[5.1.x] Fixed #35488 -- Fixed BaseModelFormSet.validate_unique() crash due to unhashable type.

Backport of d28626ecf8bd340084ed70ff2d88e8dbab001e2c from main.

2 files changed, 27 insertions, 2 deletions

diff --git a/django/forms/models.py b/django/forms/models.py
index 4cda4e534e..09be448984 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -23,6 +23,7 @@ from django.forms.widgets import (
     SelectMultiple,
 )
 from django.utils.choices import BaseChoiceIterator
+from django.utils.hashable import make_hashable
 from django.utils.text import capfirst, get_text_list
 from django.utils.translation import gettext
 from django.utils.translation import gettext_lazy as _
@@ -834,8 +835,8 @@ class BaseModelFormSet(BaseFormSet, AltersData):
                     (
                         d._get_pk_val()
                         if hasattr(d, "_get_pk_val")
-                        # Prevent "unhashable type: list" errors later on.
-                        else tuple(d) if isinstance(d, list) else d
+                        # Prevent "unhashable type" errors later on.
+                        else make_hashable(d)
                     )
                     for d in row_data
                 )
diff --git a/tests/model_formsets/tests.py b/tests/model_formsets/tests.py
index f78772da56..e5c026cee6 100644
--- a/tests/model_formsets/tests.py
+++ b/tests/model_formsets/tests.py
@@ -1703,6 +1703,30 @@ class ModelFormsetTest(TestCase):
             [{}, {"__all__": ["Please correct the duplicate values below."]}, {}],
         )
 
+    def test_inlineformset_with_jsonfield(self):
+        class BookForm(forms.ModelForm):
+            title = forms.JSONField()
+
+            class Meta:
+                model = Book
+                fields = ("title",)
+
+        BookFormSet = inlineformset_factory(Author, Book, form=BookForm)
+        data = {
+            "book_set-TOTAL_FORMS": "3",
+            "book_set-INITIAL_FORMS": "0",
+            "book_set-MAX_NUM_FORMS": "",
+            "book_set-0-title": {"test1": "test2"},
+            "book_set-1-title": {"test1": "test2"},
+            "book_set-2-title": {"test3": "test4"},
+        }
+        author = Author.objects.create(name="test")
+        formset = BookFormSet(data, instance=author)
+        self.assertEqual(
+            formset.errors,
+            [{}, {"__all__": ["Please correct the duplicate values below."]}, {}],
+        )
+
     def test_model_formset_with_custom_pk(self):
         # a formset for a Model that has a custom primary key that still needs to be
         # added to the formset automatically