Merge branch 'correct_vec_neighbour_find' into 'master'

Correct vec neighbour find

Fixes neighbour find bug in the vectorised version of the density interactions.

See merge request !435

src/runner_doiact_vec.c

@@ -325,7 +325,7 @@ __attribute__((always_inline)) INLINE static void populate_max_index_no_cache(
   last_pj = active_id;
 
   /* Find the maximum index into cell i for each particle in range in cell j. */
-  if (last_pj > 0) {
+  if (last_pj >= 0) {
 
     /* Start from the last particle in cell i. */
     temp = ci->count - 1;

tests/testActivePair.sh.in

@@ -4,8 +4,19 @@ echo ""
 
 rm -f brute_force_pair_active.dat swift_dopair_active.dat
 
+echo "Running ./testActivePair -n 6 -r 1 -d 0 -f active"
+
 ./testActivePair -n 6 -r 1 -d 0 -f active
 
 python @srcdir@/difffloat.py brute_force_active.dat swift_dopair_active.dat @srcdir@/tolerance_pair_active.dat
 
+rm -f brute_force_pair_active.dat swift_dopair_active.dat
+
+# Run the special case that triggered a bug. See merge request !435.
+echo "Running ./testActivePair -n 6 -r 1 -d 0 -f active -s 1506434777"
+
+./testActivePair -n 6 -r 1 -d 0 -f active -s 1506434777
+
+python @srcdir@/difffloat.py brute_force_active.dat swift_dopair_active.dat @srcdir@/tolerance_pair_active.dat
+
 exit $?