Fix some compiler and Coverity warnings

common/rc_item.cpp

@@ -332,6 +332,7 @@ void RC_TREE_MODEL::GetValue( wxVariant&              aVariant,
         case RPT_SEVERITY_ERROR:   prefix += _( "Error: " ); break;
         case RPT_SEVERITY_WARNING: prefix += _( "Warning: " ); break;
 
+        case RPT_SEVERITY_EXCLUSION:
         case RPT_SEVERITY_UNDEFINED:
         case RPT_SEVERITY_INFO:
         case RPT_SEVERITY_ACTION:

eeschema/dialogs/dialog_change_symbols.cpp

@@ -237,6 +237,9 @@ void DIALOG_CHANGE_SYMBOLS::launchNewIdSymbolBrowser( wxCommandEvent& aEvent )
 void DIALOG_CHANGE_SYMBOLS::updateFieldsList()
 {
     SCH_EDIT_FRAME* frame = dynamic_cast<SCH_EDIT_FRAME*>( GetParent() );
+
+    wxCHECK( frame, /* void */ );
+
     SCH_SHEET_LIST  hierarchy = frame->Schematic().GetSheets();
 
     // Load non-mandatory fields from all matching symbols and their library parts

eeschema/schematic.cpp

@@ -146,9 +146,9 @@ std::vector<SCH_MARKER*> SCHEMATIC::ResolveERCExclusions()
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_MARKER_T ) )
         {
             SCH_MARKER* marker = static_cast<SCH_MARKER*>( item );
-            auto        it = ErcSettings().m_ErcExclusions.find( marker->Serialize() );
+            auto        it = settings.m_ErcExclusions.find( marker->Serialize() );
 
-            if( it != ErcSettings().m_ErcExclusions.end() )
+            if( it != settings.m_ErcExclusions.end() )
             {
                 marker->SetExcluded( true );
                 settings.m_ErcExclusions.erase( it );

eeschema/tools/ee_grid_helper.cpp

@@ -314,7 +314,7 @@ VECTOR2I EE_GRID_HELPER::BestSnapAnchor( const VECTOR2I& aOrigin, int aLayer,
         if( m_enableGrid && std::abs( nearestGrid.y - aOrigin.y ) < snapDist.y )
         {
             pt.y = nearestGrid.y;
-            snapDist.x = std::abs( nearestGrid.y - aOrigin.y );
+            snapDist.y = std::abs( nearestGrid.y - aOrigin.y );
             snapLineY = false;
         }
 

pcbnew/tools/board_inspection_tool.cpp

@@ -115,6 +115,10 @@ int BOARD_INSPECTION_TOOL::ShowStatisticsDialog( const TOOL_EVENT& aEvent )
 
 wxString BOARD_INSPECTION_TOOL::getItemDescription( BOARD_ITEM* aItem )
 {
+    // Null items have no description
+    if( !aItem )
+        return wxString();
+
     wxString s = aItem->GetSelectMenuText( m_frame->GetUserUnits() );
 
     if( aItem->IsConnected() )
@@ -309,7 +313,7 @@ int BOARD_INSPECTION_TOOL::InspectClearance( const TOOL_EVENT& aEvent )
 
     if( b->Type() == PCB_GROUP_T )
     {
-        PCB_GROUP* bg = static_cast<PCB_GROUP*>( a );
+        PCB_GROUP* bg = static_cast<PCB_GROUP*>( b );
 
         if( bg->GetItems().empty() )
         {
@@ -317,7 +321,7 @@ int BOARD_INSPECTION_TOOL::InspectClearance( const TOOL_EVENT& aEvent )
             return 0;
         }
 
-        a = *bg->GetItems().begin();
+        b = *bg->GetItems().begin();
     }
 
     if( a->Type() == PCB_TRACE_T || a->Type() == PCB_ARC_T )