From d5ec7cc296a074e8e2247ffc825c6d5c8647ed48 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Wed, 28 Sep 2022 15:47:42 +0400
Subject: [PATCH] Fix possible stack overflow crash on Windows.

---
 ui/widgets/time_input.cpp | 35 +++++++++++++++++++++++++++++++++--
 ui/widgets/time_input.h   |  1 +
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/ui/widgets/time_input.cpp b/ui/widgets/time_input.cpp
index d51a77b..d40aa26 100644
--- a/ui/widgets/time_input.cpp
+++ b/ui/widgets/time_input.cpp
@@ -7,6 +7,7 @@
 #include "ui/widgets/time_input.h"
 
 #include "ui/widgets/fields/time_part_input.h"
+#include "base/invoke_queued.h"
 
 #include <QtCore/QRegularExpression>
 #include <QTime>
@@ -146,7 +147,7 @@ void TimeInput::putNext(const object_ptr<TimePart> &field, QChar ch) {
 		field->setCursorPosition(1);
 	}
 	field->onTextEdited();
-	field->setFocus();
+	setFocusQueued(field);
 }
 
 void TimeInput::erasePrevious(const object_ptr<TimePart> &field) {
@@ -155,7 +156,37 @@ void TimeInput::erasePrevious(const object_ptr<TimePart> &field) {
 		field->setCursorPosition(text.size() - 1);
 		field->setText(text.mid(0, text.size() - 1));
 	}
-	field->setFocus();
+	setFocusQueued(field);
+}
+
+void TimeInput::setFocusQueued(const object_ptr<TimePart> &field) {
+	// There was a "Stack Overflow" crash in some input method handling.
+	//
+	// See https://github.com/telegramdesktop/tdesktop/issues/25129
+	//
+	// The stack is something like:
+	//
+	// ...
+	// QApplicationPrivate::sendMouseEvent
+	// ----
+	// QWidget::setFocus
+	// QWindow::focusObjectChanged
+	// QWindowsInputContext::setFocusObject
+	// QWindowsInputContext::reset
+	// QLineEdit::inputMethodEvent
+	// QWidgetLineControl::finishChange
+	// QLineEdit::textEdited
+	// MaskedInputField::onTextEdited
+	// TimePart::correctValue
+	// TimeInput::putNext
+	// ----
+	// QWidget::setFocus
+	// QWindow::focusObjectChanged
+	// ...
+	//
+	// So we try to break this loop by focusing the widget async.
+	const auto raw = field.data();
+	InvokeQueued(raw, [raw] { raw->setFocus(); });
 }
 
 bool TimeInput::setFocusFast() {
diff --git a/ui/widgets/time_input.h b/ui/widgets/time_input.h
index e8edd5a..3bd9aec 100644
--- a/ui/widgets/time_input.h
+++ b/ui/widgets/time_input.h
@@ -43,6 +43,7 @@ private:
 	void setInnerFocus();
 	void putNext(const object_ptr<TimePart> &field, QChar ch);
 	void erasePrevious(const object_ptr<TimePart> &field);
+	void setFocusQueued(const object_ptr<TimePart> &field);
 	void setErrorShown(bool error);
 	void setFocused(bool focused);
 	void startBorderAnimation();