[16.0][FIX] account_fiscal_year_closing: exclude cancelled moves when closing by partner

[sefirosweb]

Problem

Running the fiscal year closing on a database that contains cancelled moves produces an
unbalanced closing entry, and the module refuses to create it: the "Unbalanced journal
entry found" wizard comes up instead.

Root cause

AccountFiscalyearClosingMapping reads the journal items of the year through two
different methods, and only one of them filters out cancelled moves:

Method	Used when the closing type is	Filters move_id.state != 'cancel'
account_lines_get	balance	yes
account_partners_get	unreconciled	no

In Odoo a cancelled move keeps its account.move.line records — reports ignore them by
filtering on the state. So accounts closed by balance are computed without cancelled
moves while accounts closed by partner are computed with them.

The closing move posts, for every account, the opposite of its balance, so it only
balances if the sum of all the included balances is zero. Mixing two filtering criteria
breaks that, by exactly the net amount of the cancelled moves in the accounts closed by
partner.

This is not an edge case for companies using a single receivable account for all
customers and a single payable account for all suppliers, which is the usual setup in
Spain: those accounts have to be closed by partner to keep the detail per third party,
so the only affected branch is the one they need. On the database where this was found the
closing came out 86,613.45 € off, entirely explained by 16 journal items belonging to 15
cancelled invoices.

Fix

Add to account_partners_get the same domain leaf account_lines_get already uses, so
both closing types read the same journal items.

Test

test_account_closing already builds a closing configuration with
closing_type_default = "unreconciled" mapping the receivable and payable accounts, and
already ends by asserting that no unbalanced move is produced. Reproducing the bug only
needed a cancelled invoice, so that is all the test adds.

The expected profit and loss amounts are now computed from non-cancelled journal items as
well: they are compared against what the module writes, and the module regularises income
and expense accounts through account_lines_get, which excludes cancelled moves.

Verified on a clean database with demo data:

• without the fix → AssertionError: True is not false : There are unbalanced move/s in the closing moves!
• with the fix → 0 failed, 0 error(s) of 2 tests

Other branches

The same asymmetry is present in 14.0 and 18.0, so the fix applies there too and I am
happy to forward-port it if this is accepted. In 12.0 neither method filters the state,
so that branch is at least self-consistent.