[Django] #20872: Bad error message if INITIAL_FORMS/TOTAL_FORMS > MAX_NUM_FORMS

[Django]

#20872: Bad error message if INITIAL_FORMS/TOTAL_FORMS > MAX_NUM_FORMS
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Reporter: russellm | Owner: nobody
Type: Bug | Status: new
Component: Forms | Version: 1.5
Severity: Normal | Keywords:
Triage Stage: Accepted | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
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Formset handling currently enforces a MAX_NUM_FORMS check on incoming form
data. However, there is no checking or validation that MAX_NUM_FORMS is
actually equal to or greater than INITIAL_FORMS/TOTAL_FORMS.

As a result, it's possible to construct and display a formset, but then
have that formset fail (with a "list index out of range error") on form
submission.

This manifested for me as the following: A model in the admin with
inlines; the inline was filled with 2023 inline objects, and the default
MAX_NUM_FORMS (1000 was in use. The page takes a long time to load, but it
*does* load; when you hit submit, you get the "list index out of range"
error as a 500 page, with no suggestion of the underlying problem.

I haven't tested, but AFAICT, the same problem will manifest with a lot
less data if you set MAX_NUM_FORMS to a lower value.

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Ticket URL: <https://code.djangoproject.com/ticket/20872>
Django <https://code.djangoproject.com/>
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[Django]

#20872: Bad error message if INITIAL_FORMS/TOTAL_FORMS > MAX_NUM_FORMS

--------------------------+------------------------------------
Reporter: russellm | Owner: mburst
Type: Bug | Status: assigned
Component: Forms | Version: 1.5
Severity: Normal | Resolution:

Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

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Changes (by mburst):

* status: new => assigned
* owner: nobody => mburst

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Ticket URL: <https://code.djangoproject.com/ticket/20872#comment:1>

[Django]

#20872: Bad error message if INITIAL_FORMS/TOTAL_FORMS > MAX_NUM_FORMS

--------------------------+--------------------------------------
Reporter: russellm | Owner: mburst
Type: Bug | Status: closed
Component: Forms | Version: 1.5
Severity: Normal | Resolution: worksforme

Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

--------------------------+--------------------------------------
Changes (by mburst):

* status: assigned => closed
* resolution: => worksforme

Comment:

This has been fixed with commit
https://github.com/django/django/commit/f9ab543720532400e8b0d490cdbe67ea09ae9c17.
total_form_count can't be larger than absolute_max.

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Ticket URL: <https://code.djangoproject.com/ticket/20872#comment:2>

[Django]

#20872: Bad error message if INITIAL_FORMS/TOTAL_FORMS > MAX_NUM_FORMS

--------------------------+------------------------------------

Reporter: russellm | Owner: mburst
Type: Bug | Status: closed

Component: Forms | Version: 1.5
Severity: Normal | Resolution: fixed

Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

--------------------------+------------------------------------
Changes (by mburst):

* resolution: worksforme => fixed

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Ticket URL: <https://code.djangoproject.com/ticket/20872#comment:3>