Merge branch 'rr/rebase-sha1-by-string-query'

Allow various commit objects to be given to "git rebase" by ':/look
for this string' syntax, e.g. "git rebase --onto ':/there'".

* rr/rebase-sha1-by-string-query:
  rebase: use peel_committish() where appropriate
  sh-setup: add new peel_committish() helper
  t/rebase: add failing tests for a peculiar revision

git-rebase.sh

@@ -436,7 +436,7 @@ then
 		shift
 		;;
 	esac
-	upstream=`git rev-parse --verify "${upstream_name}^0"` ||
+	upstream=$(peel_committish "${upstream_name}") ||
 	die "$(eval_gettext "invalid upstream \$upstream_name")"
 	upstream_arg="$upstream_name"
 else
@@ -472,7 +472,7 @@ case "$onto_name" in
 	fi
 	;;
 *)
-	onto=$(git rev-parse --verify "${onto_name}^0") ||
+	onto=$(peel_committish "$onto_name") ||
 	die "$(eval_gettext "Does not point to a valid commit: \$onto_name")"
 	;;
 esac

git-sh-setup.sh

@@ -313,3 +313,15 @@ then
 	}
 	: ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}
 fi
+
+peel_committish () {
+	case "$1" in
+	:/*)
+		peeltmp=$(git rev-parse --verify "$1") &&
+		git rev-parse --verify "${peeltmp}^0"
+		;;
+	*)
+		git rev-parse --verify "${1}^0"
+		;;
+	esac
+}

t/t3400-rebase.sh

@@ -59,6 +59,17 @@ test_expect_success 'rebase against master' '
 	git rebase master
 '
 
+test_expect_success 'rebase, with <onto> and <upstream> specified as :/quuxery' '
+	test_when_finished "git branch -D torebase" &&
+	git checkout -b torebase my-topic-branch^ &&
+	upstream=$(git rev-parse ":/Add B") &&
+	onto=$(git rev-parse ":/Add A") &&
+	git rebase --onto $onto $upstream &&
+	git reset --hard my-topic-branch^ &&
+	git rebase --onto ":/Add A" ":/Add B" &&
+	git checkout my-topic-branch
+'
+
 test_expect_success 'the rebase operation should not have destroyed author information' '
 	! (git log | grep "Author:" | grep "<>")
 '

t/t3404-rebase-interactive.sh

@@ -939,4 +939,15 @@ test_expect_success 'rebase -i respects core.commentchar' '
 	test B = $(git cat-file commit HEAD^ | sed -ne \$p)
 '
 
+test_expect_success 'rebase -i, with <onto> and <upstream> specified as :/quuxery' '
+	test_when_finished "git branch -D torebase" &&
+	git checkout -b torebase branch1 &&
+	upstream=$(git rev-parse ":/J") &&
+	onto=$(git rev-parse ":/A") &&
+	git rebase --onto $onto $upstream &&
+	git reset --hard branch1 &&
+	git rebase --onto ":/A" ":/J" &&
+	git checkout branch1
+'
+
 test_done