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AccessControlAllowHeader's `iter()` might not behave properly

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
rust
Domain
networking

Research direction

Start with AccessControlAllowHeaders and its iter() implementation, then compare it with AccessControlExposeHeaders and the behavior introduced by commit 026949abc09a4fe1cc7fa3fcbbb19ff7f6e42d9f. Check the CORS and HTTP/1.1 references linked in the issue. Done means a header containing a leading comma yields the expected field-name iterator rather than an empty iterator, with matching behavior across the relevant header types.

Written by the indexing model from the issue text.

Description

According to CORS:
Access-Control-Allow-Headers: "Access-Control-Allow-Headers" ":" #field-name
You can find the definition of the construct #rule in the http1.1 rfc.

Then why calling iter() on such a header: "AccessControlAllowHeaders(",x-print") (note the comma) returns an empty iterator instead of something like "", "x-print" ?

This behavior was implemented by 026949abc09a4fe1cc7fa3fcbbb19ff7f6e42d9f but is not consistent with all the other header types having a #field-name as values (AccessControlExposeHeaders for instance).

Dominant language
Rust
Stars
200
Forks
107
PR merge metrics
No merged PRs in 30d

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