dotnet_diagnostic.CA2100.severity = none

build.psm1

@@ -2282,7 +2282,12 @@ function Start-PSBootstrap {
         [switch]$BuildLinuxArm,
         [switch]$Force,
         [Parameter(Mandatory = $true)]
-        [ValidateSet("Package", "DotNet", "Both")]
+        # Package: Install dependencies for packaging tools (fpm, rpmbuild, WiX)
+        # DotNet: Install the .NET SDK
+        # Both: Package and DotNet scenarios
+        # Tools: Install .NET global tools (e.g., dotnet-format)
+        # All: Install all dependencies (packaging, .NET SDK, and tools)
+        [ValidateSet("Package", "DotNet", "Both", "Tools", "All")]
         [string]$Scenario = "Package"
     )
 
@@ -2402,15 +2407,15 @@ function Start-PSBootstrap {
 
             # Install [fpm](https://github.com/jordansissel/fpm)
             # Note: fpm is now only needed for DEB and macOS packages; RPM packages use rpmbuild directly
-            if ($Scenario -eq 'Both' -or $Scenario -eq 'Package') {
+            if ($Scenario -in 'All', 'Both', 'Package') {
                 # Install fpm on Debian-based systems, macOS, and Mariner (where DEB packages are built)
                 if (($environment.IsLinux -and ($environment.IsDebianFamily -or $environment.IsMariner)) -or $environment.IsMacOS) {
                     Install-GlobalGem -Sudo $sudo -GemName "dotenv" -GemVersion "2.8.1"
                     Install-GlobalGem -Sudo $sudo -GemName "ffi" -GemVersion "1.16.3"
                     Install-GlobalGem -Sudo $sudo -GemName "fpm" -GemVersion "1.15.1"
                     Install-GlobalGem -Sudo $sudo -GemName "rexml" -GemVersion "3.2.5"
                 }
-                
+
                 # For RPM-based systems, ensure rpmbuild is available
                 if ($environment.IsLinux -and ($environment.IsRedHatFamily -or $environment.IsSUSEFamily -or $environment.IsMariner)) {
                     Write-Verbose -Verbose "Checking for rpmbuild..."
@@ -2422,7 +2427,7 @@ function Start-PSBootstrap {
             }
         }
 
-        if ($Scenario -eq 'DotNet' -or $Scenario -eq 'Both') {
+        if ($Scenario -in 'All', 'Both', 'DotNet') {
 
             Write-Verbose -Verbose "Calling Find-Dotnet from Start-PSBootstrap"
 
@@ -2479,6 +2484,19 @@ function Start-PSBootstrap {
             }
         }
 
+        if ($Scenario -in 'All', 'Tools') {
+            Write-Log -message "Installing .NET global tools"
+
+            # Ensure dotnet is available
+            Find-Dotnet
+
+            # Install dotnet-format
+            Write-Verbose -Verbose "Installing dotnet-format global tool"
+            Start-NativeExecution {
+                dotnet tool install --global dotnet-format
+            }
+        }
+
         if ($env:TF_BUILD) {
             Write-Verbose -Verbose "--- Start - Capturing nuget sources"
             dotnet nuget list source --format detailed
@@ -2646,6 +2664,63 @@ function Start-ResGen
     }
 }
 
+function Add-PSEnvironmentPath {
+    <#
+    .SYNOPSIS
+        Adds a path to the process PATH and persists to GitHub Actions workflow if running in GitHub Actions
+    .PARAMETER Path
+        Path to add to PATH
+    .PARAMETER Prepend
+        If specified, prepends the path instead of appending
+    #>
+    param (
+        [Parameter(Mandatory)]
+        [string]$Path,
+
+        [switch]$Prepend
+    )
+
+    # Set in current process
+    if ($Prepend) {
+        $env:PATH = $Path + [IO.Path]::PathSeparator + $env:PATH
+    } else {
+        $env:PATH += [IO.Path]::PathSeparator + $Path
+    }
+
+    # Persist to GitHub Actions workflow if running in GitHub Actions
+    if ($env:GITHUB_ACTIONS -eq 'true') {
+        Write-Verbose -Verbose "Adding $Path to GITHUB_PATH"
+        Add-Content -Path $env:GITHUB_PATH -Value $Path
+    }
+}
+
+function Set-PSEnvironmentVariable {
+    <#
+    .SYNOPSIS
+        Sets an environment variable in the process and persists to GitHub Actions workflow if running in GitHub Actions
+    .PARAMETER Name
+        The name of the environment variable
+    .PARAMETER Value
+        The value of the environment variable
+    #>
+    param (
+        [Parameter(Mandatory)]
+        [string]$Name,
+
+        [Parameter(Mandatory)]
+        [string]$Value
+    )
+
+    # Set in current process
+    Set-Item -Path "env:$Name" -Value $Value
+
+    # Persist to GitHub Actions workflow if running in GitHub Actions
+    if ($env:GITHUB_ACTIONS -eq 'true') {
+        Write-Verbose -Verbose "Setting $Name in GITHUB_ENV"
+        Add-Content -Path $env:GITHUB_ENV -Value "$Name=$Value"
+    }
+}
+
 function Find-Dotnet {
     param (
         [switch] $SetDotnetRoot
@@ -2676,25 +2751,40 @@ function Find-Dotnet {
         if ($dotnetCLIInstalledVersion -ne $chosenDotNetVersion) {
             Write-Warning "The 'dotnet' in the current path can't find SDK version ${dotnetCLIRequiredVersion}, prepending $dotnetPath to PATH."
             # Globally installed dotnet doesn't have the required SDK version, prepend the user local dotnet location
-            $env:PATH = $dotnetPath + [IO.Path]::PathSeparator + $env:PATH
+            Add-PSEnvironmentPath -Path $dotnetPath -Prepend
 
