From e5aeb674c04755f7fdeffd6d93237f68723f107d Mon Sep 17 00:00:00 2001
From: David Redondo <kde@david-redondo.de>
Date: Thu, 18 Aug 2022 10:05:00 +0200
Subject: [PATCH] Floor coordinates to check if a point is inside a region

More correct since QRegion models half open intervals (like QRect) and toPoint
rounds the coordinates. Fixes an issue where one could escape a pointer
confinement by just moving the mouse.
---
 src/input.cpp                     |  4 +++-
 src/pointer_input.cpp             | 13 ++++++++++---
 src/wayland/surface_interface.cpp |  2 +-
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/input.cpp b/src/input.cpp
index 5651e6e49c..6eb8cf44e0 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -70,6 +70,8 @@
 
 #include <xkbcommon/xkbcommon.h>
 
+#include <cmath>
+
 namespace KWin
 {
 
@@ -3440,7 +3442,7 @@ void InputDeviceHandler::updateDecoration()
     Decoration::DecoratedClientImpl *decoration = nullptr;
     auto hover = m_hover.window.data();
     if (hover && hover->decoratedClient()) {
-        if (!hover->clientGeometry().toRect().contains(position().toPoint())) {
+        if (!hover->clientGeometry().toRect().contains(QPoint(std::floor(position().x()), std::floor(position().y())))) {
             // input device above decoration
             decoration = hover->decoratedClient();
         }
diff --git a/src/pointer_input.cpp b/src/pointer_input.cpp
index 12d26bbaf5..3bc3a5f441 100644
--- a/src/pointer_input.cpp
+++ b/src/pointer_input.cpp
@@ -45,6 +45,8 @@
 
 #include <linux/input.h>
 
+#include <cmath>
+
 namespace KWin
 {
 
@@ -770,18 +772,23 @@ QPointF PointerInputRedirection::applyPointerConfinement(const QPointF &pos) con
         return pos;
     }
 
+    auto floorPoint = [](const QPointF &point) {
+        return QPoint(std::floor(point.x()), std::floor(point.y()));
+    };
+
     const QRegion confinementRegion = getConstraintRegion(focus(), cf);
-    if (confinementRegion.contains(pos.toPoint())) {
+    if (confinementRegion.contains(floorPoint(pos))) {
         return pos;
     }
     QPointF p = pos;
     // allow either x or y to pass
     p = QPointF(m_pos.x(), pos.y());
-    if (confinementRegion.contains(p.toPoint())) {
+
+    if (confinementRegion.contains(floorPoint(p))) {
         return p;
     }
     p = QPointF(pos.x(), m_pos.y());
-    if (confinementRegion.contains(p.toPoint())) {
+    if (confinementRegion.contains(floorPoint(p))) {
         return p;
     }
 
diff --git a/src/wayland/surface_interface.cpp b/src/wayland/surface_interface.cpp
index f3869f7c05..8d884cfee7 100644
--- a/src/wayland/surface_interface.cpp
+++ b/src/wayland/surface_interface.cpp
@@ -772,7 +772,7 @@ bool SurfaceInterfacePrivate::contains(const QPointF &position) const
 
 bool SurfaceInterfacePrivate::inputContains(const QPointF &position) const
 {
-    return contains(position) && inputRegion.contains(position.toPoint());
+    return contains(position) && inputRegion.contains(QPoint(std::floor(position.x()), std::floor(position.y())));
 }
 
 QRegion SurfaceInterface::damage() const