Automatically create QPainterPathStroke based on QPen

Based a recent problem where one property of QPen was not properly copied
to QPainterPathStroke, I believe we should add a method to automatically
create a QPainterPathStroke based on all the relevant information in a QPen.

This patch adds a constructor that automatically does so.

Change-Id: Id2849b36426f2e3b06b4b508292063a0917ca61c
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>

src/gui/painting/qpainterpath.cpp

@@ -2550,6 +2550,26 @@ QPainterPathStroker::QPainterPathStroker()
 {
 }
 
+/*!
+   Creates a new stroker based on \a pen.
+
+   \since 5.3
+ */
+QPainterPathStroker::QPainterPathStroker(const QPen &pen)
+    : d_ptr(new QPainterPathStrokerPrivate)
+{
+    setWidth(pen.widthF());
+    setCapStyle(pen.capStyle());
+    setJoinStyle(pen.joinStyle());
+    setMiterLimit(pen.miterLimit());
+    setDashOffset(pen.dashOffset());
+
+    if (pen.style() == Qt::CustomDashLine)
+        setDashPattern(pen.dashPattern());
+    else
+        setDashPattern(pen.style());
+}
+
 /*!
     Destroys the stroker.
 */

src/gui/painting/qpainterpath.h

@@ -57,6 +57,7 @@ class QPainterPathPrivate;
 struct QPainterPathPrivateDeleter;
 class QPainterPathData;
 class QPainterPathStrokerPrivate;
+class QPen;
 class QPolygonF;
 class QRegion;
 class QVectorPath;
@@ -243,6 +244,7 @@ class Q_GUI_EXPORT QPainterPathStroker
     Q_DECLARE_PRIVATE(QPainterPathStroker)
 public:
     QPainterPathStroker();
+    QPainterPathStroker(const QPen &pen);
     ~QPainterPathStroker();
 
     void setWidth(qreal width);