2 files changed, 75 insertions, 12 deletions

diff --git a/src/gui/painting/qpaintengine_x11.cpp b/src/gui/painting/qpaintengine_x11.cpp
index 910b2df..e521e01 100644
--- a/src/gui/painting/qpaintengine_x11.cpp
+++ b/src/gui/painting/qpaintengine_x11.cpp
@@ -696,11 +696,10 @@ void QX11PaintEngine::drawLines(const QLine *lines, int lineCount)
                 linef = d->matrix.map(QLineF(lines[i]));
             }
             if (clipLine(&linef, d->polygonClipper.boundingRect())) {
-                int x1 = qRound(linef.x1() + aliasedCoordinateDelta);
-                int y1 = qRound(linef.y1() + aliasedCoordinateDelta);
-                int x2 = qRound(linef.x2() + aliasedCoordinateDelta);
-                int y2 = qRound(linef.y2() + aliasedCoordinateDelta);
-
+                int x1 = qFloor(linef.x1() + aliasedCoordinateDelta);
+                int y1 = qFloor(linef.y1() + aliasedCoordinateDelta);
+                int x2 = qFloor(linef.x2() + aliasedCoordinateDelta);
+                int y2 = qFloor(linef.y2() + aliasedCoordinateDelta);
                 XDrawLine(d->dpy, d->hd, d->gc, x1, y1, x2, y2);
             }
         }
@@ -730,11 +729,10 @@ void QX11PaintEngine::drawLines(const QLineF *lines, int lineCount)
         for (int i = 0; i < lineCount; ++i) {
             QLineF linef = d->matrix.map(lines[i]);
             if (clipLine(&linef, d->polygonClipper.boundingRect())) {
-                int x1 = qRound(linef.x1() + aliasedCoordinateDelta);
-                int y1 = qRound(linef.y1() + aliasedCoordinateDelta);
-                int x2 = qRound(linef.x2() + aliasedCoordinateDelta);
-                int y2 = qRound(linef.y2() + aliasedCoordinateDelta);
-
+                int x1 = qFloor(linef.x1() + aliasedCoordinateDelta);
+                int y1 = qFloor(linef.y1() + aliasedCoordinateDelta);
+                int x2 = qFloor(linef.x2() + aliasedCoordinateDelta);
+                int y2 = qFloor(linef.y2() + aliasedCoordinateDelta);
                 XDrawLine(d->dpy, d->hd, d->gc, x1, y1, x2, y2);
             }
         }
@@ -1690,8 +1688,8 @@ void QX11PaintEnginePrivate::strokePolygon_dev(const QPointF *polygonPoints, int
     if (clippedCount > 0) {
         QVarLengthArray<XPoint> xpoints(clippedCount);
         for (int i = 0; i < clippedCount; ++i) {
-            xpoints[i].x = qRound(clippedPoints[i].x + aliasedCoordinateDelta);
-            xpoints[i].y = qRound(clippedPoints[i].y + aliasedCoordinateDelta);
+            xpoints[i].x = qFloor(clippedPoints[i].x + aliasedCoordinateDelta);
+            xpoints[i].y = qFloor(clippedPoints[i].y + aliasedCoordinateDelta);
         }
         uint numberPoints = qMin(clippedCount, xlibMaxLinePoints);
         XPoint *pts = xpoints.data();
diff --git a/tests/auto/qpainter/tst_qpainter.cpp b/tests/auto/qpainter/tst_qpainter.cpp
index f358681..2cbb9b2 100644
--- a/tests/auto/qpainter/tst_qpainter.cpp
+++ b/tests/auto/qpainter/tst_qpainter.cpp
@@ -118,10 +118,12 @@ private slots:
     void drawLine_task190634();
     void drawLine_task229459();
     void drawLine_task234891();
+    void drawHorizontalLineF();
 
     void drawRect_data() { fillData(); }
     void drawRect();
     void drawRect2();
+    void drawRectFHorizontalLine();
 
     void fillRect();
     void fillRect2();
@@ -251,6 +253,7 @@ private slots:
     void setPenColorOnPixmap();
 
     void QTBUG5939_attachPainterPrivate();
+    void drawHorizontalLine();
 
 private:
     void fillData();
@@ -1218,6 +1221,26 @@ void tst_QPainter::drawLine_task234891()
     QCOMPARE(expected, img);
 }
 
+void tst_QPainter::drawHorizontalLineF()
+{
+    QPixmap pixmap(100, 3);
+    pixmap.fill();
+
+    {
+        QPainter painter(&pixmap);
+        painter.drawLine(QLineF(1.5f, 1.5f, 98.5f, 1.5f));
+    }
+
+    QImage refImage(100, 3, QImage::Format_ARGB32);
+    refImage.fill(0xFFFFFFFF);
+    {
+        QPainter painter(&refImage);
+        painter.drawLine(QLineF(1.5f, 1.5f, 98.5f, 1.5f));
+    }
+
+    QCOMPARE(pixmap.toImage().convertToFormat(QImage::Format_ARGB32), refImage);
+}
+
 void tst_QPainter::drawLine_task216948()
 {
     QImage img(1, 10, QImage::Format_ARGB32_Premultiplied);
@@ -1302,6 +1325,26 @@ void tst_QPainter::drawRect2()
     }
 }
 
+void tst_QPainter::drawRectFHorizontalLine()
+{
+    QPixmap pixmap(100, 3);
+    pixmap.fill();
+
+    {
+        QPainter painter(&pixmap);
+        painter.drawRect(QRectF(1.5f, 1.5f, 98.5f, 1.5f));
+    }
+
+    QImage refImage(100, 3, QImage::Format_ARGB32);
+    refImage.fill(0xFFFFFFFF);
+    {
+        QPainter painter(&refImage);
+        painter.drawRect(QRectF(1.5f, 1.5f, 98.5f, 1.5f));
+    }
+
+    QCOMPARE(pixmap.toImage().convertToFormat(QImage::Format_ARGB32), refImage);
+}
+
 void tst_QPainter::fillRect()
 {
     QImage image(100, 100, QImage::Format_ARGB32_Premultiplied);
@@ -4522,6 +4565,28 @@ void tst_QPainter::QTBUG5939_attachPainterPrivate()
     QCOMPARE(widget->deviceTransform, proxy->deviceTransform);
 }
 
+void tst_QPainter::drawHorizontalLine()
+{
+    QPixmap pixmap(100, 3);
+    pixmap.fill();
+
+    {
+        QPainter painter(&pixmap);
+        painter.translate(0.3, 0.3);
+        painter.drawLine(QLine(1, 1, 99, 1));
+    }
+
+    QImage refImage(100, 3, QImage::Format_ARGB32);
+    refImage.fill(0xFFFFFFFF);
+    {
+        QPainter painter(&refImage);
+        painter.translate(0.3, 0.3);
+        painter.drawLine(QLine(1, 1, 99, 1));
+    }
+
+    QCOMPARE(pixmap.toImage().convertToFormat(QImage::Format_ARGB32), refImage);
+}
+
 QTEST_MAIN(tst_QPainter)
 
 #include "tst_qpainter.moc"