Reworked the implementation of create role and drop role.

Also fixed issue with drop role not clearing internal memory entry
for that role. The issue was due to a condition introduced in handle_grant_data

Updated testsuite to also check the possible error conditions.

mysql-test/r/acl_roles_create_and_drop_role.result

 use mysql;
+create role test_role1@host1;
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '@host1' at line 1
+create role test_role2@host2, test_role1@host1;
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '@host2, test_role1@host1' at line 1
 create role test_role1;
 create role test_role2, test_role3;
-select user, host, is_role from user where user like 'test';
+select user, host, is_role from user where user like 'test%';
 user	host	is_role
+test_role1		Y
+test_role2		Y
+test_role3		Y
 drop role test_role1;
 drop role test_role2, test_role3;
 create role test_role1;
@@ -10,12 +17,20 @@ create role test_role1;
 ERROR HY000: Operation CREATE ROLE failed for 'test_role1'
 create role test_role1, test_role2;
 ERROR HY000: Operation CREATE ROLE failed for 'test_role1'
-select user, host, is_role from user where user like 'test';
+select user, host, is_role from user where user like 'test%';
 user	host	is_role
+test_role1		Y
+test_role2		Y
 drop role test_role1;
 drop role test_role1;
 ERROR HY000: Operation DROP ROLE failed for 'test_role1'
 drop role test_role1, test_role2;
 ERROR HY000: Operation DROP ROLE failed for 'test_role1'
-select user, host, is_role from user where user like 'test';
+drop role root;
+ERROR HY000: Operation DROP ROLE failed for 'root'
+create user dummy@'';
+drop role dummy;
+ERROR HY000: Operation DROP ROLE failed for 'dummy'
+drop user dummy@'';
+select user, host, is_role from user where user like 'test%';
 user	host	is_role

mysql-test/t/acl_roles_create_and_drop_role.test

 connect (mysql, localhost, root,,);
 use mysql;
 
+#test valid syntax
+--error ER_PARSE_ERROR
+create role test_role1@host1;
+--error ER_PARSE_ERROR
+create role test_role2@host2, test_role1@host1;
+
 create role test_role1;
 create role test_role2, test_role3;
 
 --sorted_result
-select user, host, is_role from user where user like 'test';
+select user, host, is_role from user where user like 'test%';
 
 drop role test_role1;
 drop role test_role2, test_role3;
@@ -18,7 +24,7 @@ create role test_role1;
 create role test_role1, test_role2;
 
 --sorted_result
-select user, host, is_role from user where user like 'test';
+select user, host, is_role from user where user like 'test%';
 
 drop role test_role1;
 --error ER_CANNOT_USER
@@ -26,6 +32,14 @@ drop role test_role1;
 --error ER_CANNOT_USER
 drop role test_role1, test_role2;
 
+#test that we can not drop users when calling drop role
+--error ER_CANNOT_USER
+drop role root;
+create user dummy@'';
+--error ER_CANNOT_USER
+drop role dummy;
+drop user dummy@'';
+
 --sorted_result
-select user, host, is_role from user where user like 'test';
+select user, host, is_role from user where user like 'test%';
 disconnect mysql;

sql/share/errmsg-utf8.txt

@@ -6572,5 +6572,3 @@ ER_INVALID_CURRENT_USER
 ER_INVALID_ROLE_COMMAND
 	eng "Unable to execute role related command. The user table is in invalid format."
 	rum "Comanda asupra rolurilor nu poate fi executate. Tabelul "user" este in format invalid."
-ER_ROLE_AS_USER
-	eng "The role '%s' is marked as a user '%s'@''

sql/sql_acl.h

@@ -230,12 +230,10 @@ ulong get_column_grant(THD *thd, GRANT_INFO *grant,
 bool mysql_show_grants(THD *thd, LEX_USER *user);
 void get_privilege_desc(char *to, uint max_length, ulong access);
 void get_mqh(const char *user, const char *host, USER_CONN *uc);
-bool mysql_create_user(THD *thd, List <LEX_USER> &list);
-bool mysql_drop_user(THD *thd, List <LEX_USER> &list);
+bool mysql_create_user(THD *thd, List <LEX_USER> &list, bool handle_as_role);
+bool mysql_drop_user(THD *thd, List <LEX_USER> &list, bool handle_as_role);
 bool mysql_rename_user(THD *thd, List <LEX_USER> &list);
 bool mysql_revoke_all(THD *thd, List <LEX_USER> &list);
-bool mysql_create_role(THD *thd, List <LEX_USER> &list);
-bool mysql_drop_role(THD *thd, List <LEX_USER> &list);
 void fill_effective_table_privileges(THD *thd, GRANT_INFO *grant,
                                      const char *db, const char *table);
 bool sp_revoke_privileges(THD *thd, const char *sp_db, const char *sp_name,

sql/sql_parse.cc

@@ -3728,22 +3728,26 @@ case SQLCOM_PREPARE:
   }
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   case SQLCOM_CREATE_USER:
+  case SQLCOM_CREATE_ROLE:
   {
     if (check_access(thd, INSERT_ACL, "mysql", NULL, NULL, 1, 1) &&
         check_global_access(thd,CREATE_USER_ACL))
       break;
     /* Conditionally writes to binlog */
-    if (!(res= mysql_create_user(thd, lex->users_list)))
+    if (!(res= mysql_create_user(thd, lex->users_list,
+                                 lex->sql_command == SQLCOM_CREATE_ROLE)))
       my_ok(thd);
     break;
   }
   case SQLCOM_DROP_USER:
+  case SQLCOM_DROP_ROLE:
   {
     if (check_access(thd, DELETE_ACL, "mysql", NULL, NULL, 1, 1) &&
         check_global_access(thd,CREATE_USER_ACL))
       break;
     /* Conditionally writes to binlog */
-    if (!(res= mysql_drop_user(thd, lex->users_list)))
+    if (!(res= mysql_drop_user(thd, lex->users_list,
+                               lex->sql_command == SQLCOM_DROP_ROLE)))
       my_ok(thd);
     break;
   }
@@ -3757,26 +3761,6 @@ case SQLCOM_PREPARE:
       my_ok(thd);
     break;
   }
-  case SQLCOM_CREATE_ROLE:
-  {
-    if (check_access(thd, INSERT_ACL, "mysql", NULL, NULL, 1, 1) &&
-        check_global_access(thd,CREATE_USER_ACL))
-      break;
-    /* Conditionally writes to binlog */
-    if (!(res= mysql_create_role(thd, lex->users_list)))
-      my_ok(thd);
-    break;
-  }
-  case SQLCOM_DROP_ROLE:
-  {
-    if (check_access(thd, DELETE_ACL, "mysql", NULL, NULL, 1, 1) &&
-        check_global_access(thd,CREATE_USER_ACL))
-      break;
-    /* Conditionally writes to binlog */
-    if (!(res= mysql_drop_role(thd, lex->users_list)))
-      my_ok(thd);
-    break;
-  }
   case SQLCOM_REVOKE_ALL:
   {
     if (check_access(thd, UPDATE_ACL, "mysql", NULL, NULL, 1, 1) &&