This fix was accidentally pushed to mysql-5.1 after the 5.1.59 clone-off in
bzr revision id marko.makela@oracle.com-20110829081642-z0w992a0mrc62s6w
with the fix of Bug#12704861 Corruption after a crash during BLOB update
but not merged to mysql-5.5 and upwards.

In the Barracuda formats, the clustered index record no longer
contains a prefix of off-page columns. Because of this, the undo log
must contain these prefixes, so that purge and multi-versioning will
continue to work. However, this also means that an undo log record can
become too big to fit in an undo log page. (It is a limitation of the
undo log that undo records cannot span across multiple pages.)

In case the checks for undo log size fail when CREATE TABLE or CREATE
INDEX is executed, we need a fallback that blocks a modification
operation when the undo log record would exceed the maximum size.

trx_undo_free_last_page_func(): Renamed from trx_undo_free_page_in_rollback().
Define the trx_t parameter only in debug builds.

trx_undo_free_last_page(): Wrapper for trx_undo_free_last_page_func().
Pass the trx_t parameter only in debug builds.

trx_undo_truncate_end_func(): Renamed from trx_undo_truncate_end().
Define the trx_t parameter only in debug builds. Rewrite a for(;;) loop
as a while loop for clarity.

trx_undo_truncate_end(): Wrapper for from trx_undo_truncate_end_func().
Pass the trx_t parameter only in debug builds.

trx_undo_erase_page_end(): Return TRUE if the page was non-empty
to begin with. Refuse to erase empty pages.

trx_undo_report_row_operation(): If the page for which the undo log
was too big was empty, free the undo page and return DB_TOO_BIG_RECORD.

rb:749 approved by Inaam Rana

Post-push fix:
Enable filesort pattern two, perfschema.selects failed.

Post-push fix:
The functions write_keys() and find_all_keys() may have a slightly
different function signature, depending on compiler/platform/flags.

GROUPING BY FUNCTIONS.... (PART

The bug was introduced in a patch for bug 49897.

Problem: The assertion inserted by the original patch to guard against
zero-lenght sort keys during merge phase triggers also when the whole
set fits in memory.

Fix: Move assert so that it does not trigger if the whole set is in
memory.


mysql-test/r/group_by.result:
  Add test for bug#11765254
mysql-test/t/group_by.test:
  Add test for bug#11765254
sql/filesort.cc:
  Move assertion

rb://752 approved by Sunny Bains

Converting the number zero to binary and back yielded the number zero,
but with no digits, i.e. zero precision.
This made the multiply algorithm go haywire in various ways.


include/decimal.h:
  Document struct st_decimal_t
mysql-test/r/type_newdecimal.result:
  New test case (valgrind warnings)
mysql-test/t/type_newdecimal.test:
  New test case (valgrind warnings)
sql/my_decimal.h:
  Remove the HAVE_purify enabled/disabled code.
strings/decimal.c:
  Make a proper zero, with non-zero precision.

Use PSI_MUTEX_TRYLOCK instead of PSI_MUTEX_LOCK when acquire mutex with
"no_wait" option
      
Approved by Sunny Bains

The fix of Bug#12612184 broke crash recovery. When a record that
contains off-page columns (BLOBs) is updated, we must first write redo
log about the BLOB page writes, and only after that write the redo log
about the B-tree changes. The buggy fix would log the B-tree changes
first, meaning that after recovery, we could end up having a record
that contains a null BLOB pointer.

Because we will be redo logging the writes off the off-page columns
before the B-tree changes, we must make sure that the pages chosen for
the off-page columns are free both before and after the B-tree
changes. In this way, the worst thing that can happen in crash
recovery is that the BLOBs are written to free pages, but the B-tree
changes are not applied. The BLOB pages would correctly remain free in
this case. To achieve this, we must allocate the BLOB pages in the
mini-transaction of the B-tree operation. A further quirk is that BLOB
pages are allocated from the same file segment as leaf pages. Because
of this, we must temporarily "hide" any leaf pages that were freed
during the B-tree operation by "fake allocating" them prior to writing
the BLOBs, and freeing them again before the mtr_commit() of the
B-tree operation, in btr_mark_freed_leaves().

btr_cur_mtr_commit_and_start(): Remove this faulty function that was
introduced in the Bug#12612184 fix. The problem that this function was
trying to address was that when we did mtr_commit() the BLOB writes
before the mtr_commit() of the update, the new BLOB pages could have
overwritten clustered index B-tree leaf pages that were freed during
the update. If recovery applied the redo log of the BLOB writes but
did not see the log of the record update, the index tree would be
corrupted. The correct solution is to make the freed clustered index
pages unavailable to the BLOB allocation. This function is also a
likely culprit of InnoDB hangs that were observed when testing the
Bug#12612184 fix.

btr_mark_freed_leaves(): Mark all freed clustered index leaf pages of
a mini-transaction allocated (nonfree=TRUE) before storing the BLOBs,
or freed (nonfree=FALSE) before committing the mini-transaction.

