diff --git a/3d-viewer/3d_draw.cpp b/3d-viewer/3d_draw.cpp
index 0a703179fa..289d3c3c72 100644
--- a/3d-viewer/3d_draw.cpp
+++ b/3d-viewer/3d_draw.cpp
@@ -274,7 +274,7 @@ void EDA_3D_CANVAS::BuildBoard3DView()
     bool            hightQualityMode = false;
 
     for( LAYER_NUM layer = FIRST_COPPER_LAYER; layer <= LAST_COPPER_LAYER;
-         layer++ )
+         ++layer )
     {
         if( layer != LAST_COPPER_LAYER
             && layer >= g_Parm_3D_Visu.m_CopperLayersCount )
@@ -528,21 +528,19 @@ void EDA_3D_CANVAS::BuildTechLayers3DView()
     }
 
     int thickness = g_Parm_3D_Visu.GetCopperThicknessBIU();
-    for( TRACK* track = pcb->m_Track; track != NULL; track = track->Next() )
-    {
-       // Add via hole
-        if( track->Type() == PCB_VIA_T )
-        {
-            const VIA *via = static_cast<const VIA*>( track );
-            VIATYPE_T viatype = via->GetViaType();
-            int holediameter = via->GetDrillValue();
-            int hole_outer_radius = (holediameter + thickness) / 2;
 
-            if( viatype == VIA_THROUGH )
-                TransformCircleToPolygon( allLayerHoles,
-                                          via->GetStart(), hole_outer_radius,
-                                          segcountLowQuality );
-        }
+    // Add via holes
+    for( VIA* via = GetFirstVia( pcb->m_Track ); via != NULL;
+            via = GetFirstVia( via->Next() ) )
+    {
+        VIATYPE_T viatype = via->GetViaType();
+        int holediameter = via->GetDrillValue();
+        int hole_outer_radius = (holediameter + thickness) / 2;
+
+        if( viatype == VIA_THROUGH )
+            TransformCircleToPolygon( allLayerHoles,
+                    via->GetStart(), hole_outer_radius,
+                    segcountLowQuality );
     }
 
     // draw pads holes
@@ -562,7 +560,7 @@ void EDA_3D_CANVAS::BuildTechLayers3DView()
     allLayerHoles.ExportTo( brdpolysetHoles );
 
     for( LAYER_NUM layer = FIRST_NON_COPPER_LAYER; layer <= LAST_NON_COPPER_LAYER;
-         layer++ )
+         ++layer )
     {
         // Skip user layers, which are not drawn here
         if( IsUserLayer( layer) )
@@ -713,7 +711,7 @@ void EDA_3D_CANVAS::BuildBoard3DAuxLayers()
     bufferPolys.reserve( 5000 );    // Reserve for items not on board
 
     for( LAYER_NUM layer = FIRST_USER_LAYER; layer <= LAST_USER_LAYER;
-         layer++ )
+         ++layer )
     {
         if( !Is3DLayerEnabled( layer ) )
             continue;
diff --git a/eeschema/sch_screen.cpp b/eeschema/sch_screen.cpp
index 86a8ed9727..9a7d2a5390 100644
--- a/eeschema/sch_screen.cpp
+++ b/eeschema/sch_screen.cpp
@@ -1345,7 +1345,7 @@ SCH_SCREEN* SCH_SCREENS::GetNext()
 }
 
 
-SCH_SCREEN* SCH_SCREENS::GetScreen( unsigned int aIndex )
+SCH_SCREEN* SCH_SCREENS::GetScreen( unsigned int aIndex ) const
 {
     if( aIndex < m_screens.size() )
         return m_screens[ aIndex ];
diff --git a/eeschema/sch_sheet_path.cpp b/eeschema/sch_sheet_path.cpp
index 23ef5272c3..230ea77fe3 100644
--- a/eeschema/sch_sheet_path.cpp
+++ b/eeschema/sch_sheet_path.cpp
@@ -112,7 +112,7 @@ int SCH_SHEET_PATH::Cmp( const SCH_SHEET_PATH& aSheetPathToTest ) const
 }
 
 
-SCH_SHEET* SCH_SHEET_PATH::Last()
+SCH_SHEET* SCH_SHEET_PATH::Last() const
 {
     if( m_numSheets )
         return m_sheets[m_numSheets - 1];
@@ -121,7 +121,7 @@ SCH_SHEET* SCH_SHEET_PATH::Last()
 }
 
 
-SCH_SCREEN* SCH_SHEET_PATH::LastScreen()
+SCH_SCREEN* SCH_SHEET_PATH::LastScreen() const
 {
     SCH_SHEET* lastSheet = Last();
 
@@ -132,7 +132,7 @@ SCH_SCREEN* SCH_SHEET_PATH::LastScreen()
 }
 
 
-SCH_ITEM* SCH_SHEET_PATH::LastDrawList()
+SCH_ITEM* SCH_SHEET_PATH::LastDrawList() const
 {
     SCH_SHEET* lastSheet = Last();
 
@@ -143,7 +143,7 @@ SCH_ITEM* SCH_SHEET_PATH::LastDrawList()
 }
 
 
-SCH_ITEM* SCH_SHEET_PATH::FirstDrawList()
+SCH_ITEM* SCH_SHEET_PATH::FirstDrawList() const
 {
     SCH_ITEM* item = NULL;
 
@@ -316,7 +316,7 @@ void SCH_SHEET_PATH::GetComponents( SCH_REFERENCE_LIST& aReferences, bool aInclu
 }
 
 
-SCH_ITEM* SCH_SHEET_PATH::FindNextItem( KICAD_T aType, SCH_ITEM* aLastItem, bool aWrap )
+SCH_ITEM* SCH_SHEET_PATH::FindNextItem( KICAD_T aType, SCH_ITEM* aLastItem, bool aWrap ) const
 {
     bool hasWrapped = false;
     bool firstItemFound = false;
@@ -349,7 +349,7 @@ SCH_ITEM* SCH_SHEET_PATH::FindNextItem( KICAD_T aType, SCH_ITEM* aLastItem, bool
 }
 
