update: make the job id unsigned

Since the return value cannot be -1 anymore, we can make it unsigned.

src/command.c

@@ -807,7 +807,7 @@ static int handleUpdate(struct client *client,
 			mpd_unused int argc, char *argv[])
 {
 	char *path = NULL;
-	int ret;
+	unsigned ret;
 
 	assert(argc <= 2);
 	if (argc == 2 && !(path = sanitizePathDup(argv[1]))) {

src/database.c

@@ -41,7 +41,7 @@ static time_t directory_dbModTime;
 void
 db_init(void)
 {
-	int ret;
+	unsigned ret;
 
 	music_root = directory_new("", NULL);
 

src/update.c

@@ -48,15 +48,16 @@ static size_t update_paths_nr;
 
 static pthread_t update_thr;
 
-static const int update_task_id_max = 1 << 15;
+static const unsigned update_task_id_max = 1 << 15;
 
-static int update_task_id;
+static unsigned update_task_id;
 
 static struct song *delete;
 
 static struct condition delete_cond;
 
-int isUpdatingDB(void)
+unsigned
+isUpdatingDB(void)
 {
 	return (progress != UPDATE_PROGRESS_IDLE) ? update_task_id : 0;
 }
@@ -428,12 +429,13 @@ static void spawn_update_task(char *path)
 	DEBUG("spawned thread for update job id %i\n", update_task_id);
 }
 
-int directory_update_init(char *path)
+unsigned
+directory_update_init(char *path)
 {
 	assert(pthread_equal(pthread_self(), main_task));
 
 	if (progress != UPDATE_PROGRESS_IDLE) {
-		int next_task_id;
+		unsigned next_task_id;
 
 		if (!path)
 			return 0;

src/update.h

@@ -20,14 +20,16 @@
 #ifndef UPDATE_H
 #define UPDATE_H
 
-int isUpdatingDB(void);
+unsigned
+isUpdatingDB(void);
 
 /*
  * returns the positive update job ID on success,
  * returns 0 if busy
  * @path will be freed by this function and should not be reused
  */
-int directory_update_init(char *path);
+unsigned
+directory_update_init(char *path);
 
 void reap_update_task(void);