Router: fix Continue From End/ Attempt Finish work for diff pairs

Fixes: https://gitlab.com/kicad/code/kicad/-/issues/13772

pcbnew/router/pns_diff_pair_placer.cpp

@@ -435,6 +435,15 @@ OPT_VECTOR2I getDanglingAnchor( NODE* aNode, ITEM* aItem )
 {
     switch( aItem->Kind() )
     {
+    case ITEM::LINE_T:
+    {
+        LINE* l = static_cast<LINE*>( aItem );
+
+        if( !l->PointCount() )
+            return OPT_VECTOR2I();
+        else
+            return l->CPoint( 0 );
+    }
     case ITEM::VIA_T:
     case ITEM::SOLID_T:
         return aItem->Anchor( 0 );

pcbnew/router/pns_kicad_iface.cpp

@@ -63,6 +63,7 @@
 #include "pns_routing_settings.h"
 #include "pns_sizes_settings.h"
 #include "pns_item.h"
+#include "pns_line.h"
 #include "pns_solid.h"
 #include "pns_segment.h"
 #include "pns_node.h"
@@ -862,11 +863,18 @@ int PNS_PCBNEW_RULE_RESOLVER::DpNetPolarity( int aNet )
 
 bool PNS_PCBNEW_RULE_RESOLVER::DpNetPair( const PNS::ITEM* aItem, int& aNetP, int& aNetN )
 {
-    if( !aItem || !aItem->Parent() || !aItem->Parent()->IsConnected() )
+    if( !aItem )
         return false;
 
-    BOARD_CONNECTED_ITEM* cItem = static_cast<BOARD_CONNECTED_ITEM*>( aItem->Parent() );
+    NETINFO_ITEM* netInfo = nullptr;
-    NETINFO_ITEM*         netInfo = cItem->GetNet();
+
+    if( aItem->Parent() && aItem->Parent()->IsConnected() )
+    {
+        BOARD_CONNECTED_ITEM* cItem = static_cast<BOARD_CONNECTED_ITEM*>( aItem->Parent() );
+        netInfo = cItem->GetNet();
+    }
+    else
+        netInfo = m_board->FindNet( aItem->Net() );
 
     if( !netInfo )
         return false;

pcbnew/router/pns_router.cpp

@@ -480,7 +480,8 @@ bool ROUTER::Move( const VECTOR2I& aP, ITEM* endItem )
 }
 
 
-bool ROUTER::getNearestRatnestAnchor( VECTOR2I& aOtherEnd, LAYER_RANGE& aOtherEndLayers )
+bool ROUTER::getNearestRatnestAnchor( VECTOR2I& aOtherEnd, LAYER_RANGE& aOtherEndLayers,
+                                      ITEM*& aOtherEndItem )
 {
     // Can't finish something with no connections
     if( GetCurrentNets().empty() )
@@ -501,7 +502,8 @@ bool ROUTER::getNearestRatnestAnchor( VECTOR2I& aOtherEnd, LAYER_RANGE& aOtherEn
 
     // If the user has drawn a line, get the anchor nearest to the line end
     if( trace->SegmentCount() > 0 )
-        return topo.NearestUnconnectedAnchorPoint( trace, aOtherEnd, aOtherEndLayers );
+        return topo.NearestUnconnectedAnchorPoint( trace, aOtherEnd, aOtherEndLayers,
+                                                   aOtherEndItem );
 
     // Otherwise, find the closest anchor to our start point
 
@@ -521,6 +523,7 @@ bool ROUTER::getNearestRatnestAnchor( VECTOR2I& aOtherEnd, LAYER_RANGE& aOtherEn
 
     aOtherEnd = it->Anchor( anchor );
     aOtherEndLayers = it->Layers();
+    aOtherEndItem = it;
 
     return true;
 }
@@ -531,19 +534,24 @@ bool ROUTER::Finish()
     if( m_state != ROUTE_TRACK )
         return false;
 
-    LINE_PLACER* placer = dynamic_cast<LINE_PLACER*>( Placer() );
+    PLACEMENT_ALGO* placer = Placer();
 
-    if( placer == nullptr )
+    if( placer == nullptr || placer->Traces().Size() == 0 )
+        return false;
+
+    LINE* current = dynamic_cast<LINE*>( placer->Traces()[0] );
+
+    if( current == nullptr )
         return false;
 
     // Get our current line and position and nearest ratsnest to them if it exists
-    PNS::LINE   current = placer->Trace();
     VECTOR2I    currentEnd = placer->CurrentEnd();
     VECTOR2I    otherEnd;
     LAYER_RANGE otherEndLayers;
+    ITEM*       otherEndItem = nullptr;
 
     // Get the anchor nearest to the end of the trace the user is routing
-    if( !getNearestRatnestAnchor( otherEnd, otherEndLayers ) )
+    if( !getNearestRatnestAnchor( otherEnd, otherEndLayers, otherEndItem ) )
         return false;
 
     // Keep moving until we don't change position or hit the limit
@@ -553,14 +561,14 @@ bool ROUTER::Finish()
     do
     {
         moveResultPoint = Placer()->CurrentEnd();
-        Move( otherEnd, &current );
+        Move( otherEnd, otherEndItem );
         triesLeft--;
     } while( Placer()->CurrentEnd() != moveResultPoint && triesLeft );
 
