Stack overflow in template rendering when using django.template.loaders.cached.Loader

[Anders Roos]

If you have two template files with the same name except one is prefixed with a dash '-' where one is including the other, you will get a stack overflow.

For example if the main template named example.html looks like this:

{% include '-example.html' %}

This bug is in django.template.loaders.cached.Loader and only happens if it is used.

I believe the bug is caused by the strip('-') when building the cache key at django/template/loaders/cached.py:103 (in Loader.cache_key):

    return ("%s-%s-%s" % (template_name, skip_prefix, dirs_prefix)).strip('-')

[Simon Charette]

This is a regression introduced by fc2147152637e21bc73f991b50fa06254af02739.

Using '-'.join(filter(bool, [template_name, skip_prefix, dirs_prefix])) instead should fix the issue.

[Simon Charette]

​PR

[Simon Charette <charette.s@…>]

In bd145e7:

Fixed #26536 -- Preserved leading dashes of the cached template loader keys.

Thanks Anders Roos for the report.

[Simon Charette <charette.s@…>]

In a06fa6e7:

[1.9.x] Fixed #26536 -- Preserved leading dashes of the cached template loader keys.

Thanks Anders Roos for the report.

Backport of bd145e7209a0e628cced10384bd6f62d65c0f211 from master

[Anders Roos]

Very fast fix, thank you everyone!

[Simon Charette <charette.s@…>]

In 207c5b4:

Fixed #26603 -- Forced lazy template names to text when computing cache key.

Refs #26536.

Thanks Sylvain Fankhauser for the very detailed report.

[Simon Charette <charette.s@…>]

In 6a67dce:

[1.9.x] Fixed #26603 -- Forced lazy template names to text when computing cache key.

Refs #26536.

Thanks Sylvain Fankhauser for the very detailed report.

Backport of 207c5b4acd410dd39bac31457dae26a0d15b8b93 from master