Support get/print_info on an uninitialized system

Most code doesn't do this, but when a code does it should still get some
info, not just an assertion failure or a segfault.

Author: roystgnr

src/systems/system.C

@@ -1879,18 +1879,23 @@ std::string System::get_info() const
 
   oss << '\n';
 
-  oss << "    n_dofs()="             << this->n_dofs()             << '\n';
-  dof_id_type local_dofs = this->n_local_dofs();
-  oss << "    n_local_dofs()="       << local_dofs                 << '\n';
-  this->comm().max(local_dofs);
-  oss << "    max(n_local_dofs())="       << local_dofs                 << '\n';
+  if (this->is_initialized())
+    {
+      oss << "    n_dofs()="             << this->n_dofs()             << '\n';
+      dof_id_type local_dofs = this->n_local_dofs();
+      oss << "    n_local_dofs()="       << local_dofs                 << '\n';
+      this->comm().max(local_dofs);
+      oss << "    max(n_local_dofs())="       << local_dofs                 << '\n';
 #ifdef LIBMESH_ENABLE_CONSTRAINTS
-  oss << "    n_constrained_dofs()=" << this->n_constrained_dofs() << '\n';
-  oss << "    n_local_constrained_dofs()=" << this->n_local_constrained_dofs() << '\n';
-  dof_id_type local_unconstrained_dofs = this->n_local_dofs() - this->n_local_constrained_dofs();
-  this->comm().max(local_unconstrained_dofs);
-  oss << "    max(local unconstrained dofs)=" << local_unconstrained_dofs << '\n';
+      oss << "    n_constrained_dofs()=" << this->n_constrained_dofs() << '\n';
+      oss << "    n_local_constrained_dofs()=" << this->n_local_constrained_dofs() << '\n';
+      dof_id_type local_unconstrained_dofs = this->n_local_dofs() - this->n_local_constrained_dofs();
+      this->comm().max(local_unconstrained_dofs);
+      oss << "    max(local unconstrained dofs)=" << local_unconstrained_dofs << '\n';
 #endif
+    }
+  else
+    oss << "    (still uninitialized)\n";
 
   oss << "    " << "n_vectors()="  << this->n_vectors()  << '\n';
   oss << "    " << "n_matrices()="  << this->n_matrices()  << '\n';