Add script which can fix the broken commits in this repository

Note the resulting hashes are (of course) different.

fix-broken-commits.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+
+# xen-api-libs fails a "git fsck" because it has bad author and committer
+# email addresses of the form:
+export BAD='Jonathan.Ludlam@eu.citrix.com <Jon Ludlam <Jonathan.Ludlam@eu.citrix.com'
+
+git filter-branch -f --commit-filter '
+  echo "id = $GIT_COMMIT committer date = $GIT_COMMITTER_DATE" >> /tmp/foo
+  echo "id = $GIT_COMMIT author date = $GIT_AUTHOR_DATE" >> /tmp/foo
+  echo "id = $GIT_COMMIT committer email = \"$GIT_COMMITTER_EMAIL\"" >> /tmp/foo
+  echo "id = $GIT_COMMIT author email    = \"$GIT_AUTHOR_EMAIL\"" >> /tmp/foo
+  if [ "${GIT_COMMITTER_EMAIL}" = "${BAD}" ]
+  then
+     export GIT_COMMITTER_NAME="Jonathan Ludlam"
+     export GIT_AUTHOR_NAME="Jonathan Ludlam"
+     export GIT_COMMITTER_EMAIL="Jonathan.Ludlam@eu.citrix.com"
+     export GIT_AUTHOR_EMAIL="Jonathan.Ludlam@eu.citrix.com"
+     echo Rewrote >> /tmp/foo
+  fi
+  git commit-tree "$@";
+' --tag-name-filter cat -- --all
+
+rm -rf .git/refs/original/ && git reflog expire --all &&  git gc --aggressive --prune