Fixed #27037 -- Prevented required attribute on ClearableFileInput when initial data exists.

1 files changed, 9 insertions, 5 deletions

diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index 13d22672bf..d6b84c10ab 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -248,6 +248,9 @@ class Widget(six.with_metaclass(RenameWidgetMethods)):
         """
         return id_
 
+    def use_required_attribute(self, initial):
+        return not self.is_hidden
+
 
 class Input(Widget):
     """
@@ -429,6 +432,9 @@ class ClearableFileInput(FileInput):
             return False
         return upload
 
+    def use_required_attribute(self, initial):
+        return super(ClearableFileInput, self).use_required_attribute(initial) and not initial
+
 
 class Textarea(Widget):
     def __init__(self, attrs=None):
@@ -795,12 +801,10 @@ class CheckboxSelectMultiple(RendererMixin, SelectMultiple):
     renderer = CheckboxFieldRenderer
     _empty_value = []
 
-    def build_attrs(self, extra_attrs=None, **kwargs):
-        attrs = super(CheckboxSelectMultiple, self).build_attrs(extra_attrs, **kwargs)
-        # Remove the 'required' attribute because browser validation would
+    def use_required_attribute(self, initial):
+        # Don't use the 'required' attribute because browser validation would
         # require all checkboxes to be checked instead of at least one.
-        attrs.pop('required', None)
-        return attrs
+        return False
 
 
 class MultiWidget(Widget):