[gnlcomposition] Creating too many segments when not needed.
Submitted by Edward Hervey @bilboed
Link to original bug (#641377)
Description
+++ This bug was initially created as a clone of Bug 609792 +++
The problem is that this composition will work:
[ overlaid videomixer gnloperation]
[ source 1 ]
[ source 2 ]
Creating the 3 proper segments (oper+source1, oper+source1+source2, oper+source2)
But it also creates 3 segments for the following:
[ source 1 ]
[ source 2 ]
While it should only create 2 (the whole of source1, followed by the rest of source2).
This is a reminder so we don't forget to fix this for performance reason (to avoid useless seeking/segments).