upload-pack: use argv_array for pack_objects

Use the argv_array in the child_process structure, to avoid having to
manually maintain an array size.

Signed-off-by: Michael Procter <michael@procter.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/upload-pack.c b/upload-pack.c
index b3f6653..dc802a0 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -90,35 +90,32 @@
 		"corruption on the remote side.";
 	int buffered = -1;
 	ssize_t sz;
-	const char *argv[13];
-	int i, arg = 0;
+	int i;
 	FILE *pipe_fd;
 
 	if (shallow_nr) {
-		argv[arg++] = "--shallow-file";
-		argv[arg++] = "";
+		argv_array_push(&pack_objects.args, "--shallow-file");
+		argv_array_push(&pack_objects.args, "");
 	}
-	argv[arg++] = "pack-objects";
-	argv[arg++] = "--revs";
+	argv_array_push(&pack_objects.args, "pack-objects");
+	argv_array_push(&pack_objects.args, "--revs");
 	if (use_thin_pack)
-		argv[arg++] = "--thin";
+		argv_array_push(&pack_objects.args, "--thin");
 
-	argv[arg++] = "--stdout";
+	argv_array_push(&pack_objects.args, "--stdout");
 	if (shallow_nr)
-		argv[arg++] = "--shallow";
+		argv_array_push(&pack_objects.args, "--shallow");
 	if (!no_progress)
-		argv[arg++] = "--progress";
+		argv_array_push(&pack_objects.args, "--progress");
 	if (use_ofs_delta)
-		argv[arg++] = "--delta-base-offset";
+		argv_array_push(&pack_objects.args, "--delta-base-offset");
 	if (use_include_tag)
-		argv[arg++] = "--include-tag";
-	argv[arg++] = NULL;
+		argv_array_push(&pack_objects.args, "--include-tag");
 
 	pack_objects.in = -1;
 	pack_objects.out = -1;
 	pack_objects.err = -1;
 	pack_objects.git_cmd = 1;
-	pack_objects.argv = argv;
 
 	if (start_command(&pack_objects))
 		die("git upload-pack: unable to fork git-pack-objects");