Add support to turn off ofs-delta capability in Client when using LibGit2Sharp

[gsaralms]

Hi

for one of our scenarios we need that LibGit2Sharp communicates with Server without ofs-delta capability.
Is it currently possible to control capability set from LibGit2Sharp currenty?

Thanks

[gsaralms]

I just realized that this is currently not possible, but we can add this feature in libgit2 and libgit2sharp.
We can model this like a Global Setting, very much in line with SetEnableCaching(...)

@ethomson @carlosmn :
Thoughts ?

[gsaralms]

Quick update on this, I made changes in line with SetEnableCaching(...) and it seems to be working fine.
It will great if we can add that a functionality in LibGit2Sharp.
apart from solving our scenario I think it will also help Git Server developers to test without ofs_delta and also it will help testing LibGit2Sharp and LibGit2 without ofs_delta.

@ethomson @carlosmn ; Please let me know if this sounds like something which we can add to LibGit2Sharp and I will raise a PR

[ethomson]

Hi @gsaralms - this sounds like a bit of a bug to me. If your server is not sending the ofs-delta capability during negotiation, I think that we should not be sending offset deltas in a packfile.

Three questions:

1. Can you share a snippet from wireshark or something? I'd love to see the negotiation.
2. Is your server sending ofs-delta?
3. Is git itself able to communicate with your server?

[gsaralms]

Hi @ethomson

sorry looks like I was not clear with the scenario which I am trying to build

Our scenario is something like this
we have a repository cloned from some server
we want to periodically fetch the delta and parse/ look inside the delta pack file
parsing delta pack file will be a lot easier if it does not have ofs_delta objects
the only way it will not have ofs_delta objects if either the server or client does not support ofs_delta capability.
as the server is not in our control we want to limit this capability from client side (and our client is libgit2Sharp)

[ethomson]

Got it - I understand now.

Yes, this does make a certain amount of sense. Are you interested in working on a pull request for libgit2 to make this happen? I can provide some guidance if you are.

Once that is done, it should be quite easy to add the corresponding support into LibGit2Sharp.

[gsaralms]

@ethomson : will be happy to contribute 😃

I will raise a PR sometime tomorrow (for LibGit2)
my current understanding is that we will need one new option in git_libgit2_opt_t.

[gsaralms]

Raised a PR in libGit2 for the changes I am thinking of
PR Link

[gsaralms]

Hi @ethomson

we will need one PR in LibGit2Sharp to consume changes from libgit2/libgit2#4115 in LibGit2.

Query:
Any idea when will the LibGit2 nativebinaries package will be updated so that those (libgit2/libgit2#4115) changes can be consumed in LibGit2Sharp

I have tested some changes locally so will it make sense that I raise a PR for LibGit2Sharp ,
I think it will compile even with current LibGit2 consumed in LibGit2Sharp (but it will not work)