db_print: print extra "playlist" object for embedded CUE sheets

This finally enables the new embedded CUE sheet code: when a song file
contains a playlist, it is printed in the "lsinfo" output, so clients
get to know about this.

2 files changed, 31 insertions, 12 deletions

diff --git a/NEWS b/NEWS
index 977762e0e..aa73a618b 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,7 @@ ver 0.17 (2011/??/??)
   - "update" and "rescan" need only "CONTROL" permission
   - new command "seekcur" for simpler seeking within current song
   - add range parameter to command "load"
+  - print extra "playlist" object for embedded CUE sheets
 * input:
   - cdio_paranoia: new input plugin to play audio CDs
   - curl: enable CURLOPT_NETRC
diff --git a/src/db_print.c b/src/db_print.c
index 297a6f3f6..4d7e3f5ef 100644
--- a/src/db_print.c
+++ b/src/db_print.c
@@ -56,12 +56,33 @@ print_visitor_directory(const struct directory *directory, void *data,
 	return true;
 }
 
+static void
+print_playlist_in_directory(struct client *client,
+			    const struct directory *directory,
+			    const char *name_utf8)
+{
+	if (directory_is_root(directory))
+		client_printf(client, "playlist: %s\n", name_utf8);
+	else
+		client_printf(client, "playlist: %s/%s\n",
+			      directory_get_path(directory), name_utf8);
+}
+
 static bool
 print_visitor_song(struct song *song, void *data,
 		   G_GNUC_UNUSED GError **error_r)
 {
+	assert(song != NULL);
+	assert(song->parent != NULL);
+
 	struct client *client = data;
 	song_print_uri(client, song);
+
+	if (song->tag != NULL && song->tag->has_playlist)
+		/* this song file has an embedded CUE sheet */
+		print_playlist_in_directory(client, song->parent,
+					    song->uri);
+
 	return true;
 }
 
@@ -69,21 +90,18 @@ static bool
 print_visitor_song_info(struct song *song, void *data,
 			G_GNUC_UNUSED GError **error_r)
 {
+	assert(song != NULL);
+	assert(song->parent != NULL);
+
 	struct client *client = data;
 	song_print_info(client, song);
-	return true;
-}
 
-static void
-print_playlist_in_directory(struct client *client,
-			    const struct directory *directory,
-			    const char *name_utf8)
-{
-	if (directory_is_root(directory))
-		client_printf(client, "playlist: %s\n", name_utf8);
-	else
-		client_printf(client, "playlist: %s/%s\n",
-			      directory_get_path(directory), name_utf8);
+	if (song->tag != NULL && song->tag->has_playlist)
+		/* this song file has an embedded CUE sheet */
+		print_playlist_in_directory(client, song->parent,
+					    song->uri);
+
+	return true;
 }
 
 static bool