From 2ed5c8e174dae73459df11386dc83e8ef4154e3f Mon Sep 17 00:00:00 2001
From: Sebastian Staudt <koraktor@gmail.com>
Date: Sun, 3 Feb 2019 07:00:24 +0100
Subject: [PATCH] describe: setup working tree for --dirty
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We don't use NEED_WORK_TREE when running the git-describe builtin,
since you should be able to describe a commit even in a bare repository.
However, the --dirty flag does need a working tree. Since we don't call
setup_work_tree(), it uses whatever directory we happen to be in. That's
unlikely to match our index, meaning we'd say "dirty" even when the real
working tree is clean.

We can fix that by calling setup_work_tree() once we know that the user
has asked for --dirty.

The --broken option also needs a working tree. But because its
implementation calls git-diff-index we don‘t have to setup the working
tree in the git-describe process.

Signed-off-by: Sebastian Staudt <koraktor@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/describe.c  |  1 +
 t/t6120-describe.sh | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/builtin/describe.c b/builtin/describe.c
index cf1ae77d7c..d281dff2b3 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -617,6 +617,7 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			struct argv_array args = ARGV_ARRAY_INIT;
 			int fd, result;
 
+			setup_work_tree();
 			read_cache_preload(NULL);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index 84dd1cb690..7da57db17d 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -146,14 +146,38 @@ check_describe A-* HEAD
 
 check_describe "A-*[0-9a-f]" --dirty
 
+test_expect_success 'describe --dirty with --work-tree' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
+	) &&
+	grep "^A-[1-9][0-9]\?-g[0-9a-f]\+$" out
+'
+
 test_expect_success 'set-up dirty work tree' '
 	echo >>file
 '
 
 check_describe "A-*[0-9a-f]-dirty" --dirty
 
+test_expect_success 'describe --dirty with --work-tree (dirty)' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
+	) &&
+	grep "^A-[1-9][0-9]\?-g[0-9a-f]\+-dirty$" out
+'
+
 check_describe "A-*[0-9a-f].mod" --dirty=.mod
 
+test_expect_success 'describe --dirty=.mod with --work-tree (dirty)' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty=.mod >"$TRASH_DIRECTORY/out"
+	) &&
+	grep "^A-[1-9][0-9]\?-g[0-9a-f]\+.mod$" out
+'
+
 test_expect_success 'describe --dirty HEAD' '
 	test_must_fail git describe --dirty HEAD
 '
@@ -304,8 +328,17 @@ test_expect_success 'describe chokes on severely broken submodules' '
 	mv .git/modules/sub1/ .git/modules/sub_moved &&
 	test_must_fail git describe --dirty
 '
+
 test_expect_success 'describe ignoring a broken submodule' '
 	git describe --broken >out &&
+	grep broken out
+'
+
+test_expect_success 'describe with --work-tree ignoring a broken submodule' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --broken >"$TRASH_DIRECTORY/out"
+	) &&
 	test_when_finished "mv .git/modules/sub_moved .git/modules/sub1" &&
 	grep broken out
 '