Rounding issue in tax calculation (#10135)

* Adjust rounding loss of discount in the last item row. Fixes #8952

* Fixed rounding issue in tax calculation. Fixes #8953, #8952, #8893, #6954, #8910

* Rounding related fixes for purchase cycle
diff --git a/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py b/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
index 90b36e0..62d9a1e 100644
--- a/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
+++ b/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
@@ -167,15 +167,15 @@
 			"_Test Account S&H Education Cess - _TC": [1.5, 1619.5, 0.03, 32.39],
 			"_Test Account CST - _TC": [32.5, 1652, 0.65, 33.04],
 			"_Test Account VAT - _TC": [156.5, 1808.5, 3.13, 36.17],
-			"_Test Account Discount - _TC": [-180.5, 1628, -3.61, 32.56]
+			"_Test Account Discount - _TC": [-181.0, 1627.5, -3.62, 32.55]
 		}
 
 		for d in si.get("taxes"):
 			for i, k in enumerate(expected_values["keys"]):
 				self.assertEquals(d.get(k), expected_values[d.account_head][i])
 
-		self.assertEquals(si.base_grand_total, 1628)
-		self.assertEquals(si.grand_total, 32.56)
+		self.assertEquals(si.base_grand_total, 1627.5)
+		self.assertEquals(si.grand_total, 32.55)
 
 	def test_sales_invoice_with_discount_and_inclusive_tax(self):
 		si = create_sales_invoice(qty=100, rate=50, do_not_save=True)
@@ -235,21 +235,29 @@
 				"item_code": "_Test Item Home Desktop 100",
 				"price_list_rate": 62.5,
 				"discount_percentage": 0,
-				"rate": 62.5, "amount": 625,
+				"rate": 62.5,
+				"amount": 625,
 				"base_price_list_rate": 62.5,
-				"base_rate": 62.5, "base_amount": 625,
-				"net_rate": 46.54, "net_amount": 465.37,
-				"base_net_rate": 46.54, "base_net_amount": 465.37
+				"base_rate": 62.5,
+				"base_amount": 625,
+				"net_rate": 46.54,
+				"net_amount": 465.37,
+				"base_net_rate": 46.54,
+				"base_net_amount": 465.37
 			},
 			{
 				"item_code": "_Test Item Home Desktop 200",
 				"price_list_rate": 190.66,
 				"discount_percentage": 0,
-				"rate": 190.66, "amount": 953.3,
+				"rate": 190.66,
+				"amount": 953.3,
 				"base_price_list_rate": 190.66,
-				"base_rate": 190.66, "base_amount": 953.3,
-				"net_rate": 139.62, "net_amount": 698.08,
-				"base_net_rate": 139.62, "base_net_amount": 698.08
+				"base_rate": 190.66,
+				"base_amount": 953.3,
+				"net_rate": 139.62,
+				"net_amount": 698.08,
+				"base_net_rate": 139.62,
+				"base_net_amount": 698.08
 			}
 		]
 
@@ -270,13 +278,13 @@
 			"keys": ["tax_amount", "tax_amount_after_discount_amount", "total"],
 			"_Test Account Excise Duty - _TC": [140, 130.31, 1293.76],
 			"_Test Account Education Cess - _TC": [2.8, 2.61, 1296.37],
-			"_Test Account S&H Education Cess - _TC": [1.4, 1.31, 1297.68],
-			"_Test Account CST - _TC": [27.88, 25.96, 1323.64],
-			"_Test Account VAT - _TC": [156.25, 145.43, 1469.07],
-			"_Test Account Customs Duty - _TC": [125, 116.35, 1585.42],
-			"_Test Account Shipping Charges - _TC": [100, 100, 1685.42],
-			"_Test Account Discount - _TC": [-180.33, -168.54, 1516.88],
-			"_Test Account Service Tax - _TC": [-18.03, -16.88, 1500]
+			"_Test Account S&H Education Cess - _TC": [1.4, 1.30, 1297.67],
+			"_Test Account CST - _TC": [27.88, 25.95, 1323.62],
+			"_Test Account VAT - _TC": [156.25, 145.43, 1469.05],
+			"_Test Account Customs Duty - _TC": [125, 116.35, 1585.40],
+			"_Test Account Shipping Charges - _TC": [100, 100, 1685.40],
+			"_Test Account Discount - _TC": [-180.33, -168.54, 1516.86],
+			"_Test Account Service Tax - _TC": [-18.03, -16.86, 1500]
 		}
 
