fix(projects): use Coalesce for timesheet portal sales_invoice (not bitwise OR)

get_timesheets_list selected `timesheet.sales_invoice | detail.sales_invoice`,
intending COALESCE (pick the parent timesheet's invoice, else the detail's) -- the
original raw SQL was COALESCE(ts.sales_invoice, tsd.sales_invoice). pypika's `|` is a
bitwise OR, not a coalesce:

- Postgres: `varchar | varchar` -> "operator does not exist" (hard error).
- MariaDB: bitwise OR coerces the operands to integers; with a NULL detail invoice the
  result is NULL, so the portal showed no invoice even when the timesheet was billed.

Replace with Coalesce(table.sales_invoice, child_table.sales_invoice).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

erpnext/projects/doctype/timesheet/test_timesheet.py

@@ -391,6 +391,42 @@ class TestTimesheet(ERPNextTestSuite):
 		self.assertEqual(timesheet.time_logs[1].sales_invoice, sales_invoice2.name)
 		self.assertEqual(timesheet.status, "Billed")
 
+	def test_get_timesheets_list_portal_sales_invoice(self):
+		# get_timesheets_list selects COALESCE(timesheet.sales_invoice, detail.sales_invoice). The earlier
+		# `timesheet.sales_invoice | detail.sales_invoice` bitwise-ORed two varchars -- it errored on
+		# Postgres and returned 0 (names cast to int) on MariaDB.
+		from erpnext.projects.doctype.timesheet.timesheet import get_timesheets_list
+
+		customer = "_Test Customer"
+
+		# tie the current user (Administrator) to the customer so the portal resolves it
+		contact = frappe.get_doc(
+			{
+				"doctype": "Contact",
+				"first_name": "_Test Timesheet Portal Contact",
+				"user": "Administrator",
+				"links": [{"link_doctype": "Customer", "link_name": customer}],
+			}
+		).insert(ignore_permissions=True)
+		self.addCleanup(self._delete_if_exists, "Contact", contact.name)
+
+		si = create_sales_invoice(customer=customer)
+
+		employee = make_employee("_test_timesheet_portal@example.com", company="_Test Company")
+		timesheet = make_timesheet(employee, is_billable=0)
+		frappe.db.set_value("Timesheet", timesheet.name, "sales_invoice", si.name)
+
+		rows = get_timesheets_list("Timesheet", None, {}, 0, 500)
+
+		row = next((r for r in rows if r.name == timesheet.name), None)
+		self.assertIsNotNone(row, "billed timesheet not returned by portal list")
+		self.assertEqual(row.sales_invoice, si.name)
+
+	@staticmethod
+	def _delete_if_exists(doctype, name):
+		if frappe.db.exists(doctype, name):
+			frappe.delete_doc(doctype, name, force=True)
+
 
 def make_timesheet(
 	employee,

erpnext/projects/doctype/timesheet/timesheet.py

@@ -7,7 +7,7 @@ import json
 import frappe
 from frappe import _
 from frappe.model.document import Document
-from frappe.query_builder.functions import Concat, Date, Round
+from frappe.query_builder.functions import Coalesce, Concat, Date, Round
 from frappe.utils import flt, get_datetime, getdate
 from frappe.utils.deprecations import deprecated
 
@@ -562,7 +562,7 @@ def get_timesheets_list(doctype, txt, filters, limit_start, limit_page_length=20
 				child_table.activity_type,
 				table.status,
 				child_table.billing_hours,
-				(table.sales_invoice | child_table.sales_invoice).as_("sales_invoice"),
+				Coalesce(table.sales_invoice, child_table.sales_invoice).as_("sales_invoice"),
 				child_table.project,
 			)
 			.orderby(table.end_date)