Update DRC exclusions model to match terminology.

DRC exclusions were originally written following the C++
pragma model (ie: allow this violation here).  However, the
"exclusion" terminology we used in the GUI suggests a model
model where the exclusions go away when the violation no
longer exists.

Fixes https://gitlab.com/kicad/code/kicad/issues/14351

pcbnew/board.cpp

@@ -306,7 +306,7 @@ void BOARD::UpdateRatsnestExclusions()
 }
 
 
-std::vector<PCB_MARKER*> BOARD::ResolveDRCExclusions()
+std::vector<PCB_MARKER*> BOARD::ResolveDRCExclusions( bool aCreateMarkers )
 {
     for( PCB_MARKER* marker : GetBoard()->Markers() )
     {
@@ -321,28 +321,31 @@ std::vector<PCB_MARKER*> BOARD::ResolveDRCExclusions()
 
     std::vector<PCB_MARKER*> newMarkers;
 
-    for( const wxString& exclusionData : m_designSettings->m_DrcExclusions )
+    if( aCreateMarkers )
     {
-        PCB_MARKER* marker = PCB_MARKER::Deserialize( exclusionData );
-
-        if( !marker )
-            continue;
-
-        // Check to see if items still exist
-        for( const KIID& guid : marker->GetRCItem()->GetIDs() )
+        for( const wxString& exclusionData : m_designSettings->m_DrcExclusions )
         {
-            if( GetItem( guid ) == DELETED_BOARD_ITEM::GetInstance() )
+            PCB_MARKER* marker = PCB_MARKER::Deserialize( exclusionData );
+
+            if( !marker )
+                continue;
+
+            // Check to see if items still exist
+            for( const KIID& guid : marker->GetRCItem()->GetIDs() )
             {
-                delete marker;
-                marker = nullptr;
-                break;
+                if( GetItem( guid ) == DELETED_BOARD_ITEM::GetInstance() )
+                {
+                    delete marker;
+                    marker = nullptr;
+                    break;
+                }
             }
-        }
 
-        if( marker )
-        {
-            marker->SetExcluded( true );
-            newMarkers.push_back( marker );
+            if( marker )
+            {
+                marker->SetExcluded( true );
+                newMarkers.push_back( marker );
+            }
         }
     }
 

pcbnew/board.h

@@ -460,8 +460,12 @@ public:
 
     /**
      * Rebuild DRC markers from the serialized data in BOARD_DESIGN_SETTINGS.
+     *
+     * @param aCreateMarkers if true, create markers from serialized data; if false only
+     *                       use serialized data to set existing markers to excluded.
+     *                       The former is used on board load; the later after a DRC.
      */
-    std::vector<PCB_MARKER*> ResolveDRCExclusions();
+    std::vector<PCB_MARKER*> ResolveDRCExclusions( bool aCreateMarkers );
 
     /**
      * Update the visibility flags on the current unconnected ratsnest lines.

pcbnew/files.cpp

@@ -826,7 +826,7 @@ bool PCB_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
 
         // we should not ask PLUGINs to do these items:
         loadedBoard->BuildListOfNets();
-        ResolveDRCExclusions();
+        ResolveDRCExclusions( true );
         m_toolManager->RunAction( PCB_ACTIONS::repairBoard, true, true);
 
         if( loadedBoard->IsModified() )

pcbnew/pcb_edit_frame.cpp

@@ -984,11 +984,11 @@ void PCB_EDIT_FRAME::RecordDRCExclusions()
 }
 
 
-void PCB_EDIT_FRAME::ResolveDRCExclusions()
+void PCB_EDIT_FRAME::ResolveDRCExclusions( bool aCreateMarkers )
 {
     BOARD_COMMIT commit( this );
 
-    for( PCB_MARKER* marker : GetBoard()->ResolveDRCExclusions() )
+    for( PCB_MARKER* marker : GetBoard()->ResolveDRCExclusions( aCreateMarkers ) )
     {
         if( marker->GetMarkerType() == MARKER_BASE::MARKER_DRAWING_SHEET )
             marker->GetRCItem()->SetItems( GetCanvas()->GetDrawingSheet() );

pcbnew/pcb_edit_frame.h

@@ -238,9 +238,10 @@ public:
     void RecordDRCExclusions();
 
     /**
-     * Update markers to match recorded exclusions.
+     * If aCreateMarkers then create DRC exclusion markers from the serialized data.  If false,
+     * then use the serialized data to set exclusion flags on existing markers.
      */
-    void ResolveDRCExclusions();
+    void ResolveDRCExclusions( bool aCreateMarkers );
 
     void Process_Special_Functions( wxCommandEvent& event );
     void Tracks_and_Vias_Size_Event( wxCommandEvent& event );

pcbnew/python/scripting/pcbnew_scripting_helpers.cpp

@@ -183,7 +183,7 @@ BOARD* LoadBoard( wxString& aFileName, IO_MGR::PCB_FILE_T aFormat )
             // Best efforts...
         }
 
-        for( PCB_MARKER* marker : brd->ResolveDRCExclusions() )
+        for( PCB_MARKER* marker : brd->ResolveDRCExclusions( true ) )
             brd->Add( marker );
 
         brd->BuildConnectivity();

pcbnew/tools/drc_tool.cpp

@@ -206,7 +206,7 @@ void DRC_TOOL::updatePointers()
     // update my pointers, m_editFrame is the only unchangeable one
     m_pcb = m_editFrame->GetBoard();
 
-    m_editFrame->ResolveDRCExclusions();
+    m_editFrame->ResolveDRCExclusions( false );
 
     if( m_drcDialog )
         m_drcDialog->UpdateData();