From 07711bb8a8c618ad79db62e741e6454c26906d05 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Thu, 17 Nov 2022 15:46:06 +0100
Subject: [PATCH] App: fix endless-loop when recursively determining placement
 of an object

---
 src/App/GeoFeatureGroupExtension.cpp | 30 ++++++++++++++++++----------
 src/App/GeoFeatureGroupExtension.h   |  3 ++-
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/src/App/GeoFeatureGroupExtension.cpp b/src/App/GeoFeatureGroupExtension.cpp
index db154a8f0a..a3f746071d 100644
--- a/src/App/GeoFeatureGroupExtension.cpp
+++ b/src/App/GeoFeatureGroupExtension.cpp
@@ -103,25 +103,35 @@ DocumentObject* GeoFeatureGroupExtension::getGroupOfObject(const DocumentObject*
     return nullptr;
 }
 
-Base::Placement GeoFeatureGroupExtension::globalGroupPlacement() {
-
-    if(getExtendedObject()->isRecomputing())
+Base::Placement GeoFeatureGroupExtension::globalGroupPlacement()
+{
+    if (getExtendedObject()->isRecomputing()) {
         throw Base::RuntimeError("Global placement cannot be calculated on recompute");
+    }
 
-    return recursiveGroupPlacement(this);
+    std::unordered_set<GeoFeatureGroupExtension*> history;
+    history.insert(this);
+    return recursiveGroupPlacement(this, history);
 }
 
 
-Base::Placement GeoFeatureGroupExtension::recursiveGroupPlacement(GeoFeatureGroupExtension* group) {
+Base::Placement GeoFeatureGroupExtension::recursiveGroupPlacement(GeoFeatureGroupExtension* group,
+                                                                  std::unordered_set<GeoFeatureGroupExtension*>& history)
+{
+    history.insert(this);
 
-    
     auto inList = group->getExtendedObject()->getInList();
-    for(auto* link : inList) {
+    for (auto* link : inList) {
         auto parent = link->getExtensionByType<GeoFeatureGroupExtension>(true);
-        if(parent && parent->hasObject(group->getExtendedObject()))
-            return recursiveGroupPlacement(parent) * group->placement().getValue();
+        if (parent && parent->hasObject(group->getExtendedObject())) {
+            // Cyclic dependencies detected
+            if (history.count(parent) > 0) {
+                break;
+            }
+            return recursiveGroupPlacement(parent, history) * group->placement().getValue();
+        }
     }
-    
+
     return group->placement().getValue();
 }
 
diff --git a/src/App/GeoFeatureGroupExtension.h b/src/App/GeoFeatureGroupExtension.h
index 621145e1b5..351c658250 100644
--- a/src/App/GeoFeatureGroupExtension.h
+++ b/src/App/GeoFeatureGroupExtension.h
@@ -25,6 +25,7 @@
 #ifndef APP_GeoFeatureGroup_H
 #define APP_GeoFeatureGroup_H
 
+#include <unordered_set>
 #include "DocumentObject.h"
 #include "GroupExtension.h"
 #include "PropertyGeo.h"
@@ -120,7 +121,7 @@ public:
     static void getInvalidLinkObjects(const App::DocumentObject* obj, std::vector<App::DocumentObject*>& vec);
     
 private:
-    Base::Placement recursiveGroupPlacement(GeoFeatureGroupExtension* group);
+    Base::Placement recursiveGroupPlacement(GeoFeatureGroupExtension* group, std::unordered_set<GeoFeatureGroupExtension*>& history);
     static std::vector<App::DocumentObject*> getScopedObjectsFromLinks(const App::DocumentObject*, LinkScope scope = LinkScope::Local);
     static std::vector<App::DocumentObject*> getScopedObjectsFromLink(App::Property*, LinkScope scope = LinkScope::Local);