This prevents the server from selecting the charset under which the
queries are processed which can result in conflicts if the tables used are
not compatible with the charset of the string literals used in the query.
The charset sent in the handshake is now done with the following
priorities:
* First Master server
* Last Slave server
* First Running server or Down server whose charset is known
The change is that server in the Down state to which we've successfully
connected to can also be used as the charset source. This, in addition
with an "empty" default charset, helps avoid the use of the default latin1
charset unless absolutely necessary.
The code in 2.3 was changed to allow "empty" SSL definitions now that the
system CA is used. The code in 2.4 did not allow this which caused non-TLS
connections to be created when only ssl=true was defined.
The Connector-C was changed to always return only the client's charset,
not the actual charset that the connection ends up using. To cope with
this, the code has to use SQL to join the default character set name to
the default collation for it which can be used to extract the numeric ID
of the charset.
Authenticators and monitors now use SSL when configured. The fix has two parts:
1) Removed the extra SSLConfig inside SSLProvider, as SSLContext already contains
the config.
2) When inputting parameter values to mysql_ssl_set(), empty strings are converted
to NULL-pointers as the function expects those for unused values.
It was possible that a one-second outage that caused immediate rejection
of network connections would cause all of the query retry attempts to fail
within a very short period of time. By preventing rapid reconnections,
query_retries is more effective as an error filtering mechanism.
Changed getter function return values to std::string, converted
MXS_CONFIG_PARAMETER::set_from_list to take std::strings instead of const
char pointers.
SSLContext is now used everywhere except the binlogrouter which still
allocates the contexts itself. Fixing the binlogrouter's misuse of
internal structures is a rather large undertaking and for this reason the
SSLContext will be taken into use there in a separate commit.
Added core functionality for UNIX domain sockets in servers. Currently the
address parameter accepts them both but a separate `socket` parameter is
needed.
