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
if 'analytic_account_id' not in vals:
            vals['analytic_account_id'] = self.env.context.get('analytic_id', False)
        #com
        if 'credit' not in vals and 'debit' not in vals:
            amount = sum([r.amount_residual for r in self])
            vals['credit'] = amount > 0 and amount or 0.0
            vals['debit'] = amount < 0 and abs(amount) or 0.0
        vals['partner_id'] = self.env['res.partner']._find_accounting_partner(self[0].partner_id).id
        company_currency = self[0].account_id.company_id.currency_id
        writeoff_currency = self[0].currency_id or company_currency
        if not self._context.get('skip_full_reconcile_check') == 'amount_currency_excluded' and 'amount_currency' not in vals and writeoff_currency != company_currency:
            vals['currency_id'] = writeoff_currency.id
            sign = 1 if vals['debit'] > 0 else -1
            vals['amount_currency'] = sign * abs(sum([r.amount_residual_currency for r in self]))
        # Wr
        first_line_dict = self._prepare_writeoff_first_line_values(vals)
        # Wr
        second_line_dict = self._prepare_writeoff_second_line_values(vals)
        # Cr
        writeoff_move = self.env['account.move'].with_context(apply_taxes=True).create({
            'journal_id': vals['journal_id'],
            'date': vals['date'],
            'state': 'draft',
            'line_ids': [(0, 0, first_line_dict), (0, 0, second_line_dict)],
        })
        writeoff_move.post()
        # Re
        return writeoff_move.line_ids.filtered(lambda r: r.account_id == self[0].account_id)
    @api.multi
    def _prepare_writeoff_first_line_values(self, values):