The title of the bug is a little confusing. The actual fix is to
reintroduce random readahead inside InnoDB with a dynamic, global
switch innodb_random_read_ahead [default = off].

Approved by: Sunny Bains
rb://696

Before BUG#28796, an empty host was used to identify that an instance was no
longer a slave. However, BUG#28796 changed this behavior and one cannot set
an empty host. Besides, a RESET SLAVE only cleans up information on the next
event to retrieve from the master, disables ssl and resets heartbeat period.
So a call to SHOW SLAVE STATUS after issuing a RESET SLAVE still returns some
valid information, such as host, port, user and password.

To fix this problem, we have introduced the command RESET SLAVE ALL that does
what a regular RESET SLAVE does and also clears host, port, user and password
information thus allowing users to identify when an instance is no longer a
slave.

Truncate result of decimal division before converting to integer.

Turns out the DBUG_ASSERT added by fix for Bug#11792200 was overly pessimistic:
'stop0' is used in the main loop of do_div_mod, but we only dereference 'buf0'
for div operations, not for mod.

Original changeset:
revision-id: alexander.nozdrin@oracle.com-20101221122349-6h8ammcro70a4pac
parent: sven.sandberg@oracle.com-20101221121948-hnivuulyohzch1v4
committer: Alexander Nozdrin <alexander.nozdrin@oracle.com>
branch nick: mysql-trunk-bugfixing
timestamp: Tue 2010-12-21 15:23:49 +0300
message:
  A patch for Bug#59060 (Valgrind warning in Protocol_text::store()).
  
  We should not assume to have zero-terminated strings.

HA_ERR was returning 0 (null string) when no error happened 
(error=0). Since HA_ERR is used in DBUG_PRINT, regardless there 
was an error or not, the server could crash in solaris debug
builds.

We fix this by:

  - deploying an assertion that ensures that the function 
    is not called when no error has happened;
  - making sure that HA_ERR is only called when an error 
    happened;
  - making HA_ERR return "No Error", instead of 0, for 
    non-debug builds if it is called when no error happened.

This will make HA_ERR return values to work with DBUG_PRINT on
solaris debug builds.

Manual merge from mysql-5.1 into mysql-5.5.

                  
The server crashes if it processes table map events that are
corrupted, especially if they map different tables to the same
identifier. This could happen, for instance, due to BUG 56226.
                  
We fix this by checking whether the table map has already been
mapped before actually applying the event. If it has been mapped
with different settings an error is raised and the slave SQL
thread stops. If it has been mapped with same settings the event
is skipped. If the table is set to be ignored by the filtering
rules, there is no change in behavior: the event is skipped and
ids are not checked.

  
Automerged from mysql-5.1 into mysql-5.5 (empty cset).

Manually merged from mysql-5.0 into mysql-5.1.

conflicts
=========

include/Makefile.am

Follow-up patch that adds the newly added header file to
Makefile.am noinst_HEADERS.

Manually merged from mysql-5.1:

  - fixed mysqlbinlog copyright year: 2001 --> 2000
  - fixed address in license header

conflicts
=========

 - client/mysqlbinlog.cc
 - include/welcome_copyright_notice.h

Manually merged mysql-5.0 into mysql-5.1.

conflicts
=========
client/mysqlibinlog.cc

CLIENT TOOLS
      
The fix is to backport part of revision:
        
  - alexander.nozdrin@oracle.com-20101006150613-ls60rb2tq5dpyb5c
      
from mysql-5.5. In detail, we add the oracle welcome notice
header file proposed in the original patch and include/use it
in client/mysqlbinlog.cc, replacing the existing and obsolete
notice.

Bug#12637786 was fixed with rb:692 by marko.  But that fix has a remaining
bug.  It added this assert;
    ut_ad(ind_field->prefix_len);
before a section of code that assumes there is a prefix_len.  

The patch replaced code that explicitly avoided this with a check for
prefix_len.  It turns out that the purge thread can get to that assert
without a prefix_len because it does not use a row_ext_t* .
When UNIV_DEBUG is not defined, the affect of this is that the purge thread
sets the dfield->len to zero and then cannot find the entry in the index to
purge.  So secondary index entries remain unpurged.

This patch does not do the assert.  Instead, it uses
    'if (ind_field->prefix_len) {...}'
around the section of code that assumes a prefix_len.  This is the way the
patch I provided to Marko did it.

The test case is simply modified to do a sleep(10) in order to give the
purge thread a chance to run. Without the code change to row0row.c, this
modified testcase will assert if InnoDB was compiled with UNIV_DEBUG.
I tried to sleep(5), but it did not always assert.

bug.  It added this assert;
    ut_ad(ind_field->prefix_len);
before a section of code that assumes there is a prefix_len.  

The patch replaced code that explicitly avoided this with a check for
prefix_len.  It turns out that the purge thread can get to that assert
without a prefix_len because it does not use a row_ext_t* .
When UNIV_DEBUG is not defined, the affect of this is that the purge thread
sets the dfield->len to zero and then cannot find the entry in the index to
purge.  So secondary index entries remain unpurged.

This patch does not do the assert.  Instead, it uses
    'if (ind_field->prefix_len) {...}'
around the section of code that assumes a prefix_len.  This is the way the
patch I provided to Marko did it.

The test case is simply modified to do a sleep(10) in order to give the
purge thread a chance to run. Without the code change to row0row.c, this
modified testcase will assert if InnoDB was compiled with UNIV_DEBUG.
I tried to sleep(5), but it did not always assert.

Let the creation of the "test" database happen only during a new
installation, not in an RPM upgrade.

GCC 4.6 has new -Wunused-but-set-variable flag, which is enabled
by -Wall, that causes GCC to emit a warning whenever a local variable
is assigned to, but otherwise unused (aside from its declaration).

Since the maintainer mode uses -Wall and -Werror, source code which
triggers these warnings will be rejected. That is, these warnings
become hard errors.

The solution is to fix the code which triggers these specific warnings.
In most of the cases, this is a welcome cleanup as code which triggers
this warning is probably dead anyway.