db/LightSong: implicit initialization

src/db/LightSong.hxx

@@ -42,7 +42,7 @@ struct LightSong {
 	 * #uri.  To build the full URI, join directory and uri with a
 	 * slash.
 	 */
-	const char *directory;
+	const char *directory = nullptr;
 
 	const char *uri;
 
@@ -54,7 +54,7 @@ struct LightSong {
 	 * This attribute is used for songs from the database which
 	 * have a relative URI.
 	 */
-	const char *real_uri;
+	const char *real_uri = nullptr;
 
 	/**
 	 * Metadata.
@@ -65,18 +65,18 @@ struct LightSong {
 	 * The time stamp of the last file modification.  A negative
 	 * value means that this is unknown/unavailable.
 	 */
-	std::chrono::system_clock::time_point mtime;
+	std::chrono::system_clock::time_point mtime = std::chrono::system_clock::time_point::min();
 
 	/**
 	 * Start of this sub-song within the file.
 	 */
-	SongTime start_time;
+	SongTime start_time = SongTime::zero();
 
 	/**
 	 * End of this sub-song within the file.
 	 * Unused if zero.
 	 */
-	SongTime end_time;
+	SongTime end_time = SongTime::zero();
 
 	explicit LightSong(const Tag &_tag) noexcept
 		:tag(_tag) {}