From 0e31182dca166240cea6c6c4f14574243aa7b6cc Mon Sep 17 00:00:00 2001
From: Mihir Kandoi <kandoimihir@gmail.com>
Date: Thu, 17 Sep 2026 11:07:27 +0530
Subject: [PATCH] perf(stock): skip the negative batch scan when nothing is
 negative (#59061)

---
 .../stock/report/stock_ageing/stock_ageing.py | 16 ++++++
 .../report/stock_ageing/test_stock_ageing.py  | 51 +++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/erpnext/stock/report/stock_ageing/stock_ageing.py b/erpnext/stock/report/stock_ageing/stock_ageing.py
index 20508f3c4ec..ab9f3592230 100644
--- a/erpnext/stock/report/stock_ageing/stock_ageing.py
+++ b/erpnext/stock/report/stock_ageing/stock_ageing.py
@@ -288,6 +288,7 @@ class FIFOSlots:
 		self.transferred_item_details = {}
 		self.serial_no_details = {}
 		self.batch_no_details = {}
+		self.batches_with_negative_slots = set()
 		self.batchwise_valuation_by_batch = {}
 		self.valuation_method_by_item = {}
 		self.filters = filters
@@ -659,6 +660,11 @@ class FIFOSlots:
 		if not qty:
 			return qty, stock_value_difference
 
+		if (batch_no, row.warehouse) not in self.batches_with_negative_slots:
+			return qty, stock_value_difference
+
+		negative_slot_may_remain = False
+
 		for slot in list(fifo_queue):
 			if not self._is_matching_negative_batch_slot(slot, batch_no, use_batchwise_valuation):
 				continue
@@ -679,10 +685,16 @@ class FIFOSlots:
 
 			if not flt(slot[BATCH_SLOT_QTY_INDEX]) and not flt(slot[BATCH_SLOT_VALUE_INDEX]):
 				fifo_queue.remove(slot)
+			elif flt(slot[BATCH_SLOT_QTY_INDEX]) < 0:
+				negative_slot_may_remain = True
 
 			if not qty:
+				negative_slot_may_remain = True
 				break
 
+		if not negative_slot_may_remain:
+			self.batches_with_negative_slots.discard((batch_no, row.warehouse))
+
 		return qty, stock_value_difference
 
 	def _is_matching_negative_batch_slot(
@@ -795,9 +807,13 @@ class FIFOSlots:
 		qty: float,
 		stock_value_difference: float,
 	) -> None:
+		"""The only place a batch slot goes negative, so it is also where the warehouse
+		is recorded as owing stock on that batch. The record is discarded again by a walk
+		that reaches the end of the queue and leaves nothing negative behind."""
 		fifo_queue.append(
 			[batch_no, use_batchwise_valuation, -(qty), row.posting_date, -(stock_value_difference)]
 		)
+		self.batches_with_negative_slots.add((batch_no, row.warehouse))
 		self.transferred_item_details[transfer_key].append([qty, row.posting_date, stock_value_difference])
 
 	def _consume_fifo_slots(
diff --git a/erpnext/stock/report/stock_ageing/test_stock_ageing.py b/erpnext/stock/report/stock_ageing/test_stock_ageing.py
index 0dbb98c8d33..fa716394335 100644
--- a/erpnext/stock/report/stock_ageing/test_stock_ageing.py
+++ b/erpnext/stock/report/stock_ageing/test_stock_ageing.py
@@ -1884,6 +1884,57 @@ class TestStockAgeing(ERPNextTestSuite):
 			[[5.0, "2021-09-01", 50.0]],
 		)
 
+	def test_second_negative_batch_slot_survives_a_partial_refill(self):
+		"""Ledger (same wh, batch B): two issues against no stock, then two receipts.
+		The first receipt clears only the first negative slot, so the second receipt
+		must still find and clear the one left behind."""
+		from erpnext.stock.doctype.item.test_item import make_item
+
+		item_code = make_item(
+			"Test Stock Ageing Twice Negative Batch",
+			{"is_stock_item": 1, "has_batch_no": 1, "valuation_method": "FIFO"},
+		).name
+
+		batch_no = "SA-TWICE-NEGATIVE-BATCH"
+		frappe.get_doc({"doctype": "Batch", "batch_id": batch_no, "item": item_code}).insert(
+			ignore_permissions=True, ignore_if_duplicate=True
+		)
+		frappe.db.set_value("Batch", batch_no, "use_batchwise_valuation", 1)
+
+		qty_after = 0
+
+		def make_sle(posting_date, voucher_no, actual_qty):
+			nonlocal qty_after
+
+			qty_after += actual_qty
+			return frappe._dict(
+				name=item_code,
+				actual_qty=actual_qty,
+				qty_after_transaction=qty_after,
+				stock_value_difference=actual_qty * 10,
+				valuation_rate=10,
+				warehouse="WH 1",
+				posting_date=posting_date,
+				voucher_type="Stock Entry",
+				voucher_no=voucher_no,
+				has_serial_no=False,
+				has_batch_no=True,
+				serial_no=None,
+				batch_no=batch_no,
+			)
+
+		sle = [
+			make_sle("2021-12-01", "001", -10),
+			make_sle("2021-12-02", "002", -5),
+			make_sle("2021-12-03", "003", 10),
+			make_sle("2021-12-04", "004", 5),
+		]
+
+		result = FIFOSlots(self.filters, sle).generate()[item_code]
+
+		self.assertEqual(result["fifo_queue"], [])
+		self.assertEqual(result["total_qty"], 0)
+
 	def test_batchwise_valuation_negative_stock_same_voucher(self):
 		from erpnext.stock.doctype.item.test_item import make_item