Hello,
http://xenbits.xen.org/gitweb/?p=qemu-xen.git;a=summary
looking at the tags for the 2 stable branches which are involved in the recent patch to xen.gitunifying the qemu trees.
tags:
qemu-xen-4.6.0qemu-xen-4.5.2

The revisions pointed to in the above tags are not unique and cause wrong results in git queries like:git log --pretty=oneline qemu-xen-4.5.2..HEAD | wc -l   -> 8419

 git log --pretty=oneline qemu-xen-4.6.0..HEAD | wc -l  -> 4168

the last query should eval to about 85.
In a quick browse of the web view of the repo I see the same patch commit multiple times, under different hashes.So this repo is new and still only used in staging and if there are errors there is nothing serious, not yet anyway.
Thanks for your attention,PryMar56