Toponaming: import code related to ElementMapVersion from LS3

*Imported original code

src/Mod/Part/App/PartFeature.cpp

@@ -1640,6 +1640,12 @@ Feature* Feature::create(const TopoShape& shape, const char* name, App::Document
     return res;
 }
 
+void Feature::onDocumentRestored()
+{
+    // expandShapeContents();
+    App::GeoFeature::onDocumentRestored();
+}
+
 ShapeHistory Feature::buildHistory(BRepBuilderAPI_MakeShape& mkShape, TopAbs_ShapeEnum type,
                                    const TopoDS_Shape& newS, const TopoDS_Shape& oldS)
 {

src/Mod/Part/App/PartFeature.h

@@ -175,6 +175,7 @@ protected:
     App::DocumentObjectExecReturn *execute() override;
     void onBeforeChange(const App::Property* prop) override;
     void onChanged(const App::Property* prop) override;
+    void onDocumentRestored() override;
 
     void copyMaterial(Feature* feature);
     void copyMaterial(App::DocumentObject* link);

src/Mod/Part/App/PropertyTopoShape.cpp

@@ -587,11 +587,25 @@ void PropertyPartShape::SaveDocFile (Base::Writer &writer) const
 
 void PropertyPartShape::RestoreDocFile(Base::Reader &reader)
 {
+
+    // save the element map
+    auto elementMap = _Shape.resetElementMap();
+    auto hasher = _Shape.Hasher;
+
     Base::FileInfo brep(reader.getFileName());
+    TopoShape shape;
+
+    // In LS3 the following statement is executed right before shape.Hasher = hasher;
+    // https://github.com/realthunder/FreeCAD/blob/a9810d509a6f112b5ac03d4d4831b67e6bffd5b7/src/Mod/Part/App/PropertyTopoShape.cpp#L639
+    // Now it's not possible anymore because both PropertyPartShape::loadFromFile() and
+    // PropertyPartShape::loadFromStream() calls PropertyPartShape::setValue() which clears the
+    // value of _Ver.
+    // Therefor we're storing the value of _Ver here so that we don't lose it.
+
+    std::string ver = _Ver;
+
     if (brep.hasExtension("bin")) {
-        TopoShape shape;
         shape.importBinary(reader);
-        setValue(shape);
     }
     else {
         bool direct = App::GetApplication().GetParameterGroupByPath
@@ -604,7 +618,14 @@ void PropertyPartShape::RestoreDocFile(Base::Reader &reader)
             loadFromStream(reader);
             reader.exceptions(iostate);
         }
+        shape = getValue();
     }
+
+    // restore the element map
+    shape.Hasher = hasher;
+    shape.resetElementMap(elementMap);
+    setValue(shape);
+    _Ver = ver;
 }
 
 // -------------------------------------------------------------------------

src/Mod/Part/App/TopoShape.h

@@ -1502,6 +1502,8 @@ public:
     void mapSubElementsTo(std::vector<TopoShape>& shapes, const char* op = nullptr) const;
     bool hasPendingElementMap() const;
 
+    virtual std::string getElementMapVersion() const;
+
     void flushElementMap() const override;
 
     Data::ElementMapPtr resetElementMap(

src/Mod/Part/App/TopoShapeExpansion.cpp

@@ -2057,6 +2057,29 @@ TopoShape TopoShape::getSubTopoShape(TopAbs_ShapeEnum type, int idx, bool silent
     return shapeMap.getTopoShape(*this, idx);
 }
 
+static const std::string& _getElementMapVersion()
+{
+    static std::string _ver;
+    if (_ver.empty()) {
+        std::ostringstream ss;
+        unsigned occ_ver;
+        if ((OCC_VERSION_HEX & 0xFF0000) == 0x070000) {
+            occ_ver = 0x070200;
+        }
+        else {
+            occ_ver = OCC_VERSION_HEX;
+        }
+        ss << OpCodes::Version << '.' << std::hex << occ_ver << '.';
+        _ver = ss.str();
+    }
+    return _ver;
+}
+
+std::string TopoShape::getElementMapVersion() const
+{
+    return _getElementMapVersion() + Data::ComplexGeoData::getElementMapVersion();
+}
+
 TopoShape& TopoShape::makeElementEvolve(const TopoShape& spine,
                                         const TopoShape& profile,
                                         JoinType join,