[thanos] Fixed UAF in allDone callback via weak_ptr guard.

Telegram/SourceFiles/ui/effects/thanos_effect.cpp

@@ -151,10 +151,12 @@ void ThanosEffect::ensureSurface() {
 		std::move(devicePixelRatio));
 	_renderer = renderer.get();
 
-	_renderer->allDone() | rpl::on_next([=] {
-		crl::on_main(_parent, [=] {
-			hideSurface();
-			_allDone.fire({});
+	_renderer->allDone() | rpl::on_next([weak = base::make_weak(this)] {
+		crl::on_main(weak, [weak] {
+			if (const auto strong = weak.get()) {
+				strong->hideSurface();
+				strong->_allDone.fire({});
+			}
 		});
 	}, _lifetime);
 

Telegram/SourceFiles/ui/effects/thanos_effect.h

@@ -8,6 +8,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #pragma once
 
 #include "base/unique_qptr.h"
+#include "base/weak_ptr.h"
 
 #include <QImage>
 
@@ -20,7 +21,7 @@ namespace Ui {
 
 class ThanosEffectRenderer;
 
-class ThanosEffect final {
+class ThanosEffect final : public base::has_weak_ptr {
 public:
 	explicit ThanosEffect(not_null<QWidget*> parent);
 	~ThanosEffect();