Fetch failed with "Received unexpected content-type"

[suwatch]

When fetching from a certain implementation of a git repo, we got into the issue. This works with git.exe fetch.

LibGit2Sharp.LibGit2SharpException: Received unexpected content-type
   at LibGit2Sharp.Core.Ensure.HandleError(Int32 result)
   at LibGit2Sharp.Core.Ensure.ZeroResult(Int32 result)
   at LibGit2Sharp.Core.Proxy.git_remote_fetch(RemoteSafeHandle remote, Signature signature, String logMessage)
   at LibGit2Sharp.Network.DoFetch(RemoteSafeHandle remoteHandle, FetchOptions options, Signature signature, String logMessage)
   at LibGit2Sharp.Network.Fetch(Remote remote, FetchOptions options, Signature signature, String logMessage)
   at LibGitTest.Program.Main(String[] args) in c:\temp\OneDriveTest\LibGitTest\Program.cs:line 40

I compare interaction differences below.

A normal git fetch would interact as below.

> GET /info/refs?service=git-upload-pack HTTP/1.1
< HTTP/1.1 200 OK
< Content-Length: 290
< Content-Type: application/x-git-upload-pack-advertisement

> POST /git-upload-pack HTTP/1.1
> Content-Length: 150
< HTTP/1.1 200 OK
< Content-Type: application/x-git-upload-pack-result

However this specific git server return content-type as text/plain and LibGit2Sharp failed.

> GET /d0071380/info/refs?service=git-upload-pack HTTP/1.1
< HTTP/1.1 200 OK
< Content-Length: 59
< Content-Type: text/plain; charset=UTF-8

> GET /d0071380/HEAD HTTP/1.1
< HTTP/1.1 200 OK
< Content-Length: 23
< Content-Type: text/plain; charset=UTF-8

> GET /d0071380/objects/e5/5bb491ceac5433b1189d3554f7e6ffe7d523e7 HTTP/1.1
< HTTP/1.1 200 OK
< Content-Length: 121
< Content-Type: text/plain; charset=UTF-8

> GET /d0071380/objects/8f/bbafc82747ec6ad17edf4af97cb37033760812 HTTP/1.1
< HTTP/1.1 200 OK
< Content-Length: 55
< Content-Type: text/plain; charset=UTF-8

> GET /d0071380/objects/a9/21e7e8c7a688717f21bdc73eafe19c1d77d3a5 HTTP/1.1
< HTTP/1.1 200 OK
< Content-Length: 82
< Content-Type: text/plain; charset=UTF-8

Given the client git.exe works, I believe it is an also supported protocol but Libgit2Sharp did not support it.

[nulltoken]

@suwatch Would there be some public repository where the same behavior could be reproduced?

[nulltoken]

/cc @carlosmn

[nulltoken]

BTW, are you sure that a git fetch triggers a POST /git-upload-pack?

[ethomson]

This specific server is not configured to perform smart HTTP and is instead using dumb HTTP. libgit2 does not support this, nor are there plans to. I would recommend contacting your server administrator to upgrade to something more modern.

[suwatch]

@nulltoken it is our user repository so I am not at liberty to share that. yes, it was git fetch interaction.

@ethomson thank for the explanation on smart and dumb http protocol. feel free to close the issue if no intention to support it in the future.

[carlosmn]

Dumb HTTP, where the server has no idea about Git, is not something we've ever considered implementing in libgit2. The Git protocol over HTTP came in around git 1.6 and I'd recommend using that with all of the clients.