fixed getString function in NIF loader

components/nif/nif_file.hpp

@@ -193,11 +193,12 @@ public:
 
     std::string getString(size_t length)
     {
-        std::string str;
+        std::vector<char> str (length+1, 0);
-        str.resize(length);
+
         if(inp->read(&str[0], length) != length)
-            return std::string();
+            throw std::runtime_error ("string length in NIF file does not match");
-        return str.substr(0, str.find('\0'));
+
+        return &str[0];
     }
     std::string getString()
     {