Fixed scaled point drawing with square cap in raster paint engine.

With a large pen width and a small scale, due to the hacky way we draw
points (stroking a line from (x, y) to (x + tiny_amount, y)), we some
times end up snapping these two points to the same in rasterizeLine().
If we instead apply the SquareCap before we do clipping / snapping we
don't get this problem.

Task-number: QTBUG-13429
Reviewed-by: Trond
(cherry picked from commit 7c673a4cf64ba043bb27f90287517bdcdd7a21db)

1 files changed, 22 insertions, 0 deletions

diff --git a/tests/auto/qpainter/tst_qpainter.cpp b/tests/auto/qpainter/tst_qpainter.cpp
index d453b50..729dd5e 100644
--- a/tests/auto/qpainter/tst_qpainter.cpp
+++ b/tests/auto/qpainter/tst_qpainter.cpp
@@ -251,6 +251,8 @@ private slots:
 
     void QTBUG5939_attachPainterPrivate();
 
+    void drawPointScaled();
+
 private:
     void fillData();
     void setPenColor(QPainter& p);
@@ -4458,6 +4460,26 @@ void tst_QPainter::QTBUG5939_attachPainterPrivate()
     QCOMPARE(widget->deviceTransform, proxy->deviceTransform);
 }
 
+void tst_QPainter::drawPointScaled()
+{
+    QImage image(32, 32, QImage::Format_RGB32);
+    image.fill(0xffffffff);
+
+    QPainter p(&image);
+
+    p.scale(0.1, 0.1);
+
+    QPen pen;
+    pen.setWidth(1000);
+    pen.setColor(Qt::red);
+
+    p.setPen(pen);
+    p.drawPoint(0, 0);
+    p.end();
+
+    QCOMPARE(image.pixel(16, 16), 0xffff0000);
+}
+
 QTEST_MAIN(tst_QPainter)
 
 #include "tst_qpainter.moc"