             if ($SetDotnetRoot) {
                 Write-Verbose -Verbose "Setting DOTNET_ROOT to $dotnetPath"
-                $env:DOTNET_ROOT = $dotnetPath
+                Set-PSEnvironmentVariable -Name 'DOTNET_ROOT' -Value $dotnetPath
             }
         } elseif ($SetDotnetRoot) {
             Write-Verbose -Verbose "Expected dotnet version found, setting DOTNET_ROOT to $dotnetPath"
-            $env:DOTNET_ROOT = $dotnetPath
+            Set-PSEnvironmentVariable -Name 'DOTNET_ROOT' -Value $dotnetPath
         }
     }
     else {
         Write-Warning "Could not find 'dotnet', appending $dotnetPath to PATH."
-        $env:PATH += [IO.Path]::PathSeparator + $dotnetPath
+        Add-PSEnvironmentPath -Path $dotnetPath
+
+        if ($SetDotnetRoot) {
+            Write-Verbose -Verbose "Setting DOTNET_ROOT to $dotnetPath"
+            Set-PSEnvironmentVariable -Name 'DOTNET_ROOT' -Value $dotnetPath
+        }
     }
 
     if (-not (precheck 'dotnet' "Still could not find 'dotnet', restoring PATH.")) {
+        # Give up, restore original PATH.  There is nothing to persist since we didn't make a change.
         $env:PATH = $originalPath
     }
+    elseif ($SetDotnetRoot) {
+        # If we found dotnet, also add the global tools path to PATH
+        # Add .NET global tools to PATH when setting up the environment
+        $dotnetToolsPath = Join-Path $dotnetPath "tools"
+        if (Test-Path $dotnetToolsPath) {
+            Write-Verbose -Verbose "Adding .NET tools path to PATH: $dotnetToolsPath"
+            Add-PSEnvironmentPath -Path $dotnetToolsPath
+        }
+    }
 }
 
 <#

src/System.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs

@@ -4580,8 +4580,8 @@ internal static IEnumerable<CompletionResult> CompleteFilename(CompletionContext
                     return CommandCompletion.EmptyCompletionResult;
                 }
 
-                var lastAst = context.RelatedAsts[^1];
-                if (lastAst.Parent is UsingStatementAst usingStatement
+                var lastAst = context.RelatedAsts?[^1];
+                if (lastAst?.Parent is UsingStatementAst usingStatement
                     && usingStatement.UsingStatementKind is UsingStatementKind.Module or UsingStatementKind.Assembly
                     && lastAst.Extent.File is not null)
                 {

test/powershell/Host/TabCompletion/BugFix.Tests.ps1

@@ -126,4 +126,27 @@ Describe "Tab completion bug fix" -Tags "CI" {
             $Runspace.Dispose()
         }
     }
+
+    It "Issue#26277 - [CompletionCompleters]::CompleteFilename('') should work" {
+        $testDir = Join-Path $TestDrive "TempTestDir"
+        $file1 = Join-Path $testDir "abc.ps1"
+        $file2 = Join-Path $testDir "def.py"
+
+        New-Item -ItemType Directory -Path $testDir > $null
+        New-Item -ItemType File -Path $file1 > $null
+        New-Item -ItemType File -Path $file2 > $null
+
+        try {
+            Push-Location -Path $testDir
+            $result = [System.Management.Automation.CompletionCompleters]::CompleteFilename("")
+            $result | Should -Not -Be $null
+            $result | Measure-Object | ForEach-Object -MemberName Count | Should -Be 2
+
+            $item1, $item2 = @($result)
+            $item1.ListItemText | Should -BeExactly 'abc.ps1'
+            $item2.ListItemText | Should -BeExactly 'def.py'
+        } finally {
+            Pop-Location
+        }
+    }
 }