Table comment: issue a warning(error in traditional mode) if length of comment > 60 symbols
Column comment: issue a warning(error in traditional mode) if length of comment > 255 symbols
Table 'comment' is changed from char* to LEX_STRING
After view onening real view db name and table name are placed
into table_list->view_db & table_list->view_name.
Item_field class does not handle these names properly during
intialization of Send_field.
The fix is to use new class 'Item_ident_for_show'
which sets correct view db name and table name for Send_field.
It was hard to distinguish case, when one was unable to create trigger
on the table because trigger with same action time and event already
existed for this table, from the case, when one tried to create trigger
with name which was already occupied by some other trigger, since in
both these cases we emitted ER_TRG_ALREADY_EXISTS error and message.
Now we emit ER_NOT_SUPPORTED_YET error with appropriate additional
message in the first case. There is no sense in introducing separate
error for this situation since we plan to get rid of this limitation
eventually.
No test case as the bug is in an existing test case (rpl_trigger.test
when it is run under valgrind).
The warning was caused by memory corruption in replication slave: thd->db
was pointing at a stack address that was previously used by
sp_head::execute()::old_db. This happened because mysql_change_db
behaved differently in replication slave and did not make a copy of the
argument to assign to thd->db.
The solution is to always free the old value of thd->db and allocate a new
copy, regardless whether we're running in a replication slave or not.
It was possible that fetching a record by an exact key value
(including the record pointer) could return a record with a
different key value. This happened only if a concurrent insert
added a record with the searched key value after the fetching
statement locked the table for read.
The search succeded on the key value, but the record was
rejected as it was past the file length that was remembered
at start of the fetching statement. With other words it was
rejected as being a concurrently inserted record.
The action to recover from this problem was to fetch the
record that is pointed at by the next key of the index.
This was repeated until a record below the file length was
found.
I do now avoid this loop if an exact match was searched.
If this match is beyond the file length, it is now treated
as "key not found". There cannot be another key with the
same record pointer.
sp_grant_privileges(), the function that GRANTs EXECUTE + ALTER privs on a SP,
did so creating a user-entry with not password; mysql_routine_grant() would then
write that "change" to the user-table.
