--- /dev/null
+From 0726127285413829f58618b5b82fb3e2da0c3a74 Mon Sep 17 00:00:00 2001
+From: Andy Shaw <andy.shaw@digia.com>
+Date: Tue, 8 Oct 2013 15:45:42 +0200
+Subject: [PATCH] Ensure lastPixel.y is also initalized to -1 when necessary
+
+Task-number: QTBUG-31579
+
+Upstream-Status: Accepted [https://codereview.qt-project.org/#change,67624]
+Signed-off-by: Jonathan Liu <net147@gmail.com>
+
+Change-Id: Ia4916ac0d384ea523bbfad0dafbc90044da7ec3e
+Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>
+(cherry picked from qtbase/f0b950144dde85b65df0c3cf83f7c8df0e94bbbf)
+---
+ src/gui/painting/qcosmeticstroker.cpp | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/src/gui/painting/qcosmeticstroker.cpp b/src/gui/painting/qcosmeticstroker.cpp
+index 4413170..36616d4 100644
+--- a/src/gui/painting/qcosmeticstroker.cpp
++++ b/src/gui/painting/qcosmeticstroker.cpp
+@@ -305,6 +305,7 @@ void QCosmeticStroker::setup()
+ ymax = deviceRect.bottom() + 2;
+
+ lastPixel.x = -1;
++ lastPixel.y = -1;
+ }
+
+ // returns true if the whole line gets clipped away
+@@ -533,6 +534,7 @@ void QCosmeticStroker::drawPath(const QVectorPath &path)
+ QPointF p = QPointF(points[0], points[1]) * state->matrix;
+ patternOffset = state->lastPen.dashOffset()*64;
+ lastPixel.x = -1;
++ lastPixel.y = -1;
+
+ bool closed;
+ const QPainterPath::ElementType *e = subPath(type, end, points, &closed);
+@@ -587,6 +589,7 @@ void QCosmeticStroker::drawPath(const QVectorPath &path)
+ QPointF movedTo = p;
+ patternOffset = state->lastPen.dashOffset()*64;
+ lastPixel.x = -1;
++ lastPixel.y = -1;
+
+ const qreal *begin = points;
+ const qreal *end = points + 2*path.elementCount();
+--
+1.8.4
+