 		for d in si.get("taxes"):
@@ -312,13 +320,13 @@
 			[test_records[3]["items"][0]["income_account"], 0.0, 1163.45],
 			[test_records[3]["taxes"][0]["account_head"], 0.0, 130.31],
 			[test_records[3]["taxes"][1]["account_head"], 0.0, 2.61],
-			[test_records[3]["taxes"][2]["account_head"], 0.0, 1.31],
-			[test_records[3]["taxes"][3]["account_head"], 0.0, 25.96],
+			[test_records[3]["taxes"][2]["account_head"], 0.0, 1.30],
+			[test_records[3]["taxes"][3]["account_head"], 0.0, 25.95],
 			[test_records[3]["taxes"][4]["account_head"], 0.0, 145.43],
 			[test_records[3]["taxes"][5]["account_head"], 0.0, 116.35],
 			[test_records[3]["taxes"][6]["account_head"], 0.0, 100],
 			[test_records[3]["taxes"][7]["account_head"], 168.54, 0.0],
-			["_Test Account Service Tax - _TC", 16.88, 0.0],
+			["_Test Account Service Tax - _TC", 16.86, 0.0]
 		])
 
 		for gle in gl_entries:
@@ -334,6 +342,61 @@
 
 		self.assertFalse(gle)
 
+	def test_tax_calculation_with_multiple_items(self):
+		si = create_sales_invoice(qty=84, rate=4.6, do_not_save=True)
+		item_row = si.get("items")[0]
+		for qty in (54, 288, 144, 430):
+			item_row_copy = copy.deepcopy(item_row)
+			item_row_copy.qty = qty
+			si.append("items", item_row_copy)
+
+		si.append("taxes", {
+			"account_head": "_Test Account VAT - _TC",
+			"charge_type": "On Net Total",
+			"cost_center": "_Test Cost Center - _TC",
+			"description": "VAT",
+			"doctype": "Sales Taxes and Charges",
+			"rate": 19
+		})
+		si.insert()
+
+		self.assertEquals(si.net_total, 4600)
+		
+		self.assertEquals(si.get("taxes")[0].tax_amount, 874.0)
+		self.assertEquals(si.get("taxes")[0].total, 5474.0)
+
+		self.assertEquals(si.grand_total, 5474.0)
+
+	def test_tax_calculation_with_multiple_items_and_discount(self):
+		si = create_sales_invoice(qty=1, rate=75, do_not_save=True)
+		item_row = si.get("items")[0]
+		for rate in (500, 200, 100, 50, 50):
+			item_row_copy = copy.deepcopy(item_row)
+			item_row_copy.price_list_rate = rate
+			item_row_copy.rate = rate
+			si.append("items", item_row_copy)
+
+		si.apply_discount_on = "Net Total"
+		si.discount_amount = 75.0
+
+		si.append("taxes", {
+			"account_head": "_Test Account VAT - _TC",
+			"charge_type": "On Net Total",
+			"cost_center": "_Test Cost Center - _TC",
+			"description": "VAT",
+			"doctype": "Sales Taxes and Charges",
+			"rate": 24
+		})
+		si.insert()
+
+		self.assertEquals(si.total, 975)
+		self.assertEquals(si.net_total, 900)
+		
+		self.assertEquals(si.get("taxes")[0].tax_amount, 216.0)
+		self.assertEquals(si.get("taxes")[0].total, 1116.0)
+
+		self.assertEquals(si.grand_total, 1116.0)
+		
 	def test_inclusive_rate_validations(self):
 		si = frappe.copy_doc(test_records[2])
 		for i, tax in enumerate(si.get("taxes")):
@@ -416,21 +479,29 @@
 				"item_code": "_Test Item Home Desktop 100",
 				"price_list_rate": 55.56,
 				"discount_percentage": 10,
-				"rate": 50, "amount": 500,
+				"rate": 50,
+				"amount": 500,
 				"base_price_list_rate": 2778,
-				"base_rate": 2500, "base_amount": 25000,
-				"net_rate": 40, "net_amount": 399.98,
-				"base_net_rate": 2000, "base_net_amount": 19999
+				"base_rate": 2500,
+				"base_amount": 25000,
+				"net_rate": 40,
+				"net_amount": 399.98,
+				"base_net_rate": 2000,
+				"base_net_amount": 19999
 			},
 			{
 				"item_code": "_Test Item Home Desktop 200",
 				"price_list_rate": 187.5,
 				"discount_percentage": 20,
-				"rate": 150, "amount": 750,
+				"rate": 150,
+				"amount": 750,
 				"base_price_list_rate": 9375,
-				"base_rate": 7500, "base_amount": 37500,
-				"net_rate": 118.01, "net_amount": 590.05,
-				"base_net_rate": 5900.5, "base_net_amount": 29502.5
+				"base_rate": 7500,
+				"base_amount": 37500,
+				"net_rate": 118.01,
+				"net_amount": 590.05,
+				"base_net_rate": 5900.5,
+				"base_net_amount": 29502.5
 			}
 		]
 
