From f24a63fbd05990d430136506c095dfbfea9bf5e5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Krier?= <ced@b2ck.com>
Date: Fri, 4 Apr 2025 18:51:30 +0200
Subject: [PATCH] Compute digits of float value before applying factor

When applying the factor, we introduce new rounding issue which falsify the
computation of digits.
So it is better to compute the digits using the initial value (coming from the
string parsing) and update the digits based on the order of the factor.

Closes #13964
(grafted from 3606a9f176d0312d9645d05902b74192391538e4)

--HG--
branch : 7.0
---
 sao/src/common.js                     |  5 +++--
 tryton/tryton/common/domain_parser.py | 14 ++++++++------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/sao/src/common.js b/sao/src/common.js
index e2a098bafa..c6881719f6 100644
--- a/sao/src/common.js
+++ b/sao/src/common.js
@@ -2125,8 +2125,7 @@
                     return '';
                 }
                 var digit = 0;
-                var factor = Number(field.factor || 1);
-                var string = String(value * factor);
+                var string = String(value);
                 if (string.contains('e')) {
                     var exp = string.split('e')[1];
                     string = string.split('e')[0];
@@ -2135,6 +2134,8 @@
                 if (string.contains('.')) {
                     digit += string.replace(/0+$/, '').split('.')[1].length;
                 }
+                var factor = Number(field.factor || 1);
+                digit -= Math.round(Math.log10(factor));
                 return (value * factor).toFixed(digit);
             };
             var format_selection = function() {
diff --git a/tryton/tryton/common/domain_parser.py b/tryton/tryton/common/domain_parser.py
index 9b74d7c354..3252563d2b 100644
--- a/tryton/tryton/common/domain_parser.py
+++ b/tryton/tryton/common/domain_parser.py
@@ -5,6 +5,7 @@ import decimal
 import gettext
 import io
 import locale
+import math
 from collections import OrderedDict
 from decimal import Decimal
 from shlex import shlex
@@ -336,17 +337,18 @@ def format_value(field, value, target=None, context=None, _quote_empty=False):
                     or isinstance(value, bool))):
             return ''
         digit = 0
-        if isinstance(value, Decimal):
-            cast = Decimal
-        else:
-            cast = float
-        factor = cast(field.get('factor', 1))
-        string_ = str(value * factor)
+        string_ = str(value)
         if 'e' in string_:
             string_, exp = string_.split('e')
             digit -= int(exp)
         if '.' in string_:
             digit += len(string_.rstrip('0').split('.')[1])
+        if isinstance(value, Decimal):
+            cast = Decimal
+        else:
+            cast = float
+        factor = cast(field.get('factor', 1))
+        digit -= round(math.log10(factor))
         return locale.localize(
             '{0:.{1}f}'.format(value * factor or 0, digit), True)