Curl tool not following "retry-after" header for redirect request #11447
Description
As per HTTP standard (https://www.rfc-editor.org/rfc/rfc9110#field.retry-after):
Servers send the "Retry-After" header field to indicate how long the user agent ought to wait before making a follow-up request. When sent with a 503 (Service Unavailable) response, Retry-After indicates how long the service is expected to be unavailable to the client. When sent with any 3xx (Redirection) response, Retry-After indicates the minimum time that the user agent is asked to wait before issuing the redirected request.
Currently, curl respect the retry-after only for transient error conditions. Per documentation: Transient error means either: a timeout, an FTP 4xx response code or an HTTP 408, 429, 500, 502, 503 or 504 response code
The specific use case is to allow "curl" to follow "retry-after" when fetching API responses for time-consuming operation. The server can redirect the request to same URL, advertising a time when results may be expected. I'm using CURL to retrieve result for long-running calculation, via REST interface, where the server is using 303 with retry-after to implement retries, with backoff logic, based on the progress of the calculation.
Given that curl automatically respect retry-after for error condition - make sense to have this behavior by default (with command line options to override).
Tested with curl 7.29 - I do not have access to newer curl, but per documentation behavior in 8.X is the same as 7.66, when support was added to follow retry-after for error conditions.