Fixed #35870 -- Made blank choice label in forms more accessible.

Added new constant django.db.models.fields.BLANK_CHOICE_LABEL for
an accessible and translatable blank choice label in forms.
Deprecated django.db.models.fields.BLANK_CHOICE_DASH constant.
Added the immediately deprecated transitional setting
USE_BLANK_CHOICE_DASH.

Co-Authored-By: Marijke Luttekes <mail@marijkeluttekes.dev>

2 files changed, 6 insertions, 3 deletions

diff --git a/django/forms/fields.py b/django/forms/fields.py
index 8aad2d48b8..26640ed7d3 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -15,6 +15,7 @@ from io import BytesIO
 
 from django.core import validators
 from django.core.exceptions import ValidationError
+from django.db.models.utils import get_blank_choice_label
 from django.forms.boundfield import BoundField
 from django.forms.utils import from_current_timezone, to_current_timezone
 from django.forms.widgets import (
@@ -1200,7 +1201,7 @@ class FilePathField(ChoiceField):
         if self.required:
             self.choices = []
         else:
-            self.choices = [("", "---------")]
+            self.choices = [("", get_blank_choice_label())]
 
         if self.match is not None:
             self.match_re = re.compile(self.match)
diff --git a/django/forms/models.py b/django/forms/models.py
index a53f119995..9686baa6f2 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -12,7 +12,7 @@ from django.core.exceptions import (
     ValidationError,
 )
 from django.core.validators import ProhibitNullCharactersValidator
-from django.db.models.utils import AltersData
+from django.db.models.utils import AltersData, get_blank_choice_label
 from django.forms.fields import ChoiceField, Field
 from django.forms.forms import BaseForm, DeclarativeFieldsMetaclass
 from django.forms.formsets import BaseFormSet, formset_factory
@@ -1481,7 +1481,7 @@ class ModelChoiceField(ChoiceField):
         self,
         queryset,
         *,
-        empty_label="---------",
+        empty_label="",
         required=True,
         widget=None,
         label=None,
@@ -1508,6 +1508,8 @@ class ModelChoiceField(ChoiceField):
         ):
             self.empty_label = None
         else:
+            if empty_label == "":
+                empty_label = get_blank_choice_label()
             self.empty_label = empty_label
         self.queryset = queryset
         self.limit_choices_to = limit_choices_to  # limit the queryset later.