6 files changed, 22 insertions, 2 deletions
diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp
index 703c492a6b..ebce163ed3 100644
--- a/src/gui/painting/qbackingstore.cpp
+++ b/src/gui/painting/qbackingstore.cpp
@@ -249,8 +249,18 @@ void QBackingStore::flush(const QRegion &region, QWindow *window, const QPoint &
 
     Q_ASSERT(window == topLevelWindow || topLevelWindow->isAncestorOf(window, QWindow::ExcludeTransients));
 
-    handle()->flush(window, QHighDpi::toNativeLocalRegion(region, window),
-                                            QHighDpi::toNativeLocalPosition(offset, window));
+    QRegion nativeRegion = QHighDpi::toNativeLocalRegion(region, window);
+    QPoint nativeOffset;
+    if (!offset.isNull()) {
+        nativeOffset = QHighDpi::toNativeLocalPosition(offset, window);
+        // Under fractional DPR, rounding of region and offset may accumulate to an off-by-one
+        QPoint topLeft = region.boundingRect().topLeft() + offset;
+        QPoint nativeTopLeft = QHighDpi::toNativeLocalPosition(topLeft, window);
+        QPoint diff = nativeTopLeft - (nativeRegion.boundingRect().topLeft() + nativeOffset);
+        Q_ASSERT(qMax(qAbs(diff.x()), qAbs(diff.y())) <= 1);
+        nativeRegion.translate(diff);
+    }
+    handle()->flush(window, nativeRegion, nativeOffset);
 }
 
 /*!
diff --git a/src/gui/painting/qbrush.cpp b/src/gui/painting/qbrush.cpp
index 9e5605dd48..08d7055b82 100644
--- a/src/gui/painting/qbrush.cpp
+++ b/src/gui/painting/qbrush.cpp
@@ -2638,3 +2638,5 @@ void QConicalGradient::setAngle(qreal angle)
 #undef Q_DUMMY_ACCESSOR
 
 QT_END_NAMESPACE
+
+#include "moc_qbrush.cpp"
diff --git a/src/gui/painting/qcolorspace.cpp b/src/gui/painting/qcolorspace.cpp
index 5977f8f8c5..dd30c64640 100644
--- a/src/gui/painting/qcolorspace.cpp
+++ b/src/gui/painting/qcolorspace.cpp
@@ -848,3 +848,5 @@ QDebug operator<<(QDebug dbg, const QColorSpace &colorSpace)
 #endif
 
 QT_END_NAMESPACE
+
+#include "moc_qcolorspace.cpp"
diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 826a7ab27f..fdb7f331aa 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -8588,3 +8588,5 @@ void qt_draw_helper(QPainterPrivate *p, const QPainterPath &path, QPainterPrivat
 }
 
 QT_END_NAMESPACE
+
+#include "moc_qpainter.cpp"
diff --git a/src/gui/painting/qpdfwriter.cpp b/src/gui/painting/qpdfwriter.cpp
index cf30ea496c..ae140f31b5 100644
--- a/src/gui/painting/qpdfwriter.cpp
+++ b/src/gui/painting/qpdfwriter.cpp
@@ -489,4 +489,6 @@ QT_WARNING_POP
 
 QT_END_NAMESPACE
 
+#include "moc_qpdfwriter.cpp"
+
 #endif // QT_NO_PDF
diff --git a/src/gui/painting/qplatformbackingstore.cpp b/src/gui/painting/qplatformbackingstore.cpp
index c092a7153f..9c9b053b2b 100644
--- a/src/gui/painting/qplatformbackingstore.cpp
+++ b/src/gui/painting/qplatformbackingstore.cpp
@@ -751,3 +751,5 @@ bool QPlatformBackingStore::scroll(const QRegion &area, int dx, int dy)
 }
 
 QT_END_NAMESPACE
+
+#include "moc_qplatformbackingstore.cpp"