CGEvent: avoid permanent event removal after visit. Fix issue 2339

lib/mapObjects/CGPandoraBox.cpp

@@ -51,7 +51,7 @@ void CGPandoraBox::onHeroVisit(const CGHeroInstance * h) const
 
 void CGPandoraBox::giveContentsUpToExp(const CGHeroInstance *h) const
 {
-	cb->removeAfterVisit(this);
+	afterSuccessfulVisit();
 
 	InfoWindow iw;
 	iw.player = h->getOwner();
@@ -331,6 +331,11 @@ void CGPandoraBox::heroLevelUpDone(const CGHeroInstance *hero) const
 	giveContentsAfterExp(hero);
 }
 
+void CGPandoraBox::afterSuccessfulVisit() const
+{
+	cb->removeAfterVisit(this);
+}
+
 void CGEvent::onHeroVisit( const CGHeroInstance * h ) const
 {
 	if(!(availableFor & (1 << h->tempOwner.getNum())))
@@ -362,3 +367,13 @@ void CGEvent::activated( const CGHeroInstance * h ) const
 		giveContentsUpToExp(h);
 	}
 }
+
+void CGEvent::afterSuccessfulVisit() const
+{
+	if(removeAfterVisit)
+	{
+		cb->removeAfterVisit(this);
+	}
+	else if(hasGuardians)
+		hasGuardians = false;
+}

lib/mapObjects/CGPandoraBox.h

@@ -20,7 +20,7 @@ class DLL_LINKAGE CGPandoraBox : public CArmedInstance
 {
 public:
 	std::string message;
-	bool hasGuardians; //helper - after battle even though we have no stacks, allows us to know that there was battle
+	mutable bool hasGuardians; //helper - after battle even though we have no stacks, allows us to know that there was battle
 
 	//gained things:
 	ui32 gainedExp;
@@ -54,6 +54,7 @@ protected:
 private:
 	void getText( InfoWindow &iw, bool &afterBattle, int val, int negative, int positive, const CGHeroInstance * h ) const;
 	void getText( InfoWindow &iw, bool &afterBattle, int text, const CGHeroInstance * h ) const;
+	virtual void afterSuccessfulVisit() const;
 };
 
 class DLL_LINKAGE CGEvent : public CGPandoraBox  //event objects
@@ -74,4 +75,5 @@ public:
 	void onHeroVisit(const CGHeroInstance * h) const override;
 private:
 	void activated(const CGHeroInstance * h) const;
+	void afterSuccessfulVisit() const override;
 };