 
-SCH_ITEM* SCH_SHEET_PATH::FindPreviousItem( KICAD_T aType, SCH_ITEM* aLastItem, bool aWrap )
+SCH_ITEM* SCH_SHEET_PATH::FindPreviousItem( KICAD_T aType, SCH_ITEM* aLastItem, bool aWrap ) const
 {
     bool hasWrapped = false;
     bool firstItemFound = false;
diff --git a/eeschema/sch_sheet_path.h b/eeschema/sch_sheet_path.h
index dcfe9b690a..f6a32fbeb9 100644
--- a/eeschema/sch_sheet_path.h
+++ b/eeschema/sch_sheet_path.h
@@ -129,20 +129,20 @@ public:
      * returns a pointer to the last sheet of the list
      * One can see the others sheet as the "path" to reach this last sheet
      */
-    SCH_SHEET* Last();
+    SCH_SHEET* Last() const;
 
     /**
      * Function LastScreen
      * @return the SCH_SCREEN relative to the last sheet in list
      */
-    SCH_SCREEN* LastScreen();
+    SCH_SCREEN* LastScreen() const;
 
     /**
      * Function LastDrawList
      * @return a pointer to the first schematic item handled by the
      * SCH_SCREEN relative to the last sheet in list
      */
-    SCH_ITEM* LastDrawList();
+    SCH_ITEM* LastDrawList() const;
 
     /**
      * Get the last schematic item relative to the first sheet in the list.
@@ -150,7 +150,7 @@ public:
      * @return Last schematic item relative to the first sheet in the list if list
      *         is not empty.  Otherwise NULL.
      */
-    SCH_ITEM* FirstDrawList();
+    SCH_ITEM* FirstDrawList() const;
 
     /**
      * Function Push
@@ -248,7 +248,7 @@ public:
      *                is defined.
      * @return - The next schematic item if found.  Otherwise, NULL is returned.
      */
-    SCH_ITEM* FindNextItem( KICAD_T aType, SCH_ITEM* aLastItem = NULL, bool aWrap = false );
+    SCH_ITEM* FindNextItem( KICAD_T aType, SCH_ITEM* aLastItem = NULL, bool aWrap = false ) const;
 
     /**
      * Find the previous schematic item in this sheet path object.
@@ -260,7 +260,7 @@ public:
      *                is defined.
      * @return - The previous schematic item if found.  Otherwise, NULL is returned.
      */
-    SCH_ITEM* FindPreviousItem( KICAD_T aType, SCH_ITEM* aLastItem = NULL, bool aWrap = false );
+    SCH_ITEM* FindPreviousItem( KICAD_T aType, SCH_ITEM* aLastItem = NULL, bool aWrap = false ) const;
 
     SCH_SHEET_PATH& operator=( const SCH_SHEET_PATH& d1 );
 
@@ -318,7 +318,7 @@ public:
      * @return the number of sheets in list:
      * usually the number of sheets found in the whole hierarchy
      */
-    int GetCount() { return m_count; }
+    int GetCount() const { return m_count; }
 
     /**
      * Function GetFirst
diff --git a/gerbview/class_gbr_screen.h b/gerbview/class_gbr_screen.h
index 8be96b21d5..9e89373e53 100644
--- a/gerbview/class_gbr_screen.h
+++ b/gerbview/class_gbr_screen.h
@@ -26,7 +26,7 @@ public:
 
     ~GBR_SCREEN();
 
-    GBR_SCREEN* Next() { return (GBR_SCREEN*) Pnext; }
+    GBR_SCREEN* Next() const { return static_cast<GBR_SCREEN*>( Pnext ); }
 
 //    void        SetNextZoom();
 //    void        SetPreviousZoom();
diff --git a/gerbview/class_gerber_draw_item.h b/gerbview/class_gerber_draw_item.h
index 2989333c0a..70ad0a1164 100644
--- a/gerbview/class_gerber_draw_item.h
+++ b/gerbview/class_gerber_draw_item.h
@@ -116,8 +116,8 @@ public:
      */
     GERBER_DRAW_ITEM* Copy() const;
 
-    GERBER_DRAW_ITEM* Next() const { return (GERBER_DRAW_ITEM*) Pnext; }
-    GERBER_DRAW_ITEM* Back() const { return (GERBER_DRAW_ITEM*) Pback; }
+    GERBER_DRAW_ITEM* Next() const { return static_cast<GERBER_DRAW_ITEM*>( Pnext ); }
+    GERBER_DRAW_ITEM* Back() const { return static_cast<GERBER_DRAW_ITEM*>( Pback ); }
 
     /**
      * Function GetLayer
diff --git a/include/base_struct.h b/include/base_struct.h
index 8679cfdd5b..9ec7af03c8 100644
--- a/include/base_struct.h
+++ b/include/base_struct.h
@@ -375,8 +375,8 @@ public:
     void SetTimeStamp( time_t aNewTimeStamp ) { m_TimeStamp = aNewTimeStamp; }
     time_t GetTimeStamp() const { return m_TimeStamp; }
 
-    EDA_ITEM* Next() const { return (EDA_ITEM*) Pnext; }
-    EDA_ITEM* Back() const { return (EDA_ITEM*) Pback; }
+    EDA_ITEM* Next() const { return Pnext; }
+    EDA_ITEM* Back() const { return Pback; }
     EDA_ITEM* GetParent() const { return m_Parent; }
     DHEAD* GetList() const { return m_List; }
 
diff --git a/include/class_board_item.h b/include/class_board_item.h
index ceb428af5e..26a30af896 100644
--- a/include/class_board_item.h
+++ b/include/class_board_item.h
@@ -108,8 +108,8 @@ public:
      */
     static wxPoint ZeroOffset;
 