@@ -450,22 +521,22 @@
 		# check tax calculation
 		expected_values = {
 			"keys": ["base_tax_amount", "base_total", "tax_amount", "total"],
-			"_Test Account Excise Duty - _TC": [5540.5, 55042, 110.81, 1100.84],
-			"_Test Account Education Cess - _TC": [111, 55153, 2.22, 1103.06],
-			"_Test Account S&H Education Cess - _TC": [55.5, 55208.5, 1.11, 1104.17],
-			"_Test Account CST - _TC": [1104, 56312.5, 22.08, 1126.25],
-			"_Test Account VAT - _TC": [6188, 62500.5, 123.76, 1250.01],
-			"_Test Account Customs Duty - _TC": [4950.5, 67451, 99.01, 1349.02],
-			"_Test Account Shipping Charges - _TC": [ 100, 67551, 2, 1351.02],
-			"_Test Account Discount - _TC": [ -6755, 60796, -135.10, 1215.92]
+			"_Test Account Excise Duty - _TC": [5540.0, 55041.5, 110.80, 1100.83],
+			"_Test Account Education Cess - _TC": [111, 55152.5, 2.22, 1103.05],
+			"_Test Account S&H Education Cess - _TC": [55.5, 55208.0, 1.11, 1104.16],
+			"_Test Account CST - _TC": [1104, 56312.0, 22.08, 1126.24],
+			"_Test Account VAT - _TC": [6187.5, 62499.5, 123.75, 1249.99],
+			"_Test Account Customs Duty - _TC": [4950.0, 67449.5, 99.0, 1348.99],
+			"_Test Account Shipping Charges - _TC": [ 100, 67549.5, 2, 1350.99],
+			"_Test Account Discount - _TC": [ -6755, 60794.5, -135.10, 1215.89]
 		}
 
 		for d in si.get("taxes"):
 			for i, k in enumerate(expected_values["keys"]):
 				self.assertEquals(d.get(k), expected_values[d.account_head][i])
 
-		self.assertEquals(si.base_grand_total, 60796)
-		self.assertEquals(si.grand_total, 1215.92)
+		self.assertEquals(si.base_grand_total, 60794.5)
+		self.assertEquals(si.grand_total, 1215.89)
 
 	def test_outstanding(self):
 		w = self.make()
@@ -910,19 +981,20 @@
 			"_Test Account Excise Duty - _TC": [70, 70, 70],
 			"_Test Account Education Cess - _TC": [1.4, 1.4, 1.4],
 			"_Test Account S&H Education Cess - _TC": [.7, 0.7, 0.7],
-			"_Test Account CST - _TC": [17.2, 17.2, 17.2],
+			"_Test Account CST - _TC": [17.19, 17.19, 17.19],
 			"_Test Account VAT - _TC": [78.13, 78.13, 78.13],
 			"_Test Account Discount - _TC": [-95.49, -95.49, -95.49]
 		}
 
 		for d in si.get("taxes"):
 			for i, k in enumerate(expected_values["keys"]):
-				self.assertEquals(d.get(k), expected_values[d.account_head][i])
+				if expected_values.get(d.account_head):
+					self.assertEquals(d.get(k), expected_values[d.account_head][i])
 
