Cached template loader can return incorrect template

[Chris Lamb]

The cached.Loader's find_template method constructs a cache key based solely on the requested template name and does not include the template_dirs. This results in find_template returning the incorrect template where a template with the same template_name was previously loaded and cached from a different set of template_dirs. That is to say, the function is overly non-injective.

For example, the following snippets return the same Template. when they should return a different template for templates/foo/file.html and templates/bar/file.html respectfully:

from django.template import loader
a = loader.find_template('file.html', ('templates/foo',))
b = loader.find_template('file.html', ('templates/bar',))

Patch attached.

[Russell Keith-Magee]

(In [13295]) Fixed #13573 -- Corrected problem with template caching when template directories are provided. Thanks to lamby for the report.

[Alex Gaynor]

Calling hash() here seems like a really bad idea. I'm just waiting for someone to provide a collision...

[Russell Keith-Magee]

(In [13299]) Refs #13573 -- Modified the key technique added in r13295 to be more robust against potential key collisions while keeping key names human-readable. Thanks to Alex for being finicky.

[Jacob]

Milestone 1.3 deleted