-    BOARD_ITEM* Next() const { return (BOARD_ITEM*) Pnext; }
-    BOARD_ITEM* Back() const { return (BOARD_ITEM*) Pback; }
+    BOARD_ITEM* Next() const { return static_cast<BOARD_ITEM*>( Pnext ); }
+    BOARD_ITEM* Back() const { return static_cast<BOARD_ITEM*>( Pback ); }
     BOARD_ITEM* GetParent() const { return (BOARD_ITEM*) m_Parent; }
 
     /**
diff --git a/include/class_pcb_screen.h b/include/class_pcb_screen.h
index e15082be40..59f3f3d592 100644
--- a/include/class_pcb_screen.h
+++ b/include/class_pcb_screen.h
@@ -31,7 +31,7 @@ public:
 
     ~PCB_SCREEN();
 
-    PCB_SCREEN* Next() { return (PCB_SCREEN*) Pnext; }
+    PCB_SCREEN* Next() const { return static_cast<PCB_SCREEN*>( Pnext ); }
 
     void        SetNextZoom();
     void        SetPreviousZoom();
diff --git a/include/class_sch_screen.h b/include/class_sch_screen.h
index 02a6787679..acf8f20819 100644
--- a/include/class_sch_screen.h
+++ b/include/class_sch_screen.h
@@ -523,7 +523,7 @@ public:
     int GetCount() const { return m_screens.size(); }
     SCH_SCREEN* GetFirst();
     SCH_SCREEN* GetNext();
-    SCH_SCREEN* GetScreen( unsigned int aIndex );
+    SCH_SCREEN* GetScreen( unsigned int aIndex ) const;
 
     /**
      * Function ClearAnnotation
diff --git a/include/sch_item_struct.h b/include/sch_item_struct.h
index e425e1d6b1..5fe90cd69f 100644
--- a/include/sch_item_struct.h
+++ b/include/sch_item_struct.h
@@ -136,8 +136,8 @@ public:
      */
     virtual void SwapData( SCH_ITEM* aItem );
 
-    SCH_ITEM* Next() { return (SCH_ITEM*) Pnext; }
-    SCH_ITEM* Back() { return (SCH_ITEM*) Pback; }
+    SCH_ITEM* Next() const { return static_cast<SCH_ITEM*>( Pnext ); }
+    SCH_ITEM* Back() const { return static_cast<SCH_ITEM*>( Pback ); }
 
     /**
      * Function GetLayer
diff --git a/pcbnew/class_board.cpp b/pcbnew/class_board.cpp
index 2960e9e315..a7b4e35987 100644
--- a/pcbnew/class_board.cpp
+++ b/pcbnew/class_board.cpp
@@ -1563,19 +1563,12 @@ int BOARD::SetAreasNetCodesFromNetNames( void )
 
 VIA* BOARD::GetViaByPosition( const wxPoint& aPosition, LAYER_NUM aLayer) const
 {
-    for( TRACK *track = m_Track; track; track = track->Next() )
+    for( VIA *via = GetFirstVia( m_Track); via; via = GetFirstVia( via->Next() ) )
     {
-        if( track->Type() != PCB_VIA_T )
-            continue;
-
-        if( track->GetStart() != aPosition )
-            continue;
-
-        if( track->GetState( BUSY | IS_DELETED ) )
-            continue;
-
-        if( (aLayer == UNDEFINED_LAYER) || (track->IsOnLayer( aLayer )) )
-            return static_cast<VIA *>( track );
+        if( (via->GetStart() == aPosition) &&
+                (via->GetState( BUSY | IS_DELETED ) == 0) &&
+                ((aLayer == UNDEFINED_LAYER) || (via->IsOnLayer( aLayer ))) )
+            return via;
     }
 
     return NULL;
diff --git a/pcbnew/class_drawsegment.h b/pcbnew/class_drawsegment.h
index 635a3235d7..64ce5dcb8c 100644
--- a/pcbnew/class_drawsegment.h
+++ b/pcbnew/class_drawsegment.h
@@ -68,9 +68,6 @@ public:
     /// skip the linked list stuff, and parent
     const DRAWSEGMENT& operator = ( const DRAWSEGMENT& rhs );
 
-    DRAWSEGMENT* Next() const { return (DRAWSEGMENT*) Pnext; }
-    DRAWSEGMENT* Back() const { return (DRAWSEGMENT*) Pback; }
-
     void SetWidth( int aWidth )             { m_Width = aWidth; }
     int GetWidth() const                    { return m_Width; }
 
diff --git a/pcbnew/class_edge_mod.h b/pcbnew/class_edge_mod.h
index 8c6559ad74..18790d9b9b 100644
--- a/pcbnew/class_edge_mod.h
+++ b/pcbnew/class_edge_mod.h
@@ -51,9 +51,6 @@ public:
 
     ~EDGE_MODULE();
 
-    EDGE_MODULE* Next() const { return (EDGE_MODULE*) Pnext; }
-    EDGE_MODULE* Back() const { return (EDGE_MODULE*) Pback; }
-
     /// skip the linked list stuff, and parent
     const EDGE_MODULE& operator = ( const EDGE_MODULE& rhs );
 
diff --git a/pcbnew/class_mire.h b/pcbnew/class_mire.h
index da42a07fb0..0a7186b6b1 100644
--- a/pcbnew/class_mire.h
+++ b/pcbnew/class_mire.h
@@ -56,9 +56,6 @@ public:
 
     ~PCB_TARGET();
 
-    PCB_TARGET* Next() const { return (PCB_TARGET*) Pnext; }
-    PCB_TARGET* Back() const { return (PCB_TARGET*) Pnext; }
-
     void SetPosition( const wxPoint& aPos ) { m_Pos = aPos; }   // override
     const wxPoint& GetPosition() const      { return m_Pos; }   // override
 
diff --git a/pcbnew/class_module.cpp b/pcbnew/class_module.cpp
index 26527c095a..ca343a6333 100644
--- a/pcbnew/class_module.cpp
+++ b/pcbnew/class_module.cpp
@@ -422,9 +422,12 @@ EDA_RECT MODULE::GetFootprintRect() const
     area.SetEnd( m_Pos );
     area.Inflate( Millimeter2iu( 0.25 ) );   // Give a min size to the area
 
