From cc5386e1ab2006eddc030d3d41e3bc661f1cc83f Mon Sep 17 00:00:00 2001
From: Anton Stakhouski <antonstakhouski@gmail.com>
Date: Thu, 4 Apr 2024 12:21:38 +0200
Subject: [PATCH] Make Optional check on field.data instead of field.raw_data

---
 src/wtforms/validators.py         |  6 +++---
 tests/validators/test_optional.py | 16 ++++++++++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/wtforms/validators.py b/src/wtforms/validators.py
index d5b3c39a9..cc2284b82 100644
--- a/src/wtforms/validators.py
+++ b/src/wtforms/validators.py
@@ -248,9 +248,9 @@ def __init__(self, strip_whitespace=True):
 
     def __call__(self, form, field):
         if (
-            not field.raw_data
-            or isinstance(field.raw_data[0], str)
-            and not self.string_check(field.raw_data[0])
+            not field.data
+            or isinstance(field.data, str)
+            and not self.string_check(field.data)
         ):
             field.errors[:] = []
             raise StopValidation()
diff --git a/tests/validators/test_optional.py b/tests/validators/test_optional.py
index 7ccd27239..6b948ed7b 100644
--- a/tests/validators/test_optional.py
+++ b/tests/validators/test_optional.py
@@ -37,3 +37,19 @@ def test_input_optional_raises(data_v, raw_data_v, dummy_form, dummy_field):
         validator(dummy_form, dummy_field)
 
     assert len(dummy_field.errors) == 0
+
+
+def test_input_optional_raises_with_empty_formdata(dummy_form, dummy_field):
+    """
+    optional should not stop the validation chain if field.data is not empty
+    """
+    validator = optional()
+    dummy_field.data = "abc"
+    dummy_field.raw_data = None
+
+    dummy_field.errors = ["Invalid Integer Value"]
+    assert len(dummy_field.errors) == 1
+
+    validator(dummy_form, dummy_field)
+
+    assert len(dummy_field.errors) == 1