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?
addons/account/models/account_move.py
res = super(AccountMove, self).fields_view_get(
            view_id=view_id, view_type=view_type, toolbar=toolbar, submenu=submenu)
        if self._context.get('vat_domain'):
            res['fields']['line_ids']['views']['tree']['fields']['tax_line_id']['domain'] = [('tag_ids', 'in', [self.env.ref(self._context.get('vat_domain')).id])]
        return res
    @api.model
    def create(self, vals):
        move = super(AccountMove, self.with_context(check_move_validity=False, partner_id=vals.get('partner_id'))).create(vals)
        move.assert_balanced()
        return move
    @api.multi
    def write(self, vals):
        if 'line_ids' in vals:
            res = super(AccountMove, self.with_context(check_move_validity=False)).write(vals)
            self.assert_balanced()
        else:
            res = super(AccountMove, self).write(vals)
        return res
    @api.multi
    def post(self):