Fix an issue in parsing default column charset

[YAtOff]

Description

When parsing the default charset optional metadata, when handling the column index/collation number pairs, the column index is in the range of the number of columns with charset (not the number of all the columns).
Like how it's done here: https://github.com/ClickHouse/ClickHouse/blob/001b67863a57c4d734d94e375e6fdeb4a9407951/src/Core/MySQL/MySQLReplication.cpp#L353

Type of Change

• Bug fix

Checklist

• I have read and understood the CONTRIBUTING.md document.
• I have checked there aren't any other open Pull Requests for the desired changes.
• This PR resolves an issue #334.

Tests

• All tests have passed.
• New tests have been added to cover the changes. (describe below if applicable).

[sean-k1]

@YAtOff
Really Cool Pr!
Thanks a lot for spotting that issue and fixing it!
It seems like I didn't realize that the keys of 'column_charset_collation' were the order of non-numeric columns while handling that logic.

Can you describe your mysql variable? for history

• binlog_format:
• binlog_row_image:
• binlog_row_metadata:
• binlog_row_value_options:

and Can you fix lint too?

 black pymysqlreplication

[YAtOff]

MySQL variables

Name	Value
binlog_format	ROW
binlog_row_image	FULL
binlog_row_metadata	MINIMAL
binlog_row_value_options	-

[sean-k1]

@YAtOff
If binlog_row_metadata is FULL, you're probably right.

but your binlog_row_metadata = "MINIMAL" you can not enter this method.
because your self.__optional_meta_data value is False

 def _sync_column_info(self):
        if not self.__optional_meta_data: 
            # If optional_meta_data is False Do not sync Event Time Column Schemas
            return
        if len(self.optional_metadata.column_name_list) == 0:
            # May Be Now BINLOG_ROW_METADATA = FULL But Before Action BINLOG_ROW_METADATA Mode = MINIMAL
            return

[YAtOff]

Sorry, my mistake. It's full.
But if it's minimal the tests pass without asserts.

[sean-k1]

@YAtOff Cool.