Fix tab completion for filename contains literal wildcard character

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

@@ -4383,6 +4383,12 @@ internal static IEnumerable<CompletionResult> CompleteFilename(CompletionContext
                         if (CompletionRequiresQuotes(completionText, !useLiteralPath))
                         {
                             var quoteInUse = quote == string.Empty ? "'" : quote;
+
+                            if (!useLiteralPath)
+                            {
+                                completionText = WildcardPattern.Escape(completionText);
+                            }
+
                             if (quoteInUse == "'")
                             {
                                 completionText = completionText.Replace("'", "''");
@@ -4395,20 +4401,6 @@ internal static IEnumerable<CompletionResult> CompleteFilename(CompletionContext
                                 completionText = completionText.Replace("$", "`$");
                             }
 
-                            if (!useLiteralPath)
-                            {
-                                if (quoteInUse == "'")
-                                {
-                                    completionText = completionText.Replace("[", "`[");
-                                    completionText = completionText.Replace("]", "`]");
-                                }
-                                else
-                                {
-                                    completionText = completionText.Replace("[", "``[");
-                                    completionText = completionText.Replace("]", "``]");
-                                }
-                            }
-
                             completionText = quoteInUse + completionText + quoteInUse;
                         }
                         else if (quote != string.Empty)

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs

@@ -114,6 +114,9 @@ static ExperimentalFeature()
                 new ExperimentalFeature(
                     name: "PSCommandNotFoundSuggestion",
                     description: "Recommend potential commands based on fuzzy search on a CommandNotFoundException"),
+                new ExperimentalFeature(
+                    name: "PSWildcardEscapeEscape",
+                    description: "Fix WildcardPattern API: escape the escape character"),
             };
             EngineExperimentalFeatures = new ReadOnlyCollection<ExperimentalFeature>(engineFeatures);
 

src/System.Management.Automation/engine/regex.cs

@@ -194,15 +194,28 @@ internal static string Escape(string pattern, char[] charsNotToEscape)
 
             char[] temp = new char[pattern.Length * 2 + 1];
             int tempIndex = 0;
+            bool charNeedsEscaping = false;
 
             for (int i = 0; i < pattern.Length; i++)
             {
                 char ch = pattern[i];
 
-                //
-                // if it is a wildcard char, escape it
-                //
-                if (IsWildcardChar(ch) && !charsNotToEscape.Contains(ch))
+                if (ExperimentalFeature.IsEnabled("PSWildcardEscapeEscape"))
+                {
+                    //
+                    // if it is a wildcard char or escape char, escape it
+                    //
+                    charNeedsEscaping = IsWildcardChar(ch) || ch == escapeChar;
+                }
+                else
+                {
+                    //
+                    // if it is a wildcard char, escape it
+                    //
+                    charNeedsEscaping = IsWildcardChar(ch);
+                }
+
+                if (charNeedsEscaping && !charsNotToEscape.Contains(ch))
                 {
                     temp[tempIndex++] = escapeChar;
                 }

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

@@ -3363,13 +3363,11 @@ internal static string RemoveProviderQualifier(string path)
                 StringContainsGlobCharacters(leafElement) ||
                 isLastLeaf)
             {
-                string regexEscapedLeafElement = ConvertMshEscapeToRegexEscape(leafElement);
-
                 // Construct the glob filter
 
                 WildcardPattern stringMatcher =
                     WildcardPattern.Get(
-                        regexEscapedLeafElement,
+                        leafElement,
                         WildcardOptions.IgnoreCase);
 
                 // Construct the include filter
@@ -3969,13 +3967,11 @@ internal static string RemoveProviderQualifier(string path)
                 (StringContainsGlobCharacters(leafElement) ||
                  isLastLeaf))
             {
-                string regexEscapedLeafElement = ConvertMshEscapeToRegexEscape(leafElement);
-
                 // Construct the glob filter
 
                 WildcardPattern stringMatcher =
                     WildcardPattern.Get(
-                        regexEscapedLeafElement,
+                        leafElement,
                         WildcardOptions.IgnoreCase);
 
