could not get blob from packfiles

[vvatanabe]

fixes by #1149

First, I updated the test case to reproduce the problem, and I will add a patch to fix this problem.

[vvatanabe]

This problem was reproduced a build below.
https://travis-ci.org/src-d/go-git/builds/533637111

[vvatanabe]

Fixed, plz chk it.

[mcuadros]

If I am not wrong the .tmp files are files to ignore, are you sure that git is reading this files?

[vvatanabe]

Yes. We provide Git hosting service and tried go-git experimentally.

When git gc did not complete successfully on bare repository, .tmp_xxx.pack remained. And when using func (r *Repository) BlobObject(h plumbing.Hash) (*object.Blob, error) to get a packed blob read .tmp_xxx.pack internally and occured a error by to get a wrong hash.

[jfontan]

@mcuadros this fix makes it skip dangling tmp files that is the correct behavior.

[filipnavara]

Related: #1223. As I mentioned in #1149 (comment) the logic that GIT uses is actually different. I don't think the .tmp files should be ignored but the objects/info/packs file should be consulted.

[mcuadros]

Merged in go-git/go-git#6

[saracen]

@mcuadros Super happy to see go-git continuing! I only found out it'd moved from this PR. The new repository mentions there was some legal issues - are you able to post a little about that somewhere and maybe post to r/golang about where the project has now landed?

EDIT: Thank you!