Add comment in none star formation that always returns 0 and initialize the new_star_flag as zero.

src/starformation/none/starformation.h

@@ -38,6 +38,7 @@ struct star_formation {};
 
 /**
  * @brief Calculates if the gas particle gets converted
+ *        The gas will never be converted in none, so always returns 0.
  *
  * @param the #engine
  * @param starform the star formation law properties to use.

src/stars/EAGLE/stars.h

@@ -45,6 +45,7 @@ __attribute__((always_inline)) INLINE static void stars_first_init_spart(
     struct spart* sp) {
 
   sp->time_bin = 0;
+  sp->new_star_flag = 0;
 }
 
 /**