fixes

src/data/setting.h

@@ -43,6 +43,7 @@ public:
         observers.emplace(id, callback);
         return std::shared_ptr<int>(new int(id), [this](int* id) {
             observers.erase(*id);
+            delete id;
         });
     }
 

src/logic/scripting/scripting.cpp

@@ -67,6 +67,7 @@ scriptenv scripting::create_pack_environment(const ContentPack& pack) {
     state->pop();
     return std::shared_ptr<int>(new int(id), [=](int* id) {
         state->removeEnvironment(*id);
+        delete id;
     });
 }
 
@@ -90,6 +91,7 @@ scriptenv scripting::create_doc_environment(scriptenv parent, const std::string&
     state->pop();
     return std::shared_ptr<int>(new int(id), [=](int* id) {
         state->removeEnvironment(*id);
+        delete id;
     });
 }
 

src/util/ObjectsKeeper.hpp

@@ -5,6 +5,7 @@
 #include <memory>
 
 namespace util {
+    /// @brief Keeps shared pointers alive until destruction
     class ObjectsKeeper {
         std::vector<std::shared_ptr<void>> ptrs;
     public: