[PT Run][Folder]Support for paths with / (#18520)

src/modules/launcher/Plugins/Microsoft.Plugin.Folder.UnitTests/InternalQueryFolderTests.cs

@@ -52,6 +52,7 @@ namespace Microsoft.Plugin.Folder.UnitTests
         [DataRow(@"c:\not-exist", 2, 1, false, DisplayName = "Folder not exist, return root")]
         [DataRow(@"c:\not-exist\not-exist2", 0, 0, false, DisplayName = "Folder not exist, return root")]
         [DataRow(@"c:\bla.t", 2, 1, false, DisplayName = "Partial match file")]
+        [DataRow(@"c:/bla.t", 2, 1, false, DisplayName = "Partial match file with /")]
         public void Query_WhenCalled(string search, int folders, int files, bool truncated)
         {
             const int maxFolderSetting = 3;

src/modules/launcher/Plugins/Microsoft.Plugin.Folder/Sources/Path/FolderHelper.cs

@@ -84,7 +84,9 @@ namespace Microsoft.Plugin.Folder.Sources
                 throw new ArgumentNullException(nameof(search));
             }
 
-            if (search[0] == '\\' && (search.Length == 1 || search[1] != '\\'))
+            var validRoots = new char[] { '\\', '/' };
+
+            if (validRoots.Contains(search[0]) && (search.Length == 1 || !validRoots.Contains(search[1])))
             {
                 // Absolute path of system drive: \Windows\System32
                 search = Path.Combine(Path.GetPathRoot(Environment.SystemDirectory), search.Substring(1));

src/modules/launcher/Plugins/Microsoft.Plugin.Folder/Sources/QueryInternalDirectory.cs

@@ -52,7 +52,7 @@ namespace Microsoft.Plugin.Folder.Sources
             {
                 // if folder doesn't exist, we want to take the last part and use it afterwards to help the user
                 // find the right folder.
-                int index = search.LastIndexOf('\\');
+                int index = search.LastIndexOfAny(new char[] { '\\', '/' });
 
                 // No slashes found, so probably not a folder
                 if (index <= 0 || index >= search.Length - 1)