-    for( EDGE_MODULE* edge = (EDGE_MODULE*) m_Drawings.GetFirst(); edge; edge = edge->Next() )
-        if( edge->Type() == PCB_MODULE_EDGE_T )
+    for( const BOARD_ITEM* item = m_Drawings.GetFirst(); item; item = item->Next() )
+    {
+        const EDGE_MODULE *edge = dynamic_cast<const EDGE_MODULE*>( item );
+        if( edge )
             area.Merge( edge->GetBoundingBox() );
+    }
 
     for( D_PAD* pad = m_Pads;  pad;  pad = pad->Next() )
         area.Merge( pad->GetBoundingBox() );
diff --git a/pcbnew/class_module.h b/pcbnew/class_module.h
index 3127d73fb1..189abfe6be 100644
--- a/pcbnew/class_module.h
+++ b/pcbnew/class_module.h
@@ -77,8 +77,8 @@ public:
 
     ~MODULE();
 
-    MODULE* Next() const { return (MODULE*) Pnext; }
-    MODULE* Back() const { return (MODULE*) Pback; }
+    MODULE* Next() const { return static_cast<MODULE*>( Pnext ); }
+    MODULE* Back() const { return static_cast<MODULE*>( Pback ); }
 
     void Copy( MODULE* Module );        // Copy structure
 
diff --git a/pcbnew/class_pad.h b/pcbnew/class_pad.h
index 11b49568c1..3cbdcbe82a 100644
--- a/pcbnew/class_pad.h
+++ b/pcbnew/class_pad.h
@@ -106,7 +106,7 @@ public:
 
     void Copy( D_PAD* source );
 
-    D_PAD* Next() const       { return (D_PAD*) Pnext; }
+    D_PAD* Next() const       { return static_cast<D_PAD*>( Pnext ); }
 
     MODULE* GetParent() const { return (MODULE*) m_Parent; }
 
diff --git a/pcbnew/class_text_mod.h b/pcbnew/class_text_mod.h
index 97e15ab202..bc207e7254 100644
--- a/pcbnew/class_text_mod.h
+++ b/pcbnew/class_text_mod.h
@@ -98,10 +98,6 @@ public:
 
     void Flip( const wxPoint& aCentre );
 
-    TEXTE_MODULE* Next() const { return (TEXTE_MODULE*) Pnext; }
-
-    TEXTE_MODULE* Back() const { return (TEXTE_MODULE*) Pback; }
-
     /// @deprecated it seems (but the type is used to 'protect'
     //reference and value from deletion, and for identification)
     void SetType( TEXT_TYPE aType )     { m_Type = aType; }
diff --git a/pcbnew/class_track.cpp b/pcbnew/class_track.cpp
index abf4d7a732..8b454c9610 100644
--- a/pcbnew/class_track.cpp
+++ b/pcbnew/class_track.cpp
@@ -88,12 +88,9 @@ inline bool IsNear( const wxPoint& p1, const wxPoint& p2, int max_dist )
 }
 
 
-TRACK* GetTrack( TRACK* aStartTrace, TRACK* aEndTrace,
+TRACK* GetTrack( TRACK* aStartTrace, const TRACK* aEndTrace,
         const wxPoint& aPosition, LAYER_MSK aLayerMask )
 {
-    if( aStartTrace == NULL )
-        return NULL;
-
     for( TRACK *PtSegm = aStartTrace; PtSegm != NULL; PtSegm = PtSegm->Next() )
     {
         if( PtSegm->GetState( IS_DELETED | BUSY ) == 0 )
@@ -180,7 +177,6 @@ VIA::VIA( BOARD_ITEM* aParent ) :
 {
     SetViaType( VIA_THROUGH );
     m_BottomLayer = LAYER_N_BACK;
-    m_Width = Millimeter2iu( 0.5 );
     SetDrillDefault();
 }
 
@@ -369,9 +365,14 @@ void TRACK::Flip( const wxPoint& aCentre )
 {
     m_Start.y = aCentre.y - (m_Start.y - aCentre.y);
     m_End.y   = aCentre.y - (m_End.y - aCentre.y);
+    SetLayer( FlipLayer( GetLayer() ) );
+}
 
-    if( Type() != PCB_VIA_T )
-        SetLayer( FlipLayer( GetLayer() ) );
+
+void VIA::Flip( const wxPoint& aCentre )
+{
+    m_Start.y = aCentre.y - (m_Start.y - aCentre.y);
+    m_End.y   = aCentre.y - (m_End.y - aCentre.y);
 }
 
 
diff --git a/pcbnew/class_track.h b/pcbnew/class_track.h
index 63c9026967..0417048fa3 100644
--- a/pcbnew/class_track.h
+++ b/pcbnew/class_track.h
@@ -74,7 +74,7 @@ enum VIATYPE_T
  *                   layer mask.
  * @return A TRACK object pointer if found otherwise NULL.
  */
-extern TRACK* GetTrack( TRACK* aStartTrace, TRACK* aEndTrace,
+extern TRACK* GetTrack( TRACK* aStartTrace, const TRACK* aEndTrace,
         const wxPoint& aPosition, LAYER_MSK aLayerMask );
 
 class TRACK : public BOARD_CONNECTED_ITEM
@@ -100,8 +100,8 @@ public:
 
     // Do not create a copy constructor.  The one generated by the compiler is adequate.
 
