From 5a0531df019ab2217c14f5b016e1afe3913d895f Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 31 May 2023 01:17:19 +0200
Subject: [PATCH] Sync `all_regions` after region removal

The eventual goal is to keep the set of used regions
in sync, and allow to remove explicit calls to
`sync_all_regions_with_regions`.

This prevents `all_regions` to retain a reference to
a region that has been destroyed.
---
 libs/ardour/playlist.cc | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 303ef9186a..4897ab5640 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -853,6 +853,20 @@ Playlist::remove_region_internal (std::shared_ptr<Region> region, ThawList& thaw
 		}
 	}
 
+#if 0
+	for (set<std::shared_ptr<Region> >::iterator x = all_regions.begin(); x != all_regions.end(); ++x) {
+		if ((*x) == region) {
+			all_regions.erase (x);
+			break;
+		}
+	}
+#else /* sync_all_regions_with_regions */
+	all_regions.clear ();
+	for (auto const& r: regions) {
+		all_regions.insert (r);
+	}
+#endif
+
 	return -1;
 }