Toponaming: add code to implement guessing missing references

src/Mod/Part/App/PartFeature.cpp

@@ -313,6 +313,9 @@ App::ElementNamePair Feature::getExportElementName(TopoShape shape,
                 auto names =
                     shape.decodeElementComboName(idxName, mapped.name, idxName.getType(), &postfix);
                 std::vector<int> ancestors;
+                // TODO:  if names.empty() then the existing heuristic has failed to find anything
+                //   and we're going to flag this element as missing.  This is the place to add
+                //   heuristics as we develop them.
                 for (auto& name : names) {
                     auto index = shape.getIndexedName(name);
                     if (!index) {
@@ -1697,6 +1700,16 @@ bool Feature::getCameraAlignmentDirection(Base::Vector3d& direction, const char*
     return GeoFeature::getCameraAlignmentDirection(direction, subname);
 }
 
+void Feature::guessNewLink(std::string &replacementName, DocumentObject *base, const char *oldLink) {
+    for (auto &element : Part::Feature::getRelatedElements(base, oldLink)) {
+        replacementName.clear();
+        element.index.appendToStringBuffer(replacementName);
+        FC_WARN("Feature guess element reference " << oldLink << " -> " << replacementName);
+        return;
+    }
+    replacementName = oldLink;
+}
+
 // ---------------------------------------------------------
 
 PROPERTY_SOURCE(Part::FilletBase, Part::Feature)

src/Mod/Part/App/PartFeature.h

@@ -153,7 +153,10 @@ public:
 
     static bool isElementMappingDisabled(App::PropertyContainer *container);
 
-    bool getCameraAlignmentDirection(Base::Vector3d& direction, const char* subname) const override;
+    bool getCameraAlignmentDirection(Base::Vector3d &direction, const char *subname) const override;
+
+    static void guessNewLink(std::string &replacementName, DocumentObject *base, const char *oldLink);
+
 #ifdef FC_USE_TNP_FIX
 
     const std::vector<std::string>& searchElementCache(const std::string &element,

src/Mod/PartDesign/Gui/TaskDressUpParameters.cpp

@@ -461,6 +461,22 @@ TaskDlgDressUpParameters::TaskDlgDressUpParameters(ViewProviderDressUp *DressUpV
     , parameter(nullptr)
 {
     assert(DressUpView);
+    auto pcDressUp = dynamic_cast<PartDesign::DressUp*>(DressUpView->getObject());
+    auto base = pcDressUp->Base.getValue();
+    std::vector<std::string> newSubList;
+    bool changed = false;
+    auto& shadowSubs = pcDressUp->Base.getShadowSubs();
+    for ( auto &shadowSub : shadowSubs ) {
+        auto displayName = shadowSub.oldName;
+        // If there is a missing tag on the shadow sub, take a guess at a new name.
+        if ( boost::starts_with(shadowSub.oldName,Data::MISSING_PREFIX)) {
+            Part::Feature::guessNewLink(displayName, base, shadowSub.newName.c_str());
+            newSubList.emplace_back(displayName);
+            changed = true;
+        }
+    }
+    if ( changed )
+        pcDressUp->Base.setValue(base, newSubList);
 }
 
 TaskDlgDressUpParameters::~TaskDlgDressUpParameters() = default;

src/Mod/PartDesign/Gui/TaskFilletParameters.cpp

@@ -95,7 +95,7 @@ TaskFilletParameters::TaskFilletParameters(ViewProviderDressUp *DressUpView, QWi
     connect(ui->listWidgetReferences, &QListWidget::itemDoubleClicked,
         this, &TaskFilletParameters::doubleClicked);
 
-    if (strings.size() == 0)
+    if (strings.empty())
         setSelectionMode(refSel);
     else
         hideOnError();