Don't attempt to fully initialise the cosmology struct when we are not using a cosmology

src/cosmology.c

@@ -667,13 +667,15 @@ void cosmology_struct_dump(const struct cosmology *cosmology, FILE *stream) {
  * @brief Restore a cosmology struct from the given FILE as a stream of
  * bytes.
  *
+ * @param enabled whether cosmology is enabled.
  * @param cosmology the struct
  * @param stream the file stream
  */
-void cosmology_struct_restore(struct cosmology *cosmology, FILE *stream) {
+void cosmology_struct_restore(int enabled, struct cosmology *cosmology,
+                              FILE *stream) {
   restart_read_blocks((void *)cosmology, sizeof(struct cosmology), 1, stream,
                       NULL, "cosmology function");
 
-  /* Re-initialise the tables */
-  cosmology_init_tables(cosmology);
+  /* Re-initialise the tables if using a cosmology. */
+  if (enabled) cosmology_init_tables(cosmology);
 }

src/cosmology.h

@@ -192,6 +192,6 @@ void cosmology_write_model(hid_t h_grp, const struct cosmology *c);
 
 /* Dump/restore. */
 void cosmology_struct_dump(const struct cosmology *cosmology, FILE *stream);
-void cosmology_struct_restore(struct cosmology *cosmology, FILE *stream);
+void cosmology_struct_restore(int enabled, struct cosmology *cosmology, FILE *stream);
 
 #endif /* SWIFT_COSMOLOGY_H */

src/engine.c

@@ -5921,7 +5921,7 @@ void engine_struct_restore(struct engine *e, FILE *stream) {
 
   struct cosmology *cosmo =
       (struct cosmology *)malloc(sizeof(struct cosmology));
-  cosmology_struct_restore(cosmo, stream);
+  cosmology_struct_restore(e->policy & engine_policy_cosmology, cosmo, stream);
   e->cosmology = cosmo;
 
 #ifdef WITH_MPI