WP_Embed cache broken if post content is empty

[rasmusbe]

Steps to reproduce:

1. Create a post with empty post content and a metafield containing a Youtube link
2. Run apply_filters('the_content', $meta_field_content);

Expected result:
Youtube-embed code

Actual result:
Youtube link (not embed)

Possible cause:
Invalid if-state on line 221 in class-wp-embed.php
Should be $this->usecache && $cached_recentlynot $this->usecache || $cached_recently

[swissspidy]

See #37597 on why this line is intentional.

[ocean90]

Duplicate of #37597.

Hello @rasmusbe, thanks for your report.

This is by design, see ticket:37597:2 for the reasoning.