From 6295d85ef2546c4ebf454a3d2c79892d23faf50b Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 8 Dec 2017 17:36:17 +0400
Subject: [PATCH] Fix possible assertion violation in PeerListBox.

Very long stack in crash reports leads to something like that:
- PeerListBox::prepare
- PeerListBox::createMultiSelect
- PeerListBox::updateScrollSkips
- BoxContent::setInnerTopSkip
- _scroll->scrollToY
- sendSynteticMouseEvent
- ChatHelpers::TabbedPanel::showAnimated
- QWidget::render
- QWidgetPrivate::sendPendingMoveAndResizeEvents
- PeerListBox::resizeEvent
- _select->resizeToWidth(0)
- MultiSelect::Inner::computeItemsGeometry(0)

Workaround:
- Don't scrollToY if PeerListBox width was not yet set.
- Initial _scrollBottomFixed is false (at first createMultiSelect).
---
 Telegram/SourceFiles/boxes/abstract_box.cpp | 2 +-
 Telegram/SourceFiles/boxes/peer_list_box.h  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Telegram/SourceFiles/boxes/abstract_box.cpp b/Telegram/SourceFiles/boxes/abstract_box.cpp
index 0c46ecedf..33b303266 100644
--- a/Telegram/SourceFiles/boxes/abstract_box.cpp
+++ b/Telegram/SourceFiles/boxes/abstract_box.cpp
@@ -148,7 +148,7 @@ void BoxContent::setInnerTopSkip(int innerTopSkip, bool scrollBottomFixed) {
 	if (_innerTopSkip != innerTopSkip) {
 		auto delta = innerTopSkip - _innerTopSkip;
 		_innerTopSkip = innerTopSkip;
-		if (_scroll) {
+		if (_scroll && width() > 0) {
 			auto scrollTopWas = _scroll->scrollTop();
 			updateScrollAreaGeometry();
 			if (scrollBottomFixed) {
diff --git a/Telegram/SourceFiles/boxes/peer_list_box.h b/Telegram/SourceFiles/boxes/peer_list_box.h
index 09fb6913d..3982d5d41 100644
--- a/Telegram/SourceFiles/boxes/peer_list_box.h
+++ b/Telegram/SourceFiles/boxes/peer_list_box.h
@@ -807,6 +807,6 @@ private:
 
 	std::unique_ptr<PeerListController> _controller;
 	base::lambda<void(PeerListBox*)> _init;
-	bool _scrollBottomFixed = true;
+	bool _scrollBottomFixed = false;
 
 };