Clean up memory from the particle at the end of a run. Helps with sanitizer work.

src/cache.h

@@ -162,4 +162,22 @@ __attribute__((always_inline)) INLINE void cache_read_particles(
 #endif
 }
 
+/**
+ * @brief Clean the memory allocated by a #cache object.
+ *
+ * @param c The #cache to clean.
+ */
+static INLINE void cache_clean(struct cache *c) {
+  if (c->count > 0) {
+    free(c->x);
+    free(c->y);
+    free(c->z);
+    free(c->m);
+    free(c->vx);
+    free(c->vy);
+    free(c->vz);
+    free(c->h);
+  }
+}
+
 #endif /* SWIFT_CACHE_H */

src/engine.c

@@ -2381,7 +2381,7 @@ void engine_collect_kick(struct cell *c) {
   integertime_t ti_end_min = max_nr_timesteps;
 
   /* Only do something is the cell is non-empty */
-  if (c->count != 0 || c->gcount != 0) {
+  if (c->count != 0 || c->gcount != 0 || c->scount != 0) {
 
     /* If this cell is not split, I'm in trouble. */
     if (!c->split) error("Cell is not split.");
@@ -3555,6 +3555,8 @@ void engine_compute_next_snapshot_time(struct engine *e) {
  */
 void engine_clean(struct engine *e) {
 
+  for (int i = 0; i < e->nr_threads; ++i) cache_clean(&e->runners[i].par_cache);
+  free(e->runners);
   free(e->snapshotUnits);
   free(e->links);
   scheduler_clean(&e->sched);