[pitivi] timeline: Keep selection when adding a layer

[Alexandru Băluț <alexbalut src gnome org>]

commit a316e40820dde3f3e1adf615af72fa9c6c55bcf7
Author: Jan Kolarik <kotlajz gmail com>
Date:   Sun Apr 3 02:53:47 2022 +0200

    timeline: Keep selection when adding a layer
    
    Selection is left intact when no interaction with Marquee was initiated.
    
    Fixes #2437

 pitivi/timeline/timeline.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index 1cfef877c..095358b9e 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -777,7 +777,7 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         elif self.__moving_layer:
             self.__end_moving_layer()
             return False
-        elif res and button == 1:
+        elif self.layout.marquee.is_visible() and res and button == 1:
             clips = self.layout.marquee.find_clips()
             self.selection.set_selection(clips, SELECT)
             self.layout.marquee.hide()