Check that the received particles are at the correct position in time.

src/runner.c

@@ -1232,6 +1232,7 @@ void runner_dorecv_cell(struct runner *r, struct cell *c, int timer) {
   const struct gpart *const gparts = c->gparts;
   const size_t nr_parts = c->count;
   const size_t nr_gparts = c->gcount;
+  const int ti_current = r->e->ti_current;
 
   TIMER_TIC;
 
@@ -1241,13 +1242,17 @@ void runner_dorecv_cell(struct runner *r, struct cell *c, int timer) {
 
   /* Collect everything... */
   for (size_t k = 0; k < nr_parts; k++) {
-    ti_end_min = min(ti_end_min, parts[k].ti_end);
-    ti_end_max = max(ti_end_max, parts[k].ti_end);
+    const int ti_end = parts[k].ti_end;
+    if(ti_end < ti_current) error("Received invalid particle !");
+    ti_end_min = min(ti_end_min, ti_end);
+    ti_end_max = max(ti_end_max, ti_end);
     h_max = fmaxf(h_max, parts[k].h);
   }
   for (size_t k = 0; k < nr_gparts; k++) {
-    ti_end_min = min(ti_end_min, gparts[k].ti_end);
-    ti_end_max = max(ti_end_max, gparts[k].ti_end);
+    const int ti_end = gparts[k].ti_end;
+    if(ti_end < ti_current) error("Received invalid particle !");
+    ti_end_min = min(ti_end_min, ti_end);
+    ti_end_max = max(ti_end_max, ti_end);
   }
 
   /* ... and store. */