UploadPack: Verify clients send only commits for shallow lines

If a client mistakenly tries to send a tag object as a shallow line
JGit blindly assumes this is a commit and tries to parse the tag
buffer using the commit parser. This can cause an obtuse error like:

  InvalidObjectIdException: Invalid id: t c0ff331234...

The "t" comes from the "object c0ff331234..." line of the tag tring
to be parsed as though it where the "tree" line of a commit.

Run any client supplied shallow lines through the RevWalk to lookup
the object types. Fail fast with a protocol exception if any of them
are non-commit.

Skip objects not known to this repository. This matches behavior
with git-core's upload-pack, which sliently skips over any shallow
line object named by the client but not known by the server.

Change-Id: Ic6c57a90a42813164ce65c2244705fc42e84d700

1 files changed, 1 insertions, 0 deletions

diff --git a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
index 8ca3d9ae86..e2bed1873a 100644
--- a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
+++ b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
@@ -344,6 +344,7 @@ invalidPathReservedOnWindows=Invalid path (''{0}'' is reserved on Windows): {1}
 invalidReflogRevision=Invalid reflog revision: {0}
 invalidRefName=Invalid ref name: {0}
 invalidRemote=Invalid remote: {0}
+invalidShallowObject=invalid shallow object {0}, expected commit
 invalidStageForPath=Invalid stage {0} for path {1}
 invalidTagOption=Invalid tag option: {0}
 invalidTimeout=Invalid timeout: {0}