Problem:
=======
The return value from my_b_write is ignored by: `my_b_write_quoted',
`my_b_write_bit',`Query_log_event::print_query_header'

Most callers of `my_b_printf' ignore the return value. `log_event.cc' 
has many calls to it. 

Analysis:
========
`my_b_write' is used to write data into a file. If the write fails it
sets appropriate error number and error message through my_error()
function call and sets the IO_CACHE::error == -1.
`my_b_printf' function is also used to write data into a file, it
internally invokes my_b_write to do the write operation. Upon
success it returns number of characters written to file and on error
it returns -1 and sets the error through my_error() and also sets
IO_CACHE::error == -1.  Most of the event specific print functions
for example `Create_file_log_event::print', `Execute_load_log_event::print'
etc are the ones which make several calls to the above two functions and
they do not check for the return value after the 'print' call. All the above 
mentioned abuse cases deal with the client side.

Fix:
===
As part of bug fix a check for IO_CACHE::error == -1 has been added at 
a very high level after the call to the 'print' function.  There are 
few more places where the return value of "my_b_write" is ignored
those are mentioned below.

+++ mysys/mf_iocache2.c    2012-06-04 07:03:15 +0000
@@ -430,7 +430,8 @@
           memset(buffz, '0', minimum_width - length2);
         else
           memset(buffz, ' ', minimum_width - length2);
-        my_b_write(info, buffz, minimum_width - length2);

+++ sql/log.cc	2012-06-08 09:04:46 +0000
@@ -2388,7 +2388,12 @@
     {
       end= strxmov(buff, "# administrator command: ", NullS);
       buff_len= (ulong) (end - buff);
-      my_b_write(&log_file, (uchar*) buff, buff_len);

At these places appropriate return value handlers have been added.

No commit message

HANDLE_FATAL_SIGNAL IN STRNLEN

Fixed the following bounds checking problems :
1. in check_if_legal_filename() make sure the null terminated
string is long enough before accessing the bytes in it.
Prevents pottential read-past-buffer-end
2. in my_wc_mb_filename() of the filename charset check
for the end of the destination buffer before sending single
byte characters into it.
Prevents write-past-end-of-buffer (and garbaling stack in
the cases reported here) errors.

Added test cases.

This is a followup patch for the bug enabling the test
i_binlog.binlog_mysqlbinlog_file_write.test
this was disabled in mysql trunk and mysql 5.5 as in the release
build mysqlbinlog was not debug compiled whereas the mysqld was.
Since have_debug.inc script checks only for mysqld to be debug
compiled, the test was not being skipped on release builds.

We resolve this problem by creating a new inc file 
mysqlbinlog_have_debug.inc which checks exclusively for mysqlbinlog
to be debug compiled. if not it skips the test.
 

CLIENT

Added a check for a negative second part of the scramble length.

1. Clear text password client plugin disabled by default.
2. Added an environment variable LIBMYSQL_ENABLE_CLEARTEXT_PLUGIN, that
when set to something starting with '1', 'Y' or 'y' will enable the clear
text
plugin for all connections.
3. Added a new mysql_options() option : MYSQL_ENABLE_CLEARTEXT_PLUGIN
that takes an my_bool argument. When the value of the argument is non-zero
the clear text plugin is enabled for this connection only.
4. Added an enable-cleartext-plugin config file option that takes a numeric

argument. If the numeric value of the numeric argument is non-zero the
clear
text plugin is enabled for the connection
5. Added a boolean command line option "--enable_cleartext_plugin" to
mysql, mysqlslap and mysqladmin. When specified it will call mysql_options
with the effect of #3
6. Added a new CLEARTEXT option to the connect command in mysqltest.
When specified it will enable the cleartext plugin for usage.
7. Added test cases and updated existing ones that need the clear text
plugin.

executing

The problem is that mysql lacks information about the objects a view
depends on so it can't dump views and tables in the proper order.
Thus it needs to create "stand-in" myisam tables for each view while 
dumping the tables that it later drops and replaces with the actual view
view definition.
But since views can have much more columns than an actual table creating
these stand-in tables may be problematic.

There's no way to portably find out how many columns an mysiam table
can have. It's a complicated formula depending on internal server constants.
Thus we can't have a reliable error check without repeating the logic and 
the formula inside mysqldump.

1. Changed the type of the columns of the stand-in tables mysqldump
makes to satisfy view dependencies from the original type to smallint 
to save on row space.

2. Added a warning on the mysqldump's standard error for a possible 
problems replaying the dump file if the columns of a view exceed 1000.

3. Added a test case.

Details:
 - Modified test case to make sure its run for all and not only
   for archive Storage Engine.

Manual merge from mysql-5.1 to mysql-5.5

This patch fixes various compilation warnings of the type
"error: narrowing conversion of 'x' from 'datatype1' to
'datatype2'

Print the warning(note):

 YEAR(x) is deprecated and will be removed in a future release. Please use YEAR(4) instead

on "CREATE TABLE ... YEAR(x)" or "ALTER TABLE MODIFY ... YEAR(x)", where x != 4

make buf_read_page_low() to treat DB_TABLESPACE_DELETED error correctly
rb#1129 approved by Inaam

Introduction of cost based decision on filesort vs index for UPDATE
statements changed detection of the fact that the index used to scan the
table is being updated. The new design missed the case of index merge
when there is no single index to check. That was worked until a recent
change in InnoDB after which it went into infinite recursion if update of
the used index wasn't properly detected.

The fix consists of 'used key being updated' detection code from 5.1.

Patch done by Evgeny Potemkin <evgeny.potemkin@oracle.com>
and transferred into the 5.5.25a release build by Joerg Bruehe.

This changeset is the difference between MySQL 5.5.25 and 5.5.25a.

Several fixes :

* sql-common/client.c
Added a validity check of the fields metadata packet sent 
by the server.
Now libmysql will check if the length of the data sent by
the server matches what's expected by the protocol before
using the data.

* client/mysqltest.cc
Fixed the error handling code in mysqltest to avoid sending
new commands when the reading the result set failed (and 
there are unread data in the pipe).

* sql_common.h + libmysql/libmysql.c + sql-common/client.c
unpack_fields() now generates a proper error when it fails.
Added a new argument to this function to support the error 
generation.

* sql/protocol.cc
Added a debug trigger to cause the server to send a NULL
insted of the packet expected by the client for testing 
purposes.

Introduction of cost based decision on filesort vs index for UPDATE
statements changed detection of the fact that the index used to scan the
table is being updated. The new design missed the case of index merge
when there is no single index to check. That was worked until a recent
change in InnoDB after which it went into infinite recursion if update of
the used index wasn't properly detected.

The fix consists of 'used key being updated' detection code from 5.1.

              INC_HOST_ERRORS() IS CALLED.
      
Description: Merge from MySQL 5.1 to MySQL 5.5
             Reverting patch 3869 for bug#11753779