A context has `current_block_num` value greater than `irreversible_block` value

How to repeat?

1. Prepare an empty database.
2. CREATE EXTENSION hive_fork_manager CASCADE;
3. SELECT hive.app_create_context( 'any_context' )
4. SELECT hive.app_context_detach( 'any_context' )
5. SELECT hive.app_context_attach( 'any_context', 1550 )

Now the context any_context has: current_block_num=1550 and irreversible_block=0.

Description

For SELECT * FROM hive.irreversible_data we have consistent_block=null, but in hive.app_context_attach we have a check

    IF _last_synced_block > __head_of_irreversible_block THEN
        RAISE EXCEPTION 'Cannot attach context % because the block num % is grater than top of irreversible block %'
            , _context, _last_synced_block,  __head_of_irreversible_block;
    END IF;

How to solve?

We have 2 options:

• a) checking null in above condition
• b) a first record in hive.irreversible_data should have consistent_block=0