Slashes used in block templates slug is a problem on Windows

[gaft]

Generally, they are all stored flat in the theme templates or block-templates folder; we have no problem here. But when they are stored deep under some folder/s, the slug checks won't pass on Windows.

This is because finding the template paths ​https://developer.wordpress.org/reference/functions/_get_block_templates_paths return backslashes \ and https://core.trac.wordpress.org/browser/tags/6.2/src/wp-includes/block-template-utils.php#L313 currently only does substr extracts to come up with a slug that is passed to ​https://developer.wordpress.org/reference/functions/_build_block_template_result_from_file/, which eventually fails line https://core.trac.wordpress.org/browser/tags/6.2/src/wp-includes/block-template-utils.php#L981 as the slugs in the query are using forward slashes \.

[gaft]

directly to the actual check line

[gaft]

up in the unified template object

[gaft]

The fix here is just an easy str_replace. Can be either at:

1. directly to the actual check line
2. up in the unified template object

[poena]

Hi!
Can you help by providing step-by-step testing instructions for reproducing the issues?

A similar problem did occur a few years ago, but it was supposedly fixed, so if it has re-appeared it is a regression.
Context: ​https://github.com/WordPress/gutenberg/issues/20375#issuecomment-686152426

[costdev]

Hi @gaft, welcome to Trac and thanks for opening this ticket and adding patches for consideration!

In addition to reproduction steps, we also need to verify whether this behaviour can be observed in WordPress 6.1, or if a regression was introduced in WordPress 6.2.

Milestoning for 6.2.1 for visibility.

[gaft]

Hello, I am testing it now in version 6.2. Here are the quick steps to take:

1. Create a page and assign to a custom template

wp_insert_post([
    'post_status' => 'publish',
    'post_type' => 'page',
    'post_title' => 'Custom Template Page',
    'meta_input' => [
        '_wp_page_template' => 'deep/folder/test',
    ],
]);

2. Add a template file named test.html in the theme under templates/deep/folder

custom-theme/
├── parts/
├── templates/
│   ├── deep/
│   │   └── folder/
│   │       └── test.html
│   ├── 404.html
│   ├── index.html
│   └── page.html
├── screenshot.png
├── styles.css
└── theme.json

3. View the page at /custom-template-page/

Currently, it only renders the templates/page.html because https://core.trac.wordpress.org/browser/tags/6.2/src/wp-includes/block-template-utils.php#L981 evaluates to false

[gaft]

screenshot of debug

[davidbaumwald]

I haven't spent too much time tracing this, but I think wp_normalize_path would probably be a better fix than strpos. I am exactly not sure where the fix would be, but I feel like it's higher up the chain than the current patch places it. I'm thinking perhaps the paths should be normalized in _get_block_templates_files, but not 100% sure.

This looks like it might be [52062] that introduced the _get_block_templates_files code, while [52247] abstracted the base paths into get_block_theme_folders.

[gaft]

I totally agree that wp_normalize_path is a more robust function to use here. Also, I think it is best handled in _get_block_templates_files where it can be useful elsewhere that expects slug to be in forward slashes.

[gaft]

using wp_normalize_path to fix

[gaft]

screenshot with wp_normalize_path

[audrasjb]

Patch 58132-3.diff looks good, but we need to add some unit tests for this case.

[jeremyfelt]

Partially related: ​https://github.com/WordPress/gutenberg/issues/49100

Or—once this ticket is resolved, there may still be issues when trying to use / in template IDs due to _sanitize_template_id().

[audrasjb]

Since WordPress 6.2.1 Release candidate 1 is planned today, let's move this ticket to 6.2.2 to give it more time to add unit test cases and proper testing.

[desrosj]

Moving this to 6.2.3.

This PR adds the changes suggested by ​@gaft + a single PHP Unit test

Trac ticket: https://core.trac.wordpress.org/ticket/58132

[soulseekah]

Hi @gaft, welcome to Trac and thanks for opening this ticket and adding patches for consideration!

I believe that this patch would actually break things on Windows and should not be committed.

When picking a template through the UI on Windows the _wp_page_template meta is saved with backslashes. The query works fine. If we suddenly rewrite all slugs from backslashes to forward ones the query will stop working. In order for this to work, you will need to further change the _wp_page_template meta value throughout the database as well!

The only way the reported bug can be reproduced is when saving the template to a page on Windows, then moving the whole site onto Linux (or the other way around). That's when slugs start mismatching.

Your suggested steps to reproduce the issue further follow the above case. You are setting the meta value to a Linux-style slug and hoping it to work on Windows. Your slug would have been correct if you saved it via the UI.

The best course in addressing this edge case where we've migrated from Windows to Linux or the other way around would be to actually check BOTH versions of the slug slashes (using a preg_match maybe?). This way, no matter what direction the slashes are looking in _wp_page_template it would always match.

[SergeyBiryukov]

Moving to 6.4 for now, as there are no plans for 6.2.3 at this time, and this does not appear to be a regression in 6.3.

[nicolefurlan]

@gaft could you read through the latest updates in this ticket and provide feedback so that we can keep this ticket moving forward?

We also need some updated testing instructions if anyone is able to provide them.

@SergeyBiryukov are you able to test this in a Windows environment? We need more Windows specific contributors to reproduce, test the patch, and weigh into the discussion.

Thank you!

[oglekler]

This ticket was discussed during bug scrub.

This patch needs testing. Testing info: #comment:4

Add props: @mukesh27

[hellofromTonya]

This ticket was discussed today in pre-RC1 bug scrub.

In reviewing, I had some thoughts and questions.

• On the proposed patch / PR:

Rather than normalizing after the skip checks, likely need to normalize the slug for both of the skip checks, i.e. normalize just after the $template_slug is built.

• What is the impact elsewhere?

How will normalizing in this function impact where the template slug is used elsewhere? Are there impacts or side effects elsewhere?

• Next steps towards resolution.

Maybe moving it to Gutenberg could help move it forward? Or folks working on the templates could take a look here to share insights to the above questions.

Given the questions combined with 6.4 RC1 happening in 6 days, I don't think there's enough time left in the 6.4 cycle.

If the questions get answered and there's confidence from maintainers / leads / committers the fix will not cause impacts elsewhere, then please move it back into the milestone for consideration.