From 26b41d025b55fc809fd28461968cf5e6779e29f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20Ni=C3=9Fl?= <unknown>
Date: Thu, 18 Jan 2024 09:11:07 +1100
Subject: Use the multi-threaded option to Direct2D to avoid crashes when
 Scintilla instances created on different threads.

---
 doc/ScintillaHistory.html | 5 +++++
 win32/PlatWin.cxx         | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index 34013fe70..67f26fb3d 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -594,6 +594,11 @@
 	For ScintillaEdit on Qt, fix reference from ScintillaDocument to Document to match change in 5.4.1
 	using IDocumentEditable for SCI_GETDOCPOINTER and SCI_SETDOCPOINTER.
 	</li>
+	<li>
+	For Direct2D on Win32, use the multi-threaded option to avoid crashes when Scintilla instances
+	created on different threads. There may be more problems with this scenario so it should be avoided.
+	<a href="https://sourceforge.net/p/scintilla/bugs/2420/">Bug #2420</a>.
+	</li>
     </ul>
     <h3>
        <a href="https://www.scintilla.org/scintilla541.zip">Release 5.4.1</a>
diff --git a/win32/PlatWin.cxx b/win32/PlatWin.cxx
index 91af4a683..57d26a36a 100644
--- a/win32/PlatWin.cxx
+++ b/win32/PlatWin.cxx
@@ -98,8 +98,8 @@ void LoadD2DOnce() noexcept {
 	hDLLD2D = ::LoadLibraryEx(TEXT("D2D1.DLL"), 0, loadLibraryFlags);
 	D2D1CFSig fnD2DCF = DLLFunction<D2D1CFSig>(hDLLD2D, "D2D1CreateFactory");
 	if (fnD2DCF) {
-		// A single threaded factory as Scintilla always draw on the GUI thread
-		fnD2DCF(D2D1_FACTORY_TYPE_SINGLE_THREADED,
+		// A multi threaded factory in case Scintilla is used with multiple GUI threads
+		fnD2DCF(D2D1_FACTORY_TYPE_MULTI_THREADED,
 			__uuidof(ID2D1Factory),
 			nullptr,
 			reinterpret_cast<IUnknown**>(&pD2DFactory));
-- 
cgit v1.2.3