From bc7139d67af4377ea5432dfbd4374ad87cfe1c99 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 14 Apr 2017 15:12:40 +0300
Subject: [PATCH] Fix crash in AuthSession::Exists() if there is no Messenger.

Also use toggleAnimated instead of show/hideAnimated in intro.
---
 Telegram/SourceFiles/auth_session.cpp      |  5 ++++-
 Telegram/SourceFiles/intro/introwidget.cpp | 20 ++++++--------------
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/Telegram/SourceFiles/auth_session.cpp b/Telegram/SourceFiles/auth_session.cpp
index f3b614b8c7..70d5a84bf6 100644
--- a/Telegram/SourceFiles/auth_session.cpp
+++ b/Telegram/SourceFiles/auth_session.cpp
@@ -93,7 +93,10 @@ AuthSession::AuthSession(UserId userId)
 }
 
 bool AuthSession::Exists() {
-	return (Messenger::Instance().authSession() != nullptr);
+	if (auto messenger = Messenger::InstancePointer()) {
+		return (messenger->authSession() != nullptr);
+	}
+	return false;
 }
 
 AuthSession &AuthSession::Current() {
diff --git a/Telegram/SourceFiles/intro/introwidget.cpp b/Telegram/SourceFiles/intro/introwidget.cpp
index a094a3ee97..59b046d518 100644
--- a/Telegram/SourceFiles/intro/introwidget.cpp
+++ b/Telegram/SourceFiles/intro/introwidget.cpp
@@ -153,20 +153,12 @@ void Widget::historyMove(Direction direction) {
 	if (direction == Direction::Back || direction == Direction::Replace) {
 		delete base::take(wasStep);
 	}
-	if (getStep()->hasBack()) {
-		_back->showAnimated();
-	} else {
-		_back->hideAnimated();
-	}
-	if (getStep()->hasCover()) {
-		_settings->hideAnimated();
-		if (_update) _update->hideAnimated();
-		if (_changeLanguage) _changeLanguage->showAnimated();
-	} else {
-		_settings->showAnimated();
-		if (_update) _update->showAnimated();
-		if (_changeLanguage) _changeLanguage->hideAnimated();
-	}
+	_back->toggleAnimated(getStep()->hasBack());
+
+	auto stepHasCover = getStep()->hasCover();
+	_settings->toggleAnimated(!stepHasCover);
+	if (_update) _update->toggleAnimated(!stepHasCover);
+	if (_changeLanguage) _changeLanguage->toggleAnimated(stepHasCover);
 	_next->setText(getStep()->nextButtonText());
 	if (_resetAccount) _resetAccount->hideAnimated();
 	getStep()->showAnimated(direction);