From 3f3433685d04a041013e90ad507285e62d31d862 Mon Sep 17 00:00:00 2001
From: Oliver <oliver.henry.walters@gmail.com>
Date: Thu, 21 May 2026 16:43:49 +1000
Subject: [PATCH] Normalize BomItem quantity (#11975)

- Limit decimal places before save
- Prevents error in BomItem validation
---
 src/backend/InvenTree/part/models.py | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/backend/InvenTree/part/models.py b/src/backend/InvenTree/part/models.py
index 3ad08f999d..a38870df5e 100644
--- a/src/backend/InvenTree/part/models.py
+++ b/src/backend/InvenTree/part/models.py
@@ -2,14 +2,13 @@
 
 from __future__ import annotations
 
-import decimal
 import hashlib
 import inspect
 import math
 import os
 import re
 from datetime import timedelta
-from decimal import Decimal, InvalidOperation
+from decimal import ROUND_HALF_UP, Decimal, InvalidOperation
 from typing import TypedDict, cast
 
 from django.conf import settings
@@ -2052,8 +2051,9 @@ class Part(
             'part', 'sub_part'
         )
 
-        for item in bom_items:
-            item.validate_hash(valid=valid)
+        if valid:
+            for item in bom_items:
+                item.validate_hash(valid=True)
 
         self.bom_validated = valid
         self.bom_checksum = self.get_bom_hash() if valid else ''
@@ -2233,8 +2233,8 @@ class Part(
                 logger.warning('WARNING: BomItem ID %s contains itself in BOM', item.pk)
                 continue
 
-            q = decimal.Decimal(quantity)
-            i = decimal.Decimal(item.quantity)
+            q = Decimal(quantity)
+            i = Decimal(item.quantity)
 
             prices = item.sub_part.get_price_range(
                 q * i, internal=internal, purchase=purchase
@@ -3934,14 +3934,18 @@ class BomItem(InvenTree.models.MetadataMixin, InvenTree.models.InvenTreeModel):
                         'raw_amount': _('Quantity must be greater than zero')
                     })
 
-            self.quantity = Decimal(quantity.magnitude)
+            # Normalize the quantity, to maximum 5 decimal places
+            quantity = Decimal(quantity.magnitude)
 
         except ValidationError as e:
             raise ValidationError({'raw_amount': e.messages})
 
         # Ensure that the raw_amount is converted to a Decimal value
+        # and quantized to a maximum of 5 decimal places (to avoid floating point issues)
         try:
-            self.quantity = Decimal(self.quantity)
+            self.quantity = Decimal(quantity).quantize(
+                Decimal('0.00001'), rounding=ROUND_HALF_UP
+            )
         except InvalidOperation:
             msg = _('Invalid quantity provided')
             raise ValidationError({'quantity': msg, 'raw_amount': msg})