Check return values when connecting to/creating a database

convert.cc

@@ -25,7 +25,7 @@ int main(int argc, char* argv[]){
         	{"src", required_argument, NULL, 's'},
         	{"lmdb", no_argument, NULL, 'l'},
         	{"help", no_argument, NULL, 'h'},
-		{0}
+        	{0, 0, 0, 0}
 	};
 	int option_index = 0;
 	while (1) {
@@ -54,18 +54,29 @@ int main(int argc, char* argv[]){
 
 
 	DB_ * x = new Libdb();
-	x->connect_database(src);
+	if (!x->connect_database(src)) {
+	// error is printed in the connect_database function
+	delete x;
+	return 1;
+	}
 	DB_ *b;
 	if (lmdb)
 		b = new LMDB_();
 	else
 		b = new GDBM_();
-	b->create_database(dst);
+	if (!b->create_database(dst)) {
+		std::cerr<<"Failed to create destination database\n";
+		delete x;
+		delete b;
+		return 1;
+	}
 	if (!b->fill_database(x)){
 		std::cerr<<"database filling failed\n";
+		delete x;
+		delete b;
 		return 1;
 	}
-    	b->close_db();
+	b->close_db();
 	delete x;
 	delete b;
 	return 0;

convert_db.h

@@ -39,6 +39,7 @@ class DB_ {
 		virtual bool fill_database(DB_ * old_database);
 		virtual void close_db();
 		virtual DBC * get_database();
+    virtual ~DB_();
 };
 /*
  * Libdb class needs only open and read data from libdb database

db.cc

@@ -21,6 +21,10 @@ DBC * DB_::get_database() {
 	return NULL;
 }
 void DB_::close_db(){}
+
+DB_::~DB_() {
+}
+
 bool Libdb::connect_database(std::string path){
 	DB * db;
 	int status;