From 6faf4ec3a2c519b7d20325ed4eeb9d4993c3cd2f Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Sat, 30 Oct 2021 12:54:19 +0300
Subject: [PATCH] Make mapping between outputs and cached screen geometries in
 Workspace robust

Integer screen ids are not robust. On the other hand, AbstractOutput
does not change if an output has been connected or disconnected.
---
 src/workspace.cpp | 8 ++++----
 src/workspace.h   | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/workspace.cpp b/src/workspace.cpp
index e4ae1ae18f..1698ad7fcb 100644
--- a/src/workspace.cpp
+++ b/src/workspace.cpp
@@ -2091,11 +2091,11 @@ void Workspace::desktopResized()
 void Workspace::saveOldScreenSizes()
 {
     olddisplaysize = m_geometry.size();
-    oldscreensizes.clear();
+    m_oldScreenGeometries.clear();
 
     const auto outputs = kwinApp()->platform()->enabledOutputs();
     for (const AbstractOutput *output : outputs) {
-        oldscreensizes.append(output->geometry());
+        m_oldScreenGeometries.insert(output, output->geometry());
     }
 }
 
@@ -2405,9 +2405,9 @@ QRegion Workspace::previousRestrictedMoveArea(const VirtualDesktop *desktop, Str
     return strutsToRegion(areas, m_oldRestrictedAreas[desktop]);
 }
 
-QVector< QRect > Workspace::previousScreenSizes() const
+QHash<const AbstractOutput *, QRect> Workspace::previousScreenSizes() const
 {
-    return oldscreensizes;
+    return m_oldScreenGeometries;
 }
 
 int Workspace::oldDisplayWidth() const
diff --git a/src/workspace.h b/src/workspace.h
index 1157ce6dbb..d3bc39f63e 100644
--- a/src/workspace.h
+++ b/src/workspace.h
@@ -271,7 +271,7 @@ public:
     // The calls below are valid only in that case.
     bool inUpdateClientArea() const;
     QRegion previousRestrictedMoveArea(const VirtualDesktop *desktop, StrutAreas areas = StrutAreaAll) const;
-    QVector< QRect > previousScreenSizes() const;
+    QHash<const AbstractOutput *, QRect> previousScreenSizes() const;
     int oldDisplayWidth() const;
     int oldDisplayHeight() const;
 
@@ -670,7 +670,7 @@ private:
     QHash<const VirtualDesktop *, QHash<const AbstractOutput *, QRect>> m_screenAreas;
     QRect m_geometry;
 
-    QVector< QRect > oldscreensizes; // array of previous sizes of xinerama screens
+    QHash<const AbstractOutput *, QRect> m_oldScreenGeometries;
     QSize olddisplaysize; // previous sizes od displayWidth()/displayHeight()
     QHash<const VirtualDesktop *, StrutRects> m_oldRestrictedAreas;