inference: Reset m_entries and skip no-op virtual move

src/graph/inference/blockmodel/graph_blockmodel.hh

@@ -1344,7 +1344,10 @@ public:
         assert(size_t(_b[v]) == r || r == null_group);
 
         if (r == nr)
+        {
+            m_entries.set_move(r, nr, num_vertices(_bg));
             return 0;
+        }
 
         if (r != null_group && nr != null_group && !allow_move(r, nr))
             return std::numeric_limits<double>::infinity();

src/graph/inference/blockmodel/graph_blockmodel_mcmc.hh

@@ -115,6 +115,9 @@ struct MCMC
         virtual_move_dS(size_t v, size_t nr)
         {
             size_t r = _state._b[v];
+            if (r == nr)
+                return {0., 0.};
+
             double dS = _state.virtual_move(v, r, nr, _entropy_args,
                                             _m_entries);
             double a = 0;
@@ -126,7 +129,7 @@ struct MCMC
                                                  _m_entries);
                 a = log(pb) - log(pf);
             }
-            return std::make_tuple(dS, a);
+            return {dS, a};
         }
 
         void perform_move(size_t v, size_t nr)

src/graph/inference/layers/graph_blockmodel_layers.hh

@@ -468,7 +468,11 @@ struct Layers
                             MEntries& m_entries)
         {
             if (s == r)
+            {
+                m_entries.set_move(r, s, num_vertices(BaseState::_bg));
                 return 0;
+            }
+
             // assert(check_layers());
 
             double dS = 0;

src/graph/inference/overlap/graph_blockmodel_overlap.hh

@@ -597,7 +597,10 @@ public:
                         MEntries& m_entries)
     {
         if (r == nr)
+        {
+            m_entries.set_move(r, nr, num_vertices(_bg));
             return 0;
+        }
 
         if (!allow_move(r, nr))
             return std::numeric_limits<double>::infinity();