Those shorthands are explained in the rev-parse documentation but were not

actually supported by rev-parse itself.
Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>

---

 builtin-rev-parse.c          |   32 ++++++++++++++++++++++++++++++++

 t/t6101-rev-parse-parents.sh |    2 ++

 2 files changed, 34 insertions(+), 0 deletions(-)
diff --git a/builtin-rev-parse.c b/builtin-rev-parse.c

index aa71f4a..9aa049e 100644

--- a/builtin-rev-parse.c

+++ b/builtin-rev-parse.c

@@ -241,6 +241,36 @@ static int try_difference(const char *arg)

 	return 0;

 }
+static int try_parent_shorthands(const char *arg)

+{

+	char *dotdot;

+	unsigned char sha1[20];

+	struct commit *commit;

+	struct commit_list *parents;

+	int parents_only;

+

+	if ((dotdot = strstr(arg, "^!")))

+		parents_only = 0;

+	else if ((dotdot = strstr(arg, "^@")))

+		parents_only = 1;

+

+	if (!dotdot || dotdot[2])

+		return 0;

+

+	*dotdot = 0;

+	if (get_sha1(arg, sha1))

+		return 0;

+

+	if (!parents_only)

+		show_rev(NORMAL, sha1, arg);

+	commit = lookup_commit_reference(sha1);

+	for (parents = commit->parents; parents; parents = parents->next)

+		show_rev(parents_only ? NORMAL : REVERSED,

+				parents->item->object.sha1, arg);

+

+	return 1;

+}

+

 static int parseopt_dump(const struct option *o, const char *arg, int unset)

 {

 	struct strbuf *parsed = o->value;

@@ -573,6 +603,8 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)

 		/* Not a flag argument */

 		if (try_difference(arg))

 			continue;

+		if (try_parent_shorthands(arg))

+			continue;

 		name = arg;

 		type = NORMAL;

 		if (*arg == '^') {

diff --git a/t/t6101-rev-parse-parents.sh b/t/t6101-rev-parse-parents.sh

index efc8313..919552a 100755

--- a/t/t6101-rev-parse-parents.sh

+++ b/t/t6101-rev-parse-parents.sh

@@ -28,6 +28,8 @@ test_expect_success 'final^1^2 != final^1^1' "test $(git rev-parse final^1^2) !=

 test_expect_success 'final^1^3 not valid' "if git rev-parse --verify final^1^3; then false; el...
[ message continues ]

Ah crap, forgot to say that I wrote this because I wanted gitk to

support the ^! syntax and that uses rev-parse to parse its revision

arguments. My use-case with gitk is to quickly verify a bunch of grafts

I used to fixup the history in a git-svn repo.
Björn

--