[FIX] purchase_request: bind name before use in onchange_product_id

[mav-adhoc]

Bug

onchange_product_id on the make-purchase-order wizard item raised
UnboundLocalError: cannot access local variable 'name' when
keep_description was set.

name was only assigned inside if not self.keep_description:, so when
keep_description is True it stayed unbound and was then read:

• on the supplier-info branch, f"[...] {p_name if p_name else name}",
  when the matched product.supplierinfo had no product_name;
• and by the final if name: guard when there was no supplier info and
  the product had no internal reference.

Fix

Always bind name: keep the description already provided on the wizard
line when keep_description is set, otherwise fall back to the product
name. Behaviour for keep_description = False is unchanged.

Test

Added test_onchange_product_id_keep_description: a product without an
internal reference plus a product.supplierinfo with an empty
product_name, keep_description=True, then calls the onchange. It
raises UnboundLocalError on the previous code and passes with the fix.

[ACBRI]

Functional review on 18.0 — tested on a clean database (Odoo 18.0-20260528, purchase_request installed on its own).

First, a small thing: I could not find test_onchange_product_id_keep_description anywhere. It is not in this PR (the diff is one file, +3/-2), it is not on 18.0, and it is not on any other branch. I suspect the test file was left out of the commit.

I wrote one to check the fix anyway, and I can confirm both the bug and the fix.

Before the patch, two paths raise:

Scenario (keep_description = True)	Line	Result
supplierinfo found, product_name empty	400, p_name if p_name else name	UnboundLocalError
no supplierinfo, product without internal reference	407, if name:	UnboundLocalError

The remaining keep_description = True paths survive by accident: line 403 both reads and assigns name, and the conditional expressions short-circuit whenever p_name or code is set.

That also explains why CI stays green today. test_purchase_request_to_rfq does set keep_description = True and does call onchange_product_id(), but on two different wizard items, so the failing combination is never exercised.

After the patch, the three tests below pass and the full purchase_request suite is green (42 tests, 0 failures, 0 errors).

Here is the test I used, in case it is useful:

# Copyright 2026
# License LGPL-3.0 or later (https://www.gnu.org/licenses/lgpl-3.0)

from odoo import SUPERUSER_ID
from odoo.tests import common


class TestOnchangeProductIdKeepDescription(common.TransactionCase):
    @classmethod
    def setUpClass(cls):
        super().setUpClass()
        cls.vendor = cls.env["res.partner"].create({"name": "Vendor OCA Review"})
        cls.product_supinfo_no_name = cls.env["product.product"].create(
            {
                "name": "Product With Nameless Supplierinfo",
                "type": "consu",
                "default_code": "TEST-SUP",
            }
        )
        cls.env["product.supplierinfo"].create(
            {
                "partner_id": cls.vendor.id,
                "product_tmpl_id": cls.product_supinfo_no_name.product_tmpl_id.id,
                "product_name": False,
                "product_code": False,
            }
        )
        cls.product_no_code = cls.env["product.product"].create(
            {
                "name": "Product Without Internal Reference",
                "type": "consu",
                "default_code": False,
            }
        )

    def _build_item(self, product, keep_description=True, name="Existing description"):
        request = self.env["purchase.request"].create(
            {
                "picking_type_id": self.env.ref("stock.picking_type_in").id,
                "requested_by": SUPERUSER_ID,
                "line_ids": [
                    (
                        0,
                        0,
                        {
                            "product_id": product.id,
                            "product_uom_id": product.uom_id.id,
                            "product_qty": 1.0,
                        },
                    )
                ],
            }
        )
        request.button_approved()
        wiz = (
            self.env["purchase.request.line.make.purchase.order"]
            .with_context(
                active_model="purchase.request.line",
                active_ids=request.line_ids.ids,
            )
            .create({"supplier_id": self.vendor.id})
        )
        return self.env["purchase.request.line.make.purchase.order.item"].new(
            {
                "wiz_id": wiz.id,
                "line_id": request.line_ids[0].id,
                "name": name,
                "product_qty": 1.0,
                "product_uom_id": product.uom_id.id,
                "keep_description": keep_description,
            }
        )

    def test_01_supplierinfo_without_product_name(self):
        item = self._build_item(self.product_supinfo_no_name)
        item.onchange_product_id()
        self.assertEqual(item.name, "[TEST-SUP] Existing description")

    def test_02_no_supplierinfo_and_no_internal_reference(self):
        item = self._build_item(self.product_no_code)
        item.onchange_product_id()
        self.assertEqual(item.name, "Existing description")

    def test_03_keep_description_false_is_unchanged(self):
        item = self._build_item(self.product_no_code, keep_description=False)
        item.onchange_product_id()
        self.assertEqual(item.name, "Product Without Internal Reference")

The code change itself looks right to me: for keep_description = False the behaviour is byte-for-byte the same, and for keep_description = True it now falls back to the description already present on the wizard line, which is what the option promises.

I am happy to approve as soon as a test lands, either the one above or your own version.