 
-		self.assertEquals(si.total_taxes_and_charges, 234.44)
-		self.assertEquals(si.base_grand_total, 859.44)
-		self.assertEquals(si.grand_total, 859.44)
+		self.assertEquals(si.total_taxes_and_charges, 234.43)
+		self.assertEquals(si.base_grand_total, 859.43)
+		self.assertEquals(si.grand_total, 859.43)
 
 	def test_multi_currency_gle(self):
 		set_perpetual_inventory(0)
diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
index b6f8b7d..97bd771 100644
--- a/erpnext/controllers/taxes_and_totals.py
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -179,7 +179,6 @@
 
 		for n, item in enumerate(self.doc.get("items")):
 			item_tax_map = self._load_item_tax_rate(item.item_tax_rate)
-
 			for i, tax in enumerate(self.doc.get("taxes")):
 				# tax_amount represents the amount of tax for the current step
 				current_tax_amount = self.get_current_tax_amount(item, tax, item_tax_map)
@@ -202,36 +201,45 @@
 				# set tax after discount
 				tax.tax_amount_after_discount_amount += current_tax_amount
 
-				if getattr(tax, "category", None):
-					# if just for valuation, do not add the tax amount in total
-					# hence, setting it as 0 for further steps
-					current_tax_amount = 0.0 if (tax.category == "Valuation") \
-						else current_tax_amount
+				current_tax_amount = self.get_tax_amount_if_for_valuation_or_deduction(current_tax_amount, tax)
 
-					current_tax_amount *= -1.0 if (tax.add_deduct_tax == "Deduct") else 1.0
-
-				# Calculate tax.total viz. grand total till that step
 				# note: grand_total_for_current_item contains the contribution of
 				# item's amount, previously applied tax and the current tax on that item
 				if i==0:
-					tax.grand_total_for_current_item = flt(item.net_amount + current_tax_amount, tax.precision("total"))
+					tax.grand_total_for_current_item = flt(item.net_amount + current_tax_amount)
 				else:
 					tax.grand_total_for_current_item = \
-						flt(self.doc.get("taxes")[i-1].grand_total_for_current_item + current_tax_amount, tax.precision("total"))
-
-				# in tax.total, accumulate grand total of each item
-				tax.total += tax.grand_total_for_current_item
+						flt(self.doc.get("taxes")[i-1].grand_total_for_current_item + current_tax_amount)
 
 				# set precision in the last item iteration
 				if n == len(self.doc.get("items")) - 1:
 					self.round_off_totals(tax)
+					self.set_cumulative_total(i, tax)
+
+					self._set_in_company_currency(tax,
+						["total", "tax_amount", "tax_amount_after_discount_amount"])
 
 					# adjust Discount Amount loss in last tax iteration
 					if i == (len(self.doc.get("taxes")) - 1) and self.discount_amount_applied \
 						and self.doc.discount_amount and self.doc.apply_discount_on == "Grand Total":
 							self.adjust_discount_amount_loss(tax)
 
+	def get_tax_amount_if_for_valuation_or_deduction(self, tax_amount, tax):
+		# if just for valuation, do not add the tax amount in total
+		# if tax/charges is for deduction, multiply by -1
+		if getattr(tax, "category", None):
+			tax_amount = 0.0 if (tax.category == "Valuation") else tax_amount
+			tax_amount *= -1.0 if (tax.add_deduct_tax == "Deduct") else 1.0
+		return tax_amount
 
+	def set_cumulative_total(self, row_idx, tax):
+		tax_amount = tax.tax_amount_after_discount_amount
+		tax_amount = self.get_tax_amount_if_for_valuation_or_deduction(tax_amount, tax)
+
+		if row_idx == 0:
+			tax.total = flt(self.doc.net_total + tax_amount, tax.precision("total"))
+		else:
+			tax.total = flt(self.doc.get("taxes")[row_idx-1].total + tax_amount, tax.precision("total"))
 
 	def get_current_tax_amount(self, item, tax, item_tax_map):
 		tax_rate = self._get_tax_rate(tax, item_tax_map)
@@ -251,8 +259,6 @@
 			current_tax_amount = (tax_rate / 100.0) * \
 				self.doc.get("taxes")[cint(tax.row_id) - 1].grand_total_for_current_item
 
