DXF export preserve dashed line style

We do not (yet) support an option to guarantee stroked parts at corners.
So also do not set this flag in the DXF export.

python/core/auto_additions/qgsdxfexport.py

@@ -24,3 +24,14 @@ QgsDxfExport.HAlign.HFit.__doc__ = "Fit into point = (5) (if VAlign==0)"
 QgsDxfExport.HAlign.Undefined.__doc__ = "Undefined"
 QgsDxfExport.HAlign.__doc__ = 'Horizontal alignments.\n\n' + '* ``HLeft``: ' + QgsDxfExport.HAlign.HLeft.__doc__ + '\n' + '* ``HCenter``: ' + QgsDxfExport.HAlign.HCenter.__doc__ + '\n' + '* ``HRight``: ' + QgsDxfExport.HAlign.HRight.__doc__ + '\n' + '* ``HAligned``: ' + QgsDxfExport.HAlign.HAligned.__doc__ + '\n' + '* ``HMiddle``: ' + QgsDxfExport.HAlign.HMiddle.__doc__ + '\n' + '* ``HFit``: ' + QgsDxfExport.HAlign.HFit.__doc__ + '\n' + '* ``Undefined``: ' + QgsDxfExport.HAlign.Undefined.__doc__
 # --
+# monkey patching scoped based enum
+QgsDxfExport.DxfPolylineFlag.Closed.__doc__ = "This is a closed polyline (or a polygon mesh closed in the M direction)"
+QgsDxfExport.DxfPolylineFlag.Curve.__doc__ = "Curve-fit vertices have been added"
+QgsDxfExport.DxfPolylineFlag.Spline.__doc__ = ""
+QgsDxfExport.DxfPolylineFlag.Is3DPolyline.__doc__ = "This is a 3D polyline"
+QgsDxfExport.DxfPolylineFlag.Is3DPolygonMesh.__doc__ = "This is a 3D polygon mesh"
+QgsDxfExport.DxfPolylineFlag.PolygonMesh.__doc__ = "The polygon mesh is closed in the N direction"
+QgsDxfExport.DxfPolylineFlag.PolyfaceMesh.__doc__ = "The polyline is a polyface mesh"
+QgsDxfExport.DxfPolylineFlag.ContinuousPattern.__doc__ = "The linetype pattern is generated continuously around the vertices of this polyline"
+QgsDxfExport.DxfPolylineFlag.__doc__ = '\n\n' + '* ``Closed``: ' + QgsDxfExport.DxfPolylineFlag.Closed.__doc__ + '\n' + '* ``Curve``: ' + QgsDxfExport.DxfPolylineFlag.Curve.__doc__ + '\n' + '* ``Spline``: ' + QgsDxfExport.DxfPolylineFlag.Spline.__doc__ + '\n' + '* ``Is3DPolyline``: ' + QgsDxfExport.DxfPolylineFlag.Is3DPolyline.__doc__ + '\n' + '* ``Is3DPolygonMesh``: ' + QgsDxfExport.DxfPolylineFlag.Is3DPolygonMesh.__doc__ + '\n' + '* ``PolygonMesh``: ' + QgsDxfExport.DxfPolylineFlag.PolygonMesh.__doc__ + '\n' + '* ``PolyfaceMesh``: ' + QgsDxfExport.DxfPolylineFlag.PolyfaceMesh.__doc__ + '\n' + '* ``ContinuousPattern``: ' + QgsDxfExport.DxfPolylineFlag.ContinuousPattern.__doc__
+# --

python/core/auto_generated/dxf/qgsdxfexport.sip.in

@@ -13,6 +13,7 @@
 
 
 
+
 class QgsDxfExport
 {
 
@@ -91,6 +92,21 @@ unique value.
       Undefined
     };
 
+    enum class DxfPolylineFlag
+    {
+      Closed,
+      Curve,
+      Spline,
+      Is3DPolyline,
+      Is3DPolygonMesh,
+      PolygonMesh,
+      PolyfaceMesh,
+      ContinuousPattern,
+    };
+
+    typedef QFlags<QgsDxfExport::DxfPolylineFlag> DxfPolylineFlags;
+
+
     QgsDxfExport();
 %Docstring
 Constructor for QgsDxfExport.

src/core/dxf/qgsdxfexport.cpp

@@ -1097,7 +1097,17 @@ void QgsDxfExport::writePolyline( const QgsCurve &curve, const QString &layer, c
     writeGroup( color );
 
     writeGroup( 90, points.size() );
-    writeGroup( 70, ( curve.isClosed() ? 1 : 0 ) | ( curve.hasCurvedSegments() ? 2 : 0 ) );
+    QgsDxfExport::DxfPolylineFlags polylineFlags;
+    if ( curve.isClosed() )
+      polylineFlags.setFlag( QgsDxfExport::DxfPolylineFlag::Closed );
+    if ( curve.hasCurvedSegments() )
+      polylineFlags.setFlag( QgsDxfExport::DxfPolylineFlag::Curve );
+
+    // Might need to conditional once this feature is implemented
+    //   https://github.com/qgis/QGIS/issues/32468
+    polylineFlags.setFlag( QgsDxfExport::DxfPolylineFlag::ContinuousPattern );
+
+    writeGroup( 70, static_cast<int>( polylineFlags ) );
     writeGroup( 43, width );
 
     for ( int i = 0; i < points.size(); i++ )

src/core/dxf/qgsdxfexport.h

@@ -49,6 +49,7 @@ namespace pal // SIP_SKIP
   class LabelPosition;
 }
 
+
 /**
  * \ingroup core
  * \class QgsDxfExport
@@ -142,6 +143,20 @@ class CORE_EXPORT QgsDxfExport
       Undefined = 9999 //!< Undefined
     };
 
+    enum class DxfPolylineFlag : int
+    {
+      Closed = 1, //!< This is a closed polyline (or a polygon mesh closed in the M direction)
+      Curve = 2, //!< Curve-fit vertices have been added
+      Spline = 4, //! < Spline-fit vertices have been added
+      Is3DPolyline = 8, //!< This is a 3D polyline
+      Is3DPolygonMesh = 16, //!< This is a 3D polygon mesh
+      PolygonMesh = 32, //!< The polygon mesh is closed in the N direction
+      PolyfaceMesh = 64, //!< The polyline is a polyface mesh
+      ContinuousPattern = 128, //!< The linetype pattern is generated continuously around the vertices of this polyline
+    };
+
+    Q_DECLARE_FLAGS( DxfPolylineFlags, DxfPolylineFlag )
+
     /**
      * Constructor for QgsDxfExport.
      */