Re: [PATCH] remote-curl: Use auth for probe_rpc() requests too

>If a large request requires post_rpc() to call probe_rpc(), the latter
>does not use the authorization credentials used for other requests. If
>this fails with an HTTP 401 error and http_auth.multistage isn't set,
>then the whole request just fails.
>
>For example, using git-credential-msal [1], the following attempt to clone a
>large repository fails partway through because the initial request to download
>the commit history and promisor packs succeeds, but the
>subsequent request to download the blobs needed to construct the working
>tree fails with a 401 error and the checkout fails.
>
>(lines removed for brevity)
>
>  git clone --filter=blob:none https://secure-server.example/repo
>  11:03:26.855369 git.c:502               trace: built-in: git clone --filter=blob:none https://secure-server.example/repo
>  Cloning into 'sw'...
>  warning: templates not found in /home/aaron/share/git-core/templates
>  11:03:26.857169 run-command.c:673       trace: run_command: git remote-https origin https://secure-server.example/repo
>  11:03:27.012104 http.c:849              => Send header: GET repo/info/refs?service=git-upload-pack HTTP/1.1
>  11:03:27.049243 http.c:849              <= Recv header: HTTP/1.1 401 Unauthorized
>  11:03:27.049270 http.c:849              <= Recv header: WWW-Authenticate: Bearer error="invalid_request", error_description="No bearer token found in the request", msal-tenant-id="<tenant>", msal-client-id="<client>"
>  11:03:27.053786 run-command.c:673       trace: run_command: 'git credential-msal get'
>  11:03:27.952830 http.c:849              => Send header: GET repo/info/refs?service=git-upload-pack HTTP/1.1
>  11:03:27.952849 http.c:849              => Send header: Authorization: Bearer <redacted>
>  11:03:27.995419 http.c:849              <= Recv header: HTTP/1.1 200 OK
>  11:03:28.230039 http.c:890              == Info: Reusing existing https: connection with host secure-server.example
>  11:03:28.230208 http.c:849              => Send header: POST repo/git-upload-pack HTTP/1.1
>  11:03:28.230216 http.c:849              => Send header: Content-Type: application/x-git-upload-pack-request
>  11:03:28.230221 http.c:849              => Send header: Authorization: Bearer <redacted>
>  11:03:28.269085 http.c:849              <= Recv header: HTTP/1.1 200 OK
>  11:03:28.684163 http.c:890              == Info: Reusing existing https: connection with host secure-server.example
>  11:03:28.684379 http.c:849              => Send header: POST repo/git-upload-pack HTTP/1.1
>  11:03:28.684391 http.c:849              => Send header: Accept: application/x-git-upload-pack-result
>  11:03:28.684393 http.c:849              => Send header: Authorization: Bearer <redacted>
>  11:03:28.869546 run-command.c:673       trace: run_command: git index-pack --stdin --fix-thin '--keep=fetch-pack 43856 on dgx-spark' --promisor
>  11:06:39.861237 run-command.c:673       trace: run_command: git -c fetch.negotiationAlgorithm=noop fetch origin --no-tags --no-write-fetch-head --recurse-submodules=no --filter=blob:none --stdin
>  11:06:39.865981 run-command.c:673       trace: run_command: git remote-https origin https://secure-server.example/repo
>  11:06:39.868039 run-command.c:673       trace: run_command: git-remote-https origin https://secure-server.example/repo
>  11:07:30.412575 http.c:849              => Send header: GET repo/info/refs?service=git-upload-pack HTTP/1.1
>  11:07:30.456285 http.c:849              <= Recv header: HTTP/1.1 401 Unauthorized
>  11:07:30.456318 http.c:849              <= Recv header: WWW-Authenticate: Bearer error="invalid_request", error_description="No bearer token found in the request", msal-tenant-id="<tenant>", msal-client-id="<client>"
>  11:07:30.456439 run-command.c:673       trace: run_command: 'git credential-cache get'
>  11:07:30.461266 http.c:849              => Send header: GET repo/info/refs?service=git-upload-pack HTTP/1.1
>  11:07:30.461282 http.c:849              => Send header: Authorization: Bearer <redacted>
>  11:07:30.501628 http.c:849              <= Recv header: HTTP/1.1 200 OK
>  11:07:34.725262 http.c:849              => Send header: POST repo/git-upload-pack HTTP/1.1
>  11:07:34.725279 http.c:849              => Send header: Content-Type: application/x-git-upload-pack-request
>  11:07:34.761407 http.c:849              <= Recv header: HTTP/1.1 401 Unauthorized
>  11:07:34.761443 http.c:890              == Info: Bearer authentication problem, ignoring.
>  11:07:34.761453 http.c:849              <= Recv header: WWW-Authenticate: Bearer error="invalid_request", error_description="No bearer token found in the request", msal-tenant-id="<tenant>", msal-client-id="<client>"
>  11:07:34.761509 http.c:890              == Info: The requested URL returned error: 401
>  11:07:34.761530 http.c:890              == Info: closing connection #0
>  11:07:34.761913 run-command.c:673       trace: run_command: 'git credential-cache erase'
>  11:07:34.761927 run-command.c:765       trace: start_command: /bin/sh -c 'git credential-cache erase' 'git credential-cache erase'
>  11:07:34.768069 git.c:502               trace: built-in: git credential-cache erase
>  11:07:34.768690 run-command.c:673       trace: run_command: 'git credential-msal erase'
>  11:07:34.768713 run-command.c:765       trace: start_command: /bin/sh -c 'git credential-msal erase' 'git credential-msal erase'
>  11:07:34.772742 git.c:808               trace: exec: git-credential-msal erase
>  11:07:34.772783 run-command.c:673       trace: run_command: git-credential-msal erase
>  11:07:34.772819 run-command.c:765       trace: start_command: /usr/bin/git-credential-msal erase
>  error: RPC failed; HTTP 401 curl 22 The requested URL returned error: 401
>  fatal: unable to write request to remote: Broken pipe
>  fatal: could not fetch c4fff0229c9be06ecf576356a4d39a8a755b8d81 from promisor remote
>  warning: Clone succeeded, but checkout failed.
>  You can inspect what was checked out with 'git status'
>  and retry with 'git restore --source=HEAD :/'
>
>Fix the immediate problem by including the authorization headers in the
>probe_rpc() request as well.
>
>Signed-off-by: Aaron Plattner <aplattner@nvidia.com>