From 5bc7629eda277b6c27360287e5adb908646cd3fc Mon Sep 17 00:00:00 2001
From: Northn <57762732+Northn@users.noreply.github.com>
Date: Tue, 5 Jul 2022 11:50:42 +0400
Subject: [PATCH] Lock clipboard before emptying it

According to remark about EmptyDialog(), an application must open the clipboard before emptying it by using the OpenClipboard function. If the application specifies a NULL window handle when opening the clipboard, EmptyClipboard succeeds but sets the clipboard owner to NULL. This can cause SetClipboardData to fail.
https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-emptyclipboard
---
 src/win/ClipboardWin.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/win/ClipboardWin.cpp b/src/win/ClipboardWin.cpp
index cc6bcda..412861b 100644
--- a/src/win/ClipboardWin.cpp
+++ b/src/win/ClipboardWin.cpp
@@ -4,7 +4,10 @@
 namespace ultralight {
 
 void ClipboardWin::Clear() {
+  if (!OpenClipboard(0))
+    return;
   EmptyClipboard();
+  CloseClipboard();
 }
 
 String ClipboardWin::ReadPlainText() {
@@ -55,4 +58,4 @@ void ClipboardWin::WritePlainText(const String& text) {
   CloseClipboard();
 }
 
-}  // namespace ultralight
\ No newline at end of file
+}  // namespace ultralight