This happens upon CREATE USER and DROP ROLE.
The underlying problem is that our HASH implementation shuffles elements
around when performing an update or delete. This means that when doing a
scan through the HASH table by index, in search of elements to delete or
update one must restart the scan to make sure nothing is missed if at least
one delete / update happened.
More specifically, what happened in this case:
The hash has 131 element, DROP ROLE removes the element
[119]. Its [119]->next was element [129], so [129] is moved to [119].
Now we need to compact the hash, removing the last element [130]. It
gets one bit off its hash value and becomes element [2]. The existing
element [2] is moved to [129], and old [130] is moved to [2].
We cannot simply move [130] to [129] and make [2]->next=130, it won't
work if [2] is itself in the collision list and doesn't belong in [2].
The handle_grant_struct code assumed that it is safe to continue by only
reexamining the currently modified / deleted element index, but that is
not true.
Missing to delete an element in the hash triggered the assertion in
the test case. DROP ROLE would not clear all necessary role->role or
role->user mappings.
To fix the problem we ensure that the scan is restarted, only if an
element was deleted / updated, similar to how bubble-sort keeps sorting
until it finds no more elements to swap.
The code erroneously used buff[100] in a fiew places to make
a GRANTEE value in the form:
'user'@'host'
Fix:
- Fixing the code to use (USER_HOST_BUFF_SIZE + 6) instead of 100.
- Adding a DBUG_ASSERT to make sure the buffer is enough
- Wrapping the code into a class Grantee_str, to reuse it easier in 4 places.
- `SET DEFAULT ROLE xxx [FOR yyy]` should say:
"User yyy has not been granted a role xxx" if:
- The current user (not the user `yyy` in the FOR clause) can see the
role xxx. It can see the role if:
* role exists in `mysql.roles_mappings` (traverse the graph),
* If the current user has read access on `mysql.user` table - in
that case, it can see all roles, granted or not.
- Otherwise it should be "Invalid role specification".
In other words, it should not be possible to use `SET DEFAULT ROLE` to discover whether a specific role exist or not.
- Any temporary tables created under read-only mode will never be logged
to binary log. Any usage of these tables to update normal tables, even
after read-only has been disabled, will use row base logging (as the
temporary table will not be on the slave).
- Analyze, check and repair table will not be logged in read-only mode.
Other things:
- Removed not used varaibles in
MYSQL_BIN_LOG::flush_and_set_pending_rows_event.
- Set table_share->table_creation_was_logged for all normal tables.
- THD::binlog_query() now returns -1 if statement was not logged., This
is used to update table_share->table_creation_was_logged.
- Don't log admin statements in opt_readonly is set.
- Table's that doesn't have table_creation_was_logged will set binlog format to row
logging.
- Removed not needed/wrong setting of table->s->table_creation_was_logged
in create_table_from_items()
cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Debug
Maintainer mode makes all warnings errors. This patch fix warnings. Mostly about
deprecated `register` keyword.
Too much warnings came from Mroonga and I gave up on it.