     // If we've made it, fix the route and we're done
     if( moveResultPoint == otherEnd && otherEndLayers.Overlaps( GetCurrentLayer() ) )
     {
-        return FixRoute( otherEnd, &current, false );
+        return FixRoute( otherEnd, otherEndItem, false );
     }
 
     return false;
@@ -583,9 +591,10 @@ bool ROUTER::ContinueFromEnd()
     VECTOR2I    currentEnd = placer->CurrentEnd();
     VECTOR2I    otherEnd;
     LAYER_RANGE otherEndLayers;
+    ITEM*       otherEndItem = nullptr;
 
     // Get the anchor nearest to the end of the trace the user is routing
-    if( !getNearestRatnestAnchor( otherEnd, otherEndLayers ) )
+    if( !getNearestRatnestAnchor( otherEnd, otherEndLayers, otherEndItem ) )
         return false;
 
     CommitRouting();
@@ -593,7 +602,7 @@ bool ROUTER::ContinueFromEnd()
     // Commit whatever we've fixed and restart routing from the other end
     int nextLayer = otherEndLayers.Overlaps( currentLayer ) ? currentLayer : otherEndLayers.Start();
 
-    if( !StartRouting( otherEnd, current, nextLayer ) )
+    if( !StartRouting( otherEnd, otherEndItem, nextLayer ) )
         return false;
 
     // Attempt to route to our current position

pcbnew/router/pns_router.h

@@ -228,7 +228,8 @@ private:
     void markViolations( NODE* aNode, ITEM_SET& aCurrent, NODE::ITEM_VECTOR& aRemoved );
     bool isStartingPointRoutable( const VECTOR2I& aWhere, ITEM* aItem, int aLayer );
 
-    bool getNearestRatnestAnchor( VECTOR2I& aOtherEnd, LAYER_RANGE& aOtherEndLayers );
+    bool getNearestRatnestAnchor( VECTOR2I& aOtherEnd, LAYER_RANGE& aOtherEndLayers,
+                                  ITEM*& aOtherEndItem );
 
 
 private:

pcbnew/router/pns_topology.cpp

@@ -94,7 +94,7 @@ const TOPOLOGY::JOINT_SET TOPOLOGY::ConnectedJoints( JOINT* aStart )
 
 
 bool TOPOLOGY::NearestUnconnectedAnchorPoint( const LINE* aTrack, VECTOR2I& aPoint,
-                                              LAYER_RANGE& aLayers )
+                                              LAYER_RANGE& aLayers, ITEM*& aItem )
 {
     LINE track( *aTrack );
     VECTOR2I end;
@@ -115,6 +115,7 @@ bool TOPOLOGY::NearestUnconnectedAnchorPoint( const LINE* aTrack, VECTOR2I& aPoi
     {
         end = jt->Pos();
         aLayers = jt->Layers();
+        aItem = jt->LinkList()[0];
     }
     else
     {
@@ -128,6 +129,7 @@ bool TOPOLOGY::NearestUnconnectedAnchorPoint( const LINE* aTrack, VECTOR2I& aPoi
 
         end = it->Anchor( anchor );
         aLayers = it->Layers();
+        aItem = it;
     }
 
     aPoint = end;
@@ -140,8 +142,9 @@ bool TOPOLOGY::LeadingRatLine( const LINE* aTrack, SHAPE_LINE_CHAIN& aRatLine )
     VECTOR2I end;
     // Ratline doesn't care about the layer
     LAYER_RANGE layers;
+    ITEM*       unusedItem;
 
-    if( !NearestUnconnectedAnchorPoint( aTrack, end, layers ) )
+    if( !NearestUnconnectedAnchorPoint( aTrack, end, layers, unusedItem ) )
         return false;
 
     aRatLine.Clear();

pcbnew/router/pns_topology.h

@@ -50,8 +50,8 @@ public:
     ITEM* NearestUnconnectedItem( JOINT* aStart, int* aAnchor = nullptr,
                                   int aKindMask = ITEM::ANY_T );
 
-    bool NearestUnconnectedAnchorPoint( const LINE* aTrack, VECTOR2I& aPoint,
+    bool NearestUnconnectedAnchorPoint( const LINE* aTrack, VECTOR2I& aPoint, LAYER_RANGE& aLayers,
-                                        LAYER_RANGE& aLayers );
+                                        ITEM*& aItem );
     bool LeadingRatLine( const LINE* aTrack, SHAPE_LINE_CHAIN& aRatLine );
 
     const JOINT_SET ConnectedJoints( JOINT* aStart );

pcbnew/router/router_tool.cpp

@@ -1369,6 +1369,10 @@ void ROUTER_TOOL::performRouting()
                 // We want the next router commit to be one undo at the UI layer
                 m_iface->SetCommitFlags( needsAppend ? APPEND_UNDO : 0 );
             }
+            else
+            {
+                frame()->ShowInfoBarError( m_router->FailureReason(), true );
+            }
         }
         else if( evt->IsClick( BUT_LEFT ) || evt->IsDrag( BUT_LEFT ) || evt->IsAction( &PCB_ACTIONS::routeSingleTrack ) )
         {