This ensures that all thumbnail images are real uploads, and not hotlinked to another site. It also paves the way for optimising post/topic icons
A migration attempts to match existing urls to upload records. If a match cannot be found then the posts will be queued for rebake.
This has a couple of negative side effects
- Hotlinked images are now never used as thumbnails
- All thumbnails are now full-resolution original images. Previously, the URL was extracted from
cooked, which contained optimized URLs for large images.
Because of (2), I am opening this as a draft PR until we build a solution