setup_temporary_shallow(): use tempfile module

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

shallow.c

 #include "cache.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "commit.h"
 #include "tag.h"
@@ -208,50 +209,28 @@ int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 	return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
 }
 
-static struct strbuf temporary_shallow = STRBUF_INIT;
-
-static void remove_temporary_shallow(void)
-{
-	if (temporary_shallow.len) {
-		unlink_or_warn(temporary_shallow.buf);
-		strbuf_reset(&temporary_shallow);
-	}
-}
-
-static void remove_temporary_shallow_on_signal(int signo)
-{
-	remove_temporary_shallow();
-	sigchain_pop(signo);
-	raise(signo);
-}
+static struct tempfile temporary_shallow;
 
 const char *setup_temporary_shallow(const struct sha1_array *extra)
 {
 	struct strbuf sb = STRBUF_INIT;
 	int fd;
 
-	if (temporary_shallow.len)
-		die("BUG: attempt to create two temporary shallow files");
-
 	if (write_shallow_commits(&sb, 0, extra)) {
-		strbuf_addstr(&temporary_shallow, git_path("shallow_XXXXXX"));
-		fd = xmkstemp(temporary_shallow.buf);
-
-		atexit(remove_temporary_shallow);
-		sigchain_push_common(remove_temporary_shallow_on_signal);
+		fd = xmks_tempfile(&temporary_shallow, git_path("shallow_XXXXXX"));
 
 		if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 			die_errno("failed to write to %s",
-				  temporary_shallow.buf);
-		close(fd);
+				  get_tempfile_path(&temporary_shallow));
+		close_tempfile(&temporary_shallow);
 		strbuf_release(&sb);
-		return temporary_shallow.buf;
+		return get_tempfile_path(&temporary_shallow);
 	}
 	/*
 	 * is_repository_shallow() sees empty string as "no shallow
 	 * file".
 	 */
-	return temporary_shallow.buf;
+	return get_tempfile_path(&temporary_shallow);
 }
 
 void setup_alternate_shallow(struct lock_file *shallow_lock,