RevCommit toRevCommit = walk.lookupCommit(toObjectId);
walk.markStart(toRevCommit);
RevCommit fromRevCommit = walk.lookupCommit(fromObjectId);
walk.markUninteresting(fromRevCommit);
RevCommit next = walk.next();
walk.reset();
walk.setRevFilter(RevFilter.ALL);
aheadCount = RevWalkUtils.count(walk, toRevCommit, next);
behindCount = RevWalkUtils.count(walk, fromRevCommit, next);
toObjectId = next.toObjectId();
fromObjectId = null;