Error when reading commits for some git repositories

[davidfowl]

Repro steps:

1. clone this project (libgit2) locally
2. Write the following code:

var r = new Repository(@"C:\dev\github\libgit2sharp\.git");
foreach (var c in r.Commits.ToList()) {
    Console.WriteLine(c);
}

It blows up with:

Unhandled Exception: System.ApplicationException: An error was raised by libgit2
. Error code = GIT_EOBJCORRUPTED (-28).
An error occured
   at LibGit2Sharp.Core.Ensure.Success(Int32 result, Boolean allowPositiveResult
)
   at LibGit2Sharp.Repository.Lookup(ObjectId id, GitObjectType type)
   at LibGit2Sharp.RepositoryExtensions.Lookup[T](Repository repository, ObjectI
d id)
   at LibGit2Sharp.CommitCollection.CommitEnumerator.get_Current()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)

[nulltoken]

@davidfowl a ticket (#278) has been opened in libgit2 issue tracker

[nulltoken]

Temporay fix pushed up on the nulltoken/vNext branch.

Final fix requires a full rewriting of the signature parsing in order to make it more tolerant/relaxed. Thanks to @schu, this may be happening sooner than later.

[nulltoken]

see libgit2 PR #293

[nulltoken]

Merged in LibGit2Sharp/vNext