P&S router bugfixes

- fixed walkaround bug causing unwanted overlap/clearance violation when the first segment of trace being laid intersects the obstacle's hull at the same point twice (ie. goes in, turns around and goes out).
- fixed placer bug not splitting the start segment after toggling via placement or changing trace width

common/geometry/shape_line_chain.cpp

@@ -150,10 +150,7 @@ int SHAPE_LINE_CHAIN::Split( const VECTOR2I& aP )
     int ii = -1;
     int min_dist = 2;
 
-    ii = Find( aP );
-
-    if( ii >= 0 )
-        return ii;
+    int found_index = Find( aP );
 
     for( int s = 0; s < SegmentCount(); s++ )
     {
@@ -165,10 +162,16 @@ int SHAPE_LINE_CHAIN::Split( const VECTOR2I& aP )
         if( dist < min_dist && seg.A != aP && seg.B != aP )
         {
             min_dist = dist;
-            ii = s;
+            if(found_index < 0)
+                ii = s;
+            else if(s < found_index)
+                ii = s;
         }
     }
 
+    if( ii < 0 )
+        ii = found_index;
+
     if( ii >= 0 )
     {
         m_points.insert( m_points.begin() + ii + 1, aP );

pcbnew/router/pns_line.cpp

@@ -190,6 +190,9 @@ bool PNS_LINE::Walkaround( SHAPE_LINE_CHAIN aObstacle, SHAPE_LINE_CHAIN& aPre,
 
     line.Intersect( aObstacle, ips );
 
+    aWalk.Clear();
+    aPost.Clear();
+
     int nearest_dist = INT_MAX;
     int farthest_dist = 0;
 

pcbnew/router/pns_line_placer.cpp

@@ -735,7 +735,8 @@ bool PNS_LINE_PLACER::SetLayer( int aLayer )
         return false;
     } else if (!m_startItem || (m_startItem->OfKind(PNS_ITEM::VIA) && m_startItem->Layers().Overlaps( aLayer ))) {
         m_currentLayer = aLayer;
-        initPlacement ( );
+        m_splitSeg = false;
+        initPlacement ( m_splitSeg );
         Move ( m_currentEnd, NULL );
         return true;
     }
@@ -766,10 +767,11 @@ void PNS_LINE_PLACER::Start( const VECTOR2I& aP, PNS_ITEM* aStartItem )
     m_startItem = aStartItem;
     m_placingVia = false;
     m_chainedPlacement = false;
+    m_splitSeg = splitSeg;
 
     setInitialDirection( Settings().InitialDirection() );
     
-    initPlacement( splitSeg );    
+    initPlacement( m_splitSeg );    
 }
 
 void PNS_LINE_PLACER::initPlacement( bool aSplitSeg )
@@ -918,7 +920,8 @@ bool PNS_LINE_PLACER::FixRoute( const VECTOR2I& aP, PNS_ITEM* aEndItem )
         m_startItem = NULL;
         m_placingVia = false;
         m_chainedPlacement = !pl.EndsWithVia();
-        initPlacement(); 
+        m_splitSeg = false;
+        initPlacement( ); 
     } else {
         m_idle = true;
     }
@@ -1000,7 +1003,7 @@ void PNS_LINE_PLACER::UpdateSizes( const PNS_SIZES_SETTINGS& aSizes )
     m_sizes = aSizes;
     if( !m_idle )
     {
-        initPlacement ( );
+        initPlacement ( m_splitSeg );
         Move ( m_currentEnd, NULL );
     }
 }

pcbnew/router/pns_line_placer.h

@@ -402,6 +402,7 @@ private:
 
     bool m_idle;
     bool m_chainedPlacement;
+    bool m_splitSeg;
 };
 
 #endif    // __PNS_LINE_PLACER_H

pcbnew/router/pns_walkaround.cpp

@@ -57,7 +57,7 @@ PNS_WALKAROUND::WALKAROUND_STATUS PNS_WALKAROUND::singleStep( PNS_LINE& aPath,
 
     VECTOR2I last = aPath.CPoint( -1 );
 
-    if( ( current_obs->m_hull ).PointInside( last ) )
+    if( ( current_obs->m_hull ).PointInside( last ) || ( current_obs->m_hull ).PointOnEdge( last ) )
     {
         m_recursiveBlockageCount++;
 
@@ -99,7 +99,10 @@ PNS_WALKAROUND::WALKAROUND_STATUS PNS_WALKAROUND::singleStep( PNS_LINE& aPath,
         pnew.Append( path_walk[1] );
         pnew.Append( path_post[1] );
 
-        current_obs = nearestObstacle( PNS_LINE( aPath, path_post[1] ) );
+        if(!path_post[1].PointCount() || !path_walk[1].PointCount())
+            current_obs = nearestObstacle( PNS_LINE( aPath, path_pre[1] ) );
+        else
+            current_obs = nearestObstacle( PNS_LINE( aPath, path_post[1] ) );
         prev_recursive = false;
     }
     else
@@ -108,7 +111,10 @@ PNS_WALKAROUND::WALKAROUND_STATUS PNS_WALKAROUND::singleStep( PNS_LINE& aPath,
         pnew.Append( path_walk[0] );
         pnew.Append( path_post[0] );
 
-        current_obs = nearestObstacle( PNS_LINE( aPath, path_walk[0] ) );
+        if(!path_post[0].PointCount() || !path_walk[0].PointCount())
+            current_obs = nearestObstacle( PNS_LINE( aPath, path_pre[0] ) );
+        else
+            current_obs = nearestObstacle( PNS_LINE( aPath, path_walk[0] ) );
 
         if( !current_obs )
         {