From 5679d4807367e7341a0ac8dd4758d762d302e6d8 Mon Sep 17 00:00:00 2001
From: Manuel Serra <nitroin@hotmail.com>
Date: Fri, 18 Jun 2021 16:53:23 +0200
Subject: [PATCH] Fix `CurrentVirtualDesktop` fetching from registry (#11760)

* fix(#11125): fallback to canonical regkey session unaware

* chore(#11125): use wil::unique_hkey instead of HKEY for fallback CurrentVirtualDesktop

* refactor: extract new explorer current virtual desktop behavior into a separate method
---
 .../fancyzones/lib/VirtualDesktopUtils.cpp    | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/modules/fancyzones/lib/VirtualDesktopUtils.cpp b/src/modules/fancyzones/lib/VirtualDesktopUtils.cpp
index 50491529b6..136eaa0d61 100644
--- a/src/modules/fancyzones/lib/VirtualDesktopUtils.cpp
+++ b/src/modules/fancyzones/lib/VirtualDesktopUtils.cpp
@@ -51,6 +51,23 @@ namespace VirtualDesktopUtils
         return SUCCEEDED(CLSIDFromString(virtualDesktopId.c_str(), desktopId));
     }
 
+    bool NewGetCurrentDesktopId(GUID* desktopId)
+    {
+        wil::unique_hkey key{};
+        if (RegOpenKeyExW(HKEY_CURRENT_USER, NonLocalizable::RegKeyVirtualDesktops, 0, KEY_ALL_ACCESS, &key) == ERROR_SUCCESS)
+        {
+            GUID value{};
+            DWORD size = sizeof(GUID);
+            if (RegQueryValueExW(key.get(), NonLocalizable::RegCurrentVirtualDesktop, 0, nullptr, reinterpret_cast<BYTE*>(&value), &size) == ERROR_SUCCESS)
+            {
+                *desktopId = value;
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     bool GetDesktopIdFromCurrentSession(GUID* desktopId)
     {
         DWORD sessionId;
@@ -76,11 +93,19 @@ namespace VirtualDesktopUtils
                 return true;
             }
         }
+
         return false;
     }
 
     bool GetCurrentVirtualDesktopId(GUID* desktopId)
     {
+        // On newer Windows builds, the current virtual desktop is persisted to
+        // a totally different reg key. Look there first.
+        if (NewGetCurrentDesktopId(desktopId))
+        {
+            return true;
+        }
+
         // Explorer persists current virtual desktop identifier to registry on a per session basis, but only
         // after first virtual desktop switch happens. If the user hasn't switched virtual desktops in this
         // session, value in registry will be empty.