kdecoration: Fix outline gap with fractional scale

There was some old code lying around from when there was only one outline
which was on top of titlebar. This removes all that, which fixes the bug.

BUG: 461358
FIXED-IN: 5.27


(cherry picked from commit dc404b0c00930d72487ad2fe5745677b8eec3d1f)

kdecoration/breezedecoration.cpp

@@ -571,11 +571,8 @@ void Decoration::paint(QPainter *painter, const QRect &repaintRegion)
 void Decoration::paintTitleBar(QPainter *painter, const QRect &repaintRegion)
 {
     const auto c = client().toStrongRef();
-    // Check if the window is maximized and if so, remove the extra gap that makes room for outlines,
+    const QRect frontRect(QPoint(0, 0), QSize(size().width(), borderTop()));
-    // since they're not even drawn when window is maximized
+    const QRect backRect(QPoint(0, 0), QSize(size().width(), borderTop()));
-    const int outlineGap = isMaximized() ? 0 : 1;
-    const QRect frontRect(QPoint(0, 1), QSize(size().width(), borderTop()));
-    const QRect backRect(QPoint(0, outlineGap), QSize(size().width(), borderTop() - outlineGap));
 
     QBrush frontBrush;
     QBrush backBrush(this->titleBarColor());
@@ -827,8 +824,7 @@ QSharedPointer<KDecoration2::DecorationShadow> Decoration::createShadowObject(co
     const qreal outlineWidth = 1.001;
     const qreal penOffset = outlineWidth / 2;
 
-    // Titlebar already has an outline, so move the top of the outline on the same level to avoid 2px width on top outline.
+    QRectF outlineRect = innerRect + QMarginsF(penOffset, penOffset, penOffset, penOffset);
-    QRectF outlineRect = innerRect + QMarginsF(penOffset, -penOffset, penOffset, penOffset);
     qreal cornerSize = m_scaledCornerRadius * 2;
     QRectF cornerRect(outlineRect.x(), outlineRect.y(), cornerSize, cornerSize);
     QPainterPath outlinePath;