From fdfc1ab87ed2955bbbbd9544b83972987b844be1 Mon Sep 17 00:00:00 2001
From: andreas loeffler <aloeff@de.ibm.com>
Date: Sun, 13 Nov 2022 17:55:02 +0100
Subject: [PATCH] for Regexp validator set html input tag 'pattern' attribute
 (used if novalidate not set on a form)

---
 src/wtforms/validators.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/wtforms/validators.py b/src/wtforms/validators.py
index 86337c99f..35ec77fdc 100644
--- a/src/wtforms/validators.py
+++ b/src/wtforms/validators.py
@@ -341,6 +341,7 @@ def __init__(self, regex, flags=0, message=None):
             regex = re.compile(regex, flags)
         self.regex = regex
         self.message = message
+        self.field_flags = {"pattern": regex.pattern}
 
     def __call__(self, form, field, message=None):
         match = self.regex.match(field.data or "")