From d5dfa3ef5e2f603db4fc2388a29719839217a62d Mon Sep 17 00:00:00 2001
From: Seungha Yang <seungha@centricular.com>
Date: Fri, 30 May 2025 00:07:25 +0900
Subject: [PATCH] d3d12screencapturesrc: Fix desktop handle leak

Calling CloseDesktop() on a handle that is currently in use will fail.
Close the handle after current desktop handle change

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/9136>
---
 .../gst-plugins-bad/sys/d3d12/gstd3d12dxgicapture.cpp  | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/subprojects/gst-plugins-bad/sys/d3d12/gstd3d12dxgicapture.cpp b/subprojects/gst-plugins-bad/sys/d3d12/gstd3d12dxgicapture.cpp
index 1ecf94acf0..fa9ad5ea9c 100644
--- a/subprojects/gst-plugins-bad/sys/d3d12/gstd3d12dxgicapture.cpp
+++ b/subprojects/gst-plugins-bad/sys/d3d12/gstd3d12dxgicapture.cpp
@@ -429,13 +429,13 @@ public:
       }
     }
 
-    HDESK hdesk = OpenInputDesktop (0, FALSE, GENERIC_ALL);
+    auto prev_hdesk = GetThreadDesktop (GetCurrentThreadId ());
+    auto hdesk = OpenInputDesktop (0, FALSE, GENERIC_ALL);
     if (hdesk) {
       if (!SetThreadDesktop (hdesk)) {
         GST_WARNING ("SetThreadDesktop() failed, error %lu", GetLastError());
       }
 
-      CloseDesktop (hdesk);
     } else {
       GST_WARNING ("OpenInputDesktop() failed, error %lu", GetLastError());
     }
@@ -469,6 +469,12 @@ public:
     if (FAILED (hr))
       hr = output1->DuplicateOutput(device, &dupl_);
 
+    if (prev_hdesk)
+      SetThreadDesktop (prev_hdesk);
+
+    if (hdesk)
+      CloseDesktop (hdesk);
+
     if (FAILED (hr)) {
       if (hr == DXGI_ERROR_NOT_CURRENTLY_AVAILABLE) {
         GST_ERROR ("Hit the max allowed number of Desktop Duplication session");