From 068cd559e11dd5b95229d4e18710dffe27fa9ae9 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max.kellermann@gmail.com>
Date: Mon, 22 May 2023 15:41:20 +0200
Subject: [PATCH] db/update/Walk: clear `Song::in_playlist`

Without clearing all `in_playlist` flags, the songs will never be
revealed again if they were hidden once by a CUE sheet, not even after
the CUE sheet gets deleted or modified.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1784
---
 NEWS                                |  2 ++
 src/db/plugins/simple/Directory.cxx | 12 ++++++++++++
 src/db/plugins/simple/Directory.hxx |  8 ++++++++
 src/db/update/Walk.cxx              |  1 +
 4 files changed, 23 insertions(+)

diff --git a/NEWS b/NEWS
index 69d88b777..cd9636d6f 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,8 @@ ver 0.23.13 (not yet released)
   - curl: fix busy loop after connection failed
 * archive
   - zzip: fix crash bug
+* database
+  - simple: reveal hidden songs after deleting containing CUE
 * decoder
   - ffmpeg: reorder to a lower priority than "gme"
   - gme: require GME 0.6 or later
diff --git a/src/db/plugins/simple/Directory.cxx b/src/db/plugins/simple/Directory.cxx
index 313709a31..f00215355 100644
--- a/src/db/plugins/simple/Directory.cxx
+++ b/src/db/plugins/simple/Directory.cxx
@@ -126,6 +126,18 @@ Directory::LookupTargetSong(std::string_view _target) noexcept
 	return lr.directory->FindSong(lr.rest);
 }
 
+void
+Directory::ClearInPlaylist() noexcept
+{
+	assert(holding_db_lock());
+
+	for (auto &child : children)
+		child.ClearInPlaylist();
+
+	for (auto &song : songs)
+		song.in_playlist = false;
+}
+
 void
 Directory::PruneEmpty() noexcept
 {
diff --git a/src/db/plugins/simple/Directory.hxx b/src/db/plugins/simple/Directory.hxx
index e13b556ff..3b4b280fe 100644
--- a/src/db/plugins/simple/Directory.hxx
+++ b/src/db/plugins/simple/Directory.hxx
@@ -287,6 +287,14 @@ public:
 	 */
 	SongPtr RemoveSong(Song *song) noexcept;
 
+	/**
+	 * Recursively walk through the whole tree and set all
+	 * `Song::in_playlist` fields to `false`.
+	 *
+	 * Caller must lock the #db_mutex.
+	 */
+	void ClearInPlaylist() noexcept;
+
 	/**
 	 * Caller must lock the #db_mutex.
 	 */
diff --git a/src/db/update/Walk.cxx b/src/db/update/Walk.cxx
index be71e7195..4fdec28d9 100644
--- a/src/db/update/Walk.cxx
+++ b/src/db/update/Walk.cxx
@@ -531,6 +531,7 @@ UpdateWalk::Walk(Directory &root, const char *path, bool discard) noexcept
 
 	{
 		const ScopeDatabaseLock protect;
+		root.ClearInPlaylist();
 		PurgeDanglingFromPlaylists(root);
 	}