[PATCH v2] git-rebase: Teach rebase "-" shorthand.

[Brian Gesiak <modocache@gmail.com>]

Teach rebase the same shorthand as checkout and merge; that is, that "-"
means "the branch we were previously on".

Reported-by: Tim Chase <git@tim.thechases.com>
Signed-off-by: Brian Gesiak <modocache@gmail.com>
---
 git-rebase.sh     |  4 ++++
 t/t3400-rebase.sh | 11 +++++++++++
 2 files changed, 15 insertions(+)

diff --git a/git-rebase.sh b/git-rebase.sh
index 5f6732b..2c75e9f 100755
--- a/git-rebase.sh
+++ b/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
diff --git a/t/t3400-rebase.sh b/t/t3400-rebase.sh
index 6d94b1f..6176754 100755
--- a/t/t3400-rebase.sh
+++ b/t/t3400-rebase.sh
@@ -88,6 +88,17 @@ test_expect_success 'rebase from ambiguous branch name' '
 	git rebase master
 '
 
+test_expect_success 'rebase using shorthand' '
+	git checkout master &&
+	git checkout -b shorthand HEAD^ &&
+	git rebase - 1>shorthand.stdout &&
+	git checkout master &&
+	git branch -D shorthand &&
+	git checkout -b shorthand HEAD^ &&
+	git rebase @{-1} 1>without_shorthand.stdout &&
+	test_i18ncmp without_shorthand.stdout shorthand.stdout
+'
+
 test_expect_success 'rebase a single mode change' '
 	git checkout master &&
 	git branch -D topic &&
-- 
1.8.5.2 (Apple Git-48)