Post-merge fixes

src/engine.c

@@ -2504,11 +2504,11 @@ void engine_step(struct engine *e) {
 
   FILE *file = fopen("grav_swift.dat", "w");
   for (size_t k = 0; k < s->nr_gparts; ++k) {
-    fprintf(file, "%lld %f %f %f %e %e %e\n", s->gparts[k].id,
+    fprintf(file, "%lld %f %f %f %e %e %e\n", s->gparts[k].id_or_neg_offset,
             s->gparts[k].x[0], s->gparts[k].x[1], s->gparts[k].x[2],
             s->gparts[k].a_grav[0], s->gparts[k].a_grav[1],
             s->gparts[k].a_grav[2]);
-    if (s->gparts[k].id == -1)
+    if (s->gparts[k].id_or_neg_offset == 1)
       message("interacting mass= %f (%f)", s->gparts[k].mass_interacted,
               s->gparts[k].mass_interacted + s->gparts[k].mass);
   }
@@ -2521,9 +2521,9 @@ void engine_step(struct engine *e) {
   gravity_n2(temp, s->nr_gparts, e->physical_constants, rlr);
   file = fopen("grav_brute.dat", "w");
   for (size_t k = 0; k < s->nr_gparts; ++k) {
-    fprintf(file, "%lld %f %f %f %e %e %e\n", temp[k].id, temp[k].x[0],
-            temp[k].x[1], temp[k].x[2], temp[k].a_grav[0], temp[k].a_grav[1],
-            temp[k].a_grav[2]);
+    fprintf(file, "%lld %f %f %f %e %e %e\n", temp[k].id_or_neg_offset,
+            temp[k].x[0], temp[k].x[1], temp[k].x[2], temp[k].a_grav[0],
+            temp[k].a_grav[1], temp[k].a_grav[2]);
   }
   fclose(file);
 

src/runner.c

@@ -414,8 +414,8 @@ void runner_do_init(struct runner *r, struct cell *c, int timer) {
         /* Get ready for a density calculation */
         gravity_init_part(gp);
 
-        if (gp->id == -ICHECK)
-          message("id=%lld a=[%f %f %f]\n", gp->id, gp->a_grav[0],
+        if (gp->id_or_neg_offset == ICHECK)
+          message("id=%lld a=[%f %f %f]\n", gp->id_or_neg_offset, gp->a_grav[0],
                   gp->a_grav[1], gp->a_grav[2]);
       }
     }

src/space.c

@@ -1427,7 +1427,8 @@ struct cell *space_getcell(struct space *s) {
  * @param Npart The number of Gas particles in the space.
  * @param Ngpart The number of Gravity particles in the space.
  * @param periodic flag whether the domain is periodic or not.
- * @param verbose Print messages to stdout or not
+ * @param gravity flag whether we are doing gravity or not.
+ * @param verbose Print messages to stdout or not.
  * @param dry_run If 1, just initialise stuff, don't do anything with the parts.
  *
  * Makes a grid of edge length > r_max and fills the particles