Merge branch 'mg/rebase-i-onto-reflog-in-full' into maint-1.7.11

The reflog entries left by "git rebase" and "git rebase -i" were
inconsistent (the interactive one gave an abbreviated object name).

* mg/rebase-i-onto-reflog-in-full:
  rebase -i: use full onto sha1 in reflog

Author: gitster

git-rebase--interactive.sh

@@ -548,11 +548,10 @@ do_next () {
 	test -s "$todo" && return
 
 	comment_for_reflog finish &&
-	shortonto=$(git rev-parse --short $onto) &&
 	newhead=$(git rev-parse HEAD) &&
 	case $head_name in
 	refs/*)
-		message="$GIT_REFLOG_ACTION: $head_name onto $shortonto" &&
+		message="$GIT_REFLOG_ACTION: $head_name onto $onto" &&
 		git update-ref -m "$message" $head_name $newhead $orig_head &&
 		git symbolic-ref \
 		  -m "$GIT_REFLOG_ACTION: returning to $head_name" \