Uploading a large image through the block editor fails

[azaozz]

Seems the new functionality to retry post-processing is triggered correctly but the new REST API end point post-process always returns a 404 error.

[azaozz]

Testing in both trunk and the 5.3 branch, requests to wp/v2/media/12345/post-process?_locale=user and to wp/v2/media/12345?force=true&_locale=user with X-HTTP-Method-Override: DELETE are 404.

Discussion in Slack: ​https://wordpress.slack.com/archives/C02RQC26G/p1573246877137300.

[azaozz]

In 48542.diff: move wp.apiFetch.createRootURLMiddleware() before wp.apiFetch.use( wp.apiFetch.mediaUploadMiddleware ); as suggested on Slack: ​https://wordpress.slack.com/archives/C02RQC26G/p1573247239138300.

The alternative solution of doing apiFetch() instead of next() in /middlewares/media-upload.js seems perhaps riskier change at this point.

Thanks @mikeschroder, @TimothyBlynJacobs, and @epiqueras for looking at this asap :)

[azaozz]

I know this is somewhat hard to test/trigger the retry requests. Here's an image that may do it: ​https://upload.wikimedia.org/wikipedia/commons/f/ff/Pizigani_1367_Chart_10MB.jpg

To test: download that image, then drop it in a new "image" block in the block editor (make sure the Gutenberg plugin is not installed or is disabled), and watch the network tab in the browser tools.

As this is a "high density" 10MB JPEG image it fails to get post-processed on the initial request on my test server, even with the default sub-sizes and PHP settings. Alternatively few more large sub-sizes may need to be added or the max_execution_time=30 setting in php.ini may need to be reduced for this test.

[johnbillion]

I reproduced the issue with the Pizigani_1367_Chart_10MB.jpg image locally and saw the Media upload failed error message due to a 500 response from wp-json/wp/v2/media?_locale=user and the successive 404s from wp/v2/media/141/post-process?_locale=user.

After applying 48542.diff​, the request to wp-json/wp/v2/media?_locale=user still returns a 500 as expected, but the subsequent request to wp-json/wp/v2/media?_locale=user now uses the correct URL and returns a 200. The image appears as expected and the image sizes are all generated correctly.

I'm unable to assess whether the fix is a technically good one, but I can confirm that it fixes the issue.

[youknowriad]

I'd say that the best solution would be to ensure the media middleware is independent of the root URL middleware by using the full URL there too. I think landing the currently proposed core patch is a good change regardless.

LGTM 👍

[SergeyBiryukov]

Marking for commit, per the above comments.

[SergeyBiryukov]

In 46703:

Script Loader: In wp_default_packages_inline_scripts(), make sure the root URL middleware is registered before using the media middleware.

This allows for requests to retry post-processing large images using the post-process REST API endpoint to work as expected.

Props azaozz, mikeschroder, TimothyBlynJacobs, epiqueras, johnbillion, youknowriad.
Fixes #48542.

[SergeyBiryukov]

In 46704:

Script Loader: In wp_default_packages_inline_scripts(), make sure the root URL middleware is registered before using the media middleware.

This allows for requests to retry post-processing large images using the post-process REST API endpoint to work as expected.

Reviewed by johnbillion, youknowriad, SergeyBiryukov.
Props azaozz, mikeschroder, TimothyBlynJacobs, epiqueras, johnbillion, youknowriad.
Merges [46703] to the 5.3 branch.
Fixes #48542.