WP has a new image scaling feature added in WP 5.3 (https://developer.wordpress.org/reference/hooks/big_image_size_threshold/).
This feature makes that when you upload images to the media library above a certain size (Default 2560), WP will automatically scale that image, and rename the asset just uploaded by appending a
suffix.
Now, when you use these images in a Toolset Image Custom Field, the field will (after either uploading image in it directly, or inserting one already uploaded), use the "original" name (thus without "-scaled" suffix).
This, per se, is not an issue:
when using the shortcode to display the image of the Toolset field, the image will still display. But, not the "-scaled" version, instead, the full original image version.
That would be OK, however, the issue goes deeper as when you use
to get the ID of that image from the URL saved in the Toolset Image Field, you will get
returned.
That, is a real issue, because you cannot at all change the URL saved in the Toolset Image field. Even if manually editing it to use the suffixed "-scaled" image, it will immediately revert to the original image attachment url.
Steps to replicate:
1. Create an image Field with Toolset.
2. Upload a big image to this field (for example hidden link)
3. Insert that Image to your new Image Field
4. Try to convert that value saved in the field to the Attachment ID using this code:
attachment_url_to_postid( types_render_field( "image-field-slug" ) );
You will get
returned.
The right value returned however would be the ID of the attachment, which is the case as long you use the real attachment URL (which will have a "-scaled" suffixed).
So there are 2 problems surging from this bug:
1. The scaled images are not used
2. The full (original) image URL (attachment URL) produces false on attachment_url_to_postid
This was tested and confirmed on a clean fresh WP install with Toolset Types only.