My workflow is to use the normal polygon buffering on each river line to generate the geometries for each river line separately. Then I need to get rid of the bits that are inside the "overall" buffer so I intersect the buffer outlines with one another and use a spatial filter to remove the intersected parts that are "within" the dissolved overall buffer polygon itself.
This works absolutely fine in FME 2012. In FME 2013, at seemingly random locations it fails in that some of the buffer outline portions are found by the spatial filter to be inside the buffer polygon. These are the SAME geometry!
I have noticed similar problems on other occasions. Given a general workflow of take a feature, do something with it, match the unaffected portion of the geometry back to the original - this generally seems to fail and a snapper or similar is required to get them to match again. This is annoying by itself but here something has definitely changed for the worse between 2012 and 2013.
How can I get around this without having to go through tediously snapping every line back to itself every time?
