Why does curl CLI strip a trailing ? and it can't be disabled?

[llimllib]

As far as I can tell, it's legal by spec to send and act on a trailing ?; it's a present but empty query component¹. The curl CLI strips it, however:

$ /opt/homebrew/Cellar/curl/8.20.0/bin/curl -sv 'https://httpbingo.org/?' 2>&1 | grep :path   
* [HTTP/2] [1] [:path: /]

This appears to have been introduced in release 8.8.0 in commit 3eac21d, and there's no easy way to disable it. The agent suggested as a workaround:

$ curl -v --request-target '/get?' 'https://httpbingo.org/get?' 2>&1 | grep :path
* [HTTP/2] [1] [:path: /get?]

Which works, but is awkward.

My question is, why does curl strip a trailing ? by default? As a user I find it to be surprising behavior.

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¹: I know I am not a spec expert, so if I'm mistaken here I will be happy to be corrected

[llimllib]

okay so some people have dug into this in the past.

This person filed an issue on requests: psf/requests#2912

• They declined to implement it

and on go: golang/go#13488

• Initially declined, then course reversed and they implemented it

Somebody asked on stack overflow, which is probably where the agent's answer came from: https://superuser.com/questions/1929792/how-do-i-pass-question-marks-to-server-when-newer-curl-8-11-1-strips-questio

[bagder]

See #21584

[llimllib]

Thank you!