Update copyright comment in innochecksum.

Some ut_a(!rec_offs_any_null_extern()) assertion failures are indicating
genuine BLOB bugs, others are bogus failures when rolling back incomplete
transactions at crash recovery. This needs more work, and until I get a
chance to work on it, other testing must not be disrupted by this.

revno 2995.37.209
revision id marko.makela@oracle.com-20110518120508-qhn7vz814vn77v5k
parent marko.makela@oracle.com-20110517121555-lmple24qzxqkzep4
timestamp: Wed 2011-05-18 15:05:08 +0300
message:
  Fix a bogus UNIV_SYNC_DEBUG failure in the fix of Bug #59641
  or Oracle Bug #11766513.

  trx_undo_free_prepared(): Do not acquire or release trx->rseg->mutex.
  This code is invoked in the single-threaded part of shutdown, therefore
  a mutex is not needed.

SYNTAX TRIGGERS IN ANY WAY

Table with triggers which were using deprecated (5.0-only) syntax became
unavailable for any DML and DDL after upgrade to 5.1 version of server.
Attempt to execute any statement on such a table resulted in parsing
error reported. Since this included DROP TRIGGER and DROP TABLE
statements (actually, the latter was allowed but was not functioning
properly for such tables) it was impossible to fix the problem without
manual operations on .TRG and .TRN files in data directory.

The problem was that failure to parse trigger body (due to 5.0-only
syntax) when opening trigger file for a table prevented the table
from being open. This made all operations on the table impossible
(except DROP TABLE which due to peculiarity in its implementation
dropped the table but left trigger files around).

This patch solves this problem by silencing error which occurs when
we parse trigger body during table open. Error message is preserved
for the future use and table is marked as having a broken trigger.
We also try to analyze parse tree to recover trigger name, which
will be needed in order to drop the broken trigger. DML statements
which invoke triggers on the table marked as having broken trigger
are prohibited and emit saved error message. The same happens for
DDL which change triggers except DROP TRIGGER and DROP TABLE which
try their best to do what was requested. Table becomes no longer
marked as having broken trigger when last such trigger is dropped.

row_build(): The record may contain null BLOB pointers when the server
is rolling back an insert that was interrupted by a server crash.

THE EVENT STATUS.

Any ALTER EVENT statement on a disabled event enabled it back
(unless this ALTER EVENT statement explicitly disabled the event).

The problem was that during processing of an ALTER EVENT statement
value of status field was overwritten unconditionally even if new
value was not specified explicitly. As a consequence this field
was set to default value for status which corresponds to ENABLE.

The solution is to check if status field was explicitly specified in
ALTER EVENT statement before assigning new value to status field.

SEEMS TO BE 'LEAKING' INTO THE SCHEMA NAME SPACE)
and bug#12428824 (Parser stack overflow and crash in sp_add_used_routine
with obscure query).

The first problem was that attempts to call a stored function by
its fully qualified name ended up with unwarranted error "ERROR 1305
(42000): FUNCTION someMixedCaseDb.my_function_name does not exist"
if this function belonged to a schema that had uppercase letters in
its name AND --lower_case_table_names was equal to either 1 or 2.

The second problem was that 5.5 version of MySQL server might have
crashed when a user tried to call stored function with too long name
or too long database name (i.e if a function and database name combined
occupied more than 2*3*64 bytes in utf8). This issue didn't affect
versions of server < 5.5.
 
The first problem was caused by the fact that in cases when a stored
function was called by its fully qualified name we didn't lowercase
name of its schema before performing look up of the function in
mysql.proc table even although lower_case_table_names mode was on.
As result we were unable to find this function since during its
creation we store lowercased version of schema name in the system
table in this mode and field for schema name uses binary collation.

Calls to stored functions were unaffected by this problem since for
them schema name is converted to lowercase as necessary.

The reason for the second bug was that MySQL Server didn't check length
of function name and database name before proceeding with execution of
stored function. As a consequence too long database name or function
name caused buffer overruns in places where the code assumes that their
length is within fixed limits, like mdl_key_init() in 5.5.

Again this issue didn't affect calls to stored procedures as for them
length of schema name and procedure name are properly checked.

This patch fixes both these bugs by adding calls to check_db_name()
and check_routine_name() to grammar rule which corresponds to a call
to a stored function. These functions ensure that length of database
name and function name for routine called is within standard limit.
Moreover call to check_db_name() handles conversion of database name
to lowercase if --lower_case_table_names mode is on.

Note that even although the second issue seems to be only reproducible
in 5.5 we still add code fixing it to 5.1 to be on the safe side (and
make code a bit more robust against possible future changes).