-		current_tax_amount = flt(current_tax_amount, tax.precision("tax_amount"))
-
 		self.set_item_wise_tax(item, tax, tax_rate, current_tax_amount)
 
 		return current_tax_amount
@@ -267,11 +273,9 @@
 		tax.item_wise_tax_detail[key] = [tax_rate,flt(item_wise_tax_amount, tax.precision("base_tax_amount"))]
 
 	def round_off_totals(self, tax):
-		tax.total = flt(tax.total, tax.precision("total"))
 		tax.tax_amount = flt(tax.tax_amount, tax.precision("tax_amount"))
-		tax.tax_amount_after_discount_amount = flt(tax.tax_amount_after_discount_amount, tax.precision("tax_amount"))
-
-		self._set_in_company_currency(tax, ["total", "tax_amount", "tax_amount_after_discount_amount"])
+		tax.tax_amount_after_discount_amount = flt(tax.tax_amount_after_discount_amount, 
+			tax.precision("tax_amount"))
 
 	def adjust_discount_amount_loss(self, tax):
 		discount_amount_loss = self.doc.grand_total - flt(self.doc.discount_amount) - tax.total
diff --git a/erpnext/public/js/controllers/taxes_and_totals.js b/erpnext/public/js/controllers/taxes_and_totals.js
index 83644db..5209295 100644
--- a/erpnext/public/js/controllers/taxes_and_totals.js
+++ b/erpnext/public/js/controllers/taxes_and_totals.js
@@ -5,7 +5,7 @@
 	setup: function() {},
 	apply_pricing_rule_on_item: function(item){
 		if(item.margin_type == "Percentage"){
-			item.rate_with_margin = flt(item.price_list_rate) 
+			item.rate_with_margin = flt(item.price_list_rate)
 				+ flt(item.price_list_rate) * ( flt(item.margin_rate_or_amount) / 100);
 		} else {
 			item.rate_with_margin = flt(item.price_list_rate) + flt(item.margin_rate_or_amount);
@@ -70,12 +70,11 @@
 			} else {
 				frappe.throw(repl('%(conversion_rate_label)s' +
 					__(' is mandatory. Maybe Currency Exchange record is not created for ') +
-					'%(from_currency)s' + __(" to ") + '%(to_currency)s',
-					{
-						"conversion_rate_label": conversion_rate_label,
-						"from_currency": this.frm.doc.currency,
-						"to_currency": company_currency
-					}));
+				'%(from_currency)s' + __(" to ") + '%(to_currency)s', {
+					"conversion_rate_label": conversion_rate_label,
+					"from_currency": this.frm.doc.currency,
+					"to_currency": company_currency
+				}));
 			}
 
 		}
@@ -101,7 +100,7 @@
 		var me = this;
 		$.each(fields, function(i, f) {
 			doc["base_"+f] = flt(flt(doc[f], precision(f, doc)) * me.frm.doc.conversion_rate, precision("base_" + f, doc));
-		})
+		});
 	},
 
 	initialize_taxes: function() {
@@ -111,14 +110,14 @@
 			tax.item_wise_tax_detail = {};
 			var tax_fields = ["total", "tax_amount_after_discount_amount",
 				"tax_amount_for_current_item", "grand_total_for_current_item",
-				"tax_fraction_for_current_item", "grand_total_fraction_for_current_item"]
+				"tax_fraction_for_current_item", "grand_total_fraction_for_current_item"];
 
 			if (cstr(tax.charge_type) != "Actual" &&
 				!(me.discount_amount_applied && me.frm.doc.apply_discount_on=="Grand Total")) {
 				tax_fields.push("tax_amount");
 			}
 
-			$.each(tax_fields, function(i, fieldname) { tax[fieldname] = 0.0 });
+			$.each(tax_fields, function(i, fieldname) { tax[fieldname] = 0.0; });
 
 			if (!this.discount_amount_applied && cur_frm) {
 				cur_frm.cscript.validate_taxes_and_charges(tax.doctype, tax.name);
@@ -134,7 +133,7 @@
 		var has_inclusive_tax = false;
 		$.each(me.frm.doc["taxes"] || [], function(i, row) {
 			if(cint(row.included_in_print_rate)) has_inclusive_tax = true;
-		})
+		});
 		if(has_inclusive_tax==false) return;
 