                 // Construct the include filter

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

@@ -882,6 +882,9 @@ dir -Recurse `
                 @{ inputStr = "Get-Process >'.\My ``[Path``]\'"; expected = "'.${separator}My ``[Path``]${separator}test.ps1'" }
                 @{ inputStr = "Get-Process >${tempDir}\My"; expected = "'${tempDir}${separator}My ``[Path``]'" }
                 @{ inputStr = "Get-Process > '${tempDir}\My ``[Path``]\'"; expected = "'${tempDir}${separator}My ``[Path``]${separator}test.ps1'" }
+                @{ inputStr = "Set-Location -Path 'My ``["; expected = "'.${separator}My ``[Path``]'" }
+                @{ inputStr = "Get-Process > 'My ``["; expected = "'.${separator}My ``[Path``]'" }
+                @{ inputStr = "Get-Process > '${tempDir}\My ``["; expected = "'${tempDir}${separator}My ``[Path``]'" }
             )
 
             Push-Location -Path $tempDir

test/powershell/engine/Api/WildcardPattern.Tests.ps1

@@ -0,0 +1,68 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+Describe "WildcardPattern Escape - Experimental-Feature-Disabled" -Tags "CI" {
+
+    BeforeAll {
+        $testName = 'PSWildcardEscapeEscape'
+        $skipTest = $EnabledExperimentalFeatures.Contains($testName)
+
+        if ($skipTest) {
+            Write-Verbose "Test Suite Skipped. The test suite requires the experimental feature '$testName' to be disabled." -Verbose
+            $originalDefaultParameterValues = $PSDefaultParameterValues.Clone()
+            $PSDefaultParameterValues["it:skip"] = $true
+        }
+    }
+
+    AfterAll {
+        if ($skipTest) {
+            $global:PSDefaultParameterValues = $originalDefaultParameterValues
+        }
+    }
+
+    It "Unescaping '<escapedStr>' which escaped from '<inputStr>' should get the original" -TestCases @(
+        @{inputStr = '*This'; escapedStr = '`*This'}
+        @{inputStr = 'Is?'; escapedStr = 'Is`?'}
+        @{inputStr = 'Real[ly]'; escapedStr = 'Real`[ly`]'}
+        @{inputStr = 'Ba`sic'; escapedStr = 'Ba`sic'}
+        @{inputStr = 'Test `[more`]?'; escapedStr = 'Test ``[more``]`?'}
+    ) {
+        param($inputStr, $escapedStr)
+
+        [WildcardPattern]::Escape($inputStr) | Should -BeExactly $escapedStr
+        [WildcardPattern]::Unescape($escapedStr) | Should -BeExactly $inputStr
+    }
+}
+
+Describe "WildcardPattern Escape - Experimental-Feature-Enabled" -Tags "CI" {
+
+    BeforeAll {
+        $testName = 'PSWildcardEscapeEscape'
+        $skipTest = -not $EnabledExperimentalFeatures.Contains($testName)
+
+        if ($skipTest) {
+            Write-Verbose "Test Suite Skipped. The test suite requires the experimental feature '$testName' to be enabled." -Verbose
+            $originalDefaultParameterValues = $PSDefaultParameterValues.Clone()
+            $PSDefaultParameterValues["it:skip"] = $true
+        }
+    }
+
+    AfterAll {
+        if ($skipTest) {
+            $global:PSDefaultParameterValues = $originalDefaultParameterValues
+        }
+    }
+
+    It "Unescaping '<escapedStr>' which escaped from '<inputStr>' should get the original" -TestCases @(
+        @{inputStr = '*This'; escapedStr = '`*This'}
+        @{inputStr = 'Is?'; escapedStr = 'Is`?'}
+        @{inputStr = 'Real[ly]'; escapedStr = 'Real`[ly`]'}
+        @{inputStr = 'Ba`sic'; escapedStr = 'Ba``sic'}
+        @{inputStr = 'Test `[more`]?'; escapedStr = 'Test ```[more```]`?'}
+    ) {
+        param($inputStr, $escapedStr)
+
+        [WildcardPattern]::Escape($inputStr) | Should -BeExactly $escapedStr
+        [WildcardPattern]::Unescape($escapedStr) | Should -BeExactly $inputStr
+    }
+}

test/tools/TestMetadata.json

@@ -1,6 +1,7 @@
 {
   "ExperimentalFeatures": {
     "Microsoft.PowerShell.Utility.PSDebugRunspaceWithBreakpoints": ["test/powershell/Modules/Microsoft.PowerShell.Utility/New-PSBreakpoint.Tests.ps1"],
+    "PSWildcardEscapeEscape": [ "test/powershell/engine/Api/WildcardPattern.Tests.ps1" ],
     "ExpTest.FeatureOne": [ "test/powershell/engine/ExperimentalFeature/ExperimentalFeature.Basic.Tests.ps1" ]
   }
 }