If UNIV_DEBUG or UNIV_BLOB_LIGHT_DEBUG is enabled, add
!rec_offs_any_null_extern() assertions, ensuring that records do not
contain null pointers to externally stored columns in inappropriate
places.

btr_cur_optimistic_update(): Assert !rec_offs_any_null_extern().
Incomplete records must never be updated or deleted. This assertion
will cover also the pessimistic route.

row_build(): Assert !rec_offs_any_null_extern(). Search tuples must
never be built from incomplete index entries.

row_rec_to_index_entry(): Assert !rec_offs_any_null_extern() unless
ROW_COPY_DATA is requested. ROW_COPY_DATA is used for
multi-versioning, and therefore it might be valid to copy the most
recent (uncommitted) version while it contains a null pointer to
off-page columns.

row_vers_build_for_consistent_read(),
row_vers_build_for_semi_consistent_read(): Assert !rec_offs_any_null_extern()
on all versions except the most recent one.

trx_undo_prev_version_build(): Assert !rec_offs_any_null_extern() on
the previous version.

rb:682 approved by Sunny Bains

Problem: in case of wrong data insert into indexed GEOMETRY fields 
(e.g. NULL value for a not NULL field) MyISAM reported 
"ERROR 126 (HY000): Incorrect key file for table; try to repair it"
due to misuse of the key deletion function.

Fix: always use R-tree key functions for R-tree based indexes
and B-tree key functions for B-tree based indexes.

This is the 5.1 version of the fix.
      
Need to free the memory allocated by the option parsing code for empty 
strings when resetting the pointer to NULL.
No test case needed, as the existing ones already cover this path.

row_build_index_entry(): In innodb_file_format=Barracuda
(ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED), a secondary index on a
full column can refer to a field that is stored off-page in the
clustered index record. Take that into account.

rb:692 approved by Jimmy Yang

around the declaration of trx_assert_recovered().

Refactor the !rec_offs_any_extern relaxation in row_build().

trx_assert_active(trx_id): Assert that the given transaction is active.
(In the 5.1 built-in InnoDB, there is no trx->is_recovered field.)

trx_assert_recovered(trx_id): Assert that the given transaction is
active and has been recovered after a crash.

row_build(): Replace a bunch of code with an assertion that invokes
trx_assert_active() or trx_assert_recovered() and row_get_rec_trx_id().

row_get_trx_id_offset(): Make the function inlined. Remove the unused
parameter rec, and make all parameters const.

row_get_rec_trx_id(), row_get_rec_roll_ptr(): Make all parameters const.

rb:691 approved by Jimmy Yang

page_zip_dir_elems(): New function, refactored from page_zip_dir_size().

page_zip_dir_size(): Use page_zip_dir_elems()

page_zip_dir_start_offs(): New function: Gets an offset to the
compressed page trailer (the dense page directory), including deleted
records (the free list)

page_zip_dir_start_low(page_zip, n_dense): Constness-preserving
wrapper macro for page_zip_dir_start_offs().

page_zip_dir_start(page_zip): Constness-preserving
wrapper macro for page_zip_dir_start_offs().

page_zip_decompress_node_ptrs(), page_zip_decompress_clust(): Replace
a formula with a fully equivalent page_zip_dir_start_low() call.

page_zip_write_rec(), page_zip_parse_write_node_ptr(),
page_zip_write_node_ptr(), page_zip_write_trx_id_and_roll_ptr(),
page_zip_clear_rec(): Replace a formula with an almost equivalent
page_zip_dir_start() call.
It is OK to replace page_dir_get_n_heap(page) with
page_dir_get_n_heap(page_zip->data), because
ut_ad(page_zip_header_cmp(page_zip, page)) or
page_zip_validate(page_zip, page) asserts that the
page headers are identical.

rb:687 approved by Jimmy Yang

BOGUS "THE TABLE MYSQL.PROC IS MISSING,..."

There was a race condition between loading a stored routine
(function/procedure/trigger) specified by fully qualified name
SCHEMA_NAME.PROC_NAME and dropping the stored routine database.

The problem was that there is a window for race condition when one server
thread tries to load a stored routine being executed and the other thread
tries to drop the stored routine schema.

This condition race window exists in implementation of function
mysql_change_db() called by db_load_routine() during loading of stored
routine to cache. Function mysql_change_db() calls check_db_dir_existence()
that might failed because specified database was dropped during concurrent
execution of DROP SCHEMA statement. db_load_routine() calls mysql_change_db()
with flag 'force_switch' set to 'true' value so when referenced db is not found
then my_error() is not called and function mysql_change_db() returns ok.
This shadows information about schema opening error in db_load_routine().
Then db_load_routine() makes attempt to parse stored routine that is failed.
This makes to return error to sp_cache_routines_and_add_tables_aux() but since
during error generation a call to my_error wasn't made and hence
THD::main_da wasn't set we set the generic "mysql.proc table corrupt" error
when running sp_cache_routines_and_add_tables_aux().

The fix is to install an error handler inside db_load_routine() for
the mysql_op_change_db() call, and check later if the ER_BAD_DB_ERROR
was caught.