isStateBlock..Derived not crashing because of associatedMemBlock

include/core/ceres_wrapper/solver_ceres.h

@@ -173,18 +173,22 @@ inline ceres::Solver::Options& SolverCeres::getSolverOptions()
 
 inline bool SolverCeres::isFactorRegisteredDerived(const FactorBasePtr& fac_ptr) const
 {
-    return fac_2_residual_idx_.find(fac_ptr) != fac_2_residual_idx_.end() and
-           fac_2_costfunction_.find(fac_ptr) != fac_2_costfunction_.end();
+    return fac_2_residual_idx_.count(fac_ptr) == 1 and
+           fac_2_costfunction_.count(fac_ptr) == 1;
 }
 
 inline bool SolverCeres::isStateBlockRegisteredDerived(const StateBlockPtr& state_ptr) const
 {
+    if (state_blocks_.count(state_ptr) == 0)
+        return false;
     return ceres_problem_->HasParameterBlock(getAssociatedMemBlockPtr(state_ptr));
 }
 
 inline bool SolverCeres::isStateBlockFixedDerived(const StateBlockPtr& st)
 {
-    return ceres_problem_->IsParameterBlockConstant(SolverManager::getAssociatedMemBlockPtr(st));
+    if (state_blocks_.count(st) == 0)
+        return false;
+    return ceres_problem_->IsParameterBlockConstant(getAssociatedMemBlockPtr(st));
 };
 
 inline bool SolverCeres::hasLocalParametrizationDerived(const StateBlockPtr& st) const