Pcbnew, connectivity: fix incorrect detection of dangling track ends when a end is inside a zone.

This end was not detected as connected by the IsDangling method.
Fix incorrect cleaning of dangling tracks in track cleaner.
Remove also a dead code.
The merge co-linear track segments is still full bugged in track cleaner.

pcbnew/connectivity/connectivity_items.cpp

@@ -2,7 +2,7 @@
  * This program source code file is part of KICAD, a free EDA CAD application.
  *
  * Copyright (C) 2016-2018 CERN
- * Copyright (C) 2018  KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2019  KiCad Developers, see AUTHORS.txt for contributors.
  *
  * @author Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
  *
@@ -265,12 +265,20 @@ bool CN_ANCHOR::IsDangling() const
     if( m_item->AnchorCount() == 1 )
         return connected_count < minimal_count;
 
-    // Only items with multiple anchors might have additional items connected that we
+    // Items with multiple anchors have usually items connected to each anchor.
-    // should ignore for this calculation.
+    // We want only the item count of this anchor point
+    connected_count = 0;
     for( auto item : m_item->ConnectedItems() )
     {
-        if( !item->Parent()->HitTest( wxPoint( Pos().x, Pos().y ) ) )
+        if( item->Parent()->Type() == PCB_ZONE_AREA_T )
-            connected_count--;
+        {
+            ZONE_CONTAINER* zone = static_cast<ZONE_CONTAINER*>( item->Parent() );
+
+            if( zone->HitTestFilledArea( wxPoint( Pos().x, Pos().y ) ) )
+                connected_count++;
+        }
+        else if( item->Parent()->HitTest( wxPoint( Pos().x, Pos().y ) ) )
+            connected_count++;
     }
 
     return connected_count < minimal_count;

pcbnew/tracks_cleaner.cpp

@@ -223,21 +223,6 @@ bool TRACKS_CLEANER::cleanupVias()
 }
 
 
-bool TRACKS_CLEANER::testTrackHasPad( const TRACK* aTrack ) const
-{
-    auto connectivity = m_brd->GetConnectivity();
-
-    // Mark track if connected to pads
-    for( auto pad : connectivity->GetConnectedPads( aTrack ) )
-    {
-        if( pad->HitTest( aTrack->GetStart() ) || pad->HitTest( aTrack->GetEnd() ) )
-            return true;
-    }
-
-    return false;
-}
-
-
 bool TRACKS_CLEANER::testTrackEndpointDangling( TRACK* aTrack )
 {
     auto connectivity = m_brd->GetConnectivity();
@@ -275,19 +260,16 @@ bool TRACKS_CLEANER::deleteDanglingTracks()
     do // Iterate when at least one track is deleted
     {
         item_erased = false;
+        // Ensure the connectivity is up to date, especially after removind a dangling segment
+        m_brd->BuildConnectivity();
 
         for( TRACK* track : m_brd->Tracks() )
         {
             bool flag_erase = false; // Start without a good reason to erase it
 
-            if( track->Type() != PCB_TRACE_T )
+            // Tst if a track (or a via) endpoint is not connected to another track or to a zone.
-                continue;
+            if( testTrackEndpointDangling( track ) )
-
+                flag_erase = true;
-            // if a track endpoint is not connected to a pad, test if
-            // the endpoint is connected to another track or to a zone.
-
-            if( !testTrackHasPad( track ) )
-                flag_erase |= testTrackEndpointDangling( track );
 
             if( flag_erase )
             {
@@ -307,11 +289,12 @@ bool TRACKS_CLEANER::deleteDanglingTracks()
                      * now perhaps is not connected and should be deleted */
                     item_erased = true;
                     modified = true;
-                    break;
+                }
+                // Fix me: In dry run we should disable the track to erase and retry with this disabled track
+                // However the connectivity algo does not handle disabled items.
             }
         }
-        }
+    } while( item_erased ); // A segment was erased: test for some new dangling segments
-    } while( item_erased );
 
     return modified;
 }

pcbnew/tracks_cleaner.h

@@ -56,13 +56,6 @@ private:
      */
     bool removeBadTrackSegments();
 
-    /**
-     * Checks whether the track is connected to a pad
-     * @param aTrack pointer to the track
-     * @return true if the track has a pad
-     */
-    bool testTrackHasPad( const TRACK* aTrack ) const;
-
     /**
      * Removes redundant vias like vias at same location
      * or on pad through