fix(accounts): round journal entry totals to field precision (backport #58629) (#58875)

Co-authored-by: Sudharsanan Ashok <135326972+Sudharsanan11@users.noreply.github.com>

erpnext/accounts/doctype/journal_entry/journal_entry.js

@@ -472,8 +472,8 @@ cur_frm.cscript.update_totals = function (doc) {
 		tc += flt(accounts[i].credit, precision("credit", accounts[i]));
 	}
 	doc = locals[doc.doctype][doc.name];
-	doc.total_debit = td;
+	doc.total_debit = flt(td, precision("total_debit"));
-	doc.total_credit = tc;
+	doc.total_credit = flt(tc, precision("total_credit"));
 	doc.difference = flt(td - tc, precision("difference"));
 	refresh_many(["total_debit", "total_credit", "difference"]);
 };

erpnext/accounts/doctype/journal_entry/journal_entry.py

@@ -960,12 +960,14 @@ class JournalEntry(AccountsController):
 			if d.debit and d.credit:
 				frappe.throw(_("You cannot credit and debit same account at the same time"))
 
-			self.total_debit = flt(self.total_debit) + flt(d.debit, d.precision("debit"))
+			self.total_debit = flt(
-			self.total_credit = flt(self.total_credit) + flt(d.credit, d.precision("credit"))
+				self.total_debit + flt(d.debit, d.precision("debit")), self.precision("total_debit")
-
-		self.difference = flt(self.total_debit, self.precision("total_debit")) - flt(
-			self.total_credit, self.precision("total_credit")
 			)
+			self.total_credit = flt(
+				self.total_credit + flt(d.credit, d.precision("credit")), self.precision("total_credit")
+			)
+
+		self.difference = flt(self.total_debit - self.total_credit, self.precision("difference"))
 
 	def validate_multi_currency(self):
 		alternate_currency = []

erpnext/accounts/doctype/journal_entry/test_journal_entry.py

@@ -409,6 +409,59 @@ class TestJournalEntry(ERPNextTestSuite):
 
 		self.check_gl_entries()
 
+	def make_jv_with_fractional_totals(self):
+		"""0.10 + 0.20 sums to 0.30000000000000004, the residue this guards against."""
+		jv = frappe.new_doc("Journal Entry")
+		jv.posting_date = nowdate()
+		jv.company = "_Test Company"
+		jv.voucher_type = "Journal Entry"
+		jv.remark = "test"
+		for amount in (0.10, 0.20):
+			jv.append(
+				"accounts",
+				{
+					"account": "_Test Cash - _TC",
+					"cost_center": "_Test Cost Center - _TC",
+					"debit_in_account_currency": amount,
+				},
+			)
+		jv.append(
+			"accounts",
+			{
+				"account": "_Test Bank - _TC",
+				"cost_center": "_Test Cost Center - _TC",
+				"credit_in_account_currency": 0.30,
+			},
+		)
+		jv.insert()
+		return jv
+
+	def test_totals_are_rounded_to_precision(self):
+		jv = self.make_jv_with_fractional_totals()
+		jv.submit()
+
+		stored = frappe.db.get_value(
+			"Journal Entry", jv.name, ["total_debit", "total_credit", "difference"], as_dict=True
+		)
+		self.assertEqual(jv.total_debit, flt(jv.total_debit, jv.precision("total_debit")))
+		self.assertEqual(jv.total_credit, flt(jv.total_credit, jv.precision("total_credit")))
+		self.assertEqual(jv.total_debit, stored.total_debit)
+		self.assertEqual(jv.total_credit, stored.total_credit)
+		self.assertEqual(jv.difference, stored.difference)
+
+	def test_update_after_submit_with_fractional_totals(self):
+		"""An unrounded total is stored rounded, so updating a submitted entry used to throw."""
+		jv = self.make_jv_with_fractional_totals()
+		jv.submit()
+
+		jv.pay_to_recd_from = "_Test Supplier"
+		jv.save()
+
+		self.assertEqual(jv.docstatus, 1)
+		self.assertEqual(
+			jv.pay_to_recd_from, frappe.db.get_value("Journal Entry", jv.name, "pay_to_recd_from")
+		)
+
 	def test_jv_account_and_party_balance_with_cost_centre(self):
 		from erpnext.accounts.doctype.cost_center.test_cost_center import create_cost_center
 		from erpnext.accounts.utils import get_balance_on