Make sure lines/wires/busses get default widths if not spec'ed.

Fixes https://gitlab.com/kicad/code/kicad/issues/4854

eeschema/sch_junction.cpp

@@ -83,8 +83,8 @@ const EDA_RECT SCH_JUNCTION::GetBoundingBox() const
 {
     EDA_RECT rect;
 
-    int size =
-            Schematic() ? Schematic()->Settings().m_JunctionSize : Mils2iu( DEFAULT_JUNCTION_DIAM );
+    int size = Schematic() ? Schematic()->Settings().m_JunctionSize
+                           : Mils2iu( DEFAULT_JUNCTION_DIAM );
 
     if( m_diameter != 0 )
         size = m_diameter;

eeschema/sch_line.cpp

@@ -271,13 +271,41 @@ int SCH_LINE::GetPenWidth() const
 {
     NETCLASSPTR netclass = NetClass();
 
+    switch ( m_Layer )
+    {
+    default:
+        if( m_stroke.GetWidth() > 0 )
+            return m_stroke.GetWidth();
+
+        if( Schematic() )
+            return Schematic()->Settings().m_DefaultLineWidth;
+
+        return DEFAULT_LINE_THICKNESS;
+
+    case LAYER_WIRE:
         if( netclass )
-        return ( m_Layer == LAYER_BUS ) ? netclass->GetBusWidth() : netclass->GetWireWidth();
+            return netclass->GetWireWidth();
 
-    if( m_stroke.GetWidth() == 0 && Schematic() )
-        return std::max( Schematic()->Settings().m_DefaultLineWidth, 1 );
+        if( m_stroke.GetWidth() > 0 )
+            return m_stroke.GetWidth();
 
-    return std::max( m_stroke.GetWidth(), 1 );
+        if( Schematic() )
+            return Schematic()->Settings().m_DefaultWireThickness;
+
+        return DEFAULT_WIRE_THICKNESS;
+
+    case LAYER_BUS:
+        if( netclass )
+            return netclass->GetBusWidth();
+
+        if( m_stroke.GetWidth() > 0 )
+            return m_stroke.GetWidth();
+
+        if( Schematic() )
+            return Schematic()->Settings().m_DefaultBusThickness;
+
+        return DEFAULT_BUS_THICKNESS;
+    }
 }
 
 

eeschema/tools/sch_line_wire_bus_tool.cpp

@@ -731,6 +731,8 @@ SCH_LINE* SCH_LINE_WIRE_BUS_TOOL::startSegments( int aType, const VECTOR2D& aPos
         break;
     }
 
+    // Give segments a parent so they find the default line/wire/bus widths
+    segment->SetParent( &m_frame->Schematic() );
     segment->SetFlags( IS_NEW | IS_MOVED );
     m_wires.push_back( segment );