-    TRACK* Next() const { return (TRACK*) Pnext; }
-    TRACK* Back() const { return (TRACK*) Pback; }
+    TRACK* Next() const { return static_cast<TRACK*>( Pnext ); }
+    TRACK* Back() const { return static_cast<TRACK*>( Pback ); }
 
     virtual void Move( const wxPoint& aMoveVector )
     {
@@ -350,7 +350,7 @@ public:
     }
 
 
-    SEGZONE* Next() const { return (SEGZONE*) Pnext; }
+    SEGZONE* Next() const { return static_cast<SEGZONE*>( Pnext ); }
 
     wxString GetSelectMenuText() const;
 
@@ -415,6 +415,8 @@ public:
     /// @copydoc VIEW_ITEM::ViewGetLayers()
     virtual void ViewGetLayers( int aLayers[], int& aCount ) const;
 
+    virtual void Flip( const wxPoint& aCentre );
+
 #if defined (DEBUG)
     virtual void Show( int nestLevel, std::ostream& os ) const { ShowDummy( os ); }    // override
 #endif
@@ -469,5 +471,13 @@ private:
     int       m_Drill;          // for vias: via drill (- 1 for default value)
 };
 
+/// Scan a track list for the first VIA o NULL if not found (or NULL passed)
+inline VIA *GetFirstVia( TRACK *aTrk, const TRACK *aStopPoint = NULL )
+{
+    while( aTrk && (aTrk != aStopPoint) && (aTrk->Type() != PCB_VIA_T) )
+        aTrk = aTrk->Next();
+
+    return static_cast<VIA*>( aTrk );
+}
 
 #endif /* CLASS_TRACK_H */
diff --git a/pcbnew/clean.cpp b/pcbnew/clean.cpp
index 4bcfb5127e..127f0cbae5 100644
--- a/pcbnew/clean.cpp
+++ b/pcbnew/clean.cpp
@@ -87,6 +87,11 @@ private:
      */
     TRACK* mergeCollinearSegmentIfPossible( TRACK* aTrackRef,
                                            TRACK* aCandidate, ENDPOINT_T aEndType );
+
+    const ZONE_CONTAINER* zoneForTrackEndpoint( const TRACK *aTrack,
+            ENDPOINT_T aEndPoint );
+
+    bool testTrackEndpointDangling( TRACK *aTrack, ENDPOINT_T aEndPoint );
 };
 
 /* Install the cleanup dialog frame to know what should be cleaned
@@ -101,7 +106,7 @@ void PCB_EDIT_FRAME::Clean_Pcb()
     wxBusyCursor( dummy );
     TRACKS_CLEANER cleaner( GetBoard() );
 
-    cleaner.CleanupBoard( this, dlg.m_cleanVias, dlg.m_mergeSegments, 
+    cleaner.CleanupBoard( this, dlg.m_cleanVias, dlg.m_mergeSegments,
                           dlg.m_deleteUnconnectedSegm );
     m_canvas->Refresh( true );
 }
@@ -134,8 +139,6 @@ bool TRACKS_CLEANER::CleanupBoard( PCB_EDIT_FRAME *aFrame,
     if( modified )
     {
         // Clear undo and redo lists to avoid inconsistencies between lists
-        // XXX This is very involved... maybe a member in PCB_EDIT_FRAME
-        // would be better?
         aFrame->GetScreen()->ClearUndoRedoList();
         aFrame->SetCurItem( NULL );
         aFrame->Compile_Ratsnest( NULL, true );
@@ -158,7 +161,7 @@ void TRACKS_CLEANER::buildTrackConnectionInfo()
     BuildTracksCandidatesList( m_Brd->m_Track, NULL);
 
     // clear flags and variables used in cleanup
-    for( TRACK * track = m_Brd->m_Track; track; track = track->Next() )
+    for( TRACK *track = m_Brd->m_Track; track != NULL; track = track->Next() )
     {
         track->start = NULL;
         track->end = NULL;
@@ -168,7 +171,7 @@ void TRACKS_CLEANER::buildTrackConnectionInfo()
 
     // Build connections info tracks to pads
     SearchTracksConnectedToPads();
-    for( TRACK * track = m_Brd->m_Track; track; track = track->Next() )
+    for( TRACK *track = m_Brd->m_Track; track != NULL; track = track->Next() )
     {
         // Mark track if connected to pads
         for( unsigned jj = 0; jj < track->m_PadsConnected.size(); jj++ )
@@ -194,70 +197,50 @@ bool TRACKS_CLEANER::clean_vias()
 {
     bool modified = false;
 
-    for( TRACK* track = m_Brd->m_Track; track; track = track->Next() )
+    for( VIA* via = GetFirstVia( m_Brd->m_Track ); via != NULL;
+            via = GetFirstVia( via->Next() ) )
     {
-        // Correct via m_End defects (if any)
-        if( track->Type() == PCB_VIA_T )
+        // Correct via m_End defects (if any), should never happen
+        if( via->GetStart() != via->GetEnd() )
         {
-            if( track->GetStart() != track->GetEnd() )
-                track->SetEnd( track->GetStart() );
-
-            VIA *via = static_cast<VIA*>( track );
-            /* Important: this cleanup only does thru hole vias, it doesn't
-            * (yet) handle high density interconnects */
-            if( via->GetViaType() != VIA_THROUGH )
-                continue;
+            wxFAIL_MSG( "Via with mismatching ends" );
+            via->SetEnd( via->GetStart() );
         }
-        else
-            continue;
 
-        // Search and delete others vias at same location
-        TRACK* alt_track = track->Next();
-
-        TRACK* next_track;
-        for( ; alt_track != NULL; alt_track = next_track )
+        /* Important: these cleanups only do thru hole vias, they don't
+         * (yet) handle high density interconnects */
+        if( via->GetViaType() != VIA_THROUGH )
         {
-            next_track = alt_track->Next();
-            VIA *alt_via = dynamic_cast<VIA*>( alt_track );
-            if( alt_via )
+            // Search and delete others vias at same location
+            VIA* next_via;
+            for( VIA* alt_via = GetFirstVia( via->Next() ); alt_via != NULL;
+                    alt_via = next_via )
             {
-                if( alt_via->GetViaType() != VIA_THROUGH )
-                    continue;
+                next_via = GetFirstVia( alt_via->Next() );
 
