Fix New-Item to work correctly when given path is drive root and $PWD is a sub folder of the drive root. (#6600)

src/System.Management.Automation/namespaces/LocationGlobber.cs

@@ -2013,6 +2013,9 @@ namespace System.Management.Automation
             // Check to see if the path is relative or absolute
             bool isPathForCurrentDrive = false;
 
+            // Check to see if the path is to the root of a drive
+            bool isPathForRootOfDrive = false;
+
             if (IsAbsolutePath(path, out driveName))
             {
                 Dbg.Diagnostics.Assert(
@@ -2080,6 +2083,12 @@ namespace System.Management.Automation
                         // this is the default behavior for all windows drives, and all non-filesystem
                         // drives on non-windows
                         path = path.Substring(driveName.Length + 1);
+
+                        if (String.IsNullOrEmpty(path))
+                        {
+                            // path was to the root of a drive such as 'c:'
+                            isPathForRootOfDrive = true;
+                        }
                     }
                 }
             }
@@ -2111,14 +2120,23 @@ namespace System.Management.Automation
                 // have access to it.
                 context.Drive = workingDriveForPath;
 
-                string relativePath =
-                    GenerateRelativePath(
-                        workingDriveForPath,
-                        path,
-                        escapeCurrentLocation,
-                        providerInstance,
-                        context);
+                string relativePath = String.Empty;
 
+                if (isPathForRootOfDrive)
+                {
+                    relativePath = context.Drive.Root;
+                }
+                else
+                {
+                    relativePath =
+                        GenerateRelativePath(
+                            workingDriveForPath,
+                            path,
+                            escapeCurrentLocation,
+                            providerInstance,
+                            context);
+                }
+                
                 return relativePath;
             }
             catch (PSNotSupportedException)

test/powershell/Modules/Microsoft.PowerShell.Management/New-Item.Tests.ps1

@@ -117,6 +117,33 @@ Describe "New-Item" -Tags "CI" {
         $fileInfo.Target | Should -BeNullOrEmpty
         $fileInfo.LinkType | Should -BeExactly "HardLink"
     }
+
+    It "Should create a file at the root of the drive while the current working directory is not the root" {
+        try {
+            New-Item -Name $testfolder -Path "TestDrive:\" -ItemType directory > $null
+            Push-Location -Path "TestDrive:\$testfolder"
+            New-Item -Name $testfile -Path "TestDrive:\" -ItemType file > $null
+            $FullyQualifiedFile | Should -Exist
+        }
+        finally {
+            Pop-Location
+        }
+    }
+
+    It "Should create a folder at the root of the drive while the current working directory is not the root" {
+        $testfolder2 = "newDirectory2"
+        $FullyQualifiedFolder2 = Join-Path -Path $tmpDirectory -ChildPath $testfolder2
+
+        try {
+            New-Item -Name $testfolder -Path "TestDrive:\" -ItemType directory > $null
+            Push-Location -Path "TestDrive:\$testfolder"
+            New-Item -Name $testfolder2 -Path "TestDrive:\" -ItemType directory > $null
+            $FullyQualifiedFolder2 | Should -Exist
+        }
+        finally {
+            Pop-Location
+        }
+    }
 }
 
 # More precisely these tests require SeCreateSymbolicLinkPrivilege.
@@ -186,7 +213,7 @@ Describe "New-Item with links" -Tags @('CI', 'RequireAdminOnWindows') {
     }
 
     It "New-Item -ItemType SymbolicLink should understand directory path ending with slash" {
-        $folderName = [System.IO.Path]::GetRandomFileName()            
+        $folderName = [System.IO.Path]::GetRandomFileName()
         $symbolicLinkPath = New-Item -ItemType SymbolicLink -Path "$tmpDirectory/$folderName/" -Value "/bar/"
         $symbolicLinkPath | Should -Not -BeNullOrEmpty
     }