p4est initialization in t8_cmesh_new_from_p4est does not work

[lukasdreyer]

t8_cmesh_new_from_p4est checks that p4est was initialized, and does it itself if it was not initialized before.

But forgetting to initialize p4est leads to memory balance errors as shown below:

#include <t8_cmesh/t8_cmesh_examples.h>

int
main (int argc, char **argv)
{
  t8_cmesh_t          cmesh;
  p4est_connectivity_t *conn;

  SC_CHECK_MPI(sc_MPI_Init (&argc, &argv));

  sc_init (sc_MPI_COMM_WORLD, 1, 1, NULL, SC_LP_ESSENTIAL);
//  p4est_init (NULL, SC_LP_DEFAULT);
  t8_init (SC_LP_DEFAULT);
  
  conn = p4est_connectivity_new_brick (1, 1, 0, 0);
  cmesh = t8_cmesh_new_from_p4est (conn, sc_MPI_COMM_WORLD, 0);
  
  t8_cmesh_destroy (&cmesh);
  p4est_connectivity_destroy (conn);

  sc_finalize ();
  SC_CHECK_MPI (sc_MPI_Finalize ());
  return 0;
}

leads to

[libsc] This is libsc 2.8.5.67-edbe8-dirty
[t8] This is t8 1.6.1.130-4af3-dirty
[t8] CPP                      mpicc -E
[t8] CPPFLAGS                 
[t8] CC                       mpicc
[t8] CFLAGS                   -Wall -O0 -g
[t8] LDFLAGS                  
[t8] LIBS                     -lz -lm  -lstdc++
[libsc 0] Invalid package id -1
[t8] WARNING: p4est is not yet initialized. Doing it now for you.
[p4est] This is p4est 2.8.5.69-aee0b-dirty
[t8 0] Registering geometry t8_geom_linear_2
[t8 0] Committing geom handler. Set 't8_geom_linear_2' as active geometry.
[t8 0] Cmesh is not partitioned.
[t8 0] committed cmesh with 1 local and 1 global trees and 0 ghosts.
[libsc 0] Memory balance (p4est)
[0] Memory balance (default)
Abort: Finalize
Abort: ../../t8code/sc/src/sc.c:1404
Abort
Aborted

but reintroducing the p4est_init call in the main resolves the memory balance issue