-                if( alt_via->GetStart() != track->GetStart() )
-                    continue;
-
-                // delete via
-                alt_track->UnLink();
-                delete alt_track;
-                modified = true;
+                if( (alt_via->GetViaType() == VIA_THROUGH) &&
+                    (alt_via->GetStart() == via->GetStart()) )
+                {
+                    // delete via
+                    alt_via->DeleteStructure();
+                    modified = true;
+                }
             }
-        }
-    }
 
-    // Delete Via on pads at same location
-    TRACK* next_track;
-    for( TRACK* track = m_Brd->m_Track; track != NULL; track = next_track )
-    {
-        next_track = track->Next();
-
-        VIA *via = dynamic_cast<VIA*>( track );
-        if( !via || (via->GetViaType() != VIA_THROUGH ))
-            continue;
-
-        // Examine the list of connected pads:
-        // if one pad through is found, the via can be removed
-        for( unsigned ii = 0; ii < track->m_PadsConnected.size(); ii++ )
-        {
-            D_PAD * pad = track->m_PadsConnected[ii];
-
-            if( (pad->GetLayerMask() & ALL_CU_LAYERS) == ALL_CU_LAYERS )
+            /* To delete through Via on THT pads at same location
+             * Examine the list of connected pads:
+             * if one through pad is found, the via can be removed */
+            for( unsigned ii = 0; ii < via->m_PadsConnected.size(); ++ii )
             {
-                // redundant: via delete it
-                track->UnLink();
-                delete track;
-                modified = true;
-                break;
+                const D_PAD *pad = via->m_PadsConnected[ii];
+
+                if( (pad->GetLayerMask() & ALL_CU_LAYERS) == ALL_CU_LAYERS )
+                {
+                    // redundant: delete the via
+                    via->DeleteStructure();
+                    modified = true;
+                    break;
+                }
             }
         }
     }
@@ -265,6 +248,64 @@ bool TRACKS_CLEANER::clean_vias()
     return modified;
 }
 
+/// Utility for checking if a track/via ends on a zone
+const ZONE_CONTAINER* TRACKS_CLEANER::zoneForTrackEndpoint( const TRACK *aTrack,
+        ENDPOINT_T aEndPoint )
+{
+    // Vias are special cased, since they get a layer range, not a single one
+    LAYER_NUM top_layer, bottom_layer;
+    const VIA *via = dynamic_cast<const VIA*>( aTrack );
+
+    if( via )
+        via->LayerPair( &top_layer, &bottom_layer );
+    else
+    {
+        top_layer = aTrack->GetLayer();
+        bottom_layer = top_layer;
+    }
+    return m_Brd->HitTestForAnyFilledArea( aTrack->GetEndPoint( aEndPoint ),
+            top_layer, bottom_layer, aTrack->GetNetCode() );
+}
+
+/** Utility: does the endpoint unconnected processed for one endpoint of one track
+ * Returns true if the track must be deleted, false if not necessarily */
+bool TRACKS_CLEANER::testTrackEndpointDangling( TRACK *aTrack, ENDPOINT_T aEndPoint )
+{
+    bool flag_erase = false;
+
+    TRACK* other = aTrack->GetTrack( m_Brd->m_Track, NULL, aEndPoint );
+    if( (other == NULL) &&
+            (zoneForTrackEndpoint( aTrack, aEndPoint ) == NULL) )
+        flag_erase = true; // Start endpoint is neither on pad, zone or other track
+    else    // segment, via or zone connected to this end
+    {
+        // Fill connectivity informations
+        if( aEndPoint == ENDPOINT_START )
+            aTrack->start = other;
+        else
+            aTrack->end = other;
+
+        /* If a via is connected to this end, test if this via has a second item connected.
+         * If not, remove the current segment (the via would then become
+         * unconnected and remove on the following pass) */
+        VIA* via = dynamic_cast<VIA*>( other );
+        if( via )
+        {
+            // search for another segment following the via
+            aTrack->SetState( BUSY, true );
+
+            other = via->GetTrack( m_Brd->m_Track, NULL, aEndPoint );
+
+            // There is a via on the start but it goes nowhere
+            if( (other == NULL) &&
+                    (zoneForTrackEndpoint( via, aEndPoint ) == NULL) )
+                flag_erase = true;
+
+            aTrack->SetState( BUSY, false );
+        }
+    }
+    return flag_erase;
+}
 
 /*
  *  Delete dangling tracks
@@ -277,161 +318,44 @@ bool TRACKS_CLEANER::deleteUnconnectedTracks()
         return false;
 
     bool modified = false;
-    bool item_erased = true;
-    while( item_erased )    // Iterate when at least one track is deleted
+    bool item_erased;
+    do // Iterate when at least one track is deleted
     {
         item_erased = false;
         TRACK* next_track;
-        for( TRACK * track = m_Brd->m_Track; track ; track = next_track )
+        for( TRACK *track = m_Brd->m_Track; track != NULL; track = next_track )
         {
             next_track = track->Next();
 
-            int flag_erase = 0; //Not connected indicator
-            int type_end = 0;
+            bool flag_erase = false; // Start without a good reason to erase it
 
-            if( track->GetState( START_ON_PAD ) )
-                type_end |= START_ON_PAD;
+            /* if a track endpoint is not connected to a pad, test if
+             * the endpoint is connected to another track or to a zone.
+             * For via test, an enhancement could be to test if
+             * connected to 2 items on different layers. Currently
+             * a via must be connected to 2 items, that can be on the
+             * same layer */
 
-            if( track->GetState( END_ON_PAD ) )
-                type_end |= END_ON_PAD;
+            // Check if there is nothing attached on the start
+            if( !(track->GetState( START_ON_PAD )) )
+                flag_erase |= testTrackEndpointDangling( track, ENDPOINT_START );
 
