Merge branch 'bg/rebase-off-of-previous-branch'

* bg/rebase-off-of-previous-branch:
  rebase: allow "-" short-hand for the previous branch

git-rebase.sh

@@ -453,6 +453,10 @@ then
 		test "$fork_point" = auto && fork_point=t
 		;;
 	*)	upstream_name="$1"
+		if test "$upstream_name" = "-"
+		then
+			upstream_name="@{-1}"
+		fi
 		shift
 		;;
 	esac

t/t3400-rebase.sh

@@ -88,6 +88,23 @@ test_expect_success 'rebase from ambiguous branch name' '
 	git rebase master
 '
 
+test_expect_success 'rebase off of the previous branch using "-"' '
+	git checkout master &&
+	git checkout HEAD^ &&
+	git rebase @{-1} >expect.messages &&
+	git merge-base master HEAD >expect.forkpoint &&
+
+	git checkout master &&
+	git checkout HEAD^ &&
+	git rebase - >actual.messages &&
+	git merge-base master HEAD >actual.forkpoint &&
+
+	test_cmp expect.forkpoint actual.forkpoint &&
+	# the next one is dubious---we may want to say "-",
+	# instead of @{-1}, in the message
+	test_i18ncmp expect.messages actual.messages
+'
+
 test_expect_success 'rebase a single mode change' '
 	git checkout master &&
 	git branch -D topic &&