pcbnew: Synchronize zone removal

After refilling zones, we need to unconditionally remove the filled
polys from the map because their fills map have changed.  Left-over
filled polygons will not map to current polygons, creating "ghost"
islands in the connectivity.  Removing these can overflow the polygon
count.

Fixes: lp:1778454
* https://bugs.launchpad.net/kicad/+bug/1778454

pcbnew/connectivity_algo.cpp

@@ -303,7 +303,7 @@ bool CN_CONNECTIVITY_ALGO::Add( BOARD_ITEM* aItem )
 }
 
 
-void CN_CONNECTIVITY_ALGO::searchConnections( bool aIncludeZones )
+void CN_CONNECTIVITY_ALGO::searchConnections()
 {
 #ifdef CONNECTIVITY_DEBUG
     printf("Search start\n");
@@ -341,10 +341,23 @@ void CN_CONNECTIVITY_ALGO::searchConnections( bool aIncludeZones )
     PROF_COUNTER search_basic( "search-basic" );
 #endif
 
+    if( m_progressReporter )
+    {
+        m_progressReporter->SetMaxProgress(
+                m_zoneList.Size() + ( m_itemList.IsDirty() ? m_itemList.Size() : 0 ) );
+    }
+
+#ifdef USE_OPENMP
+    #pragma omp parallel shared( m_itemList ) num_threads( std::max( omp_get_num_procs(), 2 ) )
+    {
+        if( omp_get_thread_num() == 0 && m_progressReporter )
+            m_progressReporter->KeepRefreshing( true );
+#endif
+
         if( m_itemList.IsDirty() )
         {
 #ifdef USE_OPENMP
-            #pragma omp parallel for schedule(dynamic)
+            #pragma omp parallel for
 #endif
             for( int i = 0; i < m_itemList.Size(); i++ )
             {
@@ -353,10 +366,11 @@ void CN_CONNECTIVITY_ALGO::searchConnections( bool aIncludeZones )
                 {
                     CN_VISITOR visitor( item, &m_listLock );
                     m_itemList.FindNearby( item, visitor );
-
-                if( aIncludeZones )
                     m_zoneList.FindNearby( item, visitor );
                 }
+
+                if( m_progressReporter )
+                    m_progressReporter->AdvanceProgress();
             }
         }
 
@@ -364,15 +378,8 @@ void CN_CONNECTIVITY_ALGO::searchConnections( bool aIncludeZones )
         search_basic.Show();
 #endif
 
-    if( aIncludeZones )
-    {
-        if( m_progressReporter )
-        {
-            m_progressReporter->SetMaxProgress( m_zoneList.Size() );
-        }
-
 #ifdef USE_OPENMP
-            #pragma omp parallel for schedule(dynamic)
+        #pragma omp for
 #endif
         for( int i = 0; i < m_zoneList.Size(); i++ )
         {
@@ -385,12 +392,17 @@ void CN_CONNECTIVITY_ALGO::searchConnections( bool aIncludeZones )
                 m_itemList.FindNearby( item, visitor );
                 m_zoneList.FindNearby( item, visitor );
             }
+
+            if( m_progressReporter )
+                m_progressReporter->AdvanceProgress();
         }
 
+#ifdef USE_OPENMP
+    }
+#endif
+
     m_zoneList.ClearDirtyFlags();
     m_itemList.ClearDirtyFlags();
-    }
-
 
 #ifdef CONNECTIVITY_DEBUG
     printf("Search end\n");
@@ -465,7 +477,7 @@ const CN_CONNECTIVITY_ALGO::CLUSTERS CN_CONNECTIVITY_ALGO::SearchClusters( CLUST
     CLUSTERS clusters;
 
     if( isDirty() )
-        searchConnections( includeZones );
+        searchConnections();
 
     auto addToSearchList = [&head, withinAnyNet, aSingleNet, aTypes] ( CN_ITEM *aItem )
     {
@@ -703,11 +715,11 @@ void CN_CONNECTIVITY_ALGO::FindIsolatedCopperIslands( ZONE_CONTAINER* aZone, std
 void CN_CONNECTIVITY_ALGO::FindIsolatedCopperIslands( std::vector<CN_ZONE_ISOLATED_ISLAND_LIST>& aZones )
 {
     for ( auto& z : aZones )
-    {
-        if( z.m_zone->GetFilledPolysList().IsEmpty() )
-            continue;
-
         Remove( z.m_zone );
+
+    for ( auto& z : aZones )
+    {
+        if( !z.m_zone->GetFilledPolysList().IsEmpty() )
             Add( z.m_zone );
     }
 

pcbnew/connectivity_algo.h

@@ -692,7 +692,7 @@ public:
     std::vector<bool> m_dirtyNets;
     PROGRESS_REPORTER* m_progressReporter = nullptr;
 
-    void    searchConnections( bool aIncludeZones = false );
+    void    searchConnections();
 
     void    update();
     void    propagateConnections();
@@ -768,6 +768,13 @@ public:
 
     void    PropagateNets();
     void    FindIsolatedCopperIslands( ZONE_CONTAINER* aZone, std::vector<int>& aIslands );
+
+    /**
+     * Finds the copper islands that are not connected to a net.  These are added to
+     * the m_islands vector.
+     * N.B. This must be called after aZones has been refreshed.
+     * @param: aZones The set of zones to search for islands
+     */
     void    FindIsolatedCopperIslands( std::vector<CN_ZONE_ISOLATED_ISLAND_LIST>& aZones );
 
     bool    CheckConnectivity( std::vector<CN_DISJOINT_NET_ENTRY>& aReport );