Fix segfault in traildb by fixing shallow copy of PowertrailDB

powertrail.cpp

@@ -143,7 +143,7 @@ void PowertrailDB::save_to_json(std::string file) {
 	datafile << j;
 };
 
-Caches_in_Powertrails::Caches_in_Powertrails(PowertrailDB db) {
+Caches_in_Powertrails::Caches_in_Powertrails(const PowertrailDB& db) {
 	for (auto& t : db.data) {
 		for (auto& c : t.second.caches) {
 			data.insert({ c, t.second.number });

powertrail.h

@@ -53,7 +53,7 @@ class Caches_in_Powertrails {
 public:
 	std::unordered_map<std::string, int> data;
 
-	Caches_in_Powertrails(PowertrailDB db);
+	Caches_in_Powertrails(const PowertrailDB& db);
 	Caches_in_Powertrails(){};
 
 	void read_from_json(std::string file);