From a56c8f5aab5a6ffdd687de5134883df60cc4c919 Mon Sep 17 00:00:00 2001
From: Aaron M Watson <watsona4@gmail.com>
Date: Mon, 24 Oct 2016 19:40:13 -0400
Subject: [PATCH] stash: allow stashes to be referenced by index only
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Instead of referencing "stash@{n}" explicitly, make it possible to
simply reference as "n".  Most users only reference stashes by their
position in the stash stack (what I refer to as the "index" here).

The syntax for the typical stash (stash@{n}) is slightly annoying and
easy to forget, and sometimes difficult to escape properly in a
script. Because of this the capability to do things with the stash by
simply referencing the index is desirable.

This patch includes the superior implementation provided by Ă˜sse Walle
(thanks for that), with a slight change to fix a broken test in the test
suite. I also merged the test scripts as suggested by Jeff King, and
un-wrapped the documentation as suggested by Junio Hamano.

Signed-off-by: Aaron M Watson <watsona4@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
---
 Documentation/git-stash.txt |  3 ++-
 git-stash.sh                | 15 +++++++++++++--
 t/t3903-stash.sh            | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-stash.txt b/Documentation/git-stash.txt
index 92df596e5f..2e9cef06e6 100644
--- a/Documentation/git-stash.txt
+++ b/Documentation/git-stash.txt
@@ -39,7 +39,8 @@ The latest stash you created is stored in `refs/stash`; older
 stashes are found in the reflog of this reference and can be named using
 the usual reflog syntax (e.g. `stash@{0}` is the most recently
 created stash, `stash@{1}` is the one before it, `stash@{2.hours.ago}`
-is also possible).
+is also possible). Stashes may also be referenced by specifying just the
+stash index (e.g. the integer `n` is equivalent to `stash@{n}`).
 
 OPTIONS
 -------
diff --git a/git-stash.sh b/git-stash.sh
index 90d63f293e..4546abaaef 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -384,9 +384,8 @@ parse_flags_and_rev()
 	i_tree=
 	u_tree=
 
-	REV=$(git rev-parse --no-flags --symbolic --sq "$@") || exit 1
-
 	FLAGS=
+	REV=
 	for opt
 	do
 		case "$opt" in
@@ -404,6 +403,9 @@ parse_flags_and_rev()
 					die "$(eval_gettext "unknown option: \$opt")"
 				FLAGS="${FLAGS}${FLAGS:+ }$opt"
 			;;
+			*)
+				REV="${REV}${REV:+ }'$opt'"
+			;;
 		esac
 	done
 
@@ -422,6 +424,15 @@ parse_flags_and_rev()
 		;;
 	esac
 
+	case "$1" in
+		*[!0-9]*)
+			:
+		;;
+		*)
+			set -- "${ref_stash}@{$1}"
+		;;
+	esac
+
 	REV=$(git rev-parse --symbolic --verify --quiet "$1") || {
 		reference="$1"
 		die "$(eval_gettext "\$reference is not a valid reference")"
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 2142c1fa92..e1a6ccc00c 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -131,6 +131,26 @@ test_expect_success 'drop middle stash' '
 	test 1 = $(git show HEAD:file)
 '
 
+test_expect_success 'drop middle stash by index' '
+	git reset --hard &&
+	echo 8 >file &&
+	git stash &&
+	echo 9 >file &&
+	git stash &&
+	git stash drop 1 &&
+	test 2 = $(git stash list | wc -l) &&
+	git stash apply &&
+	test 9 = $(cat file) &&
+	test 1 = $(git show :file) &&
+	test 1 = $(git show HEAD:file) &&
+	git reset --hard &&
+	git stash drop &&
+	git stash apply &&
+	test 3 = $(cat file) &&
+	test 1 = $(git show :file) &&
+	test 1 = $(git show HEAD:file)
+'
+
 test_expect_success 'stash pop' '
 	git reset --hard &&
 	git stash pop &&
@@ -604,6 +624,21 @@ test_expect_success 'invalid ref of the form stash@{n}, n >= N' '
 	git stash drop
 '
 
+test_expect_success 'invalid ref of the form "n", n >= N' '
+	git stash clear &&
+	test_must_fail git stash drop 0 &&
+	echo bar5 >file &&
+	echo bar6 >file2 &&
+	git add file2 &&
+	git stash &&
+	test_must_fail git stash drop 1 &&
+	test_must_fail git stash pop 1 &&
+	test_must_fail git stash apply 1 &&
+	test_must_fail git stash show 1 &&
+	test_must_fail git stash branch tmp 1 &&
+	git stash drop
+'
+
 test_expect_success 'stash branch should not drop the stash if the branch exists' '
 	git stash clear &&
 	echo foo >file &&