Index: ogrvrtlayer.cpp
===================================================================
--- ogrvrtlayer.cpp	(revision 15551)
+++ ogrvrtlayer.cpp	(working copy)
@@ -69,7 +69,7 @@
     iFIDField = -1;
 
     eGeometryType = VGS_Direct;
-    iGeomField = iGeomXField = iGeomYField = iGeomZField = -1;
+    iGeomField = iGeomXField = iGeomYField = iGeomZField = iGeomAggrField = -1;
 
     pszAttrFilter = NULL;
     panSrcField = NULL;
@@ -375,6 +375,30 @@
              return FALSE;
          }
      }
+     else if( EQUAL(pszEncoding,"PolylineFromColumns") )
+     {
+     	eGeometryType = VGS_PolylineFromColumns;
+	bUseSpatialSubquery =
+             CSLTestBoolean(
+                 CPLGetXMLValue(psLTree, 
+                                "GeometryField.useSpatialSubquery",
+                                "TRUE"));
+         iGeomXField = poSrcLayer->GetLayerDefn()->GetFieldIndex(
+             CPLGetXMLValue( psLTree, "GeometryField.x", "missing" ) );
+         iGeomYField = poSrcLayer->GetLayerDefn()->GetFieldIndex(
+             CPLGetXMLValue( psLTree, "GeometryField.y", "missing" ) );
+         iGeomZField = poSrcLayer->GetLayerDefn()->GetFieldIndex(
+             CPLGetXMLValue( psLTree, "GeometryField.z", "missing" ) );
+         iGeomAggrField = poSrcLayer->GetLayerDefn()->GetFieldIndex(
+             CPLGetXMLValue( psLTree, "GeometryField.aggr", "missing" ) );
+
+         if( iGeomXField == -1 || iGeomYField == -1 || iGeomAggrField == -1 )
+         {
+             CPLError( CE_Failure, CPLE_AppDefined, 
+                       "Unable to identify source X, Y or Aggr field for PolylineFromColumns encoding." );
+             return FALSE;
+         }
+     }
      else
      {
          CPLError( CE_Failure, CPLE_AppDefined, 
@@ -476,7 +500,8 @@
 /*      Do we want to let source layer do spatial restriction?          */
 /* -------------------------------------------------------------------- */
     char *pszFilter = NULL;
-    if( m_poFilterGeom && bUseSpatialSubquery && eGeometryType == VGS_PointFromColumns )
+    if( m_poFilterGeom && bUseSpatialSubquery &&
+        (eGeometryType == VGS_PointFromColumns || eGeometryType == VGS_PolylineFromColumns))
     {
         const char *pszXField, *pszYField;
 
@@ -543,29 +568,78 @@
         if( !ResetSourceReading() )
             return NULL;
     }
+    
+    if( eGeometryType == VGS_PolylineFromColumns )
+    {
+    	OGRMultiLineString *poMulti = new OGRMultiLineString;
+	OGRFeature *poFeature = new OGRFeature( poFeatureDefn );
+	OGRFeature *poSrcFeat;
+	int aggr = -1;
+	OGRLineString *current = NULL;
 
-    for( ; TRUE; )
+
+	while ((poSrcFeat = poSrcLayer->GetNextFeature()) != NULL) {
+		double dfZ = 0.0;
+		
+		if (aggr < poSrcFeat->GetFieldAsInteger( iGeomAggrField )) {
+			if (current)
+				poMulti->addGeometryDirectly( current );
+
+			/* Create new Linestring */
+			current = new OGRLineString();
+		}
+		
+		aggr = poSrcFeat->GetFieldAsInteger( iGeomAggrField );
+
+		if( iGeomZField != -1 )
+			dfZ = poSrcFeat->GetFieldAsDouble( iGeomZField );
+
+		current->addPoint(poSrcFeat->GetFieldAsDouble( iGeomXField ),
+				  poSrcFeat->GetFieldAsDouble( iGeomYField ),
+				  dfZ );
+
+		delete poSrcFeat;
+	}
+
+	if (current)
+		poMulti->addGeometryDirectly( current );
+
+	poFeature->SetGeometryDirectly(poMulti);
+
+	delete poSrcLayer;
+
+	poSrcLayer = NULL;
+
+	return poFeature;
+    }
+    else
     {
-        OGRFeature      *poSrcFeature, *poFeature;
+        for( ; TRUE; )
+        {
+            OGRFeature      *poSrcFeature, *poFeature;
 
-        poSrcFeature = poSrcLayer->GetNextFeature();
-        if( poSrcFeature == NULL )
-            return NULL;
+            poSrcFeature = poSrcLayer->GetNextFeature();
+            if( poSrcFeature == NULL )
+                return NULL;
 
-        poFeature = TranslateFeature( poSrcFeature );
-        delete poSrcFeature;
+            poFeature = TranslateFeature( poSrcFeature );
+            delete poSrcFeature;
 
-        if( poFeature == NULL )
-            return NULL;
+            if( poFeature == NULL )
+                return NULL;
 
-        if( (m_poFilterGeom == NULL
-            || FilterGeometry( poFeature->GetGeometryRef() ) )
-            && (m_poAttrQuery == NULL
-                || m_poAttrQuery->Evaluate( poFeature )) )
-            return poFeature;
+            if( (m_poFilterGeom == NULL
+                || FilterGeometry( poFeature->GetGeometryRef() ) )
+                && (m_poAttrQuery == NULL
+                   || m_poAttrQuery->Evaluate( poFeature )) )
+               return poFeature;
 
-        delete poFeature;
+            delete poFeature;
+        }
     }
+
+    /* Should not happen */
+    return NULL;
 }
 
 /************************************************************************/
Index: ogr_vrt.h
===================================================================
--- ogr_vrt.h	(revision 15551)
+++ ogr_vrt.h	(working copy)
@@ -37,7 +37,8 @@
 typedef enum { 
     VGS_None,
     VGS_Direct,
-    VGS_PointFromColumns, 
+    VGS_PointFromColumns,
+    VGS_PolylineFromColumns,
     VGS_WKT, 
     VGS_WKB,
     VGS_Shape
@@ -74,7 +75,7 @@
     int                 iGeomField; 
 
                         // VGS_PointFromColumn
-    int                 iGeomXField, iGeomYField, iGeomZField;
+    int                 iGeomXField, iGeomYField, iGeomZField, iGeomAggrField;
 
     int                 bUseSpatialSubquery;