btr_freed_leaves_validate(): A debug function for checking that all
clustered index leaf pages that have been marked free in the
mini-transaction are consistent (have not been zeroed out).

btr_page_alloc_low(): Refactored from btr_page_alloc(). Return the
number of the allocated page, or FIL_NULL if out of space. Add the
parameter "mtr_t* init_mtr" for specifying the mini-transaction where
the page should be initialized, or if this is a "fake allocation"
(init_mtr=NULL) by btr_mark_freed_leaves(nonfree=TRUE).

btr_page_alloc(): Add the parameter init_mtr, allowing the page to be
initialized and X-latched in a different mini-transaction than the one
that is used for the allocation. Invoke btr_page_alloc_low(). If a
clustered index leaf page was previously freed in mtr, remove it from
the memo of previously freed pages.

btr_page_free(): Assert that the page is a B-tree page and it has been
X-latched by the mini-transaction. If the freed page was a leaf page
of a clustered index, link it by a MTR_MEMO_FREE_CLUST_LEAF marker to
the mini-transaction.

btr_store_big_rec_extern_fields_func(): Add the parameter alloc_mtr,
which is NULL (old behaviour in inserts) and the same as local_mtr in
updates. If alloc_mtr!=NULL, the BLOB pages will be allocated from it
instead of the mini-transaction that is used for writing the BLOBs.

fsp_alloc_from_free_frag(): Refactored from
fsp_alloc_free_page(). Allocate the specified page from a partially
free extent.

fseg_alloc_free_page_low(), fseg_alloc_free_page_general(): Add the
parameter "mtr_t* init_mtr" for specifying the mini-transaction where
the page should be initialized, or NULL if this is a "fake allocation"
that prevents the reuse of a previously freed B-tree page for BLOB
storage. If init_mtr==NULL, try harder to reallocate the specified page
and assert that it succeeded.

fsp_alloc_free_page(): Add the parameter "mtr_t* init_mtr" for
specifying the mini-transaction where the page should be initialized.
Do not allow init_mtr == NULL, because this function is never to be
used for "fake allocations".

mtr_t: Add the operation MTR_MEMO_FREE_CLUST_LEAF and the flag
mtr->freed_clust_leaf for quickly determining if any
MTR_MEMO_FREE_CLUST_LEAF operations have been posted.

row_ins_index_entry_low(): When columns are being made off-page in
insert-by-update, invoke btr_mark_freed_leaves(nonfree=TRUE) and pass
the mini-transaction as the alloc_mtr to
btr_store_big_rec_extern_fields(). Finally, invoke
btr_mark_freed_leaves(nonfree=FALSE) to avoid leaking pages.

row_build(): Correct a comment, and add a debug assertion that a
record that contains NULL BLOB pointers must be a fresh insert.

row_upd_clust_rec(): When columns are being moved off-page, invoke
btr_mark_freed_leaves(nonfree=TRUE) and pass the mini-transaction as
the alloc_mtr to btr_store_big_rec_extern_fields(). Finally, invoke
btr_mark_freed_leaves(nonfree=FALSE) to avoid leaking pages.

buf_reset_check_index_page_at_flush(): Remove. The function
fsp_init_file_page_low() already sets
bpage->check_index_page_at_flush=FALSE.

There is a known issue in tablespace extension. If the request to
allocate a BLOB page leads to the tablespace being extended, crash
recovery could see BLOB writes to pages that are off the tablespace
file bounds. This should trigger an assertion failure in fil_io() at
crash recovery. The safe thing would be to write redo log about the
tablespace extension to the mini-transaction of the BLOB write, not to
the mini-transaction of the record update. However, there is no redo
log record for file extension in the current redo log format.

rb:693 approved by Sunny Bains

Background: Backporting fix for BUG 11752963 to Mysql5.1 branch.
Problem: Fix of bug 11752963 was only available for trunk and 5.5 branch.
Partial fix has been pushed to 5.1 branch as well. 
Fix: backporting the fixes of bug 11752963 to 5.1 branch. 
1. Made all major changes to make 5.1 branch in line with 5.5 and the trunk.
2. skipped the partial patch that was already applied to the 5.1 branch. 

sql/rpl_rli.h:
  Made inited Volatile (find inline comments)
sql/slave.cc:
  backported all changes from the fix of BUG#11752963.

Suppress the known warnings generated by filesort().

The real fix belongs to worklog 1509:
Pack values of non-sorted fields in the sort buffer
(which is basically the same issue, but in an optimization context:
 We are writing the entire sort buffer to disk, 
 including un-used space for varchar columns.)



mysql-test/valgrind.supp:
  Add new Memcheck suppressions for filesort.
sql/filesort.cc:
  Remove the ifdef HAVE_purify/bzero code, use valgrind suppressions instead.

     Also look into directories lib64 in addition to lib

The fix in revision id marko.makela@oracle.com-20110815091143-h3zbvm0pv8ni3qql
introduced a false UNIV_SYNC_DEBUG alarm. Relax the assertion.