[PATCH] builtin-clone.c: allow multiple cmd_clone() calls

[Ali Gholami Rudi <ali@rudi.ir>]

With this patch, cmd_clone() safely frees its xstrdup()-allocated
memory.  Also cmd_clone() registers remove_junk() (for getting called in
a signal handler or atexit()) at most once.

junk_work_tree and junk_git_dir (used in remove_junk()) were changed to
use static arrays rather than sharing the memory allocated in
cmd_clone().  The junk_* global variables are overwritten in each
cmd_clone() call.  But if concurrent cmd_clone() calls are disallowed
that won't be an issue since we only care about the currently executing
cmd_clone() in remove_junk().

Signed-off-by: Ali Gholami Rudi <ali@rudi.ir>
---
 builtin-clone.c |   30 +++++++++++++++++++-----------
 1 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/builtin-clone.c b/builtin-clone.c
index 880373f..6ef31cd 100644
--- a/builtin-clone.c
+++ b/builtin-clone.c
@@ -268,8 +268,9 @@ static const struct ref *clone_local(const char *src_repo,
 	return ret;
 }
 
-static const char *junk_work_tree;
-static const char *junk_git_dir;
+static int junk_registered;
+static char junk_work_tree[PATH_MAX];
+static char junk_git_dir[PATH_MAX];
 static pid_t junk_pid;
 
 static void remove_junk(void)
@@ -277,12 +278,12 @@ static void remove_junk(void)
 	struct strbuf sb = STRBUF_INIT;
 	if (getpid() != junk_pid)
 		return;
-	if (junk_git_dir) {
+	if (*junk_git_dir) {
 		strbuf_addstr(&sb, junk_git_dir);
 		remove_dir_recursively(&sb, 0);
 		strbuf_reset(&sb);
 	}
-	if (junk_work_tree) {
+	if (*junk_work_tree) {
 		strbuf_addstr(&sb, junk_work_tree);
 		remove_dir_recursively(&sb, 0);
 		strbuf_reset(&sb);
@@ -320,8 +321,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 {
 	int is_bundle = 0;
 	struct stat buf;
-	const char *repo_name, *repo, *work_tree, *git_dir;
-	char *path, *dir;
+	const char *repo_name, *work_tree;
+	char *path, *dir, *repo, *git_dir;
 	int dest_exists;
 	const struct ref *refs, *head_points_at, *remote_head, *mapped_refs;
 	struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
@@ -362,7 +363,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	else if (!strchr(repo_name, ':'))
 		repo = xstrdup(make_absolute_path(repo_name));
 	else
-		repo = repo_name;
+		repo = xstrdup(repo_name);
 
 	if (argc == 2)
 		dir = xstrdup(argv[1]);
@@ -393,7 +394,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	}
 
 	if (!option_bare) {
-		junk_work_tree = work_tree;
+		strcpy(junk_work_tree, work_tree);
 		if (safe_create_leading_directories_const(work_tree) < 0)
 			die("could not create leading directories of '%s': %s",
 					work_tree, strerror(errno));
@@ -402,9 +403,12 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 					work_tree, strerror(errno));
 		set_git_work_tree(work_tree);
 	}
-	junk_git_dir = git_dir;
-	atexit(remove_junk);
-	sigchain_push_common(remove_junk_on_signal);
+	strcpy(junk_git_dir, git_dir);
+	if (!junk_registered) {
+		junk_registered = 1;
+		atexit(remove_junk);
+		sigchain_push_common(remove_junk_on_signal);
+	}
 
 	setenv(CONFIG_ENVIRONMENT, mkpath("%s/config", git_dir), 1);
 
@@ -590,6 +594,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	strbuf_release(&branch_top);
 	strbuf_release(&key);
 	strbuf_release(&value);
+	free(path);
+	free(repo);
+	free(dir);
+	free(git_dir);
 	junk_pid = 0;
 	return err;
 }