-            // if the track start point is not connected to a pad,
-            // test if this track start point is connected to another track
-            // For via test, an enhancement could be to test if connected
-            // to 2 items on different layers.
-            // Currently a via must be connected to 2 items, that can be on the same layer
-            LAYER_NUM top_layer, bottom_layer;
-            ZONE_CONTAINER* zone;
-
-            if( (type_end & START_ON_PAD ) == 0 )
-            {
-                TRACK* other = track->GetTrack( m_Brd->m_Track, NULL, ENDPOINT_START );
-
-                if( other == NULL )     // Test a connection to zones
-                {
-                    if( track->Type() != PCB_VIA_T )
-                    {
-                        zone = m_Brd->HitTestForAnyFilledArea( track->GetStart(),
-                                                               track->GetLayer(),
-                                                               track->GetLayer(),
-                                                               track->GetNetCode() );
-                    }
-                    else
-                    {
-                        ((VIA*)track)->LayerPair( &top_layer, &bottom_layer );
-                        zone = m_Brd->HitTestForAnyFilledArea( track->GetStart(),
-                                                               top_layer, bottom_layer,
-                                                               track->GetNetCode() );
-                    }
-                }
-
-                if( (other == NULL) && (zone == NULL) )
-                {
-                    flag_erase |= 1;
-                }
-                else    // segment, via or zone connected to this end
-                {
-                    track->start = other;
-                    // If a via is connected to this end,
-                    // test if this via has a second item connected.
-                    // If no, remove it with the current segment
-
-                    if( other && other->Type() == PCB_VIA_T )
-                    {
-                        // search for another segment following the via
-                        track->SetState( BUSY, true );
-
-                        VIA* via = (VIA*) other;
-                        other = via->GetTrack( m_Brd->m_Track, NULL, ENDPOINT_START );
-
-                        if( other == NULL )
-                        {
-                            via->LayerPair( &top_layer, &bottom_layer );
-                            zone = m_Brd->HitTestForAnyFilledArea( via->GetStart(),
-                                                                   bottom_layer,
-                                                                   top_layer,
-                                                                   via->GetNetCode() );
-                        }
-
-                        if( (other == NULL) && (zone == NULL) )
-                            flag_erase |= 2;
-
-                        track->SetState( BUSY, false );
-                    }
-                }
-            }
-
-            // if track end point is not connected to a pad,
-            // test if this track end point is connected to an other track
-            if( (type_end & END_ON_PAD ) == 0 )
-            {
-                TRACK* other = track->GetTrack( m_Brd->m_Track, NULL, ENDPOINT_END );
-
-                if( other == NULL )     // Test a connection to zones
-                {
-                    if( track->Type() != PCB_VIA_T )
-                    {
-                        zone = m_Brd->HitTestForAnyFilledArea( track->GetEnd(),
-                                                               track->GetLayer(),
-                                                               track->GetLayer(),
-                                                               track->GetNetCode() );
-                    }
-                    else
-                    {
-                        ((VIA*)track)->LayerPair( &top_layer, &bottom_layer );
-                        zone = m_Brd->HitTestForAnyFilledArea( track->GetEnd(),
-                                                               top_layer, bottom_layer,
-                                                               track->GetNetCode() );
-                    }
-                }
-
-                if ( (other == NULL) && (zone == NULL) )
-                {
-                    flag_erase |= 0x10;
-                }
-                else     // segment, via or zone connected to this end
-                {
-                    track->end = other;
-
-                    // If a via is connected to this end, test if this via has a second item connected
-                    // if no, remove it with the current segment
-
-                    if( other && other->Type() == PCB_VIA_T )
-                    {
-                        // search for another segment following the via
-
-                        track->SetState( BUSY, true );
-
-                        VIA* via = (VIA*) other;
-                        other = via->GetTrack( m_Brd->m_Track, NULL, ENDPOINT_END );
-
-                        if( other == NULL )
-                        {
-                            via->LayerPair( &top_layer, &bottom_layer );
-                            zone = m_Brd->HitTestForAnyFilledArea( via->GetEnd(),
-                                                                   bottom_layer, top_layer,
-                                                                   via->GetNetCode() );
-                        }
-
-                        if( (other == NULL) && (zone == NULL) )
-                            flag_erase |= 0x20;
-
-                        track->SetState( BUSY, false );
-                    }
-                }
-            }
+            // Check if there is nothing attached on the end
+            if( !(track->GetState( END_ON_PAD )) )
+                flag_erase |= testTrackEndpointDangling( track, ENDPOINT_END );
 
             if( flag_erase )
             {
                 // remove segment from board
                 track->DeleteStructure();
-                // iterate, because a track connected to the deleted track
-                // is now perhaps now not connected and should be deleted
+
+                /* keep iterating, because a track connected to the deleted track
+                 * now perhaps is not connected and should be deleted */
                 item_erased = true;
                 modified = true;
             }
         }
-    }
+    } while( item_erased );
 
     return modified;
 }
diff --git a/pcbnew/edgemod.cpp b/pcbnew/edgemod.cpp
index 7239dc37a8..77019494f2 100644
--- a/pcbnew/edgemod.cpp
+++ b/pcbnew/edgemod.cpp
@@ -169,12 +169,11 @@ void FOOTPRINT_EDIT_FRAME::Edit_Edge_Width( EDGE_MODULE* aEdge )
     {
         aEdge = (EDGE_MODULE*) (BOARD_ITEM*) module->GraphicalItems();
 
