Add and display Tree icon for Part_RuledSurface

src/Mod/Part/App/PartFeatures.h

@@ -46,6 +46,9 @@ public:
     /// recalculate the feature
     App::DocumentObjectExecReturn *execute(void);
     short mustExecute() const;
+    const char* getViewProviderName(void) const {
+        return "PartGui::ViewProviderRuledSurface";
+    }
     //@}
 
 protected: