Impacted versions:
At least version 10, version 11(Can only re-produce the problem sometimes)

Steps to reproduce:
Please see this screencast recorded on odoo runbot.
https://youtu.be/cSPQvp9jQJc

Current behavior:
When users search by account in Journal Entries List View. A special value "dummy_account_id" is set in context, in order to facilitate search by account on account.move level.
With this context value , when users create a journal entries, the system will add default value before the creation.

https://github.com/odoo/odoo/blob/fc69b37cf710623ea215cd085e998679d8c50985/odoo/models.py#L3802

This method will set "dummy_account_id" to the previously searched account in vals.

Then the system continue creating account.move and related account.move.line records.
It is fine until the system run this:
https://github.com/odoo/odoo/blob/fc69b37cf710623ea215cd085e998679d8c50985/odoo/models.py#L3830

Since "dummy_account_id" is related field, and it now has value. The system will change the first related  account.move.line record to dummy_account_id.

Eventualy, the account is wrongly set to "dummy_account_id".

Expected behavior:
This is a feature which will fill the form field value with searched value for users. But the journal entry creation should not be affected by dummy_account_id, since it is only for searching purpose.

@Yenthe666 Would you please review this issue and help to bring related odoo staff to this issue?
invoice = self._context.get('invoice', False)
        self._post_validate()
        for move in self:
            move.line_ids.create_analytic_lines()
            if move.name == '/':
                new_name = False
                journal = move.journal_id
                if invoice and invoice.move_name and invoice.move_name != '/':
                    new_name = invoice.move_name
                else:
                    if journal.sequence_id:
                        
                        sequence = journal.sequence_id
                        if invoice and invoice.type in ['out_refund', 'in_refund'] and journal.refund_sequence:
                            if not journal.refund_sequence_id:
                                raise UserError(_('Please define a sequence for the refunds'))
                            sequence = journal.refund_sequence_id
                                                            
                        new_name = sequence.with_context(ir_sequence_date=move.date).next_by_id()
                    else:
                        raise UserError(_('Please define a sequence on the journal.'))
                if new_name:
                    move.name = new_name
        return self.write({'state': 'posted'})
    @api.multi
    def button_cancel(self):