Issue #3616491 by luigisa: Avoid a protocol-relative image style URL when the...

Luisrequested to merge
issue/flysystem-3616491:3616491-getexternalurl-returns-a into 3.0.x

Issue #3616491 by luigisa: Avoid a protocol-relative image style URL when the public directory path is empty.

getPublicDirectoryPath() returns '' (not NULL) for a bare CDN domain. Joining with '/' on both sides produced '//styles/...', which browsers treat as protocol-relative after file_url_transform_relative() strips the base.

Closes #3616491

Merge request reports