Get correct decoration margins region

Size we use to calculate margins region already contains size including
margins. This resulted into bigger region and not properly damaging
region we need to update.

Change-Id: Id1b7f4cd2a7b894b82db09c5af2b2d1f1f43fa2a
Reviewed-by: David Edmundson <davidedmundson@kde.org>
(cherry picked from commit 1631315387faff3b4ae5c5ff1afb95e42f986e4c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/client/qwaylandabstractdecoration.cpp b/src/client/qwaylandabstractdecoration.cpp
index 17b42c0fe..583344273 100644
--- a/src/client/qwaylandabstractdecoration.cpp
+++ b/src/client/qwaylandabstractdecoration.cpp
@@ -108,11 +108,11 @@ void QWaylandAbstractDecoration::setWaylandWindow(QWaylandWindow *window)
 static QRegion marginsRegion(const QSize &size, const QMargins &margins)
 {
     QRegion r;
-    const int widthWithMargins = margins.left() + size.width() + margins.right();
-    r += QRect(0, 0, widthWithMargins, margins.top()); // top
-    r += QRect(0, size.height()+margins.top(), widthWithMargins, margins.bottom()); //bottom
+
+    r += QRect(0, 0, size.width(), margins.top()); // top
+    r += QRect(0, size.height()-margins.bottom(), size.width(), margins.bottom()); //bottom
     r += QRect(0, margins.top(), margins.left(), size.height()); //left
-    r += QRect(size.width()+margins.left(), margins.top(), margins.right(), size.height()); // right
+    r += QRect(size.width()-margins.left(), margins.top(), margins.right(), size.height()-margins.top()); // right
     return r;
 }