[Django] #26900: Defer FileFields causes errors when accessing them
Django
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Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.10
Severity: Release blocker | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
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The problem is in `FileDescriptor.__get__()`. That method obtains the file
directly from `instance.__dict__` but, from Django 1.10, deferred fields
don't create any item in `instance.__dict__`, so a KeyError is raised.
Moreover, ImageFields access the file each time a model is instantiated to
update dimension fields, so a KeyError is raised whenever an instance with
a deferred ImageField is created.
The obvious solution is change `file = instance.__dict__[self.field.name]`
for `file = instance.__dict__.get(self.field.name)` inside of
`FileDescriptor.__get__()` but I am not sure about the consequences.
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Ticket URL: <https://code.djangoproject.com/ticket/26900>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.10
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Easy pickings: 0
UI/UX: 0 |
Changes (by timgraham):
* Attachment "26900-test.diff" added.
A regression test for Django's test suite
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: new
(models, ORM) |
Severity: Release blocker | Resolution:
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 timgraham):
* needs_better_patch: => 0
* stage: Unreviewed => Accepted
* needs_tests: => 0
* needs_docs: => 0
--
Ticket URL: <https://code.djangoproject.com/ticket/26900#comment:1>
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: new
(models, ORM) |
Severity: Release blocker | Resolution:
Keywords: | Triage Stage: Accepted
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by timgraham):
* has_patch: 0 => 1
Comment:
[https://github.com/django/django/pull/6920 PR]
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Ticket URL: <https://code.djangoproject.com/ticket/26900#comment:2>
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: new
(models, ORM) |
Severity: Release blocker | Resolution:
| checkin
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Changes (by charettes):
* stage: Accepted => Ready for checkin
--
Ticket URL: <https://code.djangoproject.com/ticket/26900#comment:3>
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: new
(models, ORM) |
Severity: Release blocker | Resolution:
Keywords: | Triage Stage: Ready for
| checkin
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Comment (by samuelmaudo):
The patch has a problem with ImageFields, I thought. Since image file is
requiered whenever the model is instantiated, defer a ImageField results
in an extra database query for each object in the QuerySet. That could
generate hundreds of database queries.
--
Ticket URL: <https://code.djangoproject.com/ticket/26900#comment:4>
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: new
(models, ORM) |
Severity: Release blocker | Resolution:
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Changes (by timgraham):
* needs_better_patch: 0 => 1
* stage: Ready for checkin => Accepted
--
Ticket URL: <https://code.djangoproject.com/ticket/26900#comment:5>
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: new
(models, ORM) |
Severity: Release blocker | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Changes (by timgraham):
* needs_better_patch: 1 => 0
Comment:
I've updated the patch.
--
Ticket URL: <https://code.djangoproject.com/ticket/26900#comment:6>
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: closed
Component: Database layer | Version: 1.10
(models, ORM) |
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Tim Graham <timograham@…>):
* status: new => closed
* resolution: => fixed
Comment:
In [changeset:"7c33aa8a87d323f0e8e5368705aa8ba96f9819d0" 7c33aa8a]:
{{{
#!CommitTicketReference repository=""
revision="7c33aa8a87d323f0e8e5368705aa8ba96f9819d0"
Fixed #26900 -- Fixed crash accessing deferred FileFields.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/26900#comment:7>
Django
Reporter: samuelmaudo | Owner: nobody
Type: Bug | Status: closed
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Release blocker | Resolution: fixed
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Tim Graham <timograham@…>):
In [changeset:"a03ac61332fe356a60e25d5ecd7d4cd7ee07c345" a03ac613]:
{{{
#!CommitTicketReference repository=""
revision="a03ac61332fe356a60e25d5ecd7d4cd7ee07c345"
[1.10.x] Fixed #26900 -- Fixed crash accessing deferred FileFields.
Backport of 7c33aa8a87d323f0e8e5368705aa8ba96f9819d0 from master
}}}
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Ticket URL: <https://code.djangoproject.com/ticket/26900#comment:8>