From b028af43efbb92ff6cc5413ffb11207481870116 Mon Sep 17 00:00:00 2001
From: Eike Ziller <eike.ziller@qt.io>
Date: Mon, 10 Jan 2022 15:15:58 +0100
Subject: [PATCH] ToolTip: Guard against nullptr access

screenAt(pos) can be nullptr if pos is outside the current screen
configuration. Seems to be possible when screen configurations change.

Fixes: QTCREATORBUG-26019
Change-Id: I5def200b14247e7fbcf62ad68cda991e8c10c9d7
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
---
 src/libs/utils/tooltip/tooltip.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/libs/utils/tooltip/tooltip.cpp b/src/libs/utils/tooltip/tooltip.cpp
index 681524372d1..60f10f5d71a 100644
--- a/src/libs/utils/tooltip/tooltip.cpp
+++ b/src/libs/utils/tooltip/tooltip.cpp
@@ -156,7 +156,10 @@ void ToolTip::show(
     if (content && content->count()) {
         auto tooltipWidget = new FakeToolTip;
         // limit the size of the widget to 90% of the screen size to have some context around it
-        tooltipWidget->setMaximumSize(QGuiApplication::screenAt(pos)->availableSize() * 0.9);
+        QScreen *qscreen = QGuiApplication::screenAt(pos);
+        if (!qscreen)
+            qscreen = QGuiApplication::primaryScreen();
+        tooltipWidget->setMaximumSize(qscreen->availableSize() * 0.9);
         if (contextHelp.isNull()) {
             tooltipWidget->setLayout(content);
         } else {