admin.TabularInline custom form field header displaying as None on admin page

[Kartik Anand]

While using admin.TabularInline with a custom form, for any form field if one doesn't specify a label, then it would come up as "None" on admin page, but one doesn't need to specify it for admin.StackedInline.

Attached Image

To reproduce:

models.py

from django.db import models

class Foo(models.Model):
    title = models.CharField(max_length=128)

    class Meta:
        verbose_name = "Foo"
        verbose_name_plural = "Foo"

    def __str__(self):
        pass

class Bar(models.Model):
    title = models.CharField(max_length=128)
    foo = models.ForeignKey(Foo)

    class Meta:
        verbose_name = "Bar"
        verbose_name_plural = "Bars"

    def __str__(self):
        return self.title

admin.py

from django.contrib import admin
from django import forms
from . import models

class BarInlineForm(forms.ModelForm):
    title = forms.CharField(max_length=128)
 
    class Meta:
        model = models.Bar
        fields = ('title',)
 
class BarInline(admin.TabularInline):
    model = models.Bar
    form = BarInlineForm
    extra = 3

class FooAdmin(admin.ModelAdmin):
    inlines = [BarInline]

admin.site.register(models.Foo, FooAdmin)

[Kartik Anand]

Screenshot of admin page

[matiasb]

Pull request created: ​https://github.com/django/django/pull/5403
All tests passing for SQLite.

[Tim Graham <timograham@…>]

In 12aeed8:

Fixed #24976 -- Fixed missing form label in tabular inline.

If the model form had a form field specified, the label rendered
as "None".