[PATCH] worktree: add -z option for list subcommand

From

PWPhillip Wood <phillip.wood123@gmail.com>

Date

Jan 5, 2021, 11:02 UTC

Message-ID

<20210105110219.99610-1-phillip.wood123@gmail.com>

In-Reply-To

<428d16e8-fdb8-a587-6a0b-39c6c50eba99@gmail.com>

From: Phillip Wood <phillip.wood@dunelm.org.uk>

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
---
I found an old patch that added NUL termination. I've rebased it
but the new test fails as there seems to be another worktree thats
been added since I wrote this, anyway I thought it might be a useful
start for adding a `-z` option.

 Documentation/git-worktree.txt | 13 +++++++++---
 builtin/worktree.c             | 36 ++++++++++++++++++++++------------
 t/t2402-worktree-list.sh       | 22 +++++++++++++++++++++
 3 files changed, 56 insertions(+), 15 deletions(-)

diff --git a/Documentation/git-worktree.txt b/Documentation/git-worktree.txt
index af06128cc9..a07b593cc3 100644
--- a/Documentation/git-worktree.txt
+++ b/Documentation/git-worktree.txt
@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git worktree add' [-f] [--detach] [--checkout] [--lock] [-b <new-branch>] <path> [<commit-ish>]
-'git worktree list' [--porcelain]
+'git worktree list' [--porcelain [-z]]
 'git worktree lock' [--reason <string>] <worktree>
 'git worktree move' <worktree> <new-path>
 'git worktree prune' [-n] [-v] [--expire <expire>]
@@ -217,7 +217,13 @@ This can also be set up as the default behaviour by using the
 --porcelain::
 	With `list`, output in an easy-to-parse format for scripts.
 	This format will remain stable across Git versions and regardless of user
-	configuration.  See below for details.
+	configuration.  It is recommended to combine this with `-z`.
+	See below for details.
+
+-z::
+	When `--porcelain` is specified with `list` terminate each line with a
+	NUL rather than a newline. This makes it possible to parse the output
+	when a worktree path contains a newline character.
 
 -q::
 --quiet::
@@ -369,7 +375,8 @@ $ git worktree list
 
 Porcelain Format
 ~~~~~~~~~~~~~~~~
-The porcelain format has a line per attribute.  Attributes are listed with a
+The porcelain format has a line per attribute.  If `-z` is given then the lines
+are terminated with NUL rather than a newline.  Attributes are listed with a
 label and value separated by a single space.  Boolean attributes (like `bare`
 and `detached`) are listed as a label only, and are present only
 if the value is true.  The first attribute of a working tree is always
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 197fd24a55..0cd331873c 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -640,19 +640,25 @@ static int add(int ac, const char **av, const char *prefix)
 	return add_worktree(path, branch, &opts);
 }
 
-static void show_worktree_porcelain(struct worktree *wt)
+static void show_worktree_porcelain(struct worktree *wt, int line_terminator)
 {
-	printf("worktree %s\n", wt->path);
-	if (wt->is_bare)
-		printf("bare\n");
-	else {
-		printf("HEAD %s\n", oid_to_hex(&wt->head_oid));
-		if (wt->is_detached)
-			printf("detached\n");
-		else if (wt->head_ref)
-			printf("branch %s\n", wt->head_ref);
+	printf("worktree %s", wt->path);
+	fputc(line_terminator, stdout);
+	if (wt->is_bare) {
+		printf("bare");
+		fputc(line_terminator, stdout);
+	} else {
+		printf("HEAD %s", oid_to_hex(&wt->head_oid));
+		fputc(line_terminator, stdout);
+		if (wt->is_detached) {
+			printf("detached");
+			fputc(line_terminator, stdout);
+		} else if (wt->head_ref) {
+			printf("branch %s", wt->head_ref);
+			fputc(line_terminator, stdout);
+		}
 	}
-	printf("\n");
+	fputc(line_terminator, stdout);
 }
 
 static void show_worktree(struct worktree *wt, int path_maxlen, int abbrev_len)
@@ -720,15 +726,20 @@ static void pathsort(struct worktree **wt)
 static int list(int ac, const char **av, const char *prefix)
 {
 	int porcelain = 0;
+	int line_terminator = '\n';
 
 	struct option options[] = {
 		OPT_BOOL(0, "porcelain", &porcelain, N_("machine-readable output")),
+		OPT_SET_INT('z', NULL, &line_terminator,
+			    N_("fields are separated with NUL character"), '\0'),
 		OPT_END()
 	};
 
 	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
 	if (ac)
 		usage_with_options(worktree_usage, options);
+	else if (!line_terminator && !porcelain)
+		die(_("'-z' requires '--porcelain'"));
 	else {
 		struct worktree **worktrees = get_worktrees();
 		int path_maxlen = 0, abbrev = DEFAULT_ABBREV, i;
@@ -741,7 +752,8 @@ static int list(int ac, const char **av, const char *prefix)
 
 		for (i = 0; worktrees[i]; i++) {
 			if (porcelain)
-				show_worktree_porcelain(worktrees[i]);
+				show_worktree_porcelain(worktrees[i],
+							line_terminator);
 			else
 				show_worktree(worktrees[i], path_maxlen, abbrev);
 		}
diff --git a/t/t2402-worktree-list.sh b/t/t2402-worktree-list.sh
index 795ddca2e4..acd9f8ab84 100755
--- a/t/t2402-worktree-list.sh
+++ b/t/t2402-worktree-list.sh
@@ -71,6 +71,28 @@ test_expect_success '"list" all worktrees with locked annotation' '
 	! grep "/unlocked  *[0-9a-f].* locked$" out
 '
 
+test_expect_success '"list" all worktrees --porcelain -z' '
+	test_when_finished "rm -rf here _actual actual expect &&
+				git worktree prune" &&
+	printf "worktree %sQHEAD %sQbranch %sQQ" \
+		"$(git rev-parse --show-toplevel)" \
+		"$(git rev-parse HEAD)" \
+		"$(git symbolic-ref HEAD)" >expect &&
+	git worktree add --detach here master &&
+	printf "worktree %sQHEAD %sQdetachedQQ" \
+		"$(git -C here rev-parse --show-toplevel)" \
+		"$(git rev-parse HEAD)" >>expect &&
+	git worktree list --porcelain -z >_actual &&
+	cat _actual | tr "\0" Q >actual	&&
+	test_cmp expect actual
+'
+
+test_expect_success '"list" -z fails without --porcelain' '
+	test_when_finished "rm -rf here && git worktree prune" &&
+	git worktree add --detach here master &&
+	test_must_fail git worktree list -z
+'
+
 test_expect_success 'bare repo setup' '
 	git init --bare bare1 &&
 	echo "data" >file1 &&

-- 
2.30.0