#36447: HttpRequest.get_preferred_type misorders types when more specific
accepted
types have lower q
--------------------------------+-----------------------------------------
Reporter: Anders Kaseorg | Type: Bug
Status: new | Component: HTTP handling
Version: 5.2 | Severity: Normal
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
--------------------------------+-----------------------------------------
Consider this example from [https://www.rfc-
editor.org/rfc/rfc9110.html#section-12.5.1-18 RFC 9110 §12.5.1]:
The media type quality factor associated with a given type is determined
by finding the media range with the highest precedence that matches the
type. For example,
{{{
Accept: text/*;q=0.3, text/plain;q=0.7, text/plain;format=flowed,
text/plain;format=fixed;q=0.4, */*;q=0.5
}}}
would cause the following values to be associated:
||= Media Type =||= Quality Value =||
|| text/plain;format=flowed || 1 ||
|| text/plain || 0.7 ||
|| text/html || 0.3 ||
|| image/jpeg || 0.5 ||
|| text/plain;format=fixed || 0.4 ||
|| text/html;level=3 || 0.7 ||
Django’s `HttpRequest.get_preferred_type` fails to match this behavior.
{{{
>>> from django.conf import settings
>>> from django.http import HttpRequest
>>> settings.configure()
>>> request = HttpRequest()
>>> request.META["HTTP_ACCEPT"] = "text/*;q=0.3, text/plain;q=0.7,
text/plain;format=flowed, text/plain;format=fixed;q=0.4, */*;q=0.5"
>>> request.get_preferred_type(['text/plain', 'text/plain;format=fixed'])
# expected text/plain (0.7 > 0.4)
'text/plain;format=fixed'
>>> request.get_preferred_type(['text/html', 'image/jpeg']) # expected
image/jpeg (0.3 < 0.5)
'text/html'
>>> request.get_preferred_type(['text/html', 'text/html;level=3']) #
expected text/html;level=3 (0.3 < 0.7)
'text/html'
>>> request.get_preferred_type(['image/jpeg', 'text/html']) # expected
image/jpeg (0.5 > 0.3)
'text/html'
>>> request.get_preferred_type(['image/jpeg', 'text/plain;format=fixed'])
# expected image/jpeg (0.5 > 0.4)
'text/plain;format=fixed'
>>> request.get_preferred_type(['text/plain;format=fixed', 'text/plain'])
# expected text/plain (0.4 < 0.7)
'text/plain;format=fixed'
>>> request.get_preferred_type(['text/plain;format=fixed', 'image/jpeg'])
# expected image/jpeg (0.4 < 0.5)
'text/plain;format=fixed'
>>> request.get_preferred_type(['text/plain;format=fixed',
'text/html;level=3']) # expected text/html;level=3 (0.4 < 0.7)
'text/plain;format=fixed'
>>> request.get_preferred_type(['text/html;level=3',
'text/plain;format=fixed']) # expected text/html;level=3 (0.7 > 0.4)
'text/plain;format=fixed'
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/36447>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion visit
https://groups.google.com/d/msgid/django-updates/01070197470e8d80-21677d4c-032e-4e8b-92c0-44715872f801-000000%40eu-central-1.amazonses.com.
