Fix Resolve-Path -Relative output for dot-prefixed names (#28087)

src/Microsoft.PowerShell.Commands.Management/commands/management/ResolvePathCommand.cs

@@ -117,6 +117,19 @@ namespace Microsoft.PowerShell.Commands
 
         #endregion parameter data
 
+        private static bool StartsWithRelativePathToken(string path, ProviderInfo provider)
+        {
+            if (path.Length == 0 || path[0] != '.')
+            {
+                return false;
+            }
+
+            int separatorIndex = path.Length > 1 && path[1] == '.' ? 2 : 1;
+            return path.Length == separatorIndex ||
+                path[separatorIndex] == provider.ItemSeparator ||
+                path[separatorIndex] == provider.AltItemSeparator;
+        }
+
         #region Command code
 
         /// <summary>
@@ -233,7 +246,7 @@ namespace Microsoft.PowerShell.Commands
                             // Do not insert './' if result path is not relative
                             if (!adjustedPath.StartsWith(
                                     currentPath.Drive?.Root ?? currentPath.Path, StringComparison.OrdinalIgnoreCase) &&
-                                !adjustedPath.StartsWith('.'))
+                                !StartsWithRelativePathToken(adjustedPath, currentPath.Provider))
                             {
                                 adjustedPath = SessionState.Path.Combine(".", adjustedPath);
                             }

test/powershell/Modules/Microsoft.PowerShell.Management/Resolve-Path.Tests.ps1

@@ -67,6 +67,31 @@ Describe "Resolve-Path returns proper path" -Tag "CI" {
             Pop-Location
         }
     }
+
+    It "Resolve-Path -Relative prepends the current directory to every result" {
+        $directoryNames = ".directory", "..directory", "directory"
+        foreach ($directoryName in $directoryNames) {
+            $directory = New-Item -Path (Join-Path $TestDrive $directoryName) -ItemType Directory
+            $null = New-Item -Path $directory -Name "file1.txt" -ItemType File
+            $null = New-Item -Path $directory -Name "file2.txt" -ItemType File
+        }
+
+        try {
+            Push-Location -Path $TestDrive
+            foreach ($directoryName in $directoryNames) {
+                $expected = @(
+                    Join-Path "." $directoryName "file1.txt"
+                    Join-Path "." $directoryName "file2.txt"
+                )
+                Resolve-Path -Path (Join-Path $directoryName "*.txt") -Relative |
+                    Should -BeExactly $expected
+            }
+        }
+        finally {
+            Pop-Location
+        }
+    }
+
     It 'Resolve-Path RelativeBasePath should handle <Scenario>' -TestCases @(
         @{
             Scenario = "Absolute Path, Absolute ReleativeBasePath"