Fix sequence deletion after nextval call

[agscpp]

CREATE SEQUENCE serial_01 CYCLE;
SELECT nextval('serial_01');
DROP SEQUENCE serial_01;

Tarantool error: DropSequence: Can't drop sequence 'serial_01': the sequence has data

[agscpp]

Hi, @gmoshkin .

Can you please take a look at my pull request?

[gmoshkin]

Hi, thanks for the patch!

Could you explain, how are the provided SQL commands related to the test?

CREATE SEQUENCE serial_01 CYCLE; SELECT nextval('serial_01'); DROP SEQUENCE serial_01

The code in question will not be invoked when this SQL is executed.

Could you also add a test, so that we don't break the fix accidentally in the future.

[agscpp]

This is an abstract example that I used to compare the behavior with other DBMSs.

Okay, I'll write tests for this logic.

[agscpp]

@gmoshkin I wrote the tests

[gmoshkin]

Also please update CHANGELOG.md, we try keeping it up to date with every merge we make into the master branch.

[agscpp]

@gmoshkin

[agscpp]

@gmoshkin ping