The 6.x-1.x branch contains 7.x code.

The 6.x-1.x branch of syndication is a duplicate of the 7.x-1.x branch.

The master branch actually contains the 6.x-1.x code.

Either the 6.x-1.x branch should be deleted, or it should be merged with the master branch.

Here is a patch to do the merge.