Prevent storing Decimal with too much trailing zero

The trailing zero are kept in the Decimal and rendered in the string
representation which is unexpected for a field with limited digits.

Closes #12587

tryton/tryton/common/number_entry.py

@@ -2,6 +2,7 @@
 # this repository contains the full copyright notices and license terms.
 import gettext
 import locale
+from decimal import Decimal
 
 from gi.repository import Gdk, GObject, Gtk
 
@@ -60,11 +61,12 @@ class NumberEntry(Gtk.Entry, Gtk.Editable):
         value = None
         if text not in ['-', self.__decimal_point, self.__thousands_sep]:
             try:
-                value = self.convert(locale.delocalize(text, self.monetary))
+                value = Decimal(locale.delocalize(text, self.monetary))
             except ValueError:
                 return position
         if (value and self.__digits is not None
-                and round(value, self.__digits) != value):
+                and (round(value, self.__digits) != value
+                    or value.as_tuple().exponent < -self.__digits)):
             return position
         buffer_.insert_text(position, new_text, len(new_text))
         return position + len(new_text)

trytond/trytond/model/modelstorage.py

@@ -1436,13 +1436,10 @@ class ModelStorage(Model):
                             or not digits
                             or any(d is None for d in digits)):
                         return
-                    if isinstance(value, Decimal):
-                        exp = Decimal('.'.join(['0', '0' * digits[1]]))
-                        if value.quantize(exp) != value:
-                            raise_error(value)
-                    else:
-                        if not (round(value, digits[1]) == float(value)):
-                            raise_error(value)
+                    if (round(value, digits[1]) != value
+                            or (isinstance(value, Decimal)
+                                and value.as_tuple().exponent < -digits[1])):
+                        raise_error(value)
                 # validate digits
                 if getattr(field, 'digits', None):
                     if is_pyson(field.digits):

trytond/trytond/tests/test_field_numeric.py

@@ -167,6 +167,17 @@ class FieldNumericTestCase(unittest.TestCase):
                         'numeric': Decimal('1.11111111111'),
                         }])
 
+    @with_transaction()
+    def test_create_trailing_zero_digits_invalid(self):
+        "Test create numeric with invalid trailing zero digits"
+        Numeric = Pool().get('test.numeric_digits')
+
+        with self.assertRaises(DigitsValidationError):
+            Numeric.create([{
+                    'digits': 1,
+                    'numeric': Decimal('1.10'),
+                    }])
+
     @with_transaction()
     def test_search_equals(self):
         "Test search numeric equals"