3 files changed, 22 insertions, 19 deletions

diff --git a/src/alg.c b/src/alg.c
index 6a16d9a..f00453d 100644
--- a/src/alg.c
+++ b/src/alg.c
@@ -632,7 +632,7 @@ void
 sort_alglist(AlgList *al)
 {
         int i, n = al->len;
-        Alg* alg_array[n];
+        Alg* alg_array[n+1];
         AlgListNode *node;
 
         for (i = 0, node = al->first; i < n; i++, node = node->next)
diff --git a/src/solve.c b/src/solve.c
index 39437fb..5581964 100644
--- a/src/solve.c
+++ b/src/solve.c
@@ -11,11 +11,11 @@ static bool        dfs_check_solved(DfsArg *arg);
 static bool        dfs_switch(DfsArg *arg);
 static void        dfs_niss(DfsArg *arg);
 static bool        dfs_stop(DfsArg *arg);
+static bool        dfs_useless_niss(DfsArg *arg);
 static void *      instance_thread(void *arg);
 static void        invert_branch(DfsArg *arg);
 static void        multidfs(Cube c, Trans t, Step *s, SolveOptions *opts,
                             AlgList *sols, int d);
-static bool        niss_makes_sense(DfsArg *arg);
 static bool        solvestop(int d, int op, SolveOptions *opts, AlgList *sols);
 
 /* Local functions ***********************************************************/
@@ -97,7 +97,7 @@ dfs(DfsArg *arg)
                 invert_branch(arg);
         dfs_branch(arg);
 
-        if (arg->opts->nisstype == NISS && !arg->niss && niss_makes_sense(arg))
+        if (arg->opts->nisstype == NISS && !arg->niss && !arg->step->final)
                 dfs_niss(arg);
 
         if (sw)
@@ -139,7 +139,7 @@ dfs_check_solved(DfsArg *arg)
         if (!arg->step->is_done(arg->cube))
                 return false;
 
-        if (arg->current_alg->len == arg->d) {
+        if (arg->current_alg->len == arg->d && !dfs_useless_niss(arg)) {
                 if ((arg->step->is_valid(arg->current_alg) || arg->opts->all)
                     && (!arg->step->final || !cancel_niss(arg))) {
 
@@ -233,6 +233,20 @@ dfs_switch(DfsArg *arg)
         return bi < bn;
 }
 
+static bool
+dfs_useless_niss(DfsArg *arg)
+{
+        Cube c;
+        Move m = arg->last1inv;
+
+        if (m == NULLMOVE || !arg->niss)
+                return false;
+
+        c = apply_move(inverse_move(m), arg->cube);
+
+        return arg->step->is_done(c);
+}
+
 static void *
 instance_thread(void *arg)
 {
@@ -363,15 +377,6 @@ multidfs(Cube c, Trans tr, Step *s, SolveOptions *opts, AlgList *sols, int d)
 }
 
 static bool
-niss_makes_sense(DfsArg *arg)
-{
-        Cube testcube;
-
-        testcube = apply_move(inverse_move(arg->last1), (Cube){0});
-        return arg->current_alg->len == 0 || !arg->step->is_done(testcube);
-}
-
-static bool
 solvestop(int d, int op, SolveOptions *opts, AlgList *sols)
 {
         bool opt_done, max_moves_exceeded, max_sols_exceeded;
diff --git a/src/steps.c b/src/steps.c
index 383acaa..e7e4834 100644
--- a/src/steps.c
+++ b/src/steps.c
@@ -33,7 +33,6 @@ static int              estimate_cp_drud(DfsArg *arg);
 static int              estimate_htrfin_htr(DfsArg *arg);
 static int              estimate_nxopt31_HTM(DfsArg *arg);
 static int              estimate_light_HTM(DfsArg *arg);
-
 static int              estimate_nxoptlike(DfsArg *arg, PruneData *pd);
 
 static bool             always_valid(Alg *alg);
@@ -976,7 +975,7 @@ corners_dr_any = {
         .shortname = "corners-dr",
         .name      = "Solve corners from DR",
 
-        .final     = false,
+        .final     = true,
         .is_done   = check_corners_HTM,
         .estimate  = estimate_cp_drud,
         .ready     = check_coud_HTM,
@@ -995,7 +994,7 @@ corners_drud = {
         .shortname = "corners-drud",
         .name      = "Solve corners from DR on U/D",
 
-        .final     = false,
+        .final     = true,
         .is_done   = check_corners_HTM,
         .estimate  = estimate_cp_drud,
         .ready     = check_coud_HTM,
@@ -1014,7 +1013,7 @@ corners_drrl = {
         .shortname = "corners-drrl",
         .name      = "Solve corners from DR on R/L",
 
-        .final     = false,
+        .final     = true,
         .is_done   = check_corners_HTM,
         .estimate  = estimate_cp_drud,
         .ready     = check_coud_HTM,
@@ -1033,7 +1032,7 @@ corners_drfb = {
         .shortname = "corners-drfb",
         .name      = "Solve corners from DR on F/B",
 
-        .final     = false,
+        .final     = true,
         .is_done   = check_corners_HTM,
         .estimate  = estimate_cp_drud,
         .ready     = check_coud_HTM,
@@ -1570,7 +1569,6 @@ estimate_nxoptlike(DfsArg *arg, PruneData *pd)
         return arg->ed->oldret = ret;
 }
 
-
 static bool
 always_valid(Alg *alg)
 {