[PATCH v3 06/15] scalar: let 'unregister' handle a deleted enlistment directory gracefully

["Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

When a user deleted an enlistment manually, let's be generous and
_still_ unregister it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 contrib/scalar/scalar.c          | 46 ++++++++++++++++++++++++++++++++
 contrib/scalar/t/t9099-scalar.sh | 15 +++++++++++
 2 files changed, 61 insertions(+)

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 2b5c52a25f5..d114c038b64 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -275,6 +275,24 @@ static int cmd_register(int argc, const char **argv)
 	return register_dir();
 }
 
+static int remove_deleted_enlistment(struct strbuf *path)
+{
+	int res = 0;
+	strbuf_realpath_forgiving(path, path->buf, 1);
+
+	if (run_git("config", "--global",
+		    "--unset", "--fixed-value",
+		    "scalar.repo", path->buf, NULL) < 0)
+		res = -1;
+
+	if (run_git("config", "--global",
+		    "--unset", "--fixed-value",
+		    "maintenance.repo", path->buf, NULL) < 0)
+		res = -1;
+
+	return res;
+}
+
 static int cmd_unregister(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -288,6 +306,34 @@ static int cmd_unregister(int argc, const char **argv)
 	argc = parse_options(argc, argv, NULL, options,
 			     usage, 0);
 
+	/*
+	 * Be forgiving when the enlistment or worktree does not even exist any
+	 * longer; This can be the case if a user deleted the worktree by
+	 * mistake and _still_ wants to unregister the thing.
+	 */
+	if (argc == 1) {
+		struct strbuf src_path = STRBUF_INIT, workdir_path = STRBUF_INIT;
+
+		strbuf_addf(&src_path, "%s/src/.git", argv[0]);
+		strbuf_addf(&workdir_path, "%s/.git", argv[0]);
+		if (!is_directory(src_path.buf) && !is_directory(workdir_path.buf)) {
+			/* remove possible matching registrations */
+			int res = -1;
+
+			strbuf_strip_suffix(&src_path, "/.git");
+			res = remove_deleted_enlistment(&src_path) && res;
+
+			strbuf_strip_suffix(&workdir_path, "/.git");
+			res = remove_deleted_enlistment(&workdir_path) && res;
+
+			strbuf_release(&src_path);
+			strbuf_release(&workdir_path);
+			return res;
+		}
+		strbuf_release(&src_path);
+		strbuf_release(&workdir_path);
+	}
+
 	setup_enlistment_directory(argc, argv, usage, options, NULL);
 
 	return unregister_dir();
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 16f2b72b126..ef0e8d680d5 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -14,4 +14,19 @@ test_expect_success 'scalar shows a usage' '
 	test_expect_code 129 scalar -h
 '
 
+test_expect_success 'scalar unregister' '
+	git init vanish/src &&
+	scalar register vanish/src &&
+	git config --get --global --fixed-value \
+		maintenance.repo "$(pwd)/vanish/src" &&
+	scalar list >scalar.repos &&
+	grep -F "$(pwd)/vanish/src" scalar.repos &&
+	rm -rf vanish/src/.git &&
+	scalar unregister vanish &&
+	test_must_fail git config --get --global --fixed-value \
+		maintenance.repo "$(pwd)/vanish/src" &&
+	scalar list >scalar.repos &&
+	! grep -F "$(pwd)/vanish/src" scalar.repos
+'
+
 test_done
-- 
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