Consistent ControlList freezing -- fixes #7419

AudioRegion::set_fade_in() freezes the original ControlList, then
assigns a new one and thaws that.
Frozen state needs to be retained during assignment.

Related: The overloaded assignment operator in AutomationList
performed duplicate signal emission and didn't freeze the list.

1 files changed, 5 insertions, 4 deletions

diff --git a/libs/ardour/automation_list.cc b/libs/ardour/automation_list.cc
index 8ceab4f3ea..27bc64462e 100644
--- a/libs/ardour/automation_list.cc
+++ b/libs/ardour/automation_list.cc
@@ -167,13 +167,14 @@ AutomationList&
 AutomationList::operator= (const AutomationList& other)
 {
 	if (this != &other) {
-
+		ControlList::freeze ();
+		/* ControlList::operator= calls copy_events() which calls
+		 * mark_dirty() and maybe_signal_changed()
+		 */
 		ControlList::operator= (other);
 		_state = other._state;
 		_touching = other._touching;
-
-		mark_dirty ();
-		maybe_signal_changed ();
+		ControlList::thaw ();
 	}
 
 	return *this;