fix(validators): Disabled validation with provided formdata

CHANGES.rst

@@ -1,5 +1,12 @@
 .. currentmodule:: wtforms
 
+Unreleased
+-------------
+
+Unreleased
+
+- Fix :class:`~validators.Disabled` validation with provided formdata. :pr:`880`
+
 Version 3.2.1
 -------------
 

src/wtforms/validators.py

@@ -711,7 +711,7 @@ def __init__(self):
         self.field_flags = {"disabled": True}
 
     def __call__(self, form, field):
-        if field.raw_data is not None:
+        if field.raw_data:
             raise ValidationError(
                 field.gettext("This field is disabled and cannot have a value.")
             )

tests/validators/test_disabled.py

@@ -16,5 +16,8 @@ class F(Form):
     )
     assert form.validate()
 
+    form = F(DummyPostData())
+    assert form.validate()
+
     form = F(DummyPostData(disabled=["foobar"]))
     assert not form.validate()