Fixed issue #641 - Unexpected behaviour with tab drag on scrollable tab bar

Author: githubuser0xFFFF

src/DockAreaTabBar.cpp

@@ -390,15 +390,18 @@ void CDockAreaTabBar::onTabWidgetMoved(const QPoint& GlobalPos)
 
 	int fromIndex = d->TabsLayout->indexOf(MovingTab);
 	auto MousePos = mapFromGlobal(GlobalPos);
-	MousePos.rx() = qMax(d->firstTab()->geometry().left(), MousePos.x());
-	MousePos.rx() = qMin(d->lastTab()->geometry().right(), MousePos.x());
+	MousePos.rx() = qMax(0, MousePos.x());
+	MousePos.rx() = qMin(width(), MousePos.x());
 	int toIndex = -1;
 	// Find tab under mouse
 	for (int i = 0; i < count(); ++i)
 	{
 		CDockWidgetTab* DropTab = tab(i);
+		auto TabGeometry = DropTab->geometry();
+		TabGeometry.setTopLeft(d->TabsContainerWidget->mapToParent(TabGeometry.topLeft()));
+		TabGeometry.setBottomRight(d->TabsContainerWidget->mapToParent(TabGeometry.bottomRight()));
 		if (DropTab == MovingTab || !DropTab->isVisibleTo(this)
-		    || !DropTab->geometry().contains(MousePos))
+		    || !TabGeometry.contains(MousePos))
 		{
 			continue;
 		}