odb: guard optional dbId getters against invalid id resolution

Signed-off-by: osamahammad21 <osama@precisioninno.com>

Author: osamahammad21

src/odb/src/db/dbMetalWidthViaMap.cpp

@@ -209,6 +209,9 @@ bool dbMetalWidthViaMap::isPgVia() const
 dbTechLayer* dbMetalWidthViaMap::getCutLayer() const
 {
   _dbMetalWidthViaMap* obj = (_dbMetalWidthViaMap*) this;
+  if (!obj->cut_layer_.isValid()) {
+    return nullptr;
+  }
   dbTech* tech = (dbTech*) obj->getOwner();
   return dbTechLayer::getTechLayer(tech, obj->cut_layer_);
 }

src/odb/src/db/dbTechLayerAreaRule.cpp

@@ -276,6 +276,9 @@ void dbTechLayerAreaRule::setTrimLayer(dbTechLayer* trim_layer)
 dbTechLayer* dbTechLayerAreaRule::getTrimLayer() const
 {
   _dbTechLayerAreaRule* obj = (_dbTechLayerAreaRule*) this;
+  if (!obj->trim_layer_.isValid()) {
+    return nullptr;
+  }
   odb::dbTech* tech = getDb()->getTech();
   return odb::dbTechLayer::getTechLayer(tech, obj->trim_layer_);
 }