Symfony version(s) affected

7.4, 7.3, most likely earlier versions as well (did not check, but I doubt that valid behavior was broken later on)

Description

The mentioned method is "loosing" important negotiation information when there is more than one accepted type given with different additional attributes/parameters. Think of text/plain;format=flowed and text/plain;format=fixed;q=0.4 (example from RFC9110, https://www.rfc-editor.org/rfc/rfc9110.html#name-accept). AcceptHeader::fromString() will contain solely text/plain;format=fixed;q=0.4 and forget/ignore text/plain;format=flowed with its quality of 1.0 (fallback value if not specified).

The reason for that is that internally, the AcceptHeader::add() method is using solely $item->getValue() as the array key of AcceptHeaderItems added, ignoring any other attributes. So the last "value" overwrites all others.

Fixing that might lead to a BC break potentially, as the behavior would change for such cases. But as it seems that this issue has not been raised before, the question is if it still could/should be fixed? Also the aspect of "Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies to a given type, the most specific reference has precedence." would be needed to be taken into account 🤔

How to reproduce

I've copied some example Accept headers from the related RFC9110 and its predecessor RFC7231 into the available unit tests in a created branch: 7.4...andesk:symfony:bug-reproduction/accept-header-from-string The misalignment should be visible with the according tests breaking.

Possible Solution

Creating a different array key appending attribute key+value pairs to its string representation somehow to avoid overriding existing value expectations for other attribute combinations.

Additional Context

No response