[pitivi] ruler: Handle negative position values

[Alexandru Băluț <alexbalut src gnome org>]

commit 255a6b8241134ab9e5229e860a019706c8fc18f5
Author: Hugo Eduardo Ziviani <hugo_ziviani hotmail com>
Date:   Sun Apr 26 23:38:35 2020 -0300

    ruler: Handle negative position values
    
    Fixes #2445

 pitivi/timeline/ruler.py | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/pitivi/timeline/ruler.py b/pitivi/timeline/ruler.py
index a5f27b8a..3d7baada 100644
--- a/pitivi/timeline/ruler.py
+++ b/pitivi/timeline/ruler.py
@@ -223,6 +223,7 @@ class ScaleRuler(Gtk.DrawingArea, Loggable):
 
     def __set_tooltip_text(self, position, seeking=False):
         """Updates the tooltip."""
+        position = max(0, position)
         if seeking:
             timeline_duration = self.ges_timeline.props.duration
             if position > timeline_duration: