Re: [Django] #10808: Multiple inheritance (model-based) broken for __init__ of common fields in diamond inheritance

[Django]

#10808: Multiple inheritance (model-based) broken for __init__ of common fields in
diamond inheritance
-------------------------------------+-------------------------------------
Reporter: mikemintz | Owner: mtredinnick
Type: Bug | Status: new
Milestone: | Component: Database layer
Version: SVN | (models, ORM)
Resolution: | Severity: Normal
Triage Stage: Accepted | Keywords:
Needs documentation: 0 | Has patch: 1
Patch needs improvement: 1 | Needs tests: 0
| Easy pickings: 0
-------------------------------------+-------------------------------------
Changes (by patchhammer):

* needs_better_patch: 0 => 1
* easy: => 0

Comment:

10808b-14404.diff fails to apply cleanly on to trunk

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Ticket URL: <http://code.djangoproject.com/ticket/10808#comment:16>
Django <https://code.djangoproject.com/>
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[Django]

#10808: Multiple inheritance (model-based) broken for __init__ of common fields in
diamond inheritance
-------------------------------------+-------------------------------------
Reporter: mikemintz | Owner:

Type: Bug | mtredinnick
Component: Database layer | Status: new
(models, ORM) | Version: master
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 1
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by lsaffre):

The following workaround uses the class_prepared signal to removes any
duplicate fields from `_meta._field_cache`:


{{{
def on_class_prepared(signal,sender=None,**kw):
cache = []
field_names = set()
for f,m in model._meta._field_cache:
if f.attname not in field_names:
field_names.add(f.attname)
cache.append( (f,m) )
model._meta._field_cache = tuple(cache)
model._meta._field_name_cache = [x for x, _ in cache]

models.signals.class_prepared.connect(on_class_prepared)
}}}

Works for me and has the advantage of not needing to patch Django.

--
Ticket URL: <https://code.djangoproject.com/ticket/10808#comment:18>

[Django]

#10808: Multiple inheritance (model-based) broken for __init__ of common fields in
diamond inheritance
-------------------------------------+-------------------------------------
Reporter: mikemintz | Owner:

| mtredinnick
Type: Bug | Status: new

Component: Database layer | Version: master
(models, ORM) |

Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 1
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by timgraham):

Closed #17232 as a duplicate.

--
Ticket URL: <https://code.djangoproject.com/ticket/10808#comment:19>

[Django]

#10808: Multiple inheritance (model-based) broken for __init__ of common fields in
diamond inheritance
-------------------------------------+-------------------------------------
Reporter: mikemintz | Owner:
| mtredinnick

Type: Bug | Status: closed

Component: Database layer | Version: master
(models, ORM) |

Severity: Normal | Resolution: invalid

Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 1
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by timgraham):

* status: new => closed
* resolution: => invalid

Comment:

Closing as invalid because the provided models don't validate:
{{{
PizzeriaBar: (models.E005) The field 'restaurant_ptr' from parent model
'polls.bar' clashes with the field 'restaurant_ptr' from parent model
'polls.pizzeria'.
}}}

--
Ticket URL: <https://code.djangoproject.com/ticket/10808#comment:20>

[Django]

#10808: Multiple inheritance (model-based) broken for __init__ of common fields in
diamond inheritance
-------------------------------------+-------------------------------------

Reporter: mikemintz | Owner: Malcolm
| Tredinnick
Type: Bug | Status: new
Component: Database layer | Version: dev

(models, ORM) |
Severity: Normal | Resolution:

Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 1
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by ElectronicRU):

* status: closed => new
* resolution: invalid =>

Comment:

I'm experiencing the bug with trying to inherit from wagtail's Page and
Collection models.

Closing the ticket about the models being invalid because provided models
were invalid doesn't look like a sound decision, so reopening.

--
Ticket URL: <https://code.djangoproject.com/ticket/10808#comment:21>

[Django]

#10808: Multiple inheritance (model-based) broken for __init__ of common fields in
diamond inheritance
-------------------------------------+-------------------------------------
Reporter: mikemintz | Owner: Malcolm
| Tredinnick

Type: Bug | Status: closed

Component: Database layer | Version: dev
(models, ORM) |

Severity: Normal | Resolution: invalid

Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 1
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Mariusz Felisiak):

* status: new => closed
* resolution: => invalid

Comment:

Please don't reopen old tickets without providing new details. We cannot
accept or investigate reports based on model definitions that are not
supported.

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Ticket URL: <https://code.djangoproject.com/ticket/10808#comment:22>