 		$.each(me.frm.doc["items"] || [], function(n, item) {
@@ -223,7 +222,6 @@
 
 		$.each(this.frm.doc["items"] || [], function(n, item) {
 			var item_tax_map = me._load_item_tax_rate(item.item_tax_rate);
-
 			$.each(me.frm.doc["taxes"] || [], function(i, tax) {
 				// tax_amount represents the amount of tax for the current step
 				var current_tax_amount = me.get_current_tax_amount(item, tax, item_tax_map);
@@ -232,7 +230,7 @@
 				if (tax.charge_type == "Actual") {
 					actual_tax_dict[tax.idx] -= current_tax_amount;
 					if (n == me.frm.doc["items"].length - 1) {
-						current_tax_amount += actual_tax_dict[tax.idx]
+						current_tax_amount += actual_tax_dict[tax.idx];
 					}
 				}
 
@@ -258,23 +256,25 @@
 					current_tax_amount *= (tax.add_deduct_tax == "Deduct") ? -1.0 : 1.0;
 				}
 
-				// Calculate tax.total viz. grand total till that step
 				// note: grand_total_for_current_item contains the contribution of
 				// item's amount, previously applied tax and the current tax on that item
 				if(i==0) {
-					tax.grand_total_for_current_item = flt(item.net_amount + current_tax_amount, precision("total", tax));
+					tax.grand_total_for_current_item = flt(item.net_amount + current_tax_amount);
 				} else {
 					tax.grand_total_for_current_item =
-						flt(me.frm.doc["taxes"][i-1].grand_total_for_current_item + current_tax_amount, precision("total", tax));
+						flt(me.frm.doc["taxes"][i-1].grand_total_for_current_item + current_tax_amount);
 				}
 
-				// in tax.total, accumulate grand total for each item
-				tax.total += tax.grand_total_for_current_item;
-
 				// set precision in the last item iteration
 				if (n == me.frm.doc["items"].length - 1) {
 					me.round_off_totals(tax);
 
+					// in tax.total, accumulate grand total for each item
+					tax.total = me.set_cumulative_total(i, tax);
+
+					this.set_in_company_currency(tax,
+						["total", "tax_amount", "tax_amount_after_discount_amount"]);
+
 					// adjust Discount Amount loss in last tax iteration
 					if ((i == me.frm.doc["taxes"].length - 1) && me.discount_amount_applied
 							&& me.frm.doc.apply_discount_on == "Grand Total" && me.frm.doc.discount_amount)
@@ -284,6 +284,16 @@
 		});
 	},
 
+	set_cumulative_total: function(row_idx, tax) {
+		if(row_idx==0) {
+			tax.total = flt(this.frm.doc.net_total + tax.tax_amount_after_discount_amount,
+				precision("total", tax));
+		} else {
+			tax.total = flt(this.frm.doc.get("taxes")[row_idx-1].total + tax.tax_amount_after_discount_amount,
+				precision("total", tax));
+		}
+	},
+
 	_load_item_tax_rate: function(item_tax_rate) {
 		return item_tax_rate ? JSON.parse(item_tax_rate) : {};
 	},
@@ -300,7 +310,6 @@
 
 		} else if(tax.charge_type == "On Net Total") {
 			current_tax_amount = (tax_rate / 100.0) * item.net_amount;
-
 		} else if(tax.charge_type == "On Previous Row Amount") {
 			current_tax_amount = (tax_rate / 100.0) *
 				this.frm.doc["taxes"][cint(tax.row_id) - 1].tax_amount_for_current_item;
@@ -310,8 +319,6 @@
 				this.frm.doc["taxes"][cint(tax.row_id) - 1].grand_total_for_current_item;
 		}
 
-		current_tax_amount = flt(current_tax_amount, precision("tax_amount", tax));
-
 		this.set_item_wise_tax(item, tax, tax_rate, current_tax_amount);
 
 		return current_tax_amount;
@@ -322,18 +329,14 @@
 		var key = item.item_code || item.item_name;
 		var item_wise_tax_amount = current_tax_amount * this.frm.doc.conversion_rate;
 		if (tax.item_wise_tax_detail && tax.item_wise_tax_detail[key])
-			item_wise_tax_amount += tax.item_wise_tax_detail[key][1]
+			item_wise_tax_amount += tax.item_wise_tax_detail[key][1];
 
