[PATCH 23/32] checkout: clean up half-prepared directories in --to mode

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 builtin/checkout.c     | 54 ++++++++++++++++++++++++++++++++++++++++++++++++--
 t/t2025-checkout-to.sh |  6 ++++++
 2 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 6373823..4ae925a 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -20,6 +20,7 @@
 #include "resolve-undo.h"
 #include "submodule.h"
 #include "argv-array.h"
+#include "sigchain.h"
 
 static const char * const checkout_usage[] = {
 	N_("git checkout [options] <branch>"),
@@ -814,6 +815,35 @@ static int switch_branches(const struct checkout_opts *opts,
 	return ret || writeout_error;
 }
 
+static char *junk_work_tree;
+static char *junk_git_dir;
+static int is_junk;
+static pid_t junk_pid;
+
+static void remove_junk(void)
+{
+	struct strbuf sb = STRBUF_INIT;
+	if (!is_junk || getpid() != junk_pid)
+		return;
+	if (junk_git_dir) {
+		strbuf_addstr(&sb, junk_git_dir);
+		remove_dir_recursively(&sb, 0);
+		strbuf_reset(&sb);
+	}
+	if (junk_work_tree) {
+		strbuf_addstr(&sb, junk_work_tree);
+		remove_dir_recursively(&sb, 0);
+	}
+	strbuf_release(&sb);
+}
+
+static void remove_junk_on_signal(int signo)
+{
+	remove_junk();
+	sigchain_pop(signo);
+	raise(signo);
+}
+
 static int prepare_linked_checkout(const struct checkout_opts *opts,
 				   struct branch_info *new)
 {
@@ -822,7 +852,7 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
 	const char *path = opts->new_worktree, *name;
 	struct stat st;
 	struct child_process cp;
-	int counter = 0, len;
+	int counter = 0, len, ret;
 
 	if (!new->commit)
 		die(_("no branch specified"));
@@ -850,13 +880,21 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
 		strbuf_addf(&sb_repo, "%d", counter);
 	}
 	name = strrchr(sb_repo.buf, '/') + 1;
+
+	junk_pid = getpid();
+	atexit(remove_junk);
+	sigchain_push_common(remove_junk_on_signal);
+
 	if (mkdir(sb_repo.buf, 0777))
 		die_errno(_("could not create directory of '%s'"), sb_repo.buf);
+	junk_git_dir = xstrdup(sb_repo.buf);
+	is_junk = 1;
 
 	strbuf_addf(&sb_git, "%s/.git", path);
 	if (safe_create_leading_directories_const(sb_git.buf))
 		die_errno(_("could not create leading directories of '%s'"),
 			  sb_git.buf);
+	junk_work_tree = xstrdup(path);
 
 	write_file(sb_git.buf, 1, "gitdir: %s/repos/%s\n",
 		   real_path(get_git_common_dir()), name);
@@ -881,7 +919,19 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
 	memset(&cp, 0, sizeof(cp));
 	cp.git_cmd = 1;
 	cp.argv = opts->saved_argv;
-	return run_command(&cp);
+	ret = run_command(&cp);
+	if (!ret) {
+		is_junk = 0;
+		free(junk_work_tree);
+		free(junk_git_dir);
+		junk_work_tree = NULL;
+		junk_git_dir = NULL;
+	}
+	strbuf_release(&sb);
+	strbuf_release(&sb_repo);
+	strbuf_release(&sb_git);
+	return ret;
+
 }
 
 static int git_checkout_config(const char *var, const char *value, void *cb)
diff --git a/t/t2025-checkout-to.sh b/t/t2025-checkout-to.sh
index 8c73b18..75ac420 100755
--- a/t/t2025-checkout-to.sh
+++ b/t/t2025-checkout-to.sh
@@ -17,6 +17,12 @@ test_expect_success 'checkout --to an existing worktree' '
 	test_must_fail git checkout --detach --to existing master
 '
 
+test_expect_success 'checkout --to refuses to checkout locked branch' '
+	test_must_fail git checkout --to zere master &&
+	! test -d zere &&
+	! test -d .git/repos/zere
+'
+
 test_expect_success 'checkout --to a new worktree' '
 	git checkout --to here master &&
 	(
-- 
2.1.0.rc0.78.gc0d8480