DecimalValidator raises ValidationError for decimals in scientific notation

[Maksim Iakovlev]

>>> validator = DecimalValidator(20, 2)
>>> value = Decimal('7.42403889818E+17')
>>> try:
...     validator(value)
... except Exception as e:
...     print(e)
... 
[u'Ensure that there are no more than 2 decimal places.']
>>> value = Decimal(742403889818000000)
>>> try:
...     validator(value)
... except Exception as e:
...     print(e)
... 
>>> 

[Josh Schneier]

​PR

[Tim Graham <timograham@…>]

In e8c45963:

Fixed #28562 -- Fixed DecimalValidator handling of positive exponent scientific notation.

[Tim Graham <timograham@…>]

In 7c6590af:

[2.0.x] Fixed #28562 -- Fixed DecimalValidator handling of positive exponent scientific notation.

Backport of e8c45963296eb8bf3938bf9ece30b585a8cbb097 from master

[Josh Harwood]

Running version Django==2.0.1

With Example form

class UpdateBalanceForm(forms.Form):
    balance = forms.DecimalField(decimal_places=2, max_digits=16, required=True)

Running the following you get

form = UpdateBalanceForm({'balance':Decimal('5.420575188741E-12')})
form.is_valid()
False
form.errors
{'balance': ['Ensure that there are no more than 16 digits in total.']}

This is surprising because the value has 13 digits minus the scientific notation

edit 1: Simplified example

[Tim Graham]

Please open a new ticket as the fix for this ticket has been released.