-		tax.item_wise_tax_detail[key] = [tax_rate,flt(item_wise_tax_amount, precision("base_tax_amount", tax))]
-
+		tax.item_wise_tax_detail[key] = [tax_rate, flt(item_wise_tax_amount, precision("base_tax_amount", tax))];
 	},
 
 	round_off_totals: function(tax) {
-		tax.total = flt(tax.total, precision("total", tax));
 		tax.tax_amount = flt(tax.tax_amount, precision("tax_amount", tax));
 		tax.tax_amount_after_discount_amount = flt(tax.tax_amount_after_discount_amount, precision("tax_amount", tax));
-
-		this.set_in_company_currency(tax, ["total", "tax_amount", "tax_amount_after_discount_amount"]);
 	},
 
 	adjust_discount_amount_loss: function(tax) {
@@ -391,7 +394,7 @@
 							me.frm.doc.taxes_and_charges_deducted += flt(tax.tax_amount_after_discount_amount);
 						}
 					}
-				})
+				});
 
 				frappe.model.round_floats_in(this.frm.doc, ["taxes_and_charges_added", "taxes_and_charges_deducted"]);
 			}
@@ -437,7 +440,7 @@
 
 		if(this.frm.doc["taxes"] && this.frm.doc["taxes"].length) {
 			var temporary_fields = ["tax_amount_for_current_item", "grand_total_for_current_item",
-				"tax_fraction_for_current_item", "grand_total_fraction_for_current_item"]
+				"tax_fraction_for_current_item", "grand_total_fraction_for_current_item"];
 
 			if(!frappe.meta.get_docfield(this.frm.doc["taxes"][0].doctype, "tax_amount_after_discount_amount", this.frm.doctype)) {
 				temporary_fields.push("tax_amount_after_discount_amount");
@@ -473,13 +476,24 @@
 				precision("base_discount_amount"));
 
 			var total_for_discount_amount = this.get_total_for_discount_amount();
+			var net_total = 0;
 			// calculate item amount after Discount Amount
 			if (total_for_discount_amount) {
 				$.each(this.frm.doc["items"] || [], function(i, item) {
 					distributed_amount = flt(me.frm.doc.discount_amount) * item.net_amount / total_for_discount_amount;
-					item.net_amount = flt(item.net_amount - distributed_amount, precision("base_amount", item));
-					item.net_rate = flt(item.net_amount / item.qty, precision("net_rate", item));
+					item.net_amount = flt(item.net_amount - distributed_amount,
+						precision("base_amount", item));
+					net_total += item.net_amount;
 
+					// discount amount rounding loss adjustment if no taxes
+					if ((!(me.frm.doc.taxes || []).length || (me.frm.doc.apply_discount_on == "Net Total"))
+							&& i == (me.frm.doc.items || []).length - 1) {
+						var discount_amount_loss = flt(me.frm.doc.net_total - net_total
+							- me.frm.doc.discount_amount, precision("net_total"));
+						item.net_amount = flt(item.net_amount + discount_amount_loss,
+							precision("net_amount", item));
+					}
+					item.net_rate = flt(item.net_amount / item.qty, precision("net_rate", item));
 					me.set_in_company_currency(item, ["net_rate", "net_amount"]);
 				});
 
@@ -490,10 +504,8 @@
 	},
 
 	get_total_for_discount_amount: function() {
-		var me = this;
-
 		if(this.frm.doc.apply_discount_on == "Net Total") {
-			return this.frm.doc.net_total
+			return this.frm.doc.net_total;
 		} else {
 			var total_actual_tax = 0.0;
 			var actual_taxes_dict = {};
@@ -517,7 +529,7 @@
 
 	calculate_total_advance: function(update_paid_amount) {
 		var total_allocated_amount = frappe.utils.sum($.map(this.frm.doc["advances"] || [], function(adv) {
-			return flt(adv.allocated_amount, precision("allocated_amount", adv))
+			return flt(adv.allocated_amount, precision("allocated_amount", adv));
 		}));
 		this.frm.doc.total_advance = flt(total_allocated_amount, precision("total_advance"));
 
