From b4df87e545143f8e21eea41bdc80224bdf60cb8f Mon Sep 17 00:00:00 2001
From: Sagar Vora <16315650+sagarvora@users.noreply.github.com>
Date: Sat, 18 Oct 2025 00:00:36 +0530
Subject: [PATCH] refactor: simplify logic

(cherry picked from commit 95f604457d42e601d39108a658d36cbe8c214df6)
---
 erpnext/controllers/accounts_controller.py | 13 ++++---------
 erpnext/controllers/taxes_and_totals.py    |  5 ++++-
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/erpnext/controllers/accounts_controller.py b/erpnext/controllers/accounts_controller.py
index 01b10e460c1..f60fe003b0d 100644
--- a/erpnext/controllers/accounts_controller.py
+++ b/erpnext/controllers/accounts_controller.py
@@ -3010,16 +3010,11 @@ class AccountsController(TransactionBase):
 			# returns have negative discount
 			discount_already_applied *= -1
 
-		if (source_doc.discount_amount * (discount_already_applied - source_doc.discount_amount)) >= 0:
-			# full discount already applied or exceeded
-			self.discount_amount = 0
-		else:
-			discount_amount = source_doc.discount_amount - discount_already_applied
-			if is_return:
-				# returns have negative discount
-				discount_amount *= -1
+		discount_amount = max(source_doc.discount_amount - discount_already_applied, 0)
+		if discount_amount and is_return:
+			discount_amount *= -1
 
-			self.discount_amount = flt(discount_amount, self.precision("discount_amount"))
+		self.discount_amount = flt(discount_amount, self.precision("discount_amount"))
 
 		self.calculate_taxes_and_totals()
 
diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
index 0048ec9acab..3aa2a88a17c 100644
--- a/erpnext/controllers/taxes_and_totals.py
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -690,7 +690,10 @@ class calculate_taxes_and_totals:
 		grand_total = self.doc.grand_total
 
 		# validate that discount amount cannot exceed the total before discount
-		if grand_total * (discount_amount - grand_total) > 0:
+		if (
+			(grand_total >= 0 and discount_amount > grand_total)
+			or (grand_total < 0 and discount_amount < grand_total)  # returns
+		):
 			frappe.throw(
 				_(
 					"Additional Discount Amount ({discount_amount}) cannot exceed "