[PATCH 1/2] reset: allow "-" short hand for previous commit

[Sudhanshu Shekhar <sudshekhar02@gmail.com>]

Teach reset the same shorthand as checkout and merge. "-" means the
"previous commit".

Signed-off-by: Sudhanshu Shekhar <sudshekhar02@gmail.com>
---
 builtin/reset.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/builtin/reset.c b/builtin/reset.c
index 4c08ddc..9f8967d 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -192,6 +192,7 @@ static void parse_args(struct pathspec *pathspec,
 {
 	const char *rev = "HEAD";
 	unsigned char unused[20];
+	int substituted_minus = 0;
 	/*
 	 * Possible arguments are:
 	 *
@@ -205,6 +206,10 @@ static void parse_args(struct pathspec *pathspec,
 	 */
 
 	if (argv[0]) {
+		if(!strcmp(argv[0], "-")) {
+			argv[0] = "@{-1}";
+			substituted_minus = 1;
+		}
 		if (!strcmp(argv[0], "--")) {
 			argv++; /* reset to HEAD, possibly with paths */
 		} else if (argv[1] && !strcmp(argv[1], "--")) {
@@ -225,12 +230,14 @@ static void parse_args(struct pathspec *pathspec,
 			verify_non_filename(prefix, argv[0]);
 			rev = *argv++;
 		} else {
+			/* We were treating "-" as a commit and not a file */
+			if(substituted_minus)
+				argv[0] = "-";
 			/* Otherwise we treat this as a filename */
 			verify_filename(prefix, argv[0], 1);
 		}
 	}
 	*rev_ret = rev;
-
 	if (read_cache() < 0)
 		die(_("index file corrupt"));
 
-- 
2.3.1.168.g0c82976.dirty


>From 21f0298c17768aaa11ff0a677cdefc8f54ac9515 Mon Sep 17 00:00:00 2001
From: Sudhanshu Shekhar <sudshekhar02@gmail.com>
Date: Sun, 8 Mar 2015 02:13:57 +0530
Subject: [PATCH 2/2] Added test cases for reset -

Four test cases have been added

1) when user does reset - without any previous branch => Leads to error
2) when user does reset - with a previous branch      => Ensure it
behaves like @{-1}

Other two deal with the situation when we have a file named '-'. We
ignore such a file and - is always treated either as a previous branch
or a bad filename. Users who wish to reset a file named '-' should specify
it as './-'
---
 builtin/reset.c  |  4 ++--
 t/t7102-reset.sh | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 2 deletions(-)

diff --git a/builtin/reset.c b/builtin/reset.c
index 9f8967d..02f33ef 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -206,7 +206,7 @@ static void parse_args(struct pathspec *pathspec,
 	 */
 
 	if (argv[0]) {
-		if(!strcmp(argv[0], "-")) {
+		if (!strcmp(argv[0], "-")) {
 			argv[0] = "@{-1}";
 			substituted_minus = 1;
 		}
@@ -231,7 +231,7 @@ static void parse_args(struct pathspec *pathspec,
 			rev = *argv++;
 		} else {
 			/* We were treating "-" as a commit and not a file */
-			if(substituted_minus)
+			if (substituted_minus)
 				argv[0] = "-";
 			/* Otherwise we treat this as a filename */
 			verify_filename(prefix, argv[0], 1);
diff --git a/t/t7102-reset.sh b/t/t7102-reset.sh
index 98bcfe2..4b8d7f5 100755
--- a/t/t7102-reset.sh
+++ b/t/t7102-reset.sh
@@ -568,4 +568,66 @@ test_expect_success 'reset --mixed sets up work tree' '
 	test_cmp expect actual
 '
 
+cat > expect << EOF
+fatal: bad flag '-' used after filename
+EOF
+
+test_expect_success 'reset - with no previous branch' '
+	git init no_previous --quiet &&
+	(
+	cd no_previous
+	) &&
+	test_must_fail git reset - 2> output &&
+	test_cmp expect output
+'
+
+test_expect_success 'reset - while having file named - and no previous branch' '
+	git init no_previous --quiet &&
+	(
+	cd no_previous &&
+	touch ./-
+	) &&
+	test_must_fail git reset - 2> output &&
+	test_cmp expect output
+'
+
+cat > expect << EOF
+Unstaged changes after reset:
+M	-
+M	1
+EOF
+
+test_expect_success 'reset - in the prescence of file named - with previou branch' '
+	git init no_previous --quiet &&
+	cd no_previous &&
+	touch ./- 1 &&
+	git add 1 - &&
+	git commit -m "add base files" &&
+	git checkout -b new_branch &&
+	echo "random" > ./- &&
+	echo "wow" > 1 &&
+	git add 1 - &&
+	git reset - > output &&
+	test_cmp output ../expect
+'
+test_expect_success 'reset - works same as reset @{-1}' '
+	git init no_previous --quiet &&
+	cd no_previous &&
+	echo "random" > random &&
+	git add random &&
+	git commit -m "base commit" &&
+	git checkout -b temp &&
+	echo new-file > new-file &&
+	git add new-file &&
+	git commit -m "added new-file" &&
+	git reset - &&
+
+	git status > ../first &&
+	git add new-file &&
+	git commit -m "added new-file" &&
+	git reset @{-1} &&
+	git status > ../second &&
+	test_cmp ../first ../second
+'
+
 test_done
-- 
2.3.1.168.g0c82976.dirty