@@ -528,9 +540,9 @@
 		// NOTE:
 		// paid_amount and write_off_amount is only for POS Invoice
 		// total_advance is only for non POS Invoice
-		
+
 		if(this.frm.doc.doctype == "Sales Invoice" && this.frm.doc.is_return){
-			this.calculate_paid_amount()
+			this.calculate_paid_amount();
 		}
 
 		if(this.frm.doc.is_return || this.frm.doc.docstatus > 0) return;
@@ -558,25 +570,21 @@
 			}
 
 			if(this.frm.doc.doctype == "Sales Invoice"){
-				this.set_default_payment(total_amount_to_pay, update_paid_amount)
-				this.calculate_paid_amount()
+				this.set_default_payment(total_amount_to_pay, update_paid_amount);
+				this.calculate_paid_amount();
 			}
 
-			this.calculate_change_amount()
-			var outstanding_amount = 0.0
+			this.calculate_change_amount();
 
 			var paid_amount = (this.frm.doc.party_account_currency == this.frm.doc.currency) ?
 				this.frm.doc.paid_amount : this.frm.doc.base_paid_amount;
 
-			var change_amount = (this.frm.doc.party_account_currency == this.frm.doc.currency) ?
-				this.frm.doc.change_amount : this.frm.doc.base_change_amount;
-
 			this.frm.doc.outstanding_amount =  flt(total_amount_to_pay - flt(paid_amount) +
 				flt(this.frm.doc.change_amount * this.frm.doc.conversion_rate), precision("outstanding_amount"));
 
 		} else if(this.frm.doc.doctype == "Purchase Invoice") {
 			this.frm.doc.outstanding_amount = flt(total_amount_to_pay, precision("outstanding_amount"));
-		}		
+		}
 	},
 
 	set_default_payment: function(total_amount_to_pay, update_paid_amount){
@@ -591,7 +599,7 @@
 				}else if(me.frm.doc.paid_amount){
 					data.amount = 0.0;
 				}
-			})
+			});
 		}
 	},
 
@@ -604,7 +612,7 @@
 				data.base_amount = flt(data.amount * me.frm.doc.conversion_rate, precision("base_amount"));
 				paid_amount += data.amount;
 				base_paid_amount += data.base_amount;
-			})
+			});
 		} else if(!this.frm.doc.is_return){
 			this.frm.doc.payments = [];
 		}
@@ -617,30 +625,28 @@
 		this.frm.doc.change_amount = 0.0;
 		this.frm.doc.base_change_amount = 0.0;
 		if(this.frm.doc.paid_amount > this.frm.doc.grand_total && !this.frm.doc.is_return) {
-			var payment_types = $.map(this.frm.doc.payments, function(d) { return d.type });
+			var payment_types = $.map(this.frm.doc.payments, function(d) { return d.type; });
 			if (in_list(payment_types, 'Cash')) {
 				this.frm.doc.change_amount = flt(this.frm.doc.paid_amount - this.frm.doc.grand_total +
 					this.frm.doc.write_off_amount, precision("change_amount"));
-					
-				this.frm.doc.base_change_amount = flt(this.frm.doc.base_paid_amount - 
-					this.frm.doc.base_grand_total + this.frm.doc.base_write_off_amount, 
+
+				this.frm.doc.base_change_amount = flt(this.frm.doc.base_paid_amount -
+					this.frm.doc.base_grand_total + this.frm.doc.base_write_off_amount,
 					precision("base_change_amount"));
-				
 			}
 		}
 	},
 
 	calculate_write_off_amount: function(){
 		if(this.frm.doc.paid_amount > this.frm.doc.grand_total){
-			this.frm.doc.write_off_amount = flt(this.frm.doc.grand_total - this.frm.doc.paid_amount + this.frm.doc.change_amount,
-					precision("write_off_amount"))
-		
+			this.frm.doc.write_off_amount = flt(this.frm.doc.grand_total - this.frm.doc.paid_amount
+				+ this.frm.doc.change_amount, precision("write_off_amount"));
+
 			this.frm.doc.base_write_off_amount = flt(this.frm.doc.write_off_amount * this.frm.doc.conversion_rate,
 				precision("base_write_off_amount"));
 		}else{
-			this.frm.doc.paid_amount = 0.0
+			this.frm.doc.paid_amount = 0.0;
 		}
-		
-		this.calculate_outstanding_amount(false)
+		this.calculate_outstanding_amount(false);
 	}
-})
+});
\ No newline at end of file