Log Message:
Changes 5.5.0:

Functionality Added or Changed

The version of the tcmalloc library included in MySQL distributions was very \ 
old. It has been removed and is no longer included with MySQL.

Bugs Fixed

INSERT with ON DUPLICATE KEY UPDATE and REPLACE on a table with a foreign key \ 
constraint defined failed with an incorrect “duplicate entry” error \ 
rather than a foreign key constraint violation error.

Setting sort_buffer_size to a very large value could cause some operations to \ 
fail with an out-of-memory error.

Several potential buffer overflow issues were corrected.

If the CA certificate as given to the --ssl-ca option had an invalid path, yaSSL \ 
returned an error message different from OpenSSL. Now both return SSL connection \ 
error: SSL_CTX_set_default_verify_paths failed.

Some string functions returned one or a combination of their parameters as their \ 
result. If one of the parameters had a non-ASCII character set, the result \ 
string had the same character set, resulting in incorrect behavior when an ASCII \ 
string was expected.

A null pointer dereference of a parser structure could occur during stored \ 
procedure name validation.

mysqld_multi displayed misleading error messages when it was unable to execute \ 
my_print_defaults.