[pitivi] elements: Remove margins between clips

[Thibault Saunier <tsaunier src gnome org>]

commit 871079b8cc85971877cf1c2cb75441c590c6edc0
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Tue Jul 7 15:13:09 2015 +0200

    elements: Remove margins between clips
    
    Summary: Fixes https://bugzilla.gnome.org/show_bug.cgi?id=751245
    
    Reviewers: Mathieu_Du, aleb
    
    Differential Revision: https://phabricator.freedesktop.org/D248

 pitivi/timeline/elements.py |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/pitivi/timeline/elements.py b/pitivi/timeline/elements.py
index 021050b..5ebce0e 100644
--- a/pitivi/timeline/elements.py
+++ b/pitivi/timeline/elements.py
@@ -640,8 +640,13 @@ class Clip(Gtk.EventBox, timelineUtils.Zoomable, Loggable):
         if not parent or not self.layer:
             return
 
-        x = self.nsToPixel(self.bClip.props.start)
-        width = self.nsToPixel(self.bClip.props.duration)
+        start = self.bClip.props.start
+        duration = self.bClip.props.duration
+        x = self.nsToPixel(start)
+        # The calculation of the width assumes that the start is always
+        # int(pixels_float). In that case, the rounding can add up and a pixel
+        # might be lost if we ignore the start of the clip.
+        width = self.nsToPixel(start + duration) - x
         parent_height = parent.get_allocated_height()
 
         height, y = self.__computeHeightAndY()