Tiny/medium/long blobs are not converted correctly, MULTIPOLYGON test suite was checking against wrong value

[kilroy42]

When using use_unicode, results from tiny/medium/long blobs were not converted correctly.

[vtermanis]

I just came across the same issue. For me it happened when calling the following two queries:

SET @a = 'abc';
SELECT @a;

The 2nd query would result in b'abc' (type MEDIUM_BLOB but no binary flag) rather than 'abc'. In comparison, PyMySQL does decode it as expected.