-        for( ; aEdge != NULL; aEdge = aEdge->Next() )
+        for( BOARD_ITEM *item = module->GraphicalItems(); item; item = item->Next() )
         {
-            if( aEdge->Type() != PCB_MODULE_EDGE_T )
-                continue;
-
-            aEdge->SetWidth( GetDesignSettings().m_ModuleSegmentWidth );
+            aEdge = dynamic_cast<EDGE_MODULE*>( item );
+            if( aEdge )
+                aEdge->SetWidth( GetDesignSettings().m_ModuleSegmentWidth );
         }
     }
     else
@@ -216,14 +215,12 @@ void FOOTPRINT_EDIT_FRAME::Edit_Edge_Layer( EDGE_MODULE* aEdge )
 
     if( aEdge == NULL )
     {
-        aEdge = (EDGE_MODULE*) (BOARD_ITEM*) module->GraphicalItems();
-
-        for( ; aEdge != NULL; aEdge = aEdge->Next() )
+        for( BOARD_ITEM *item = module->GraphicalItems() ; item != NULL;
+                item = item->Next() )
         {
-            if( aEdge->Type() != PCB_MODULE_EDGE_T )
-                continue;
+            aEdge = dynamic_cast<EDGE_MODULE*>( item );
 
-            if( aEdge->GetLayer() != new_layer )
+            if( aEdge && (aEdge->GetLayer() != new_layer) )
             {
                 if( ! modified )    // save only once
                     SaveCopyInUndoList( module, UR_MODEDIT );
diff --git a/pcbnew/editrack.cpp b/pcbnew/editrack.cpp
index 683b7d41d7..220668148c 100644
--- a/pcbnew/editrack.cpp
+++ b/pcbnew/editrack.cpp
@@ -62,9 +62,9 @@ static void Abort_Create_Track( EDA_DRAW_PANEL* Panel, wxDC* DC )
 {
     PCB_EDIT_FRAME* frame = (PCB_EDIT_FRAME*) Panel->GetParent();
     BOARD* pcb = frame->GetBoard();
-    TRACK* track = (TRACK*) frame->GetCurItem();
+    TRACK* track = dynamic_cast<TRACK*>( frame->GetCurItem() );
 
-    if( track && ( track->Type()==PCB_VIA_T || track->Type()==PCB_TRACE_T ) )
+    if( track )
     {
         // Erase the current drawing
         ShowNewTrackWhenMovingCursor( Panel, DC, wxDefaultPosition, false );
diff --git a/pcbnew/exporters/export_gencad.cpp b/pcbnew/exporters/export_gencad.cpp
index 601c91ae6d..c1895cbc7b 100644
--- a/pcbnew/exporters/export_gencad.cpp
+++ b/pcbnew/exporters/export_gencad.cpp
@@ -271,12 +271,10 @@ static void CreatePadsShapesSection( FILE* aFile, BOARD* aPcb )
     }
 
     // The same for vias
-    for( TRACK* track = aPcb->m_Track; track != NULL; track = track->Next() )
+    for( VIA* via = GetFirstVia( aPcb->m_Track ); via != NULL; 
+            via = GetFirstVia( via->Next() ) )
     {
-        if( track->Type() == PCB_VIA_T )
-        {
-            vias.push_back( static_cast<VIA*>(track) );
-        }
+        vias.push_back( via );
     }
 
     qsort( &vias[0], vias.size(), sizeof(VIA*), ViaSort );
diff --git a/pcbnew/exporters/gendrill_Excellon_writer.cpp b/pcbnew/exporters/gendrill_Excellon_writer.cpp
index a8a086187a..679df5bed1 100644
--- a/pcbnew/exporters/gendrill_Excellon_writer.cpp
+++ b/pcbnew/exporters/gendrill_Excellon_writer.cpp
@@ -453,12 +453,9 @@ void EXCELLON_WRITER::BuildHolesList( int aFirstLayer,
     // build hole list for vias
     if( ! aGenerateNPTH_list )  // vias are always plated !
     {
-        for( TRACK* track = m_pcb->m_Track;  track;  track = track->Next() )
+        for( VIA* via = GetFirstVia( m_pcb->m_Track ); via;
+                via = GetFirstVia( via->Next() ) )
         {
-            if( track->Type() != PCB_VIA_T )
-                continue;
-
-            const VIA* via = (const VIA*) track;
             hole_value = via->GetDrillValue();
 
             if( hole_value == 0 )
diff --git a/pcbnew/plot_brditems_plotter.cpp b/pcbnew/plot_brditems_plotter.cpp
index 1535b3593f..8494eb560b 100644
--- a/pcbnew/plot_brditems_plotter.cpp
+++ b/pcbnew/plot_brditems_plotter.cpp
@@ -148,10 +148,11 @@ bool BRDITEMS_PLOTTER::PlotAllTextsModule( MODULE* aModule )
             PlotTextModule( &aModule->Value(), GetValueColor() );
     }
 
-    for( textModule = (TEXTE_MODULE*) aModule->GraphicalItems().GetFirst();
-         textModule != NULL; textModule = textModule->Next() )
+    for( BOARD_ITEM *item = aModule->GraphicalItems().GetFirst();
+         item != NULL; item = item->Next() )
     {
-        if( textModule->Type() != PCB_MODULE_TEXT_T )
+        textModule = dynamic_cast<TEXTE_MODULE*>( item );
+        if( !textModule )
             continue;
 
         if( !GetPlotOtherText() )
@@ -350,13 +351,11 @@ void BRDITEMS_PLOTTER::Plot_Edges_Modules()
 {
     for( MODULE* module = m_board->m_Modules;  module;  module = module->Next() )
     {
-        for( EDGE_MODULE* edge = (EDGE_MODULE*) module->GraphicalItems().GetFirst();
-             edge; edge = edge->Next() )
+        for( BOARD_ITEM* item = module->GraphicalItems().GetFirst(); item; item = item->Next() )
         {
-            if( edge->Type() != PCB_MODULE_EDGE_T )
-                continue;
+            EDGE_MODULE *edge = dynamic_cast<EDGE_MODULE*>( item );
 
-            if( ( GetLayerMask( edge->GetLayer() ) & m_layerMask ) == 0 )
+            if( !edge || (( GetLayerMask( edge->GetLayer() ) & m_layerMask ) == 0) )
                 continue;
 
             Plot_1_EdgeModule( edge );