Merge pull request #58155 from frappe/mergify/bp/version-16-hotfix/pr-58092

fix(accounts): disallow reversing a reverse journal entry (backport #58092)

erpnext/accounts/doctype/journal_entry/journal_entry.js

@@ -95,7 +95,7 @@ frappe.ui.form.on("Journal Entry", {
 			);
 		}
 
-		if (frm.doc.docstatus == 1) {
+		if (frm.doc.docstatus == 1 && !frm.doc.reversal_of) {
 			frm.add_custom_button(
 				__("Reverse Journal Entry"),
 				function () {

erpnext/accounts/doctype/journal_entry/journal_entry.py

@@ -1777,6 +1777,20 @@ def make_inter_company_journal_entry(name, voucher_type, company):
 
 @frappe.whitelist()
 def make_reverse_journal_entry(source_name, target_doc=None):
+	# `get_mapped_doc` checks this as well, but the guards below disclose which entry
+	# reverses which, so read access has to be settled before they run
+	if not frappe.has_permission("Journal Entry", doc=source_name):
+		frappe.throw(_("Not permitted"), frappe.PermissionError)
+
+	reversal_of = frappe.db.get_value("Journal Entry", source_name, "reversal_of")
+	if reversal_of:
+		frappe.throw(
+			_("{0} is already a Reverse Journal Entry of {1}. Cancel it instead of reversing it.").format(
+				get_link_to_form("Journal Entry", source_name),
+				get_link_to_form("Journal Entry", reversal_of),
+			)
+		)
+
 	existing_reverse = frappe.db.exists("Journal Entry", {"reversal_of": source_name, "docstatus": 1})
 	if existing_reverse:
 		frappe.throw(

erpnext/accounts/doctype/journal_entry/test_journal_entry.py

@@ -248,6 +248,27 @@ class TestJournalEntry(ERPNextTestSuite):
 
 		self.check_gl_entries()
 
+	def test_disallow_reversal_of_a_reversal_journal_entry(self):
+		from erpnext.accounts.doctype.journal_entry.journal_entry import make_reverse_journal_entry
+
+		jv = make_journal_entry("_Test Bank - _TC", "Sales - _TC", 100, submit=True)
+
+		rjv = make_reverse_journal_entry(jv.name)
+		rjv.posting_date = nowdate()
+		rjv.submit()
+
+		self.assertRaisesRegex(
+			frappe.ValidationError,
+			"is already a Reverse Journal Entry",
+			make_reverse_journal_entry,
+			rjv.name,
+		)
+
+		# the guard must not disclose the reversal to a user who cannot read the entry
+		frappe.set_user("Guest")
+		self.addCleanup(frappe.set_user, "Administrator")
+		self.assertRaises(frappe.PermissionError, make_reverse_journal_entry, rjv.name)
+
 	def test_disallow_change_in_account_currency_for_a_party(self):
 		# create jv in USD
 		jv = make_journal_entry("_Test Bank USD - _TC", "_Test Receivable USD - _TC", 100, save=False)