fix: clear custom_consolidated_si on SI on_trash (draft consolidated SI delete)

rmax_custom/api/delivery_note.py

@@ -672,6 +672,38 @@ def consolidate_dns_to_si(delivery_note_names):
     return si.name
 
 
+def clear_consolidated_si_links(si_name):
+    """Clear the ``custom_consolidated_si`` back-reference on every Delivery
+    Note that points to this Sales Invoice.
+
+    ``consolidate_dns_to_si`` stamps each source DN with
+    ``custom_consolidated_si = <SI>``. That Link field makes Frappe's
+    link-integrity check (``check_if_doc_is_linked``) block cancel/delete of the
+    SI. Both the cancel path (submitted SI) and the trash path (draft SI delete)
+    must clear it first, or the operation is refused with
+    "Cannot delete or cancel ... is linked with Delivery Note ...".
+    """
+    for dn_name in frappe.get_all(
+        "Delivery Note",
+        filters={"custom_consolidated_si": si_name},
+        pluck="name",
+    ):
+        frappe.db.set_value(
+            "Delivery Note", dn_name,
+            "custom_consolidated_si", None,
+            update_modified=False,
+        )
+
+
+def sales_invoice_on_trash_clear_consolidated(doc, method=None):
+    """Sales Invoice ``on_trash``: free the netted-off DN stamps so a DRAFT
+    consolidated SI can be deleted. ``on_trash`` runs before
+    ``check_if_doc_is_linked`` in ``frappe.delete_doc`` (verified against v15),
+    so clearing here lets the link-integrity check pass. The submitted-SI case
+    is handled separately on ``on_cancel``. No-op for non-consolidated SIs."""
+    clear_consolidated_si_links(doc.name)
+
+
 # ---------------------------------------------------------------------------
 # Multi-source return allocation APIs
 # ---------------------------------------------------------------------------

rmax_custom/hooks.py

@@ -227,6 +227,9 @@
 			"rmax_custom.inter_company_dn.sales_invoice_on_cancel",
 			"rmax_custom.api.delivery_note.sales_invoice_on_cancel_clear_dn_return",
 		],
+		"on_trash": [
+			"rmax_custom.api.delivery_note.sales_invoice_on_trash_clear_consolidated",
+		],
 	},
 	"Quotation": {
 		"before_insert": [

rmax_custom/inter_company_dn.py

@@ -291,17 +291,9 @@ def sales_invoice_on_cancel(doc, method=None):
 
 	# Clear the net-off consolidation stamp on every DN linked via
 	# custom_consolidated_si. (Set by api.delivery_note.consolidate_dns_to_si.)
-	consolidated_dns = frappe.get_all(
-		"Delivery Note",
-		filters={"custom_consolidated_si": doc.name},
-		pluck="name",
-	)
-	for dn_name in consolidated_dns:
-		frappe.db.set_value(
-			"Delivery Note", dn_name,
-			"custom_consolidated_si", None,
-			update_modified=False,
-		)
+	# Shared with the on_trash path. Local import avoids a circular import.
+	from rmax_custom.api.delivery_note import clear_consolidated_si_links
+	clear_consolidated_si_links(doc.name)
 
 
 def _source_dns_for_si(si_doc) -> set[str]:

rmax_custom/tests/test_dn_consolidation.py

@@ -82,6 +82,23 @@ def test_si_cancel_clears_stamp(self):
             frappe.db.get_value("Delivery Note", dn.name, "custom_consolidated_si")
         )
 
+    def test_draft_si_delete_clears_stamp_and_succeeds(self):
+        # Reproduces the bug: a DRAFT consolidated SI stamps the DN via
+        # custom_consolidated_si; deleting it must clear the stamp (on_trash)
+        # so the link-integrity check doesn't block the delete.
+        dn = _make_submitted_dn(self.customer, self.item, self.company,
+                                self.warehouse, qty=5, rate=10)
+        si_name = consolidate_dns_to_si([dn.name])
+        self.assertEqual(
+            frappe.db.get_value("Delivery Note", dn.name, "custom_consolidated_si"),
+            si_name,
+        )
+        frappe.delete_doc("Sales Invoice", si_name)
+        self.assertFalse(frappe.db.exists("Sales Invoice", si_name))
+        self.assertFalse(
+            frappe.db.get_value("Delivery Note", dn.name, "custom_consolidated_si")
+        )
+
 
 # --- fixtures helpers ---