Function update_role_table_columns

sql/sql_acl.cc:7015–7061

update GRANT_TABLE for a given table and a given role with merged privileges @param merged GRANT_TABLE of the role in question (or NULL if it wasn't found) @param first first GRANT_TABLE in an array for the table in question @param last last entry in the array of GRANT_TABLE's for a given table, all entries between first and last correspond to the *same* table @param pr

          4 - GRANT_TABLE was deleted
*/
static int update_role_table_columns(GRANT_TABLE *merged,
                                     GRANT_TABLE **first, GRANT_TABLE **last,
                                     privilege_t privs, privilege_t cols,
                                     const char *role)
{
  if (!first)
    return 0;

  DBUG_EXECUTE_IF("role_merge_stats", role_table_merges++;);

  if (merged == NULL)
  {
    /*
      there's no GRANT_TABLE for this role (all table grants come from granted
      roles) we need to create it
    */
    DBUG_ASSERT(privs | cols);
    merged= new (&grant_memroot) GRANT_TABLE("", first[0]->db, role, first[0]->tname,
                                     privs, cols);
    merged->init_privs= merged->init_cols= NO_ACL;
    update_role_columns(merged, first, last);
    column_priv_insert(merged);
    return 2;
  }
  else if ((privs | cols) == NO_ACL)
  {
    /*
      there is GRANT_TABLE object but the role has no table or column
      privileges granted (all privileges were coming from granted roles, and
      now those roles were dropped or had their privileges revoked).
      we need to remove this GRANT_TABLE
    */
    DBUG_EXECUTE_IF("role_merge_stats",
                    role_column_merges+= MY_TEST(merged->cols););
    my_hash_delete(&column_priv_hash,(uchar*) merged);
    return 4;
  }
  else
  {
    bool changed= merged->cols != cols || merged->privs != privs;
    merged->cols= cols;
    merged->privs= privs;
    if (update_role_columns(merged, first, last))
      changed= true;
    return changed;
  }
}

/**
  merges table privileges from roles granted to the role 'grantee'.