http.schannelCheckRevoke=false ignored when using HTTP proxy in 2.55.0.windows.3 (works in 2.53.0.windows.4)

[FeidongAlbert]

Existing issues matching what you're seeing

• I was not able to find an open or closed issue matching what I'm seeing
  (closest: CERT_TRUST_REVOCATION_STATUS_UNKNOWN with Git 2.41.0.windows.1 #4467 — same error class, but that report did not test schannelCheckRevoke=false; this report is specifically that the config value itself stopped working)

Git for Windows version

git version 2.55.0.windows.3   # FAILS
git version 2.53.0.windows.4   # WORKS (GitHub Desktop embedded git, same machine, same ~/.gitconfig)

Windows version

Windows 11 (build 26200), x86_64

Details

Setup: http.sslBackend=schannel (system default), global config contains:

[http "https://github.com/"]
    schannelcheckrevoke = false
    proxy = http://127.0.0.1:26561   # local HTTP proxy (CONNECT tunnel), removed later, see below

Symptom (2.55.0.windows.3, clone/fetch through the HTTP proxy):

fatal: unable to access 'https://github.com/USER/REPO.git/':
schannel: next InitializeSecurityContext failed: CRYPT_E_NO_REVOCATION_CHECK (0x80092012)

A/B tests, same machine / same proxy / same ~/.gitconfig:

git build	proxy + schannelCheckRevoke=false	result
2.55.0.windows.3 (system)	yes (global URL-scoped)	❌ CRYPT_E_NO_REVOCATION_CHECK
2.55.0.windows.3	yes (-c http.schannelCheckRevoke=false inline)	❌ same error
2.53.0.windows.4 (Desktop embedded)	yes (reads the same ~/.gitconfig)	✅ clone succeeds
2.55.0.windows.3	direct connection, no proxy	✅ clone succeeds

Additional data points:

• curl --ssl-no-revoke against the same proxy works, so the proxy path itself is functional and the failure is the revocation check that schannelCheckRevoke=false should suppress.
• The openssl backend through the same proxy fails with unable to get local issuer certificate (proxy path does not send intermediate certs; unrelated to this report but listed for completeness).
• I also tried CURL_SSL_NO_REVOKE=1 — ignored by git's libcurl, as expected per docs.

Expected: http.schannelCheckRevoke=false should disable the schannel revocation check regardless of proxy usage, per documentation ("Used to enforce or disable certificate revocation checks in cURL when http.sslBackend is set to schannel").

Actual: In 2.55.0.windows.3 the option appears to be ignored on the proxy path (the revocation check runs and fails). The identical configuration works on 2.53.0.windows.4, which suggests a regression introduced between these builds.

Workaround currently in use

Direct connection (no proxy) works on 2.55.0.windows.3, so I pinned the workaround to network topology rather than the config value. Downgrading the standalone installation to 2.53.0.windows.4 also resolves it.