alpha.txt

* When an object is corrupt in a pack, the object became unusable even
  when the same object is available in a loose form,  We now try harder to
  fall back to these redundant objects when able.  In particular, "git
  repack -a -f" can be used to fix such a corruption as long as necessary
  objects are available.

beta.txt

We used to prevent sample hook scripts shipped in templates/ from
triggering by default by relying on the fact that we install them as
unexecutable, but on some filesystems, this approach does not work.
They are now shipped with ".sample" suffix.  If you want to activate
any of these samples as-is, rename them to drop the ".sample" suffix,
instead of running "chmod +x" on them.  For example, you can rename
hooks/post-update.sample to hooks/post-update to enable the sample
hook that runs update-server-info, in order to make repositories
friendly to dumb protocols (i.e. HTTP).