inference: fix clabel enforcement in mcmc/multiflip_mcmc

src/graph/inference/blockmodel/graph_blockmodel.hh

@@ -86,7 +86,7 @@ typedef mpl::vector1<std::false_type> rmap_tr;
     ((mrm,, vmap_t, 0))                                                        \
     ((wr,, vmap_t, 0))                                                         \
     ((b,, vmap_t, 0))                                                          \
-    ((empty_blocks, & ,std::vector<size_t>&, 0))                               \
+    ((empty_blocks, &, std::vector<size_t>&, 0))                               \
     ((empty_pos,, vmap_t, 0))                                                  \
     ((candidate_blocks, &, std::vector<size_t>&, 0))                           \
     ((candidate_pos,, vmap_t, 0))                                              \
@@ -1736,12 +1736,8 @@ public:
         }
         else
         {
-            do
-            {
-                s = uniform_sample(_candidate_blocks.begin() + 1,
-                                   _candidate_blocks.end(), rng);
-            }
-            while(_bclabel[s] != _bclabel[r]);
+            s = uniform_sample(_candidate_blocks.begin() + 1,
+                               _candidate_blocks.end(), rng);
         }
         _b[v] = s;
     }

src/graph/inference/blockmodel/graph_blockmodel_multiflip_mcmc.hh

@@ -182,11 +182,16 @@ struct MCMC
             auto t = uniform_sample(_state._empty_blocks, rng);
 
             auto r = _state._b[v];
+            _state._bclabel[t] = _state._bclabel[r];
             if (_state._coupled_state != nullptr)
             {
                 if constexpr (sample_branch)
                 {
-                    _state._coupled_state->sample_branch(t, r, rng);
+                    do
+                    {
+                        _state._coupled_state->sample_branch(t, r, rng);
+                    }
+                    while(!_state.allow_move(r, t));
                 }
                 else
                 {
@@ -196,7 +201,6 @@ struct MCMC
                 auto& hpclabel = _state._coupled_state->get_pclabel();
                 hpclabel[t] = _state._pclabel[v];
             }
-            _state._bclabel[t] = _state._bclabel[r];
 
             if (t >= _groups.size())
             {