更新：我现在认为这是 Django 中的一个现有错误，报告为Ticket 14642
这让我发疯了，我认为这是由于我的表单代码，但我现在意识到我可以使用我的模型和管理员重新创建它。我想知道这里的预期行为是什么：
模型.py：
class Thingy(models.Model):
description = models.CharField(max_length=256)
class ThingyItem(models.Model):
thingy = models.ForeignKey(Thingy)
description = models.CharField(max_length=256)
管理员.py：
class ThingyItemInline(admin.TabularInline):
model = ThingyItem
extra = 0
class ThingyAdmin(admin.ModelAdmin):
inlines = [ThingyItemInline,]
admin.site.register(Thingy, ThingyAdmin)
admin.site.register(ThingyItem)
现在执行以下操作：
- 在 admin 中创建一个包含多个 ThingyItem 的新 Thingy 并保存。
- 打开编辑页面。
- 在第二个浏览器窗口中打开同一事物的编辑页面。
- 检查最后一个ThingyItem上的“删除”按钮并将其保存在第二个窗口中。
- 现在回到第一个表格并保存
当我这样做时，我得到：
Traceback:
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/core/handlers/base.py" in get_response
100. response = callback(request, *callback_args, **callback_kwargs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/contrib/admin/options.py" in wrapper
265. return self.admin_site.admin_view(view)(*args, **kwargs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/utils/decorators.py" in _wrapped_view
76. response = view_func(request, *args, **kwargs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/views/decorators/cache.py" in _wrapped_view_func
78. response = view_func(request, *args, **kwargs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/contrib/admin/sites.py" in inner
190. return view(request, *args, **kwargs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/utils/decorators.py" in _wrapper
21. return decorator(bound_func)(*args, **kwargs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/utils/decorators.py" in _wrapped_view
76. response = view_func(request, *args, **kwargs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/utils/decorators.py" in bound_func
17. return func(self, *args2, **kwargs2)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/db/transaction.py" in _commit_on_success
299. res = func(*args, **kw)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/contrib/admin/options.py" in change_view
916. queryset=inline.queryset(request))
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/forms/models.py" in __init__
701. queryset=qs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/forms/models.py" in __init__
427. super(BaseModelFormSet, self).__init__(**defaults)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/forms/formsets.py" in __init__
47. self._construct_forms()
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/forms/formsets.py" in _construct_forms
98. self.forms.append(self._construct_form(i))
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/forms/models.py" in _construct_form
714. form = super(BaseInlineFormSet, self)._construct_form(i, **kwargs)
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/forms/models.py" in _construct_form
451. kwargs['instance'] = self.get_queryset()[i]
File "/Users/poswald/.virtualenvs/hats/lib/python2.6/site-packages/django/db/models/query.py" in __getitem__
171. return self._result_cache[k]
Exception Type: IndexError at /admin/exampletest/thingy/1/
Exception Value: list index out of range
我不会在管理员中真正关心这一点，除非它在我们的生产服务器上使用我自己的表单以代码形式发生。内联表单集代码似乎很脆弱。当它确实应该检查这些假设是否仍然有效时，它会信任与管理表单一起发送的数据。
现在，我认为这值得在 Django Trac 中报告——我计划现在就这样做——但是我想知道这里是否有人曾经发生过这种情况，如果是这样，你是如何解决的？有没有一种简单的方法来测试表单假设的这些先决条件是否仍然有效？我是否应该在我的视图或表单代码中这样做？