From 73c5bdd3cb08ad0888fafe2f4018c3f2a575340c Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Fri, 28 Feb 2020 02:09:58 +0100
Subject: [PATCH] Fix double free of undo commands (amend 9e6435ff145)

This fixes a case when deleting a plugin, deletes all automation
undo/redo events:
  <UndoTransaction name="add automation event">
    <MementoCommand type-name="ARDOUR::AutomationList">
   ...


`delete this;` calls the d'tor which emits drop_references(),
that leads to UndoTransaction::command_death() destroying the
object, whichh causes a double free.
---
 libs/pbd/pbd/memento_command.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libs/pbd/pbd/memento_command.h b/libs/pbd/pbd/memento_command.h
index 6150ea111d..22b2d4a42d 100644
--- a/libs/pbd/pbd/memento_command.h
+++ b/libs/pbd/pbd/memento_command.h
@@ -127,7 +127,8 @@ public:
 	}
 
 	void binder_dying () {
-		delete this;
+		/* delegate to UndoTransaction::command_death */
+		drop_references ();
 	}
 
 	void operator() () {